Page 1




Inside 2

25th Anniversary party


25 years of OPC


Technical focus


Consultant’s corner


Statoil contract win


New contracts




Latest news

Dec 2013 Issue 17

Celebrating 25 years of OPC In order to celebrate 25 years since the foundation of OPC in 1988, 60 key clients, consultants and friends in the industry joined OPC staff for an evening of champagne & canapĂŠs in London on 17th October 2013. 2

Mark Young, Reservoir Engineering Consultant “OPC has found me good jobs which have been interesting technical work but fun at the same time. That’s why I’m happy to continue working for the company now and in the future.”

Clara Altobell, Asset Manager, Serica Energy plc “Piers is always open to you ringing up with queries. He is a real person and I enjoy that level of working relationship. OPC provide a really good service and are especially excellent in Reservoir Engineering and well testing.”

Guests were shown a slide-show of OPC from 1988 to the present day, including some entertaining pictures of staff from 1988 as well as a photo of OPC founder Piers Johnson working from his spare bedroom. The slide show featured key moments of the development of the business including the opening of offices in the USA, Aberdeen, Qatar and Kazakhstan and the growth/development of OPC technical services division. Piers Johnson, Managing Director of OPC said, “It

has been an interesting 25 years with both great moments and troubled times. I am proud of the business that we have grown and it would not have been possible without our clients, consultants and staff so I was delighted to be able to celebrate with so many contacts, old colleagues and friends. I’m pleased to say that OPC continues to grow – this year alone we have opened offices in Astana, Stavanger and Basra, and I look forward to celebrating the 50 years anniversary in 2038!”


25 years of OPC



1988 1991 1989 1995 Oilfield Production Consultants (OPC) Ltd was formed in September 1988. First contract with Phillips Petroleum.


Serviced office in Kilburn opposite Falcon pub.

Exhibiting at Offshore Europe in Aberdeen, first contract with BP.

First Competent Person’s Report for Aminex PLC on their listing on the London Stock Exchange.

2006 2007


Won QP contract on tender. Opened offices in Houston with Bill Roberts as OPC USA President.

Projects and Studies (Technical Services Division) established. PETREL and ECLIPSE purchased

Opened Qatar offices.


1997 1999


1998 Opened offices in Aberdeen with Mike Eastgate as Aberdeen Representative and consultant.

Chair of London SPE (with Red Adair). A new brochure to show a wide range of services. OPC moved from Premier House to Apollo Studios (current offices).




Opened offices in Astana, Basra and Stavanger. Jim Ayton joins as Technical Director. Opened office in Atyrau, Kazakhstan.



By Hernan de Caso, Reservoir Engineer, OPC

Why is PTA Surveillance of Injection wells useful? The benefits of pressure transient analysis (PTA) for production wells is widely recognised, however the water injection wells can sometimes be overlooked by operators. Since wellhead pressure and injection rate are very often measured continuously, there is a wealth of data that can be reaped from PTA interpretation of injection wells and shown as a variation with time such as :-

• Mechanical Skin • Injectivity Index • Average reservoir pressure • Fracture closing pressure • Information about the flood front advance With this information, remedial action can be taken such as stimulation, reperforation or even the recommendation of a production log to further understand the performance change. In the last decade the study of Injection wells has become one of the industry’s hot topics. This has been a direct consequence of the increasing number of enhanced oil recovery projects (EOR). The market force for efficient reservoir management has always been in place, but now it must also take into account injection well performance, waterflooding strategies, water disposal needs and injection facilities. Throughout the remainder of the article some examples are shown which provide an insight to the kind of information that can be obtained by doing a robust PTA surveillance analysis. Water Bank Growth and pressure support around the wellbore Characterization of water bank growth and pressure support around the wellbore relates to overall water flooding and displacement efficiency. From the cumulative injected water volumes a theoretical injected bank size can be obtained as long as the net injection thickness is known. The growth of the theoretical bank size is then compared to the apparent inner bank growth of the derivative.

For a water injection well injecting directly into the oil zone, this approach gives an immediate understanding of how the water bank is behaving in the reservoir. If discrepancies are observed between theoretical and apparent water bank sizes it must mean that the water bank growth is not homogenous within the reservoir. This could be due to a strong relative permeability contrast, existing pressure gradient or simply due to the presence of heterogeneities and/or boundaries. Understanding Changes in Temperature effects. Reservoir temperature affects viscosity which is directly related to the mobility. Since the temperature of injection water can change throughout the life time of a field (if produced water is added to the total injection yield), it is important to understand the impact that temperature changes will have in the injection performance and in the overall reservoir. An example is shown in the following plot that illustrates the effect of fast warming up of injection water. The thinking would be that cold injected water would have a higher viscosity than reservoir water, and therefore a change in mobility might be seen. The reality shows a different picture. After several millions of injected cold water barrels, the change in the derivative response is negligible. How could this be if the inner water bank is supposed to have a different mobility via a viscosity change?


Hernan de Caso Reservoir Engineer +44 (0)20 7428 1111

The answer is that the viscosity difference dissipates as soon as the injected water is warmed up. And the injected water is warmed up very quickly. Both the reservoir and the aquifer act as a massive heat exchanger that warms up the injected water to reservoir temperatures at a very fast rate (analogue to a geothermal energy system). Water injection into an aquifer does not present a significant contrast in relative permeability as long as water properties are not very dissimilar. It is concluded that wells that inject water into an aquifer will maintain almost identical derivatives until the moment the injected water front starts interacting with an oil leg with a contrasting mobility. Diagnosing variations in Injectivity Index One of the issues that always crops up when doing Injection Surveillance PTA is the diagnostic of variations in the injectivity index (II). Is the injector performing as expected? Why or why not? The truth is that the majority of events that occur to injectors will affect their performance in one way or another. For example, any kind of Skin increase or loss of injection reservoir interval will reduce the Injectivity Index; on the other hand the appearance of fractures will enhance it. All in all, injectivity index is one of the main parameters to monitor when doing PTA Surveillance of Injection wells. Some examples are illustrated below.

The plot above shows two fall-offs (FO) carried out in the same well. The first FO (blue) was done soon after the well was put into injection. The pink FO was carried out two year afterwards after relatively continuous injection: The presence of a ½ slope in the early time of the latter FO stands out immediately as the appearance of a fracture. This is reasonable taking into account the changing thermal rock properties around the well and the prolonged injection prior to it. As shown in the example above a fracture tends to increase wellbore storage duration (WBS) as per an increase of compressible volume during shut-in. In addition, the development of a fracture creates an improvement in Skin (evidenced by the decrease in separation between pressure and derivative curves when comparing the final fall-off with the initial one). This reduction in Skin led to an improvement of the Injectivity Index of the well. The plot below shows a clear example of how changing Skin over the life of a well influences the Injectivity Index.


Technical Focus The great Deconvolution debate On the 26th November, OPC Managing Director Piers Johnson gave the after-dinner presentation for the London section of the SPE. Pier’s spoke on the “Advances in Pressure Transient Analysis” and the key topic of Deconvolution prompted one of the most liveliest debates that the members of the London SPE have ever experienced…. At the start of the presentation, Piers gave a very brief operational history of well testing over the last fifty years and the respective theories on which they were based – from Darcy’s Law in the 19th century through to the development of Deconvolution theory in the last 10 years. He then progressed through a brief analysis of gauges and gauge data before introducing the topic of Deconvolution. Piers explained that in order to understand Deconvolution, we need to understand Convolution. The “Convolution” integral describes the pressure change for an arbitrary rate-history, “q(t)”:

For “q(t)” made up of ‘n’ constant-rate flow-periods which start at times “ti” and are less than “t”:

Piers simplified the theory by suggesting that “Convolution” is just “Superposition” by another name. Piers then used a visual metaphor to explain Deconvolution. Where the paleantoligist only had one part of the skeleton to work from, he would make some assumptions as to what the whole dinosaur loked like. However, once he had other parts of the skeleton as well, he could build up a far more accurate picture of the T-Rex. This was very similar to Deconvolution theory – where a full model of a reservoir is developed where only a few indiviual elements of a reservoir is actually known. The attendees enjoyed Piers’ metaphor and he went on to examine the operational practicalities of using Deconvolution. This then sparked off a lively debate. With leading Deconvolution theory specialists present in the room, the merits of using different types of algorithms were debated, along with the certain circumstances where Deconvolution theory cannot be 100% accurate. As one attendee commented “I’ve never known an evening presentation to create such a lively and impassioned debate.” The full slides are available on the SPE website, and Piers plans to run a number of webinars on the operational practicalities of Deconvolution in the New Year.

Piers Johnson Managing Director +44 (0)20 7428 1111 08

Consultant’s Corner

In this regular feature, we find out about an OPC consultant with a quick-fire 5 minute interview. For this 25th anniversary issue, we talk to Chris White, who was one of the first consultants to work for OPC back in 1989 & has worked consistently for the business since.

Chris is a petroleum engineer and well test/well intervention specialist with 38 years’ experience in the international oil and gas industry. Chris started his career in 1976 in the Gulf, working for Flopetrol International ultimately rising to field service supervisor. In 1982, Chris joined Expro International and supervised Expro’s operations both onshore and offshore in Holland, Denmark, Norway, Ireland, Spain, Egypt, Thailand, China, and West Africa. Chris became a consultant in 1988 and worked as a well test supervisor on a variety of contracts including his first contract through OPC with Phillips Petroleum and then a year as a petroleum engineer for Hydrocarbons GB (British Gas) in Heysham. Since 1994, Chris has worked exclusively through OPC, initially as a petroleum engineer/well intervention engineer for Amerada Hess in Aberdeen and then a long term assignment with ConocoPhillips in Aberdeen where Chris managed their well testing operations. He continued working for CoP, first in Norway planning two exploration HPHT wells, then in Kazakhstan where he planned the first exploration Drill Stem Test performed from a semi-submersible drilling unit in the Kazakh sector of the Caspian Sea.



Chris White

When did you first hear from OPC? I received a phone call out of the blue in 1989 from Piers Johnson, who had just set-up OPC. I met Piers in his office in a huge building in Westminster – I have this clear recollection of Piers leading me down this long corridor to a small room at the back of the building. He needed an experienced well test engineer for a contract with Phillips Petroleum and I am very pleased that I accepted – that was the start of my relationship with OPC.

How many contracts have you worked on since then? I think I’ve lost count – I’ve worked on OPC projects across four decades! Since 1994 I have worked exclusively on OPC contracts with major operators including ConocoPhillips and Amerada Hess.

What have been the highlights? My time with CoP in Aberdeen was the best technical challenge and I feel that I learnt and developed my expertise significantly in that role. Plus the golf was great! From a location point of view, I really enjoyed my time in Kazakhstan – we worked hard but the people were great, the beachfront location in Aktau was fabulous, and the team’s social life was varied and enjoyable.



Why have you worked with OPC? All of the OPC staff I have dealt with over the years have been friendly, professional and a pleasure to work with. Also OPC is not a pure “body-shop” – consequently the in-house petroleum and reservoir engineers are able to provide technical assistance when it’s required.


What have you enjoyed most from your career? Working as a consultant through OPC has provided a great variety of work and many challenging situations. As a result I have amassed a huge amount of knowledge and, over the last few years, I’ve really enjoyed passing-on this experience to young engineers, mentoring and hopefully guiding a new generation of well testing specialists!


New Client Focus Statoil awards global contract to OPC A framework agreement to supply Drilling, Wells and Petroleum Technology resources has been awarded to OPC by Statoil ASA. Commencing in January 2014, the 5 year contract runs until 2018 and has options to extend until 2023. The agreement covers the provision of consultants for the specialist disciplines of Drilling & Wells Engineering & Facilities, Offshore Drilling and QHSE Supervision, Geology, Geophysics, Reservoir and Production Technology, Data Management and Petrophysics. The geographical scope covers mainly Statoil’s Norwegian operations and may be used for international locations. Piers Johnson, Managing Director of OPC said “The contract award is a significant achievement following on from many years of working in Norway previously with non-Norwegian operators as well as Norsk Hydro, Saga and Statoil since 1991. Norway offers an opportunity for OPC to further develop the long standing relationships made there by having established a Norwegian legal entity, OPC Norge A.S in Stavanger. We look forward to working closely and productively with Statoil for many more years.”

“We are delighted to have been selected as a framework supplier by Statoil.” David Carney, Group Business Development Manager commenting on the contract award.

10 Photo credit: Harald Pettersen - Statoil ASA

New contracts

We are pleased to announce the following selection of new contracts awarded in the last quarter. This list is not comprehensive but representative. Complete evaluation study of SNS gas fields to review potential for production enhancement through infill well drilling or facilities improvements for the UK upstream business of one of the world’s largest energy companies.

Pressure transient analysis study, awarded for the full life cycle of UK offshore oil field-wide water injection wells to evaluate the changed skin factor for a Chinese owned upstream company with oil and gas assets in the UK, Africa and North America.

Provision of petrophysical and production technology resources for African national company with upstream interests in oil and gas exploration and production in Africa, North America and Asia Pacific.

Subsurface engineering and geoscience training services in co-venture with a USA specialist training services provider for GCC national oil company.

Evaluation study of SNS gas fields to review potential for production enhancement for an International E&P company headquartered in Europe. Well test analysis and provision of geoscience and reservoir engineering support for independent upstream company with onshore and offshore assets in the Caribbean, Trinidad and South Africa.

Complete data room evaluation study of SNS gas fields to include identification of the range of reserves, with the upside to include infill well opportunities and production debottlenecking for UK Independent upstream company.

Reservoir surveillance and petrophysics training services for upstream business of an Asian national company.

If you would like to know more about OPC services and how you can work with us either as a services provider or client with a need for support, please contact our Business Development Manager, David Carney.

David Carney Business Development Manager +44 (0)20 7428 1111




Wells Frac Supervisor UK

Responsible for the planning and execution of operations at the frac spread. Experience of Workover and completions operations and all of the well components is essential.

Geologists / Geophysicists We are seeking excellent senior geologists and geophysicists to work with a number of clients. We are interested in hearing from consultants with exploration and appraisal or well Planning, drilling, development/production experience. All posts offer an exciting opportunity to work in highly experienced and skilled multi-disciplinary subsurface teams on world-class reservoirs.


Technical Planner OPC requires the services of an experienced consultant engineer with a strong background in building production/development stage dynamic models for carbonate reservoirs. Office based in Doha. Responsible for supporting a subsurface technical planning team engaged in field development planning, economic/scenario analysis, upstream planning, scheduling, cost estimation budgeting, monitoring, interface management and performance analysis.


Completions Engineer – Field Development To deliver completions to support milestones for single well and field development process. Evaluate and recommend well completion and intervention needs for carbonate reservoirs. Master’s or Bachelor’s degree with minimum 10 years’ experience as a senior completion engineer. Must be fluent in English.


Well Test Engineers / Supervisors   Consultants are required to observe, supervise and advise the operators regarding onsite execution of all offshore/ onshore well testing operations.


Senior Drilling Engineers To provide overall engineering support to onshore and offshore drilling operations. Planning activities include generation of well options, basis of design documentation, project well cost estimates and well delivery schedules.

Geophysicist Experienced in well planning and follow-up during drilling/operations, seismic interpretation, well path generation, petrophysical understanding. Knowledge of well construction governing documents. Minimum 5-10 years’ experience of fields in production. Experienced user of OpenWorks, Decision Space Desktop (DSD) and WellLink. Detailed knowledge of well construction and follow-up of operations. Must be able to work independently.


Senior Reservoir Engineer   To assist Client operations in Norway. Degree qualified with a minimum of 15 years’ relevant industry experience. Norwegian experience is desirable but not essential. 12



Reservoir Engineer

Reservoir Geologist   

To provide technical support to multifunctional asset teams. Honours or Master’s Degree in petroleum engineering. In-depth knowledge and understanding of the oil & gas industry. Significant previous experience with an operator. Expert in reservoir simulation.

To provide technical support to multifunctional Asset Teams. To analyse and interpret geological data to optimise reservoir management and field development. Company technical representative ensuring the value of the assigned assets are maximised.


Completion Engineer LONDON

Manager – Strategy & Planning To lead the strategy formulation and planning processes within the client. Analyse and interpret the internal and external business environment, identify the critical strategic and planning issues and advise and support the MD and Executive Team in formulating business strategy and planning. Support the MD in preparation of Board and Conference documents and presentations. Minimum four-year degree or equivalent. MBA/ MBL or other relevant business qualifications advantageous. At least 12 years relevant upstream experience, with up to 20 years overall working experience.

Engineering, design, planning, logistic coordination and execution of completion, clean-up and testing activities performed by the wells team.


Contracts Engineer To provide contracts engineering services in tendering and contracting for the procurement of all necessary goods and services. Degree in Engineering or equivalent; Minimum 10 years’ experience in the Oil & Gas / Petrochemical industries; Minimum 5 years’ experience in the procurement field; Thorough knowledge of sound procurement practices.


Production Technologist Manage and deliver field development plan, basis of design, pre-sanction completion production technology work for the client’s assets, monitor and manage well performance and proposing remedial and production enhancement solutions where appropriate.


Petroleum Engineers A major international operating company urgently requires three petroleum engineers to be based in the UK working on Iraqi projects. Responsible for providing all technical support required to maximise the oil rate produced through a number of wells and also to maximise the value of the water injectors located in the area. Engineering degree with more than 8 years of petroleum engineering experience.

Any of these vacancies suit you or somebody you know? Please email your current resume to: We are always looking for talented individuals with 10 years + experience in E&P so if nothing here matches what you’re looking for, still feel free to send us in your details or call us on +44(0)20 7428 1111. 13

Latest news Aldo wins OPC Imperial College MSc award Aldo Lopez Marmolejo is the 2013 winner of the OPC Imperial College Well Test Analysis Award. The annual award of £500 is given by OPC to the Imperial College MSc Petroleum Engineering student whose thesis most impresses Professor Alain Gringarten and OPC Managing Director Piers Johnson.

OPC scholarship for Nottingham University Engineering students

Piers Johnson with Ashley Jones and Ross O’Brien, winners of the OPC Scholarships and the shortlisted candidates.

Aldo’s thesis, “Evaluation of the impact of scale in the well test behaviour of fissured reservoirs”, examined the effect of natural fracture orientation and frequency in naturally fractured reservoirs. Professor Gringarten, Director of the Centre for Petroleum Studies at Imperial College London, said: “The behaviour of naturally fractured reservoirs has been the subject of debate between proponents of double porosity and supporters of discrete fracture networks for the last fifty years. Aldo’s work is an attempt to reconcile the two concepts. He did a very good job of it.” Piers Johnson, OPC Managing Director, said: “I have a longstanding relationship with Imperial College and Professor Gringarten, and I am delighted to sponsor this award which recognises excellence in well test analysis. I would like to congratulate Aldo and, having listened with great interest to his excellent presentation, I’m confident that he has a great future within the industry.”

Piers Johnson, Managing Director of OPC, was delighted to present scholarship awards to two students at Nottingham University. The OPC scholarship is awarded to Engineering undergraduates who demonstrate a commitment and desire to work in the Upstream Oil and Gas industry. The financial award of £2500 is jointly funded by OPC and the University in order to encourage talented students to join the industry. Piers said “I was delighted that our scholarship programme received such a high level of interest with six applications reaching the shortlist. The two winners, Ashley and Ross, both demonstrated a real commitment to the industry and I am delighted that they have both secured job offers with BP.”

Jim Ayton provides an insight to Exploration OPC’s Technical Director Jim Ayton was a speaker at the SPE London section event “An Introduction to Exploration and Production” at the Geographical society on 21st November. Jim gave an expert insight into the role of Reservoir Engineering to more than 200 attendees who were keen to learn more about our sector. OPC were also happy to help sponsor the event and provide goodie bags to all attendees. 14

Next stop Everest…? Congratulations to James Grieve, OPC Chief Electrician on rotation on the Caspian Explorer in Kazakhstan, who climbed Cho Oyu in September. Cho Oyu, the sixth highest mountain in the world, is seen as the best possible preparation for climbing Everest, so we’re looking forward to next year’s trip then James….?

Ryan Moore promoted to Bid Manager We are pleased to announce the promotion of Ryan Moore into the role of Bid Manager for OPC. Ryan has been part of the OPC team for nearly four years, progressing from Consultant Services Advisor to Consultant Services Team Leader. Ryan will continue to build on the strong relationships he has established with his existing clients as well as bringing new clients to OPC through leading the company’s vendor registration and tender submission process. Ryan is currently studying for an MSc in Finance and looks forward to applying the skills gained to his new role.

OPC supports Georgian national rugby sevens in Dubai OPC was delighted to provide financial support to the Georgian national rugby sevens side in the Emirates Dubai rugby sevens tournament at the end of November. The Georgian side competed in the men’s International Invitational event, coming second in their pool and going on to reach the semifinal of the plate competition.

The next generation As it’s the 25th anniversary edition, we thought we’d show you a couple of photos of potential future OPCers. Stuart Cameron, OPC consultant, is seen with new son Thibault, and our long serving cleaner Mariya is holding grandson Alex.


We hope you have enjoyed this newsletter. Let us know what you thought and what you’d like to know more about. Next edition due in March. Kazakhstan Astana T: +7 7172 501977 E: Atyrau T: +7 7122 305967 E:

Qatar Doha T: +974 4 4292381 E:

USA Houston T: + 1 713 973 2151 E:

UK Aberdeen T: +44(0)1224 329 1111 E: London T: +44(0)20 7428 1111 E:

Inside opc issue 17  

Inside OPC issue 17 celebrates 25 years of OPC – featuring our anniversary event from October and a timeline of all the major milestones in...