Experience of interwell interference testing in a fractured gas reservoir

Abstract

The paper describes the results of interwell interference testing performed at a gas field of Surhandarya oil and gas region of Uzbekistan. The field is currently under appraisal program and being prepared for pilot production. The purpose of the testing: gaining dynamic data for extraction of not only flow capacity but also on a storage capacity of the complex fractured reservoir. The data are of essential need for correct and reliable design of pilot development project. As a result of the preformed test interpretation, the authors estimated: volume of movable reservoir gas at the tested area; structure of reservoir capacity (storativity of fractures/matrix, interporosity flow coefficient); reservoir conductivity; sealing capacity of subseismic-scale faults across the gas-bearing area of the field. The method of interwell interference consists of interpretation of an observation well pressure response to signal (flow/shut in) emitted from a disturbing well with known distance between completions of each well. During the test downhole battery gauges with resolution of 70 Pa were used, the rates of a producing (disturbing) well were measured by Coriolis flow meter of three-phase separator at a well site. The obtained data were interpreted using KAPPA Saphir software.