Evaluation of horizontal well productivity in the abnormal high pressure and low permeability gas reservoir in the west of the South China Sea

Abstract

Based on the actual geological reservoir characteristics of an abnormally high-pressure gas reservoir in the western South China Sea, and considering reservoir stress sensitivity, a single-well model for horizontal wells was established to study the law of non-steady-state productivity of horizontal wells. Based on the established single well model of horizontal wells, and considering stress-sensitive conditions, the rational allocation of single wells is studied. The research results show that the initial unobstructed flow rate of the horizontal well is high and it decreases rapidly; the non-resistance flow considering stress sensitivity is lower than the non-resistance flow without considering stress sensitivity. The difference between the two gradually reaches the maximum at the beginning of the well, and the difference gradually decreases at the later stage; there are interrelationships and constraints between single good production, stable production time, and final production.