Sunday, December 27, 2009

Glycol Package

What is the real function of glycol package? Why do we need this? Is that necessary to have this? Where it is located? Onshore? Offshore? What are the parameters that actually affect the performance of the glycol package which consists of glycol contactors and it's glycol regeneration skid? What do we expect if the feed conditions change in term of the performance of overall of glycol package? What should we do in order to get the optimum performance? When talk about performance, what are the parameters actually can be measured in order to get optimum performance? Which area that can be studied further if there is change in feed condition? What is the benchmark when do the optimisation?
There are lot of questions that can be raised for only simple package (I would say) compared to any other process technologies. Some people might say that first couple of questions is very fundamental relative to oil and gas industry. However, we should bear in mind that there might be some people never came accross in this glycol package before. Sometime different discipline might not really aware of this since they concern might be same regardless of the operation.
Overall picture of this glycol package can be read from GPSA section 20. However, those interested with the topic in surface and want to via this article and comment. You can do so. Experienced guys are welcomed to share their experience during designing or operation of this glycol package and very much appreciated.

Monday, November 30, 2009

Simulation Software

Why do we need simulation software? Simulation softwares always consider the ideal condition, whereby in the real world, there is no such word of ideal condition. There must be some disturbances that affecting the system which cannot perform as it is. There are some people from non-engineering background but technical people always say this to most of the engineers. "We do the real thing in lab but you all only develop the model in the simulation softwares, how true it is?", this is some of queries (in proper manner) that non-engineering but technical people always say that to us, engineers. So, where are we stand at? Nod their statement? Or argue with them? Let us think to answer this.

Monday, November 2, 2009

Fuel Saver

Now everyone is thinking of saving anything which ultimately would save money. Same goes to fuel consumption, where everyone is thinking of using more economical product. So, nowadays all big players which are competitors among themselves competing each other by promoting the more economical alternative ways. However, do the users really aware of the benefits of the product. So, any claims can be challenged by us as end user since most of the time, the customers are buying by referring to the advertisements which is actually giving more powerful impact than the real technology that is used in the product. Let us think what is the basis that been taken into account when considering the efficiency of the product.........

Wednesday, September 2, 2009

RON 95 & RON 97

This newly introduced petrol with RON 95 has been launched recently to most of petrol station. It is not saying that RON 97 is not supplied to petrol station but as higher premium product which initially was only non-premium petrol. So, it is obvious that there is no any specific reason why it is classified as premium petrol but only because of the lower RON is introduced. People might question about premium petrol was sold when RON 97 was sold as non-premium petrol. The only thing is that about the quality of the product which requires more operating cost to produce it. Besides, people might wonder also why suddenly the price of RON 95 was increased by five cents compared to RON 97 when it was sold as non-premium petrol.

There is also some news polls by voting three categories such as comfort level of using RON 95 compared to RON 97. Some of them even don’t mind using RON 97 with increase of 25 cents which looks very small amount but cumulatively very huge. Interested people can refer to the poll result at http://polls.thestar.com.my/polls/result.asp?id=129&cid=2&cdesc=News. Some of them even simply not comfortable with using RON 95 with no basis. What really makes difference in determining the level of comfort to choose either RON 95 or RON 97? Is it because of lack of knowledge in term of RON content in petrol? If so, why not conduct some quick research on it by referring to the car’s manual and the history of RON.

This is not something to blame the public but knowledge accessibility about the fact that RON 95 is good enough as long meeting the specification described in the manual. This is not something not aware by public only but also by authority that introducing all those RON 95 which they themselves don’t have basis why it is introduced and what actually term premium petrol stands for. It’s again very important to know the basis when finalizing any decision especially when purchasing something.

Thursday, August 27, 2009

HX Design - BEU and BFU

It’s very hard to see design of heat exchanger with configuration of BFU in the industry. Whereby this configuration or F-shell has its own advantage when using compared to BEU configuration. It’s again because the designer, client, owner, and whoever in the position deciding the configuration has a tendency to choose BEU. Usually when deciding on choosing the configuration, the process stream properties will be considered such as temperature approach, fouling resistance, fluid phases, etc. Issue on temperature approach will be discussed in detail here since BFU has its own beneficial to get desired temperature even the temperature approach is very low and sometime even the temperature cross happens. The TEMA configuration for BEU and BFU is shown:-

Usually when temperature cross happens, BEU configuration will be used in series to cater issue of very low temperature approach or temperature cross. This is very common to happen because the designer or the decision making authority more convenient to use series of BEU heat exchanger. There is no any other engineering reason but only based on their experience. So, if thorough engineering study is conducted some other alternative might be able to be considered such as by using BFU configuration. The only different is that the longitudinal baffle that separating the shell into two sections which is ultimately separating the inlet and outlet of shell side fluid.

Some people might say that issue on temperature cross can be resolved if the flow is counter current. However, the true counter current is not achieved in E shells if the tubeside pass is only one pass but again not to be forgotten that pressure drop across the tube should be utilized to increase the velocity of the tube side which eventually enhance the heat transfer coefficient of tube side. So, by considering the minimum number of passes as two passes, the true counter current cannot be achieved if there is no any device separating the fluids between tube and shell meeting as co-current. Here is typical configuration of BEU heat exchanger with its flow as shown:-

So, it’s again very important to consider BFU configuration which actually might give lot of impact to economic of the heat exchanger to be purchased or fabricated. It’s not that BEU in series cannot be used but on apply existing shell type not fully utilized when some circumstances such as very low temperature approach or temperature cross persist.

Thursday, August 20, 2009

Rule of Thumb

Rule of thumb basically means the experience on doing any particular job by applying the standard or reference. The variety of rule of thumb is varies among different people according to their experience. Different discipline engineers will have different rules of thumb that applicable to their work. For example, chemical engineers might have their rules of thumb when designing any process equipment. Piping engineers might have their own when routing the piping. The application of applying this rule of thumb mainly in engineering design work can shorten the time required to design.

This rules of thumb is mainly comes from research done by any institute such as American Petroleum Institute (API), Tubular Exchanger Manufacturer Associates (TEMA), etc. In addition to this, there are also from experience of the engineer him/her self all this while doing the design work. For example, pressure drop across the shell and tube heat exchanger is roughly about 0.7bar which typical value is allowed when designing it. This is purposely made so that the pumps that pumping upstream of the heat exchanger can cater the required pressure drop. There are no specific standards telling so, but from experience of people designing heat exchanger. Some people might say 1.0bar also can be considered. Some people might give more stringent value which is 0.3bar. So, if there is argument in deciding the value, it’s better to refer to the design basis that agreed by the team for that particular project.

The rule of thumb is basically would give some flavor of the rightness when getting the result. It is not only giving the standard to be used but when converting from one unit to another unit. For example, natural gas that having molecular weight 19-22kgmole/kg will give 1mmscfd equal to 1000kg/hr. Again this type of rule of thumb can be cross checked with simulation data to verify it. However, as we all doing the work with simulation interference, this can be on our finger tips.

Finally, this rule of thumb can be used to design any new equipment if you are referring very established sources such as TEMA, API, etc. That rule of thumb from your experience can be used to quick check of the calculation.

Thursday, August 6, 2009

MAN Turbo to Supply Compressors to Abu Dhabi

MAN Turbo AG of Oberhausen (Germany) has been awarded a contract for the supply of nine compressors to the value of around €60 million to the emirate of Abu Dhabi for the expansion of the Thamama-B oil field. The purchaser is the Abu Dhabi Company for Onshore Oil Operations (ADCO). The contract forms part of an overall project awarded by ADCO to SK Engineering and Construction (SKEC) of Seoul as the general contractor.

The contract that has now been signed relates to the ‘Bab Gas Compression Project’ and focuses on the expansion of Thamama-B, one of the five most important oil fields in Abu Dhabi. ADCO thereby aims to increase its production from the existing field considerably, thus further helping to safeguard the country’s energy supply. Over 94% of the United Arab Emirates’ total oil and gas reserves can be found in Abu Dhabi. The emirate has the world’s tenth-largest gas reserves.

In addition to the tendered compressor technology, the short delivery times agreed were a key factor in the award of this contract to MAN Turbo. ADCO, the biggest oil and gas producer in the United Arab Emirates, wants to commission the installation as a whole by 2011 and increase its yield from the existing field substantially by the year 2030.

The compressor trains manufactured by MAN Turbo at its Berlin plant are used in so-called gas collecting stations. Three compressor trains operate in each of the three stations. The incoming gas is conducted there to the compressor trains, which increase its pressure. The gas is then transported via pipeline to the Gasco refinery in Habshan for further processing.

For MAN Turbo and SKEC, this is the first order for ADCO. The two companies have successfully handled a similar contract in Kuwait in the past. “We are supplying compressor technology to Abu Dhabi for ADCO for the first time. This gives us a good foothold for further activities in this region. The Middle East with its emergent economy and its important oil and gas industry is of great strategic importance for our company,” said Dr Gerhard Reiff, a member of the MAN Turbo executive board.


Source: www.gulfoilandgas.com 7/27/2009, Location: Middle East

Thursday, July 30, 2009

Runway Reaction

Runaway reaction happens in a reactor most of the time if proper handling not considered during handling chemicals, operating plant, abrupt climate change, etc. This runaway reaction can be categorized as two runaway reactions; marginal and non-marginal. This is because of the allowable margin during design to allow some operating envelope fluctuation. This fluctuation to the operation might because of the abrupt climate change during monsoon season. Besides, upstream unit operation also can cause some fluctuation to downstream and eventually causing runaway reaction.

Marginal runaway reaction is expected to happen during normal operation and can be adjusted or corrected by applying relieving system. This marginal runaway reaction some time might cause unwanted incident but still in tolerable limit. However, there is a case whereby the incident caused to fatality due to some leakage and sudden pressure relief and cause explosion. This is not only happening for the new cases or process technology but even repeating incidents keep on happening from time to time.

There is non-marginal runaway reaction whereby the runaway reaction happens due to negligence of the operators, supervisors, engineers, and up to plant general manager. This is because of the discipline in following the procedures available in plant are not fully complied when operating the plant. This is eventually can cause to the runaway reaction which ends up with losses of dollars and brings to fatality. This kind of accident is not only releasing the hydrocarbons to atmosphere but explosion which made a vessel like a rocket shooting up to the sky. So, all the procedures which are available in plant must be followed even it sounds tedious procedures eventually can give big impact to the plant quality.

So, as time go on, technology also developed and there are chances to repeat the similar mistakes that happened before for different technologies. People might say that it’s very hard to stop the accident from happen but actually all these accidents caused by runaway reaction can be reduced which by reducing human error. This human error can be reduced by practicing the quality management of the plant operational. This is can be done by emphasizing the use of operating procedures with systematic by really follow the work flow given in organization chart. Besides, the authority delegation also must be looked into seriously to avoid any careless mistakes such as signing off permits without checking it properly. It’s again depending upon attitude of the personnel.

Wednesday, July 15, 2009

Competitive World

Everyone are competing to be the best and the first in supplying goods, equipments, services, consultancies, etc. In this competitiveness, the end user is the one will benefit. Everyone is competing everywhere in getting job and satisfy the customer. Even not going into detail engineering world, competitiveness can be seen in retail industry where the products are high demand if economical and quality. So, from this competitiveness, grow the innovation where the research is being done to improve the quality compared to existing technology.

Starting from small items such as chemicals for treating until very proprietary processes, there are very huge competitions to get the customer. Those days, it’s very hard to get any licensor for any particular niche technology but today the similar process technology with innovated technology can be found anywhere. Again the customer will get the benefit in getting the best product in market.

Sometimes the customer or the plant owner needs to perform study properly so that the ultimate objective can be achieved. This is basically to avoid any losses to the production as highlighted in previous article which caused losses of diesel due to jellying.

Friday, July 3, 2009

Alternative Energy

Everyday people in every corner in the world are talking about alternative energy or renewable energy. This is not something that people not realize of it but more viability of develop it. This is because of the current situation with availability of fossil fuel, every one chasing to produce oil and gas. The demand also increases as the oil and gas not only used for fuel purpose but also for other derivative products from these oil and gas. All these derivative products are being used everywhere starting from small baby to variation of age of people. We might not really realize on this if not really dealing with petrochemicals where all these oil and gas based products are produced.

Demand for fuel is keep on increasing from time to time, country to country, etc. This is because of the world circumstances where everyone all over the world is utilizing the fuel. We might see in last 15 years, all Chinese in China are using bicycle to move around and very few using cars or bikes. In those days, America is the largest importer and user of oil compared to other region. Recently, off shoring of job is being practiced everywhere to cheaper place. From there everyone starts realizing the important of urbanization and higher living style. Nowadays everyone competing to reach the highest living style which give better lifestyle and sometime not necessarily. So, as the demand increases from time to time and the source is kept on depleting, there must be something to be done to cater energy demand in future.

As the demand increases, everyone is talking about alternative or renewable energy. Sometimes is not really works if the big player such as Shell, Exxon, PETRONAS, Chevron, etc really keen to invent in this alternative energy. However, it can be seen that some of the country still using some of alternative energy for very minor application. Alternative energy like wood, animal dunk, wastes, etc are still being used but not really in commercial scale. For example in India, people quite often use animal dunk as a fuel for many applications.

So, it’s again depending upon the initiative taken by anybody to fully utilize the sources. The direct gas such flaring always has been an issue to come out with zero flaring. However, this is something that very subjective to the law. This is because of the viability of the process with current sources. So, the only way is that by enforcing the law to the operating company to come out zero flaring. For time being this initiative is only considered to produce money rather than comply with obligation of zero flaring. Same goes to waste management in landfill whereby the methane produced is simply flared or vented to atmosphere. This can be monetized if waste management company willing to take initiative to use it as fuel source.

Wednesday, July 1, 2009

Chartered Engineers

There was question raised in previous article on BEM and IEM regarding the necessity of registering with BEM and/or IEM if registered with some other body such IChemE, AMechE, SPE, etc. Again as an engineer must realize that they are not really professional engineer if there are chartered respective disciplines.

By right it is a regulatory mandatory with Board of Engineers, Malaysia (BEM) if practicing engineering and wants to be certified as professional engineer. In the mean time, engineers can practice parallel to be certified as chartered respective discipline engineer too.

Currently there is no enforcement yet on registering with BEM in Malaysia but as a preparation for facing new challenge as a develop country we as an engineer need to be qualified not only by degree but also acknowledged by regulatory body such as BEM.

Saturday, June 27, 2009

Jelly

Jellying is something bad stuff that might occur when dealing or processing liquid most of the time. It might occur directly or indirectly along the process line or even during the storage. Proper guideline is very necessary when dealing with production that having more than one train and even having slightly different configuration. The configuration might not be big difference on the process technology but there might be small differences in using the chemicals when injecting them to prevent corrosion, fouling, or waxing. This eventually will give big impact on the products.

This jellying is not only might occur due to temperature difference but due to different chemical presence in the different train which end up to the same storage tank. This is mainly because of the different chemicals used might cause undesired reaction which gives emulsion to the mixture of different streams. This emulsion eventually might give billions of dollar losses. So, it is really important to evaluate the proper chemicals to be used if there are more than one trains that streaming to same storage tanks.

This is crucially important when dealing with different vendors for the chemical supply. Sometime the owner or operator might want to see the significant benefit from different vendors which might end up with something bad stuffs. So, as a owner of the plant, need to conduct small lab analysis of emulsion for different chemicals sources. Or, the owner might use only vendor at one particular time to see the significant benefits.

Some people might argue that this might be very ridiculous mistake that can be done by human being. However, this is the fact that human errors are come from very ridiculous errors which end up with quite significant impact. This is phenomenon has happened in one of the plant or refinery which caused million dollars losses and some of end users sued the refinery due to consequent impact to their equipments. Luckily the product sold off is not fully distributed to the end users and remedies are given to the affected end users.

Since this already had happened in the refinery/plant itself where they have their own expertise in that particular area. So, there is possibility of to happen it again in end users since there is using different products from different supplier which can cause similar phenomena. This is not simply postulate done from the incident happened in plant/refinery but can be seen lot of cars, machineries, etc that end up with blockage of fuel line and need quite frequent cleaning or maintenance.

Monday, May 25, 2009

Sweet Sour Crude

How many people those really realize of this sweet sour crude? I would say that many of them not really aware of this sweet sour crude. Many of us have heard of sweet sour fish, sweet sour chicken, etc, which is actually reflecting the type of cooking. However, in oil and gas industry these are totally different categories which reflecting lot of differences. Those differences in fact not really recognized even by those personnel from oil and gas industry. Again, oil and gas industry is not really a small scope of world which can be understood by all the personnel from the industry.

There are different levels of understanding of this sweet and sour crude. Some might say that sweet crude is more expensive than sour crude which is right and they are not really sure why that is so. Besides, some people might say that refinery configuration would be different in term of the process involved which is also absolutely right. There are people would say that sour crude is nasty crude whereby sweet crude something good crude. All these are absolutely correct but there is a reason why those people saying so.

The main culprit that causing this nattiness is actually all those unwanted gaseous such as carbon dioxide (CO2), sulfur, etc that need to be treated before further processed. So, the main difference to the refinery is that additional unit area which requires additional cost. However, it does not mean that the sour crude is unwanted crude relative to sweet crude. Obviously the sweet may not to be treated to remove all those unwanted gaseous since it is within allowable limit to the downstream unit where the rest of refinery taking place such as reforming which is actually the main process to convert long chain into aromatics which gives the higher octane number.

Sunday, May 17, 2009

Industry vs. Academic

Industry and academic are very interrelated between both two. As in engineering world, they need to be some collaboration continuously in order to invent new technology which at the end will be used widely and benefited by both two sectors.

This is very crucial because of the continuity of the technology which actually is contributed from either area where any small scale or lab result that is done by academic which from university later will be used by industry to maximize the profit of the company as an ultimate objective. This is again is not something that any industry can straight away take any formulation or research done by university but there will be some agreement such as industry or more specifically an identified company that willing to pump in some fund to make move the research or development to be done without any monetary burden. This is because of the insufficient fund for academic or university stopping them from moving on with any new innovation to be invented.

In addition, there is necessity also from industry people as alumni to support their school they graduated from at least from knowledge or experience to enhance the syllabus of the school/university so that can ease the accreditation process for the related department of engineering. This is the reason why almost all the faculty that contributing growth of industrialist will have at least one industry advisor. Besides, there would be cases where academic will invite industry people to evaluate for the final year project of the students. This is really important because of the feedback that will be highlighted by them usually more than practical rather than totally theory.

Last but not least, there are some limitations to make them collaborating these areas because of some agreement issues or understanding arguments. This is the reason both industry and academic need to clarify all the commercial issues to avoid any misunderstandings. So, in order to avoid any confusion both parties should really clear of the contract of agreement.

Sunday, April 19, 2009

Inspection – Preparation

Here are some guidelines on preparing prior to inspection mainly those engineers are considered young engineers. Experienced engineer would know what to be asked or recorded during the inspection and obviously know what to prepare prior to inspection visit in site.

An engineer need to know what the equipment to be inspected obviously and any related documents to the equipments need to be brought. This is crucial because to have some understanding of the inspection process. One of the main documents that need to be brought while in site is obviously are drawings. Drawings like process flow diagram, (PFD), piping and instrumentation diagram, (P&ID), isometric drawing, and assembly drawing are really important while conducting inspection. This is because of the identity of the equipments, layouts, etc are provided in drawings. So, it would give the some idea on the internals of the equipment such as baffles, wire-meshed, inlet device, etc.
Sometime most of the preparations are done perfectly but still sometime there is a circumstance where the major license that need to have forgotten to take which is confined space entry permit. This sometime would cause unnecessary delay to overall project deliverables. This mainly happens for those had conducted any inspection during last turn-around and thought that there’s still valid but unfortunately it is already expired. So, it is advisable to cover this requirement as a part of checklist and put it as first priority.

Tuesday, April 14, 2009

Inspection

Inspection can be done for two main reasons; first for periodic check-up as human being is recommended to do medical check-up and second if there is any rectification to be done to the system as human being as well where need to go for medication.

The inspection wills actually reflecting the performance of the plant or platform in term of downtime. As for shutdown, there are planned and unplanned shutdowns. So, during the planned shutdown there will be couple of teams conducting inspection for identified equipment for respective department. Obviously department such operation, technical service, maintenance, and inspection will take part as main role player. Inspection during planned shutdown usually will be taken part by almost all of the engineers from respective department. Unplanned shutdown usually occur due plant upset where unexpected than planned happens. So, the team for the inspection will be called usually as root cause analysis, (RCA) team. For this kind of inspection, usually there will be one engineer from each department.

Inspection for planned shutdown usually will take place as mandatory for Department of Occupational, Safety, and Health (DOSH) requirement to conduct inspection during the turnaround (TA). During this period of duration, related vendors also take part to inspect. As an owner of the plant, all the observations and findings will be recorded to investigate the process behavior. Normally technical service department will do all this since most of the troubleshooting will be done by this department which acts as internal consultant for the plant. The rest of the departments might look into the findings mainly on the physical of the equipments in term of the welding, joint between connection, thickness of the wall of the equipment, etc. From all the findings, respective departments will come with the recommendations or conclusions in order to rectify it before the equipment is boxed up. For example, inspection to the shell and tube heat exchanger might be found with slurry that stagnant at any corner of tube or shell. Prior to this inspection, operation/production department might have faced problem in achieving desired temperature due to inefficient heat transfer. So, further study will be conducted so that fouling in future can be reduced so that won’t affect the performance until the next turnaround. The heat exchanger might be redesigned so that minimum velocity can be achieved so that the liquid can form turbulence enough to move any possible materials along the tube or shell. Besides, for those young engineers that desired to be design engineer can be credit since have seen the real internal part of the equipments. From there, the young engineers can take some reasonable margin or consideration when designing the equipments even not highlighted by theory.

Inspection during unplanned shutdown will be conducted in order to rectify the problem faced that causes plant upset. The RCA team will conduct a study on factors and solutions and present it to the management whereby there is no presentation to the management during inspection for planned shutdown. There will be a leader selected by plant general manager to lead the study which usually from technical division that familiar with the process involved. Historical data for the operation will be studied whether the operation follows the operating envelope while operating the plant. Typical cases for this unplanned shutdown and inspection are tube ruptures for furnace and heat exchangers.So, both inspections are really crucial for all generally and those young design engineer specifically since the real equipment can be seen in term of physical appearance and problems faced. If there is any chance to get involve, then it is recommended to grab the opportunity. It might be harshly and messy but will be end up with fruitful experience and knowledge when designing any equipments.

Monday, April 13, 2009

BEM and IEM

Engineers practicing (Malaysia) engineering must register with Board of Engineers, Malaysia (BEM) in order to acknowledge their experience when certifying the engineers to be professional engineer. The number or years acknowledged by BEM is the year started from the date registered with them. In order to certify an engineer as professional engineer, the engineer must have at least three years experience (acknowledged by BEM).

People might wonder if BEM is the one giving certification for professional engineer, what goes with Institutions of Engineers, Malaysia (IEM). So, the main difference between these two is that IEM is learning organization for engineers. In order to get privileges from IEM, an engineer need to register to be member first and there are a lot of membership types. Engineers need to register to be graduate member to start getting privileges in term of trainings, industry exposure, etc. Differ from BEM, IEM recognize experience from the graduation date.

In order to upgrade the membership from graduate member to member, the engineer needs to practice engineering work which consists of design, site, project management, etc for at least three years. The work was done by the engineer must be supervised by an engineer that member of IEM (MIEM). So, this supervision can go in two different ways; direct supervision if the engineer (MIEM) and graduate engineer in one organization and indirect supervision by mentoring scheme or log book scheme. After practicing minimum three years of working experience from the date of graduation, the graduate engineer can apply for professional interview (PI) in order to upgrade the membership to MIEM. Then, engineer with MIEM can apply for professional engineer with BEM if the number of years experience meeting minimum three years requirement.

RAM Study

Reliability, availability, and maintainability (RAM) study is a method or approach that being used in many industries many years ago. This is mainly because to optimize the reliability of the system so that can reduce the downtime of the system which eventually causing loss of production. So, by conducting this RAM study operation people will aware of the availability of the equipments respect to the system and maintenance team is aware with maintenance job need to be done. This RAM study is important so that the system reliability is reliable enough to produce the products as in agreement with customer.

There are lot of software are offered in market nowadays that claim can deliver the RAM study with minimal time consumption. However, there are skills needed when developing model for the RAM study. The model usually will be modeled with reliability block diagram (RBD) or fault tree diagram and the approach or basis of both diagrams are really dependent of the engineer develop it. Both diagrams will be modeled by referring to the process flow diagram to demonstrate the continuity of the process. However, it is more recommended to develop RBD which will give more information as a result and definitely need more info to key in when developing the model.

This RAM study usually will be done in a workshop where all personnel will be in during the session. If anyone realize this session almost like hazard and operability (HAZOP) study. So, those attended or conducted the HAZOP study might realize that if the leader/chairman prepared some draft of the node to be studied would be easier to carry the HAZOP workshop. Otherwise the session would be lengthy if the node to be identified during the workshop and there will be a lot of conflicts among participants. So, it is recommend as RAM workshop leader to construct the model prior to workshop and during the session all the information will be added as the workshop goes on.

In order to be leader/chairman for the RAM workshop, he or she needs to attend couple of RAM workshop as HAZOP chairman needs to be really experienced personnel. This is because the leader should know how to raise the issue related to any systems or equipments. Similar to HAZOP study, the chairman must be able to prompt the participants to extract the information so that can be documented during the workshop.The result or conclusion is again dependent on the input that was given to the software to run it. These RAM study software will use Monte Carlos approach to simulate probabilistic statistic and will give some figure for all three; reliability, availability, and maintainability in term of probability. Normally this probability must at least more than 90% and this is even considered as bad system that having only 90% reliability, availability, or maintainability. As HAZOP, this RAM study is only method or approach to predict any contingency plan to avoid any bad downtime.

Monday, April 6, 2009

Slugging and Pigging

Slugging and pigging are normal terms commonly used in oil and gas industry, more specifically in upstream rather than downstream. This is mainly because of the different phases of fluid with presence of other materials such as sand. Because of this slugging phenomenon, there is equipment called slug catcher to catch all this nasty stuff by stabilizing the fluids from the reservoir.

In other word, this slug catcher also can be said as stabilizer (some might not agree and it depends how they interpret it) since stabilizing among oil, gas, and water until reaching certain acceptable content level.

This slugging usually takes place when there is either liquid/gas in gas/liquid when form a pocket and starts hitting the wall of the pipe. This at the end actually will shorten the life the piping and causes more frequent maintenance which actually increases the downtime of the plant or platform due to unplanned shutdown. Besides, solids such as sands, wax, and impurities sometime can cause harm to the pipeline which can increase operating cost by increasing pumping cost due to rough surface of the pipeline. So, there must be some alternative need to be taken before the problem exists or during the operation. Slug catcher usually will be installed upstream of the most of unit operation to stabilize the crude to be processed. However, even lot of action has been considered there is also problem persists which end-up with some operational issues such as pressure loss, off-spec products, etc. Once the problems found during the operation then the pipeline need to be rectified.
Pigging is usually a common used method during construction and operation. During construction the pig launcher play a role such that the pigging process can be used for debris removal (onshore and offshore), gauging, measuring, cleaning, flooding for hydro-test, dewatering and drying, and some other specialized applications. During operation the pig launcher is being used for product’s separation (if batch process is carried out for different products), wax removal, line cleaning, condensate clearance, corrosion inhibition, meter proving, and some other specialized applications. So, this pigging is one of method commonly used to prevent, monitor, and rectify any slugging consequences which can cause to the shutdown of the plant/platform.

Tuesday, March 31, 2009

GA Drawing

GA sounds like GH but here is General Assembly which is very important when designing plot plan. This GA drawing is basically a product from plot plan design. This GA drawing will be used from the beginning of the plant/platform until infinite. This is because of the necessity as guidance for space availability. From this GA drawing most of area related to design need to be considered such as pipe rack coordination, pump location, maintainability, equipment installation, hydraulic calculation, etc.

The pipe racks really important when designing the piping route which really dependent to GA drawing which eventually will dictate overall of the process stream. This is because of the products processed are being transported through piping from one unit to another unit (processing area or storage). Besides, this GA will give some idea on the restriction area to be routed such as road access which will affect to the safety and end up with lost time injury, LTI. As everyone aware, nobody wants LTI to be recorded to show the credibility of the company.

This GA drawing will assist a lot in term of pump installation when taking into consideration of the net suction positive head. An engineer can know some idea on the location to be located when deciding the new pump during any expansion.

In addition, this GA drawing also can be used for the preparation of both owner and contractor when planning for maintenance works. This is really crucial when the works need some cranes or fork-lift which is commonly used during the maintenance work usually during turn-around. Besides this machinery they are also some other considerations need to be taken into account. For example, space availability for cleaning any tube bundle which is really common thing to happen during turn-around.

As highlighted for pump installation it goes similarly for new equipment to be installed when new expansion or initiative implemented. This is again will dictate to identify the area where the equipment to be installed before verifying it at site. This will also tell whether the equipment to be installed to be totally new big equipment or just a baby equipment to cater additional capacity. The space availability sometimes can control the design of the equipment for expansion.GA drawing will give the dimension of the distance and the size of the equipments (length and width) which actually can be used for hydraulic calculation as a rough estimation to make judgment on the routing the piping or installing the new equipment.

Monday, March 16, 2009

Confined Space

Confined space by meaning itself means that very limited or closed area. From the definition, what can be seen that something present in very few quantity which is oxygen in this case. This is the term used in oil, gas, and petrochemical industry. This is actually as requirement for personnel when dealing with entrance of the unit operation. All the personnel that involved must have entrance permit to confined space which will be issued by the doctor examined the personnel to assure that he/she is fit to conduct the job.

This confined space must be blown with air by blower in order to sustain the oxygen content so that personnel inside can breathe as usual. Besides, when entering the confined space, personnel must present their identification card to hole watcher or safety officer. This is mainly because of the safety consideration that needs to be addressed so that can monitor number of the personnel in that particular equipment to avoid crowd.

People might be asking why respective personnel need to enter the equipments and when they have to. This is mainly done during turn-around where the plant (mainly downstream) will be shutdown as planned shutdown to inspect the equipments such as vessels, towers, reactors, etc. It is not only conducted during planned shutdown but also unplanned whereby unwanted scenario happens. This is basically happens during plant upset or any unit operation upset due to any failure, rupture, leakage, etc. Therefore, there must be somebody need to go in the affected equipment(s) to inspect any findings could be observed. From the findings found, there would be some initiatives to be taken to rectify the problem and come out with plan to prevent in future.

People might be asking also why need to go inside the equipment even there are monitoring (corrosion) points as given the diagram below. Unit operation might have all those indicators but most of the time the indicators only can show us the result of from the impact such high pressure drop, off-spec product, corrosion behavior, etc. So, in order to rectify it related personnel from operation, maintenance, and inspection need to go inside to conduct detail study.

Here are sample of the signs that can be seen near to area that classified as confined space and require permit to enter with presence of safety officer.

Thursday, March 12, 2009

Corrosion Monitoring

Corrosion is a natural phenomenon which will occur but will vary on the rate depending on the environment and the material. Corrosion not only taking place in industry generally or oil and gas specifically but also everywhere which are not really noticed by human being. For instance, many of car manufactures are having some sort of antirust which giving some coating on the surface of the car body to prevent from corrosion taking place. This antirust scheme is not a whole life guarantee given by them but just for some time only. What can be seen from here is that the coating mechanism only can sustain for limited time only and again need to be coat again with the presence of car polishing companies. So, even coating mechanism itself facing corrosion problem where they lose of the coating film on the car body. Here where the material taking the action but some other scenario where environment will take action. For example, those cars exposed to beach area more prone to corrode since the environment is corrosive.



Corrosion is everyone issue which need to be addressed by everyone, everywhere, and every time. However, the corrosion that taking place in industry is more severe compared to non-industry related. This is mainly because of the function of itself where in industries, corrosion like a culprit to production. If the corrosion persists, the production line has to be shut-down since the safety always become on the top priority even ultimate aim of industries are to make profit. Therefore, there lot initiatives have been taken and being done in all level to monitor the corrosion. This mainly to study the suitable material to be used in related industry and way of minimizing the rate of corrosion. There are lot of proprietary chemicals are being used as a corrosion inhibitor to inhibit the corrosion. Again this corrosion can behave very differently for different application and they need different chemicals as a corrosion inhibitor. There is detail study to be done when procuring any vendor chemicals to avoid any off-spec products which can cause billion dollars losses. Thus, corrosion monitoring is important to identify the behavior of the fluid exposed to the material (piping, vessel, etc.). There are many ways of monitoring and one of it has been discussed on corrosion coupon. In addition to that, electrical resistance (ER) and linear polarization resistance (LPR) also have been successfully applied and are used in an increasing range of applications.



ER probes can be thought of as “electronic” corrosion coupons. Like coupons, ER probes provide a basic measurement of metal loss, but unlike coupons, the value of metal loss can be measured at any time, as frequently as required, while the probe is in-situ and permanently exposed to the process stream.




The LPR technique is based on complex electro-chemical theory. For purposes of industrial measurement applications it is simplified to a very basic concept. In fundamental terms, a small voltage (or polarization potential) is applied to an electrode in solution. The current needed to maintain a specific voltage shift (typically 10 mV) is directly related to the corrosion on the surface of the electrode in the solution. By measuring the current, a corrosion rate can be derived.

Design HX

Simulation tools always need the physical properties to define the stream or to conduct the study on any particular issue. This is crucial because of the Mother Nature to have some identification as human being as well. This principal goes same to anything and everywhere; if you are employee you must have ID number which is your identification in that organization. Generally categorization is needed when dealing with anything and characteristics of the stream needs either specifically.

In previous article on Oil Characterization, there were some key points highlighted when characterizing the crude which later will affect the sizing of whole equipments of the facility.
Similarly happens here on designing a heat exchanger where there couple of physical properties needed if the pure components not available for the streams that being studied to design or rating the heat exchanger. As goes as characterizing the crude, the right properties at right condition need to be taken or be available when keying in the data into the simulation tool (HTRI, HEXTRAN, etc.)

There are about four physical properties necessary when designing the heat exchangers which are specific heat, viscosity, thermal conductivity, and density. All these physical properties need to be taken for two different conditions. In addition, the referred conditions must be giving the range of the temperatures of the initial temperatures and targeted temperatures. This is very crucial because of the extrapolation will be done in between the range provided or else the result can be challenged because of the consistency error.

Tuesday, March 10, 2009

Wastes

Everyday wastes are being produced by us either by household or industrial. The waste itself has the category and phase. Most of human being might be thinking that industrial waste has the huge impact to the environment rather than household waste. However, this article will show that perception slightly not right to say. This is because of the way of disposing it. In this article, different types of waste such as waste gas (gas effluent), waste water, and solid waste will be covered which is really crucial when managing waste.

Waste gas or more commonly known as gas effluent or the waste produced in gas or vapor form from industry mainly and very little portion from household. There are bunch of gaseous that being monitored before it is discharged to the environment such as carbon oxide (COX), NOX, sulfur oxide (SOX), particulate matter, volatile organic compounds (VOCs), hydrogen sulfide (H2S), etc. Beware also there is also potential of harm our household sewage line that releasing hydrogen sulfide which can cause fatality. This has happened even not in house but in living quarters of ship which shows that there is tendency to occur since there function only deals with sewage system. Besides these direct releases, there are also volatile organic compound is being released from solid waste disposal which releases methane from the anaerobic reaction. There is commercial approach is being practiced to monetize the methane but so far people generally not really interested yet to monetize it since it is not really profitable enough.

Waste water generally covers most of the industry and also household effluent after the treated water has been used. Again in industrial waste there are experts working on it to come out with latest technology to minimize the impact to the environment. Whereby, lack of awareness in household application, the effluent for water is discharged to common drainage system which not really measures the containment of anything that can impact the environment. For example, used cooking oil will drained together with used water in sink which can cause troublesome to the whole line. If noticed, all these happening because of the lack enforcement of the law for the residential area. However, for those thinking that industrial can cause harm the environment are the one actually treating the effluent before it is discharge. In fact, the effluents are treated step by step to achieve all the parameters as regulated by the regulatory bodies. There are couples of elements to be covered when treating the waste water such BOD, COD, suspended solids, temperature, etc. There are guidelines to be followed by the industry but none of guideline is given to household.




Now come to solid waste where this is the ultimate waste that would come if gas and/or water are treated. As for solid waste, the waste can be easily monetized if the good practice can be practiced from the beginning of throwing the waste/rubbish to the dustbins. And again it comes from our awareness to implement it. Nowadays lot of campaigns can be seen everywhere to throw the rubbish into different dustbins so that the garbage already segregated before it is collected. Besides that the categorized can be categorized straight away such as paper, plastic, etc. In addition to direct monetization, there is also direct monetization as highlighted above such methane gas produced from solid waste landfill.

Friday, March 6, 2009

Flow Fraction – Part II

In the previous article on flow fraction, there are issues were discussed on the importance of the consideration while designing the heat exchanger. Although there are about five main streams when analyzing the flow fraction but the mainly emphasized are flow B and flow E. As highlighted in previous article, B must be greater than 40% and E must be less than 20% and the remaining can be mixture of the portion. So, some time or most of the time, heat exchanger will be over designed or over sized to cater the desired temperature but very rare consideration is given on the flow fraction analysis. In this article, flow fraction analysis will be covered on how it can be optimized.
This flow fraction takes place in shell side and directly affected by the shell side configuration and its fluid. So, configuration on the shell side can be modified in order to enhance the flow fraction.
Direct configuration that affecting the flow fraction are both baffle spacing and baffle cut. So, baffle spacing and cut shall be optimized as recommended by TEMA (Tubular Exchanger Manufacturer Association). For example, minimum baffle spacing recommend by TEMA is about 1/5 of shell inner diameter and 20-40% of baffle cut.
Nowadays all these can be done via sophisticated software such HTRI, HTFS, etc. So, as part of heat exchanger analysis, flow fraction analysis can be done since it could be presented by the software. However, as ultimate of heat exchanger warranty again dependent on vendor design and sometime the vendor would declare that they will guarantee the performance even sometime won’t behave as claimed by them. Usually the owner will let the vendor finalize it but as an engineer that designing and reviewing for engineering firm and owner respectively can use this approach to challenge the design done by the vendor. It’s again “Vendor Package” that cannot be argued so much.

Thursday, March 5, 2009

Corrosion Coupon


The Weight Loss technique is the best known and simplest of all corrosion monitoring techniques. The method involves exposing a specimen of material (the coupon) to a process environment for a given duration, then removing the specimen for analysis. The basic measurement which is determined from corrosion coupons is weight loss; the weight loss taking place over the period of exposure being expressed as corrosion rate.

The simplicity of the measurement offered by the corrosion coupon is such that the coupon technique forms the baseline method of measurement in many corrosion monitoring programs. The technique is extremely versatile, since weight loss coupons can be fabricated from any commercially available alloy. Also, using appropriate geometric designs, a wide variety of corrosion phenomena may be studied which includes, but is not limited to:

• Stress-assisted corrosion
• Bimetallic (galvanic) attack
• Differential aeration
• Heat-affected zones

Advantages of weight loss coupons are that:

• The technique is applicable to all environments - gases, liquids, solids flow.
• Visual inspection can be undertaken.
• Corrosion deposits can be observed and analyzed.
• Weight loss can be readily determined and corrosion rate easily calculated.
• Localized corrosion can be identified and measured.
• Inhibitor performance can be easily assessed.

In a typical monitoring program, coupons are exposed for 90-day duration before being removed for a laboratory analysis. This gives basic corrosion rate measurements at a frequency of four times per year. The weight loss resulting from any single coupon exposure yields the “average” value of corrosion occurring during that exposure. The disadvantage of the coupon technique is that, if a corrosion upset occurs during the period of exposure, the coupon alone will not be able to identify the time of occurrence of the upset, and depending upon the peak value of the upset and its duration, may not even register a statistically significant increased weight loss.


Therefore, coupon monitoring is most useful in environments where corrosion rates do not significantly change over long time periods. However, they can provide a useful correlation with other techniques such as electrical resistance, (ER) and linear polarization resistance, (LPR) measurements.

Tuesday, March 3, 2009

Flow Fraction

Flow fraction usually deal with the vapor fraction and liquid fraction. However, here is something different will be discussed which is related to shell and tube heat exchanger. There are bunch of criteria that need to be considered but flow fraction on the shell side flow fraction will be highlighted since this criteria is not really taken into consideration when designing a new shell and tube heat exchanger, (STHX).


As illustrated above, there are about five main flow in the shell side where only one (B) out of five is cross flow and the remaining (A, C, E, and F) are leak-flow or bypass. There are proposed calling for these streams; main cross-flow stream (B), a tube-to-baffle-hole leakage stream (A), a bundle bypass stream, a pass-partition bypass stream (F), and a baffle-to-shell leakage stream (E).
As vapor and liquid fraction, there is a requirement to meet the specification of any particular product before sell it off. So, same goes to the shell side flow fraction of the STHX where the minimum design criteria is that B fraction must be greater than 40% and for E is less than 20%. So, it’s not necessary yet to increase the size of the heat exchanger if this specification not met. There are couple of optimization can be done to get the desired temperature for any particular stream.
The tricky part of the optimization of STHX will be elaborated in detail in next article. Those will explain the areas that can be used to challenge design engineer during design review. In the meantime, design engineer can use that info also to enhance the design

Wednesday, February 25, 2009

Lean and Rich

Lean and rich are commonly jargons used in oil and gas industry which describing most of the oil, gas, and petrochemical processes. If it is looked from normal language, lean means very few and rich means enriched with something. However, in real world of oil, gas, and petrochemical industry those jargons meant vice versa.
There are bunch of processes that always say about these two lean and rich; gas processing, gas dehydration, gas treating, etc. This mainly shows that the products or the agents are almost pure or otherwise.
In gas processing, almost everywhere these terms always being used when describing the processes or the stream. As a nature of gas processing, the ultimate product are natural gas, ethane, and liquefied petroleum gas, (LPG). So, these products are basically having their specifications and require the processing which enhance the specification before it is sold off to customer. Those unprocessed gaseous are named as rich gas because containing all the irrelevant impurities such hydrogen sulfide, (H2S), and mercury, (Hg) for example. The processed gaseous are called lean gas. Same principal even goes to the agent that being used to treat the gaseous, where unused is called lean and used is called rich.
Recently in the last article, there was about gas dehydration which is crucial before exporting it as dry gas. In this article the concern is not on the gas dehydration but more on the tri-ethylene glycol (TEG) that is used for dehydration process. The TEG is being used are fresh and will be regenerated once it is in the loop. Most of the time this TEG is called lean TEG since having very high purity compared to the one in the middle of the process. TEG with a solution of water is called as rich TEG.So, whoever dealing with any designing FEED, detailed, or operation support with any processes and talks about these two jargons, bear in mind that the meaning is actually vice versa of original language.

Monday, February 23, 2009

What is RON?

The moment any of us heard the name of “RON” sounds like somebody’s name, Ron or any Hollywood hero’s name. It’s normal for anyone to classify it as anything since most of the time most of the people not aware of the jargon in this flattened world. In this article, RON is a jargon in oil and gas industry generally and in refinery industry specifically. However, no one has to quit from reading this article as though of that it is not relevant since they are not in oil and gas industry. This article gives some knowledge on the application of RON in petrol station as highlighted recently regard to fuel price. As a non oil and gas personnel, you will have better understanding to choose fuel among RON 92, RON 95, or RON 97.




“RON” itself is defined as Research Octane Number which is done in laboratory for specification of the fuel for motorcar. The RON affects the performance of any car through the combustion which is called ignition knocking, higher the RON lower the ignition knocking. Usually all the cars manufactured so far will collaborate with oil company when designing the engine so that it is compatible with the fuel that being supplied in that nation. So, most of the car has the compatibility or it’s designed it for RON 95. It tells that only fuel that can be used is that RON 95 and above. Sometime, in some countries, there is no fuel with RON 95, only RON 92 and RON 97. So, the only choice that we have is to pump in fuel with RON 97 which is slightly costly but would impact for frequent users. So, for those really aware on this issue and willing to blend it on his/her own will buy 50% of RON 92 and 50% of RON 97 to make it RON 95. However, it can be a mess for those really needs to fast to lift and put the nozzle the nozzle. So, as there will be introduction of fuel with RON 95 and it will be beneficiary for us. However, the compatibility of the engine on the RON can be seen at the cover of the tank for most of the cars. If you couldn’t find it, it must be written in the manual. So, it is not necessary to still pump in with RON 97 if your car is compatible with RON 95. There will be better if your car is designed with RON 92, and then go for it. Always bear in mind that the most expensive is not necessarily the best product but the most compatible will be the best product to be chosen. CHOOSE WISELY AND SAVE YOUR MONEY!




So, what you are waiting for, you not necessarily to wait until implementation of RON 95 in petrol station in your area but you could do it on your own since it is being practiced by most of the frequent drivers. This is because the saving can be up to 20%. People might ask also why is that fuel with higher RON is more expensive than the lesser. There are reasons behind all these since it requires more chemical processes than usual refining of crude oil or condensate. This is very costly because of the catalysts involve are really expensive and require regeneration or change to new after certain life cycle




Wednesday, February 18, 2009

Oil characterisation

Process simulation is very crucial when designing any equipment in oil facilities or refineries since the physical properties of oils will dictate the size of equipment. Therefore, process simulation software is used when conducting conceptual study of any new field or refinery even for FEED.
In order to characterize the crude from different wells, lab analysis needs to be done by petroleum engineers and/or geologist. The analysis to be done should align with requirement of process engineer when characterizing the crude simulation software. Since physical properties calculated from simulation software and the stream of the oil is defined through lab analysis keyed in manually from data collected by petroleum engineers. So, data must be representative of the oil field to be developed. Those lab analysis really needed for process simulation must be consists of density, viscosity (two different temperatures), and true boiling points (TBP). These data can be used for both oil facility and refinery.
However, some petroleum engineers would do chromatograph method when analyzing newly found oil from fields. There are some circumstances to be considered when choosing one of the methods.
There are two approaches that can be considered when analyzing newly found oil which are boiling points and chromatograph method:-

Boiling points:-
This is boiling point method can used to characterize the crude for both oil facility and refinery. This is because can give various level of gas and oil since the oil is being categorized by different cut-point which refer to the boiling points. Hence, refineries need this test’s result when modeling simulation model for refineries. This is because refinery itself will separate the crude or condensate into different categories of gas and oil such as natural gas, liquefied petroleum gas, naphta, kerosene, diesel, etc and it really needs different cut points to separate it. This only can be done through characterization of crude by boiling points. However, this method more expensive to test in lab compared to chromatograph and this makes newly found oils are being tested by chromatograph method when characterizing crude to design oil facility (onshore or offshore). This is because the main function of oil facility is to separate among oil, gas, and water, whereby, refinery requires more than that.
Chromatograph:-
Chromatograph method can be used for both oil characterization of oil facility and refinery. However, to run chromatography analysis for unknown of carbon number of hydrocarbon might cost really high compared to boiling point lab test. Therefore, chromatograph method usually is being used for only for oil facility purposes which require lesser analysis of carbon chain. Normally, the oil will be tested up to C30+, where the heavies will be lumped as one component. Cost wise, chromatograph method is considered viable if the test will be done up to C30. So, this approach only can be used for oil facility since the function of oil facility just to separate among oil, gas, and water. Whereby, the function of refinery is to process further on heavies who are having group of products and it needs more detail of the cut points. Therefore, it is advisable to characterize crude in different approach for both oil facility and refinery.

So, boiling point approach can be used for both characterization but relatively more expensive for oil facility relative to chromatograph method. Chromatograph method can be used still for both cases but relatively more expensive for refinery. As a conclusion, boiling point lab test result more viable and practical to use for refinery application and chromatography analysis for oil facility application.

Tuesday, February 10, 2009

Gas Processing Method

Gas must be treated before it can be sent on to the final customer. Three primary methods of treating gas are adsorption, absorption and catalysts. These methods are performed in closed process equipment.

Absorption is the disappearance of one substance into another so that the absorbed substance loses its identifying characteristics, while the absorbing substance retains most of its original physical aspects. Used in refining to selectively remove specific components from process streams. One simple absorption process, which is also very common, is the use of glycol to absorb water from gas.

Adsorption is the adhesion of the molecules of gases or liquids to the surface of solids, as opposed to absorption, in which the molecules actually enter the absorbing medium (see adhesion and cohesion). Certain solids have the power to adsorb great quantities of gases. Charcoal, for example, which has a great surface area because of its porous nature, adsorbs large volumes of gases, including most of the poisonous ones, and is therefore used in gas masks. Certain finely divided solids have great adsorptive properties; for example, minute particles of platinum attract and hold multitudes of hydrogen molecules on their surfaces. Its ability to adsorb other gases makes platinum very useful in the production of sulfuric acid by the contact process and in the preparation of ammonia.

Definitions
Dry Gas: Natural gas with so little natural gas liquids that it is nearly all methane
Sour Gas :Natural gas that contains corrosive, sulfur bearing compounds such as hydrogen sulfide and mercaptans.
Fuel Gas :Refinery gas used for heating
Desulfurization :a process in which the principal purpose is to remove sulfur from gas.
Knockout Drum :A vessel wherein suspended liquid is separated from gas or vapor Hydrogen Sulfide
Dehydration or drying of gas is accomplished by the use of water absorption or adsorption agents to remove water from the gas.

Refer to diagram below for a simple system.



The wet gas is sent to the glycol contactor. The contactor is a drum filled with trays or a mesh to maximize the mixing of its input products. Glycol is a liquid with a great affinity for water. Glycol does not absorb natural gas.
The glycol is pumped into the upper section of the contactor drum where it cascades down the inside of the drum coming into contact with the gas, which is bubbling upward. At this point the glycol absorbs any water that is in the gas. The dry gas goes out the top and the liquid glycol, now combined with water, goes out the bottom. The glycol is regenerated and then sent to the contactor drum again.
Not all of the glycol goes out the bottom on the contactor. A small mist of glycol will go out the top with the gas. Therefore a glycol knockout drum is used to get the last of the glycol out of the stream.
Desulfurization: Sour gases are dried and sweetened. Sweetening removes sulfur and also reduces concentrations of carbon dioxide.
Note, this section is about recovering sulfur from natural gas, keep in mind that sulfur is also removed from liquids.
Sulfur Recovery from hydrogen sulfide. Sulfur recovery converts hydrogen sulfide in sour gases and hydrocarbon streams to elemental sulfur. The most widely used recovery system is the Claus process, which uses both thermal and catalytic-conversion reactions. Sulfur is separated from natural gas as hydrogen sulfide and then converted to elemental sulfur by the Claus process, which involves the partial burning of hydrogen sulfide to sulfur dioxide


Hydrogen sulfide or h2s is an extremely toxic gas that smells like rotten eggs. It commonly occurs in natural gas and must be removed.

First, the hydrogen sulfide is absorbed from the natural gas at ambient temperature in a scrubber, either in alkanolamine-glycol solution or in aqueous alkaline carbonate solution. This scrubber works much like the glycol concentrator mentioned above/

Second, the hydrogen sulfide is partially oxidized to SO2 with considerable evolution of heat:

Third, this resulting sulfur dioxide is then reacted with hydrogen sulfide in the presence of Fe2O3 as a catalyst to yield the more conveniently handled elemental sulfur:

Removal of free sulfur: Sulfur also occurs in natural gas as a free element. This material is removed in a vessel by running the gas through an aluminum sieve. The free sulfur will adsorb on the aluminum. The aluminum then catalyzes or burns the sulfur to eliminate it. In cases of large amounts the sulfur is recovered and sold as a marketable by product.

Monday, February 9, 2009

Onshore and Offshore

There is ultimate goal of both onshore and offshore operation which is to produce oil, gas, and/or petrochemicals. This is eventually will give or produce dollar and cent which is the main business of all personnel. Besides, all the personnel in both environement are really concern also on the Health, Safety, and Environment as this is one of the companies policy. All the personnel in both operation need to go to all related technical and safety training in order to certify them as capable as a operator, supervisor, superintendent, etc.

However, there are lot more differences that not really realised by us when thinking of designing or conducting any study to both operations. Definitely, there are lot of assumptions or considereations to be taken into account as it is normal practise in engineering practise eventhough those assumptions or considerations are from experiences or best practises that being practised in oil and gas. So, there are some assumptions or considerations may valid or invalid depending on the operation to be developed.

Let us go into the differences that could be observed in this industry that sometime people very rarely realised. This is not highlighted blindly here but from the observations are being done by all the personnel that experienced in either onshore or offshore. This is because sometime because of the pressure was put to the designer of either plant or platform might cause to this to happen. All these issues raised might be very ridiculus but it might happen and already had happend nowadays and anywhere even all the lead engineers having experience more than twenty (20) years but still can make some silly mistake which can cause to additional modification even the platform already fabricated. So, this articles basically will give some ideas on what are the key area usually really need to be taken into account to avoid any unwanted to happen. There are many issues can be highlighted that can be found in oil platform usually since having very limited freedom to modify or "disturb". Some of it are such as plan layout and space availability, spare parts (start-up, normal operation, critical, etc), production profiles (water cut, sand presence, etc), etc.

When discuss about plant or platform layout dealt with all those piping engineers and partially other disciplines will get involve too. This is because all the routing of piping will be done by the piping engineer. Sometimes, there is tendency of blank spot whereby the spotted area is not occupied by the piping, equipments, valves, etc which is really crucial in platform layout design. This is mainly because of the space flexibility is not there compared to plant where still have huge area can be manipulated by rerouting the access road. Besides, when designing the layout of the platform, all the blind spots for the crane operator must be reduced to zero. This is because crane usage is really essential when dealing with maintenance work and need this crane to lift it. As usual this is not an issue for the onshore plant or oil facilities since it can be assessed by anywhere even there is some constraints but relatively much lesser than platform (in the middle of the sea). In addition, there must be couple of safety studies to be done prior to installation of crane for example which dealing with human being to operate it all the time. For instance, if crane is located near to any devices that can contribute to heat, radiation, etc might can cause lost time injury (LTI). However, there is scenario where this might still can happen.

What can be seen is that, crane operator still really is exposed to the exhaust gas from the turbine generator. Sometimes, this type of scenario might happen if the decision been made once the platform almost at the completion stage.
There will be some best practises to be published during coming articles. This is mainly to share the experience in oil, gas, and petchem industry when designing or operating it.

Monday, January 19, 2009

Relation among oil, gas, and petrochemical.....

It is normal to all young engineers or graduate engineers to seek job in oil and gas industry or petrochemical industry. This is mainly because of thinking that there lot of opportunity which ultimately gives more money relative to other industries.

So, it would be good to know the relation among those three. It is common to say oil and gas industry but very rare can hear that oil, gas, and petrochemical industry if those really doing business in upstream. Same thing goes to for those doing business in downstream, might think that upstream process nothing much than separating or removing water from oil.

There is no wrong to assume all those but slightly deviate from the track that those are interelated. For instance, upstream people might think that flaring is the safest way of release any excess hydrocarbon gaseous but those from downstream might think that up stream burning dollar and cents. Therefore, all need to come together to optimize the solution available currently to be more productive rather than blaming each other.

So, there are research and development are undergoing currently everywhere and among most of process technology licensors to turn all the product from earth to money. There is a term called monetization whereby couple of alternatives available to convert all the gaseous that being flared to money; e.g. mini LPG, mini CNG, etc. In downstream industry, lot of products those are being used are mainly from oil and gas which are called petrochemical products. The appliances might not fully made from oil and gas resource but at least finishing items are being made by petrochemical products which are called polymers. There are millions of example of polymers are being made from oil and gas such as poly vinyl chloride (PVC), poly ethylene, paint, polish (car, shoe, etc), cosmetics, etc.

Last not least, so far we are here with only fossil fuel and some countries already started thinking of alternative fuels also called renewable energy.