This year, there were approximately 200 papers on simulation to select from—and that is after a separate feature on history matching. So, the discipline continues to be active. A noticeable feature is the growing number of simulation papers that use different technology, in the broadest sense of the term—for example, using concepts from signal processing and electrical engineering to model subsurface flow or related phenomena. However, the dominant technology remains finite different representations of Darcy’s law, conservation of mass, and a fluid model.
What is also heartening is the fact that all significant papers on case studies start with descriptions of the geology and often include detailed description of 3D geological modeling. Any simulation that is based on a physical model of the field must surely depend on the quality of the geological model used as input; yet, not that long ago, it was normal to pay only scant regard to the geology when constructing a model and even less when altering it during history matching.
Recent discussion within the SPE Simulation Technical Interest Group has raised the issue of pseudorelative permeabilities, with some arguing that they are obsolete and others strongly disputing the claim. Sadly, there were no papers on the subject that I could include in this feature. The relative permeability curve is where engineering meets geology; anyone involved in complex projects—and who of us is not— knows that it is at the interfaces that complexities arise and are too often ignored. The same is true in our models, so surely relative permeabilities and their multiphase upscaling are topics worth renewed investigation.
All three of the case studies I have selected, which are all from very different settings and parts of the world, were studies directed toward making tangible decisions (e.g., selecting well locations and completion intervals). This highlights once again that good simulation studies are directed toward decision making; having a clear sight of the purpose of the work improves the quality of the work and, thus, of the ultimate decision. The converse is also true.
View the paper synopses in the July 2012 issue of JPT.
Martin Crick, SPE, is chief petroleum engineer with Tullow Oil, responsible for all aspects of reservoir and production engineering in the group worldwide. Previously a principal reservoir engineer with Schlumberger, he was responsible for the design of the reservoir-engineering features in Petrel and, most recently, for a review of well test interpretation workflows within Schlumberger. Crick’s experience over 24 years in the industry has focused on reservoir engineering and, especially, simulation in support of field development planning initially with AEA Technology on contract to the UK government on a wide range of North Sea fields and then with Texaco on Erskine, the first high-pressure/high-temperature field on production in the UK North Sea, and on Karachaganak, the giant gas/condensate field in Kazakhstan. He holds a BS degree in physics from the University of Bristol.
On behalf of the Technical Directors (TD), I would like to draw your attention to a new article series in JPT called the Young Technology Showcase. This showcase is part of the TD’s Technology Pipeline strategy and is focused on bringing young technology to the SPE membership. Young refers to early in the technology life cycle where a technology first becomes commercially available.
If you are looking for new technology to apply to your fields, check out two sections of the June 2012 issue of JPT Online: Young Technology – Editor’s Column on page 16 and Young Technology Showcase article, starting on page 40. Additional information regarding Young Technology is provided in the President’s Column of the December 2011 JPT Online.
Papers in this volume are on the topic of Tight/Shale Gas.
Read the latest content at www.spe.org/go/speree
Papers in the following areas are featured:
- Drilling Engineering Training with Directional Drilling Examples
- Well Control and Managed Pressure Drilling
- Drillstring Dynamics
- Casing Drilling
- Formation Damage
- Well Integrity
- Wellbore Strengthening
- Classic SPE Drilling Paper
Read the latest content at www.spe.org/go/spedc
Enhanced-oil-recovery (EOR) operations are what moves EOR processes from the laboratory to the field. They involve a series of activities, from a detailed planning stage to efficient application, consistent monitoring, and results analysis. When reviewing results from field pilots or full-field applications, it is noticeable that significant technical hurdles such as facilities, drilling and completion, and production-technology developments need to be overcome in order to deploy and run a successful EOR operation. Technology developments in water management, intelligent-well completions, and downhole innovation are key for EOR operations to achieve the expected increases in reserves.
Over the past year and during the first quarter of 2012, SPE was host to several events focusing on EOR operations, and more than 400 papers were presented. Several of them explored topics related to enhancements associated with the three key areas mentioned. Emphasis in many papers concerns extending the use of smart-well completion technologies to EOR operations, targeting customization to set out an EOR process and provide more flexibility for the solution to unexpected setbacks during process startup. Also, several publications stress the importance of downhole innovation aiming at oil- and gasfield production maximization by continuous optimization of steam and CO2 downhole injection rates in heavy-oil recovery and CO2-EOR processes, respectively.
Dealing with EOR operations adequately is a great challenge, and a broad and integrated set of competencies is required. Nevertheless, as some of the papers featured in this issue illustrate, success is attainable with the right use of technology and creativity. I hope that you enjoy reading these paper highlights and will search for additional interesting contributions available in the OnePetro online library.
Read the paper synopses in the June 2012 issue of JPT.
Luciane Bonet-Cunha, SPE, is a senior reservoir engineer for Petrobras America in Houston. She has 27 years of experience in applied research and development related to reservoir engineering in exploration and exploitation projects in Brazil, Canada, and the US Gulf of Mexico. Before joining Petrobras America, Bonet-Cunha was an associate professor of petroleum engineering at the University of Alberta, Canada. She also worked for 16 years with Petrobras, Brazil. Bonet-Cunha holds a PhD degree in petroleum engineering from the University of Tulsa and serves on the JPT Editorial Committee.
We wear small bands on our fingers for many reasons. The rings have many meanings; the wedding ring may be the most common. This band, signifying no beginning or end, represents a union or reminds the wearer that he or she is married. It is traditionally worn on the left hand, on the vena amoris, the digit that the Romans believed was connected directly to the heart. Puzzle rings, or gimmel bands, are another type of ring used as wedding bands that has dual meanings. The word “gimmel” comes from the Latin gemellus and means “twin” or “paired.” Engaged couples would each wear one piece of the puzzle ring and, upon marriage, join the two bands with another provided by the priest. Once joined, the bands formed a puzzle that, if removed, was difficult to piece back together. Deceit that led to infidelity was made more difficult because the wearer might not be able to put the puzzle back together. Wedding rings have different traditions in eastern and western cultures, but they always hold a strong mental connection for the wearers.
Rings also tie us to our accomplishments or recollections. School rings and championship rings can tie us to a collegiate career or a significant athletic accomplishment. The purpose of these rings is to remember. I have always been inspired by a tradition that many Canadian engineers have of wearing an iron ring. The ring is worn on the little finger of the engineer’s dominant hand so that, when writing or tasking with the dominant hand, the engineer is reminded of his or her obligations. The tradition holds that the iron in the ring came from a bridge that failed and cost many lives. The ring is small and is designed to be a constant reminder. The tradition continues when the engineer retires; the ring is returned to service as an “experienced ring.”
Preventing failures in our field is imperative for safety and economic operation. Learning from these failures, properly documenting and remembering them, is important for avoiding catastrophes. We may engineer a process, a method, or a particular part to reduce failures and enhance operations. Solid-expandable-tubular technology is a fairly new technology that is gaining more promising and important applications in oil- and gas-wellbore design. Constant improvements to the deployment of this technology are increasing its reliability and number of applications. Heat treatment of the expansion-cone material used in an expanding tubular is one such modification. The drillpipe-connection phase of the drilling operation can be one of the greater opportunities for failures and mishaps. An improperly handled connection procedure can damage drillpipe; stick a drillstring; and, in the case of managed- pressure drilling, induce an unwanted influx. One of the selected papers reviews a database of drillpipe-connection damage, and another reviews a method for making connections in the managed-pressure environment.
Read the paper synopses in the June 2012 issue of JPT.
Casey McDonough, SPE, is a drilling engineer for Chesapeake Operating. He has 7 years of practical drilling experience working in the Permian Basin and with the Barnett and Marcellus shale. McDonough has nearly 20 years of combined consulting, managerial, technical, and field experience in the oil and gas industry. He has worked as a consultant for Knowledge Systems, providing clients with pore-pressure and wellbore-stability studies. McDonough also held technical and managerial positions in downhole logging-while-drilling development for Dresser and Halliburton, where he contributed to density, neutron, vibration, and hot-hole technology. He began his career as a field engineer for Sperry Sun Drilling Services and holds a BS degree in industrial engineering from the University of Oklahoma. McDonough serves on the JPT Editorial Committee.
Well stimulation continues to be a hot topic in our industry, particularly with hydraulic fracturing of shales. Having been in the industry since the Dark Ages, (at least, it seems like it at times), it is interesting to see the technology changes over time and what areas are currently in the spotlight. Certainly, hydraulic fracturing continues to lead the industry interest; however, we do pump a lot of acid, and we have not forgotten its importance. Our acid blends have not changed much since the very early days— the late 1800s—of acidizing. Hydrochloric acid has been the mainstay, with primarily hydrofluoric acid and formic and acetic acids being the complimenting acids. Specialty acids, such as phosphonic, sulfamic, and others, have also been playing a role.
Major technology developments in nonproppant-fracturing well stimulation, as evidenced by the numerous publications over the last few years, have been primarily in carbonate acidizing. This is a continuing trend brought about by the significance of the carbonates to the world’s oil supply. However, our industry does use a lot of acid in the noncarbonates. One of those areas is in spearheading fracturing treatments to reduce near-wellbore tortuosity, most of these in sands and shales. My experience with this approach in horizontal shale wells has not always been successful; however, one of the papers selected for this month’s feature shows a unique acid blend that has shown some success in tight-gas-sand fracturing. Perhaps this and other unique acid blends could provide increased success in shales.
Horizontal wells in all reservoir types are now quite common, allowing our industry to exploit lesser-quality reservoirs economically. Shales are excellent examples. Many reservoirs have a high water cut, and stimulating wells in these reservoirs can be a real challenge. Acid-placement techniques, as well as diagnostics while acidizing, are a significant challenge to our industry. Of course, in our industry, challenges beget solutions. A recent development helping with well stimulation and production diagnostics is distributed temperature sensing (DTS) and distributed acoustic sensing (DAS). From reviewing numerous technical papers from worldwide SPE meetings held in the last year or so, the development and application of DTS and DAS appear to be in the forefront. Two of the papers selected for this month’s feature reflect on these developments and applications.
Readers are advised to review the following synopsized papers as well as the recommended additional reading to gain information on recent advancements in well stimulation.
Read the paper synopses in the June 2012 issue of JPT.
Gerald R. Coulter, SPE, is a consulting petroleum engineer and president of Coulter Energy International. He is involved in consulting and technology transfer of well-completion, formation-damage, and well-stimulation technology. Coulter is currently an instructor with PetroSkills. His industry experience includes work with Sun Oil/Oryx Energy Company, Halliburton, and Conoco. Coulter has authored numerous technical papers and holds numerous patents, has been chairman of and has served on numerous SPE committees, and is currently serving on the JPT Editorial Committee. He holds a BS degree in geology and a BA degree in chemistry from Oklahoma State University and an MS degree in petroleum engineering from the University of Oklahoma.
The coiled-tubing (CT) industry has experience unparalleled growth in the past year, driven directly by the massive expansion in multistage-fracturing operations in North America. Various sources estimate that the US consumed 50% of the world’s CT in the past 12 months, helping to contribute to a massive 80% growth in product coming off the CT production lines.
The growth in the United States was fueled primarily by three applications: milling out composite plugs, milling out fracture-sleeve ball seats, and toe shoots (the name given to the first perforating operation before plug-and-perforate operations). Because toe shoots take place without any pressure on the well, the amount of CT life consumed by fatigue during the operation is small. Plug or seat milling, on the other hand, takes place after fracturing operations are complete and with the wellbore fully pressure charged by the formation; therefore, the CT life consumed by fatigue is high. Superimposed over the wellbore pressures are the pressures arising from circulating fluids through the CT and the milling assemblies. In some of the higher-pressure shale plays, CT strings last only for a few jobs.
Accordingly, any technology that reduces the superimposed pressure could lead to longer CT life and potentially to lower completion costs. Two of the papers selected for this month’s issue involve new technologies that might be helpful to operators in this respect.
However, of possible greater concern to CT companies in North America is the fact that CT use is now clearly dominated by well-completion operations, or, to put it another way, by rig count. Until recently, the CT intervention business was primarily remedial in nature and, thus, was partially cushioned from the extreme cycles experienced by drillers. However, in North America, a change has already arrived and, with gas prices at historic lows, CT service companies, CT pipe manufacturers, and CT equipment manufacturers probably need to prepare for the same swings that the rest of the well-construction industry is used to.
Read the paper synopses in the June 2012 issue of JPT.
John Misselbrook, SPE, is senior advisor global coiled tubing with Baker Hughes. Previously, he was with Nowsco Well Service Company, which merged with BJ Services in 1996. Misselbrook has worked in various operational, engineering, research, and management roles involving CT in the North Sea, Canada, Southeast Asia, and theUnited States. He was a member of the original team of engineers involved directly in the development of improved engineering techniques for underbalanced drilling in western Canada in 1991. Misselbrook subsequently became responsible for Nowsco’s initiative to develop underbalanced-drilling technology by use of CT. He holds several US patents and has authored several SPE papers on the use of CT. Misselbrook is a mechanical sciences graduate of Cambridge University. He served on the 2008 and 2009 SPE/ICoTA Coiled Tubing and Well Intervention Conference Committees and serves on the JPT Editorial Committee.
The number and economic contribution of unconventional (tight gas/shale and steamflood) wells continued to increase rapidly in 2011, as did the participation of major operators. That increased industry focus was evident again in the distribution of papers. Also, there were more papers relating advances in plug-and-abandonment, Arctic, high-pressure/high-temperature (HP/HT), and carbon-capture technologies.
Manny Gonzalez, Chevron Energy Technology Company’s Alliance Manager, noted that the huge interest in shale-formation completions calls for efficient controlled fracturing technology to ensure economic viability and an environmentally responsible well completion. SPE 152185 outlines a direct comparison of openhole vs. cased-hole fracturing in a tight gas reservoir. The presented results are surprising, and the effects on incremental production, fracture height, and fracture half-length are significant—a good read.
Operators have been plugging nonproductive and storm-damaged wells at an increasing rate, and effective abandonment operations can prove costly and challenging. SPE 148640 relates a novel and well-detailed approach to a more efficient plug-and-abandon process and to the process of confirming plug integrity across an uncemented section of annulus. Check it out.
Industry emphasis on long-term well reliability has continued to increase, especially for steamflood projects. SPE 150022 details a very thorough look into the many design and operational factors that affect well reliability in a high-temperature (285°C) steamflood. While only briefly mentioned, the authors undertook controlling the rate of temperature change, and thus controlling temperature disparity (∆T) between casing, cement sheath, and formation during injection cycles. Controlling injection events can have a strong effect on the reliability of a steamflood well or even a deepwater or HP/HT well. This is the first field effort at controlling such events that I recall.
Read the paper synopses in the May 2012 issue of JPT.
Bob Carpenter, SPE, Research Consultant with Chevron Exploration and Technology Company’s Cement Team, has 33 years’ experience in field operations, technical support, and R&D. Previously, he was with Arco Exploration and Production Technology and BJ Services’ Technology Center. Carpenter serves on the SPE Drilling and Completions Advisory Committee, along with other industry groups. He has authored or coauthored 15 SPE papers and several JPT articles and has been granted 23 US patents. Carpenter’s areas of expertise include technical support and R&D of all areas of primary and remedial cementing. He also has extensive expertise in coiled-tubing cementing, spacer-fluid development, and remediation of sustained casing pressure. Carpenter serves on the JPT Editorial Committee.
Mitigating Risks in Development Projects
Our industry has been involved in incidents that demonstrated the need of a new approach for evaluating and mitigating the risks in well construction.
The “what’s worked well in the past” conservative approach is not possible anymore, in face of the damaged trust of the public about upstream activity. Though the criticism soars against exploration and production activities, the industry has allocated substantial investments in research for new technologies aimed to preclude risk events of recent years. New procedures and technologies, in addition to existing ones, will be deployed in the near future to eliminate blowouts or underground contamination from upstream operations.
The initial results can be seen in field operations such as the application of managed-pressure drilling (MPD) for offshore and onshore, the use of long horizontals or extended reach in the shale plays, and new fluids and techniques for fracture treatments that minimize the amount of water required in such operations.
The effects of drilling operations in the shale plays of the USA are clear, but recent research will result in a consistent reduction of environmental damage. Research is minimizing fluid losses into reservoirs and helping with mitigation of well-control situations when applying the MPD technique.
The use of nanotechnology will provide fluids that improve fracture treatments through the control of fluid losses, with a subsequent reduction in the amount of fresh water required. Today, an average fracture treatment in the Barnett shale requires 235,000 bbl of water. These treatments are essential to reduce the number of wells and to improve the performance of the fracture treatments for environmental-impact reduction.
The use of extended-reach drilling or long horizontal wells, combined with multilaterals, will reduce the number of wells without impairing expected production. This will mitigate the effect on aquifers or shallow formations with a reduction in surface infrastructure. Some of the papers featured or listed for reading show advances in the technology of extended-reach and multilateral wells that will help achieve such objectives.
Finally, the combined use of extended-reach and multilateral wells, nanotechnology fluids, and MPD will result in a more environmentally-friendly operation with a cost-effective development plan, which is essential for improving the industry’s image.
Read the paper synopses in the May 2012 issue of JPT.
Alvaro Felippe Negrão, SPE, is Senior Advisor for Woodside Energy USA. Previously, he was with Repsol, Halliburton, and Petrobras. In his 33-year career, Negrão has been involved in drilling and completion engineering and operations for wells in deepwater Gulf of Mexico, Brazil, the North Sea, West Africa, the Mediterranean, the Caribbean, and North/South America and in new-ventures evaluation and asset management. He has served on several SPE committees and currently serves on the JPT Editorial Committee and serves as vice chairperson for the SPE Subcommittee for the Offshore Technology Conference. Negrão holds a BS degree in civil engineering from the Universidade de São Paulo in Brazil, an MS degree in petroleum engineering from the Universidade de Campinas in Brazil, and a PhD degree in petroleum engineering from Louisiana State University.