油气地质与采收率2017，Vol.24Issue(5)：64-69,6.
致密气藏动态启动压力梯度实验研究
Experimental study on dynamic threshold pressure gradient of tight gas reservoir
摘要
Abstract
Present threshold pressure gradient test cannot characterize the present situation of real threshold pressure gradient.After back pressure control system with high precision was introduced,experimental approaches were carried out to evaluate the threshold pressure gradient in the tight gas reservoir under reservoir conditions.Compared with the measured result under normal pressure,the threshold pressure gradient obtained by the new method is lower under the condition of same permeability and the difference becomes larger when core permeability is lower.Results show that the threshold pressure gradient is not a constant during the development of reservoir,but varies with the pore fluid pressure,and it is called dynamic threshold pressure gradient.New concepts of threshold pressure gradient sensitivity and threshold pressure gradient sensitive coefficient were proposed and defined to describe the dynamic threshold pressure gradient in the tight gas reservoir.The influencing factors of dynamic threshold pressure gradient were experimentally studied as well.Results indicate that the threshold pressure gradient of the tight cores show a linear increase with the decrease of pore fluid pressure.When the core permeability is lower and the water saturation is larger,the threshold pressure gradient becomes larger under the condition of reservoir and the variation range of the threshold pressure gradient during the development is larger.The threshold pressure gradient sensitivity is stronger and the dynamic variation of threshold pressure gradient is more obvious.关键词
致密气藏/启动压力梯度/影响因素/渗透率/含水饱和度/实验研究Key words
tight gas reservoir/threshold pressure gradient/influencing factor/permeability/water saturation/experimental study分类
能源科技引用本文复制引用
丁景辰,杨胜来,史云清,严谨,郑荣臣..致密气藏动态启动压力梯度实验研究[J].油气地质与采收率,2017,24(5):64-69,6.基金项目
国家科技重大专项“低丰度致密低渗油气藏开发关键技术”(2016ZX05048). （2016ZX05048）
