Technology Focus: Tight Reservoirs (November 2008)

Abstract

Technology Focus Attention to tight reservoirs has moved beyond the boundaries of North America as the importance of these hydrocarbon systems as global energy assets continues to grow. In addition to the complex geology, petrophysics, and reservoir heterogeneities dealt with in our industry today, tight reservoirs (<0.1-md permeability) provide unique challenges related to hydrocarbon storage and flow. Over the coming years, drilling wells with an ever-reducing surface spacing will strain available resources. New technologies and processes (e.g., improvements to drilling and completion of horizontal wells) will be developed to increase reservoir contact and drainage, which in turn will improve operations efficiency, production, and recovery significantly. Effective exploitation of tight reservoirs will depend on new technologies and on improving the fundamental understanding of tight reservoirs over the life cycle of the field. The evolution in fundamental understanding will rely on obtaining critical reservoir data including saturations, wettability, capillary pressure, structural features, deposition and diagenetic effects, volumes, mineralogy, lithology, in-situ stress effects, and rock strength. It will also rely on the ability to incorporate the structural, mechanical, and petrophysical properties of the reservoir into simulators so one may simulate and assess different reservoir-drainage strategies. Achieving continuous subsurface monitoring and measurement during drilling, completion, stimulation, and production will be critical to evaluate the drainage behavior and to validate the optimization of the field-development strategy. In this way, we will not only lower capital expenditures, investment-recovery times, and operating costs but also ensure maximizing the recovery of the hydrocarbon from the reservoir over the life of the field. Papers selected for this month's feature focus on the industry's progress in building the tight-reservoir knowledge base and how we are crafting methodologies to improve our decision making in reservoir development, characterization, and production. Tight Reservoirs additional reading available at the SPE eLibrary: www.spe.org SPE 110050 • "A Comparative Study of Capillary-Pressure-Based Empirical Models for Estimating Absolute Permeability in Tight Gas Sands" by J.T. Comisky, SPE, Apache Corporation, et al. IPTC 11545 • "A Case Study: Using Wireline Pressure Measurements To Improve Reservoir Characterization in Tight Gas Formation—Wamsutter Field, Wyoming" by R.A. Schrooten, BP plc, et al. SPE 110809 • "Barnett Shale Completions: A Method for Assessing New Completion Strategies" by R. Leonard, ProTechnics, et al.