超深层裂缝性致密砂岩气藏储层连通性及开发启示——以塔里木盆地库车坳陷克深2气藏为例

Reservoir connectivity of ultra-deep fractured tight sandstone gas reservoir and development enlightenment:taking Keshen 2 gas reservoir in Kuqa Depression of Tarim Basin as an example

以塔里木盆地库车坳陷克深2为代表的超深层裂缝性致密砂岩气藏,是“十三五”期间塔里木油田天然气上产的重点区域。基质物性差、局部裂缝发育程度不同的特征导致储层非均质性强,井间产能差异大,储层连通性复杂,气藏开发难度大。针对该类气藏的特点,以克深2气藏为例,将动态分析法与静态分析法相结合深入分析储层连通性,并指出了气井布井方式和生产制度的优化对策。研究结果表明:储层基质致密,构造裂缝总体发育,形成高渗通道,整体上看气藏平面连通性较好,但鞍部有效裂缝发育程度、气井产能相对较低,反映该区为低渗区,对气体渗流起到一定阻挡作用。按照局部构造裂缝控制高产的开发思路,沿构造轴线高部位集中布井;为了减缓裂缝性水侵,更加均衡开发气藏,认为气井配产不宜过高。研究结果对指导超深层裂缝性致密砂岩气藏科学、合理、高效地开发具有积极意义。

The ultra-deep fractured tight sandstone gas reservoir represented by Keshen 2 in Kuqa Depression of Tarim Basin is the main gas production area in Tarim Oilfield during the 13th Five-Year Plan period.The characteristics of poor matrix properties and local fracture development lead to strong reservoir heterogeneity,large inter-well productivity differences,complex reservoir connectivity and difficult gas reservoir development.According to the characteristics of this kind of gas reservoir,taking Keshen 2 gas reservoir as an example,the reservoir connectivity is analyzed by combining the dynamic data analysis method with the static data analysis method,and optimization measures for well pattern and production work system of gas well are pointed out.The results show that the reservoir matrix is compact,the structural fractures are developed as a whole,and the high permeability channel is formed.On the whole,the plane connectivity of the gas reservoir is good,but the development degree of the effective fractures in the structural saddle and the productivity of the gas wells are relatively low,reflecting that the area is of low permeability,which plays a certain role in blocking gas seepage.According to the development idea of controlling high production by local structural fractures,well distribution is concentrated along the high part of the structural axis.In order to slow down fractured water invasion and develop this kind of gas reservoir more evenly,the proration of gas well is not suitable to be large.The research results have positive significance for guiding the scientific,rational and efficient development of ultra-deep fractured tight sandstone gas reservoirs.