Determining the Best Diversion Methods for Tight Gas Sand Stimulation

摘要

Producing natural gas from Tight Gas Sand (TGS) reservoirs is currently very important to the industry in North America and will be of increasing importance to the global energy industry in the coming decades. Many wells are completed and drilled each year in thick, tight gas reservoirs that have many individual layers that can contribute to production if adequately perforated and stimulated. It is important to select a diversion technique that allows access to the most layers with the most gas in place at minimal costs. However, we have found essentially no papers in the petroleum literature that provide a logical method for selecting the best diverting method for a given set of reservoir conditions. There are papers that discuss successful field cases where specific diversion methods seem to work for specific reservoirs. We have used many of these SPE papers to help define "best-practices" concerning the selection of diversion technologies in completing tight gas sands with thick, multiple pay zones. We then developed logic to give advice to the user on the best diverting methods for specific reservoir conditions. In this paper, we will specifically cover the logic we have developed for choosing methods for diverting fracture treatments. The effort to develop a model to determine the best diversion methods is part of our effort to build software that we call TGS Advisor. TGS Advisor can be used to provide advice to engineers developing TGS reservoirs. The program can be described as an "Advisory System". The user enters the reservoir data that are known and the program provides advice on how to drill, complete and stimulate the reservoirs identified in the well. We have combined knowledge from the petroleum literature and interviews with experts with detailed calculations to build the TGS Advisor program. We evaluated the results of the advisory system with published case histories in the SPE literature. We have included examples of how TGS Advisor can help the user to determine appropriate diversion technologies for given reservoir conditions.