延113-延133井区致密砂岩储层产能影响因素分析

Analysis on factors affecting productivity of tight sandstone reservoirs in Yan 113-Yan 133 well block

为研究致密气藏产能规律,释放鄂尔多斯盆地山_(2)^(3)气藏产能,延113-延133井区结合气井产能模型和开发实践,系统分析地质条件、储层改造和储层伤害对气藏产能的影响。通过建立无阻流量和储层参数的交会图以及压力恢复试井等方法研究不同储层条件和压裂改造技术与产能的关系。结果表明:有效厚度、渗透率和水平段有效砂体长度是气藏的地质基础,地层系数与无阻流量呈较好的线性关系,水平段有效砂体长度与无阻流量呈正相关关系。纤维压裂可以提高裂缝导流能力,增大裂缝长度,提高产能。外来流体导致的水锁效应严重影响气藏原有渗透率,降低气井的产能。通过产能影响因素的研究,延113-延133井区采用CO_(2)压裂等储层改造工艺实现了山_(2)^(3)致密气藏的高效开发,具有较好的借鉴意义。

In order to study the productivity of tight gas reservoirs and release the productivity of the Shan_(2)^(3) gas reservoir in the Ordos Basin,the influences of geological conditions,reservoir stimulation and reservoir damage on gas reservoir productivity were systematically analyzed for the Yan 113-Yan 133 well block based on gas well productivity model and development practice.By preparing the cross-plot of absolute open-flow potential(AOFP)and reservoir parameters and through pressure buildup test,the relationship between reservoir conditions or fracturing techniques and productivity was established.The results show that the effective thickness,permeability,and length of effective sand body in horizontal section are the geological basis of the gas reservoir,formation coefficient is linearly correlated with AOFP,and the length of effective sand body in horizontal section is positively correlated with AOFP.Fiber fracturing can improve fracture conductivity,increase fracture length,and enhance productivity.The water-locking effect caused by foreign fluids seriously affects the original permeability of gas reservoir,reducing the productivity of gas well.Through studying the factors influencing productivity,the Shan_(2)^(3) tight gas reservoir in the Yan 113-Yan 133 well block has been efficiently recovered by using the treatments such as CO_(2) fracturing.This study provides a good reference for similar reservoirs.