Research On Damage Of Aqueous Phase Trapping And The Prediction Method In Low-permeability Gas Reservoirs

With the development of the natural gas industry, the exploration and development oflow-permeability gas reservoirs has gradually become one of the important areas of increasingreserves and production. The geology reserves of low-permeability gas reservoirs areabundant in China and it plays an important role in oil and gas resources. It is of greatdevelopment prospect of low-permeability gas reservoir. Therefore, the well development oflow-permeability gas reservoirs is of great significance for the stable and continuousdevelopment of the future of China’s oil and gas industry.The study area in this paper, Denglouku Group gas reservoir of Songliao Basin in JilinOilfield is typically of low porosity, low permeability and low abundance. The reservoir isseriously damaged in the drilling and completion process, especially by the aqueous phasetrapping. Therefore, combined with the current aqueous phase trapping damage extent oflow-permeability gas reservoir and the construction features of Denglouku Group gasreservoir, several research items have been carried out. Denglouku Group gas reservoircharacteristics and clay minerals have been analyzed. The reservoir sensitivity evaluation,reservoir damage factor analyses, aqueous phase trapping damage and the prediction methodshave been studied and analyzed.The interior evaluation results of reservoir sensitivity show that the velocity sensitivity ismedium, water sensitivity is strong, salt sensitivity is moderate to strong, base sensitivity ismoderate to weak and there is no acid sensitivity. This article has focused on aqueous phasetrapping and some research has carried out. The damage mechanism of aqueous phasetrapping, influential factors, the serious consequences caused by aqueous phase trapping andthe interior evaluation on aqueous phase trapping have been studied and analyzed. Based onthe all prediction methods of aqueous phase trapping, prediction formulas have beencompared and analyzed. At the same time, a new prediction method of aqueous phasetrapping damage for low-permeability gas reservoir has been put forward. Compared with thelaboratory experiment data, the prediction results proved to be right and the prediction methodis practical and feasible. This prediction method provides a new scientific and effectivemethod to predict aqueous phase trapping of low-permeability gas reservoir for the laboratoryexperiment and field construction personnel.