The low-oil-price environment continues to challenge and pressure our industry to reduce costs and optimize production. While cost reductions and efficiency improvements are always the primary focus during downturns such as we are now experiencing, history tells us that many technology and application breakthroughs have been developed in such periods. This is also a time for conducting or supporting technical studies that can provide insight on how operators can optimize production—especially from unconventional-resource developments. In the meantime, major operators are increasingly stepping out, supporting development of alternative, unconventional energy sources, such as natural gas production from gas hydrates, as the industry looks to the future.
With reduced new unconventional well activity, practices such as frac-hit mitigation—pressurization of parent wells during child-well fracture stimulation—have become increasingly important to reduce parent-well proppant cleanouts as well as to maximize production from both parent and child wells. With reduced new well activity, it is also increasingly important to dampen the sharp early-time production rate declines as much as possible, having longer-term recovery as the objective rather than just high initial production. Unlike with conventional oil wells, for example, unconventional wells have not seen the same degree of attention placed on the effects of high drawdowns on productivity decline.
Two paper synopses featured this month are along those lines. The first, paper IPTC 20260, presents the results of a geomechanics study on rock sensitivity to increasing compressive stress, such as would be experienced with high drawdowns and accelerated depletion. The paper describes and quantifies the stress-dependence of compaction and permeability for anisotropic rock matrix, natural fractures, and hydraulic fractures.
The second, paper SPE 197097, discusses the enhancement of frac-hit mitigation treatments with surfactant chemistry, showing that surfactant additive to the child-well treatments can migrate to parent wells, activating oil-recovery mechanisms.
Finally, for something different but within the world of unconventional resources, the third paper featured this month, paper SPE 29516, is a report on several offshore gas hydrate production tests in offshore sand reservoirs, which have become more-viable natural gas resource targets given the advancement in hydrate production technologies. The report focuses on key production tests conducted in northern Canada, Alaska, Japan, and the South China Sea.
This Month's Technical Papers
Study Quantifies Stress Sensitivity of Fractured Tight Reservoirs
Report Outlines Knowledge Gained in Gas Hydrate Production Testing
Surfactant-Based Treatment Fluids Mitigate Fracture Hits in Parent Wells
Recommended Additional Reading
SPE 195910 Codevelopment of Multiple Targets in Permian Unconventional Reservoirs by Richard Cao, Shell, et al.
SPE 199689 Developing Upscaling Approach for Swarming Hydraulic Fractures Observed at Hydraulic Fracturing Test Site Through Multiscale Simulations by Wei Fu, Lawrence Livermore National Laboratory, et al.
| Leonard J. Kalfayan, SPE, is a principal adviser and technical authority for production engineering and stimulation with Hess Corporation in Houston. He has 39 years of experience in the oil, gas, and geothermal industries. Kalfayan’s background is in production enhancement, new technology development and implementation, global technical support, and business development. Before joining Hess in 2009, he worked for the Union Oil Company of California and BJ Services and as an industry consultant. Kalfayan was a 2005 SPE Distinguished Lecturer and a 2013 SPE Distinguished Member. He has served on several SPE program and technical committees. Kalfayan is author of more than 30 SPE and other journal publications and holds 13 US patents. He is also author of the book Production Enhancement With Acid Stimulation, now in its second edition; co-author of the book The Energy Imperative; and co-editor of the SPE monograph Acid Stimulation. He is a member of the JPT Editorial Committee and can be reached at lkalfayan@hess.com. |
