romeu

History Matching and Forecasting

Many reservoir engineers dislike the very idea of automatic history match- ing applied to real full-field studies. They believe there is no artificial substitute for experienced reasoning, deep understanding of the reservoir mechanisms, and atten- tion to real-life practical aspects of the problem. Some use terms such as art and intu- ition. For them, even if computers long ago learned to play chess, computers will never be able to perform real-case history matching on their own or at least they are still too far from this achievement. Very often, during technical sessions, immediately fol- lowing an advanced mathematical presentation on history matching, someone in the audience makes his or her point about the limits of automatic approaches. To avoid disputes, experienced speakers prefer less pretentious expressions such as assisted or semiautomatic history matching.

Indeed, history matching can be seen as a two-step iterative process, normal- ly requiring many cycles to be completed. Broadly speaking, the first step is about analysis and setting the problem parameters, and the second step is about search- ing for and computing solutions. We start our discussion with the second part, which has a more obvious algorithmic nature. There has being a great deal of research and progress in this area. The ensemble Kalman filter is dominating the scene, but gradi- ent-based methods and global-optimization stochastic methods are attracting mer- ited attention. Most published contributions come from universities, and, typical- ly, papers include examples to demonstrate successful algorithm application. These examples can be simple synthetic or somewhat-more-realistic cases, but the discus- sion is naturally focused on the solution method and not on the entire problem as found in the field.

The first part of the problem is less mathematized, for now, and involves essen- tial tasks such as to be clear about the practical purposes and requirements in the par- ticular context; to have a full understanding of the quality of the reservoir model and the production data; to design or redesign well-justified objective functions; to set adequate parameterization, considering the main uncertainties and their effect on the simulation results; to represent properly and sample the uncertainty space; and to evaluate results from the previous steps of the history-matching process judiciously. Unfortunately, the strategies used to consider this part of the problem are much less discussed and documented. In fact, many of these tasks are open to further formal- ization and, ultimately, can be automated also. We definitely need more papers illu- minating these other aspects of the reservoir-engineering problem, instead of relying on intuition.

Read the paper synopses in the April 2012 issue of JPT.

Régis Kruel Romeu, SPE, is a Senior Consultant at Petrobras Research Center (CENPES) in Rio de Janeiro. With 31 years’ experience in petroleum engineering, he has worked mostly in reservoir- characterization and -simulation applied research. Romeu’s main activities and areas of interest are heterogeneities representation, scale up, history matching and optimization, integrated reservoir studies, coordination of research projects, relationship with Brazilian universities, and reservoir studies related to Brazilian presalt fields. He holds a BS degree in civil engineering from Universidade Federal do Rio Grande do Sul, Brazil; an MS degree in petroleum engineering from Universidade Federal de Ouro Preto, Brazil; and a PhD degree in quantitative geosciences from the Université Pierre et Marie Curie, Paris. Romeu has served as Editor for SPE Res Eval & Eng and serves on the JPT Editorial Committee.

payne

High-Pressure/High-Temperature Challenges

Exciting operations are ongoing on the shallow-water US offshore continen- tal shelf (OCS) that will influence the entire high-pressure/high-temperature (HP/HT) community going forward. McMoran and their operating partners are actively drill- ing, evaluating, testing, and bringing to production several deep HP/HT plays. These prospects are named in the Treasure Island theme with identities such as Davy Jones, Blackbeard, and Lafitte. The Davy Jones 1 is in the completion phase, incorporating multiple Eocene Wilcox sands, and it represents the first 25,000-psi completion of its kind in the world. The Davy Jones 2 encountered confirmed pay and is progressing well. The original Blackbeard well was taken to 32,997-ft total depth, and operations on Blackbeard East have been permitted to 34,000 ft. As with Davy Jones, these wells represent substantial extensions to or step changes in current HP/HT technologies.

To address the substantial engineering challenges associated with these wells, the operator formed a significant project team and is drawing on the expertise of several vendors in a collaborative manner to make the many advances necessary in HP/HT drilling and completion procedures and in production equipment and proce- dures. Downhole tools have been upgraded to 30,000 psi and 500°F. It will take con- siderable effort to catalog all of the “industry firsts” and “Serial-Number 1s” associat- ed with these ongoing operations. Both Davy Jones wells are expected to be flow tested and put on production later this year.

HP/HT continues to be of international interest, with global operations ongoing from the North Sea, to Latin America, to the Middle East, and of course in the “ring- of-fire” regions in Southeast Asia. Operators, service companies, equipment suppli- ers, drilling contractors, and other involved parties share a common goal of address- ing the many HP/HT challenges successfully and in a safe and efficient manner. These goals create a need to exchange information effectively, openly share lessons learned, and embrace a collaborative spirit that respects the competitive nature of business while valuing the shared interest that we all have in safe and reliable operations. Thus, the industry looks forward to learning more from the success of these HP/HT step changes in the US OCS ventures and from advances in other HP/HT operations around the globe.

Read the paper synopses in the April 2012 issue of JPT.

Mike Payne, SPE, is a Senior Advisor in BP’s Exploration and Production Technology group. He has 29 years’ experience including drilling operations, computing technology, and consulting. Payne holds BS and PhD degrees in mechanical engineering from Rice University, an MS degree in petroleum engineering from the University of Houston, and an Executive Business Education degree from the University of Chicago. He has extensive industry publications and has held key leadership positions with the American Petroleum Institute and the International Organization for Standardization. Payne has been an SPE Distinguished Lecturer and received the SPE International Drilling Engineering Award in 2000. He has chaired or cochaired several SPE Advanced Technology Workshops and serves on the JPT Editorial Committee.

hobbs

Natural Gas Processing and Handling

In 2010, natural-gas reserves were approximately equivalent to 75% of the oil reserves (including oil sands). Unconventional gas sources continue to make up an increasingly important part of the natural-gas supply, particularly shale gas and coal- bed methane (CBM), which contribute approximately 40% to US natural-gas reserves.

Generally, very remote offshore gas reserves cannot be exploited economically by use of fixed subsea pipelines that tend to link the field with a specific geographical market. Operators can maximize market reach through natural-gas liquefaction and improved marine liquefied-natural-gas (LNG) tankers. For ultimate flexibility, four floating LNG-production facilities are predicted to come on stream within this decade.

Commercial exploitation of the known massive hydrate reserves probably is some time off; however, the chemistry research involved in hydrate management for current natural-gas production may accelerate progress in that area. Hydraulic-water reuse is key to the future of the CBM and shale-gas industries.

There are many opportunities to learn about and share natural-gas technologies. An SPE workshop, “Reducing Environmental Impact of Unconventional Resources Development,” will take place in San Antonio, Texas, 23–25 April 2012. A joint SPE/ SEG workshop, “Injection Induced Seismicity,” will be held in Broomfield, Colora- do, 12–14 September 2012. There will be an SPE “Tight Gas” workshop in Adelaide, Australia, 10–13 June 2012, and the SPE Unconventional Reservoir Technical Interest Group (TIG) provides a useful information exchange, as does the Gas Technology TIG. The 2013 SPE Unconventional Gas Conference and Exhibition will be held in Muscat, Oman, 28–30 January. The 2013 SPE International Symposium on Oilfield Chemis- try to be held in The Woodlands, Texas, 9–13 April, includes topics on gas-processing chemical applications.

Acid-gas (CO2 and H2S) removal from natural gas and sequestration/recovery/ disposal technologies are very important in exploitation of poorer-quality gas finds. Much work continues in this area, and very large acid-gas-removal units are in opera- tion or are planned for the Arabian Gulf region.

The future of natural-gas processing and handling has never looked better.

Read the paper synopses in the April 2012 issue of JPT.

George Hobbs, SPE, is Director, Strategic Chemistry Pty. Ltd., a production consulting group. Previously, he was with Nalco/Exxon, Exxon Chemical Energy Chemicals, NL Treating Chemicals, Baroid, British Gas, Kemira Oy, and Blue Circle Cement. Hobbs has 34 years’ experience in solving oil and gas and geothermal drilling and production problems in Europe, the USA, North Africa, the Middle East, the Far East, and Australasia. He studied at the University of Glasgow, Brunel University, and the University of Adelaide, earning a BS degree in applied chemistry and a Graduate Diploma in business. Hobbs is past Chairperson of the SPE Gas Technology TIG and served on the SPE TIG Advisory Committee. He serves on the SPE Production and Operations Advisory Committee and the JPT Editorial Committee. Hobbs is a Certified Corrosion Specialist and Chemical Treatment Specialist.

santos_70

Offshore Drilling and Completion

In the 2 years since the Macondo incident, we have seen a lot of action toward new regulations, procedures, and norms to be implemented in an attempt to reduce the risks of those tragic events happening again. But the industry did not stop working; wells were drilled and completed, even in the Gulf of Mexico after the long period of inactivity. As expected, we saw a big focus on subsea-equipment testing and procedures and on needed equipment improvements. But we also saw many reports highlighting improved operational performance, confirming that the industry continues with significant activity.

We should work proactively with the public and regulators to bring a framework that will lead to a safer environment for everyone. And we should not be happy with just more paperwork that may not bring needed effective improvement. For obvious reasons, the first step has been focused on the equipment responsible for providing the last barrier of protection, the blowout preventer (BOP). One paper describes BOP upgrades, and another one discusses software-based deepwater-BOP testing. We all must recognize that there has not been a significant advance in terms of BOP testing in
the last 30 years. We are still relying, most of the time, on the old paper disks to record tests and on forms filled in by hand to confirm the pressure and duration of the tests prepared on each component tested. We should do much better than that.

The third paper highlights the drilling campaign in a promising offshore area in Brazil. But do not forget the underground blowout that leaked oil into the ocean offshore Brazil a few months ago, reminding us that continuous improvement of all offshore operations must take place. The alternative is that we again will face setbacks like those in the Gulf of Mexico after the Macondo accident.

Read the paper synopses in the April 2012 issue of JPT.

Helio Santos, SPE, is President of Safekick Limited. In his 29 years in the industry, Santos worked as a Drilling Engineer for Petrobras both onshore and offshore and led several projects in the Research and Development Center. He also was with Impact Engineering Solutions as Vice-President of Technology, President of Impact Solutions Group, and President of Secure Drilling, which was acquired by Weatherford. Santos earned BS and MS degrees in civil engineering from Catholic University of Rio de Janeiro and a PhD degree in geological engineering from the University of Oklahoma. He has authored several SPE papers, holds two patents, has served on SPE conference and Advanced Technology Workshop committees, and serves on the JPT Editorial Committee.

NewIcon

New Technical Section and TIG: Petroleum Data Driven Analytics (PD2A)

Using data as the main building block of models is the new paradigm in science and technology. A new Technical Section and Technical Interest Group (TIG) has been formed to foster the application of data-driven modeling, data mining and predictive analytics research, development and practices in upstream oil and gas.

Join online communities of SPE members to:

  • Develop a strategy and plan to promote the use of artificial intelligence, supervised and unsupervised learning, and other techniques in field management as a complementary approach to traditional upstream workflows.
  • Develop and sustain a community of practice for sharing ideas and promoting the practice and application of artificial intelligence and petroleum analytics in upstream business.
  • Promote establishment of a new discipline, including curricula and training, to combine data mining and oilfield technologies.
  • Focus on promoting technology development and deployment to address key risks and opportunities in upstream oil and gas.

Join the Technical Section and Technical Interest Group today!

ogf_cover_april12

April Oil and Gas Facilities now available

The April issue of Oil and Gas Facilities features in-depth articles about decommissioning activities in the Gulf of Mexico and how a systems-wide engineering approach to facilities design helps in the planning for initial startup. View the Table of Contents to see the regular columns and peer-reviewed papers. Subscribers can view the entire issue. Learn more about Oil and Gas Facilities or view the entire first issue.