Overview: Artificial Lift (May 2007)

Abstract

Boosting ultimate recovery requires us to get more from each well and each reservoir. Clearly, while improving recovery is one of the best places to look for additional reserves, often the relationship between artificial lift and ultimate recovery has been forgotten. However, when artificial lift options are limited, as is the case for subsea wells, we quickly discover that recoveries drop to among the lowest in the industry. Today, selection of an artificial lift technique plays an increasingly important role in determining ultimate recovery. In addition to the challenges posed by subsea/deepwater production, unconventional reservoirs also require new ideas to improve recovery. For example, steam operations used to produce from heavy-oil reservoirs require downhole and surface pumps to operate at temperatures well beyond our experience base. Unconventional gas reservoirs, such as coalbed methane and ultralow-permeability sand/shale, also present unique challenges. In these cases, operating companies must solve problems associated with lifting liquids to the surface (i.e., liquid loading). The papers highlighted in this artificial-lift section illustrate some of the approaches applied in a wide variety of reservoirs. From installation of electrical submersible pumps in hot, high-gas/oil-ratio wells to rod-pumping applications for gas well unloading, these papers illustrate the adaptation of artificial-lift methods to keep wells producing and to extend field life. Work on improving the ability to predict the slug-to-annular-flow transition also is highlighted. This work is of great interest to the area of gas lift stability as well as predicting the onset of liquid loading. The recommended reading list highlights some of the latest thinking on the requirements and current state of the art in the rapidly evolving area of seafloor boosting. This particular type of artificial lift, by use of subsea multiphase pumps, is quickly becoming an integral part of the field-development plan for deepwater and ultradeepwater fields. Given the industry shift to deepwater and unconventional reservoirs, today's definition of artificial lift must encompass a much broader range of technologies than in the past. Also, the critical role that artificial lift plays in increasing ultimate recovery needs to be recognized up front so that effective artificial-lift solutions can be incorporated in field-development planning. Artificial Lift additional reading available at the SPE eLibrary: www.spe.org SPE 104037 "Stability Analysis of Gas Lift Wells Used for Deepwater Oil Production" by I. Guerrero-Sarabia, National Autonomous University of Mexico, et al. SPE 104314 "Economic Pumping Technology for Coalbed Methane (CBM), Stripper Oil, and Shallow Gas Well Deliquification" by Michael W. Dickey, SmithLift Available at the OTC Library: www.otcnet.org OTC 18261 "Subsea Processing and Boosting—Technical Challenges and Opportunities" by R.M. Bass, Shell International E&P OTC 17899 "Subsea Boosting of the Brenda Field Through Utilization of a Multipurpose Field Development Solution" by J. Elde, SPE, Framo Engineering, et al.