塔里木盆地克深地区巴什基奇克组致密砂岩储层敏感性研究

致密砂岩储层自然产能较低，经后期注水开发能有效提高油气的稳产效果，因此，控制注入流体的理化指标及注入参数对储层合理、有效开发十分关键。针对塔里木盆地克深地区白垩系巴什基奇克组致密砂岩储层，利用薄片鉴定、扫描电镜分析、X射线衍射分析及高压压汞测试，开展基于孔喉类型的储层分类研究，并在此基础上选取典型样品开展敏感性评价实验，分析不同类型储层敏感性影响因素。结果表明：巴什基奇克组致密砂岩储层按照孔隙组合类型可分为残余粒间孔型、溶蚀孔型及微裂缝型3类，有效储集空间依次减少；巴什基奇克组致密砂岩储层具有强速敏、强水敏、中等偏强盐敏、强碱敏和中等酸敏特征，敏感性与储层碎屑颗粒及黏土矿物敏感程度密切相关，较高含量的伊利石可使储层速敏性及水敏性显著增强，碱液选择性溶蚀石英颗粒，储层酸敏性主要与沸石含量相关；不同孔隙组合类型储层的敏感性有明显差别，残余粒间孔型储层敏感性受孔隙结构影响较小，溶蚀孔型储层及微裂缝型储层喉道均易被充填，导致渗流能力大幅下降。研究结果可为该区及同类型致密砂岩储层发育区的有效开发提供参考。

Sensitivity of tight sandstone reservoir of Bashijiqike Formation in Keshen area,Tarim Basin

Natural productivity of tight sandstone reservoir is lower than that of conventional reservoir and improving the injection method of water flooding is able to enhance oil and gas production efficiently. Thus, the control of physicochemical index and injection parameters of fluid is vital for reasonable and effective reservoir development. Taking tight sandstone reservoir of Cretaceous Bashijiqike Formation in Keshen area of Tarim Basin as an example, the data of casting thin slices, scanning electron microscope, X-ray diffraction and high-pressure mercury injection test were used to conduct reservoir classification based on pore structure. Typical samples were selected to carry out sensitivity evaluation experiments, and the factors affecting the sensitivity of different types of reservoirs were analyzed. The results show that the reservoirs can be divided into three types according to the types of pore assemblages:residual intergranular pores, dissolved pores and microfractures, and the effective reservoir space decreased in turn. The reservoirs have the characteristics of strong water sensitivity, velocity sensitivity and alkali sensitivity, medium-strong saline sensitivity and medium acid sensitivity. The sensitivity is closely related to the sensitivity of reservoir debris and clay minerals. Only samples with high contents of illite can enhance the velocity sensitivity and water sensitivity, alkali sensitivity is controlled by selective dissolution of quartz, and high content of zeolite is an important factor for improving reservoir acid sensitivity. Different types of reservoirs respond differently to the sensitivity. The sensitivity of residual intergranular reservoirs is less affected by pore structure. The throats of dissolved pore reservoirs and micro-fractured reservoirs are more likely to be filled, resulting in a significant decrease in seepage capacity. The research results can provide reference for the effective development of tight sandstone reservoirs.