Numerical simulation on the re-injection capacity of drainage water in Area H of E gas field

Abstract

The E gas field is a typical dense sandstone gas reservoir. It faces the problem of sewage treatment during production and development due to the influence of water formation. The H area with weak production capacity is selected for sewage re-injection and evaluating its re-injection capacity is a significant step before sewage treatment. In this paper, geological modeling and numerical simulation are carried out to evaluate the re-injection of the drainage water in Area H of the East E gas field, to maximize the amount of water injection within the acceptable range of the reservoir, and to analyze the leakage simulation of the two main possible leaky layers. The results show that: the formation rupture pressure in the study area is 42 MPa; the injection flow rate should be controlled at 60-80 m3/d, and the recommended injection wellhead pressure is 16-20 MPa; the leakage problem in He 7 sections should be considered in the subsequent wastewater re-injection.