关键词: 低渗透, 注采井距, 期望产能, 启动压力梯度, 应力敏感

Abstract: To ultralow permeability reservoir,the key point of development effectiveness is producerinjector spacing,at the present,it is determined by means of permeability and threshold pressure gradient(TPG).In this paper,its restriction is illustrated,the change law of TPG and stress sensitivity factor analyzed according to physic simulation experiment,and its expression regressed with permeability as variable,at the same time,mathematical model of nonlinear flow in porous media built.A new method for determing reasonable well spacing in ultralow permeability reservoir is presented based on the model and superposition theory.A new methord is presented to extract reasonable injectorproducer spacing in ultralow permeability reservoir,by this method,not only reservoir permeability and injectionproduction pressure difference can be considered,but also fluid viscosity,expected production,TPG and stress sensitivity.Finally,relevant theory chart board is convenient for field application.

Key words: ultralow permeability, producerinjector spacing, expected productivity, threshold pressure gradient, stress sensitivity