Investigation on controlling parameters on zonal gas production of multilayer system

Abstract

This study is intended to investigate controlling parameters of rate allocation from multi-layer system. The study is concentrated on the condition that rate allocation is proportional to gas volume in each layer. The effects from rock properties and flow rate to the gas volume allocation are investigated. The twolayered gas reservoir is used for investigation under various cases and the five-layered system is used for test of validity of this study to more layers reservoir. From the study, rate allocation of multi-layered gas reservoir is proportional to gas volume ratio during the stabilized flow on the conditions that flow rate is less than flow capacity of reservoir. The rate allocation of multi-layered gas reservoir is also proportional to a product of gas volume, rate of change of reservoir pressure, and inverse of reservoir pressure of each layer for longer period (the whole pseudo-steady state period). However, during the stabilized flow (part of the pseudo-steady stage period) the ratio of rate of change of reservoir pressure and reservoir pressure of all layers are very close to each other and can be cancelled out. The rate allocation obey kh ratio during the early stage of flow when flow rate is close to flow capacity. The other controlling parameters are flow rate and permeability