电成像测井在苏里格气田勘探开发中的应用

摘要

Sulige gas ifeld is a typical gas reservoir of low permeability, low yield, low abundance and large lithology trap. The main gas layer is the eighth member of Shihezi Formation and the ifrst member of Shanxi Formation. Based on electric imaging logging data, seven lithofacies were identified in the eighth member of Shihezi Formation and the first member of Shanxi Formation, including cross-bedding medium-coarse sandstone, cross-bedding medium-coarse sandstone containing gravel, parallel-bedding sandstone, clumpy conglomerate, graded bedding glutenite, massive-bedding sandstone, and micro-fracture sandstone. Fracture in the eighth member of Shihezi Formation and the ifrst member of Shanxi Formation was also identiifed. In this paper, the relationship between the fracture and the gas production in gas-bearing zone was discussed, and the distribution law of fracture in plane was summed up. It was shown that physical property, lithology, gas content and thickness of reservoir were main factors controlling single well, while fracture was less important. Based on petrographic analysis, paleocurrent and sedimentary facies were analyzed. It was believed that low-sinuosity meander sedimentary facies developed the upper section of the eight member of Shihezi Formation, and braded river sedimentary facies mainly developed in the lower section. This was of certain directive signiifcance to natural gas exploration and development in this area.%苏里格气田是典型的低渗、低产、低丰度大型岩性圈闭气藏，其主力含气层为盒8段、山1段。利用电成像测井资料，在盒8段、山1段识别出了交错层理中-粗砂岩、交错层理含砾中-粗砂岩、平行层理砂岩、块状砾岩、递变层理砂砾岩、块状层理砂岩、微裂缝砂岩7种岩相，识别出了主力层的裂缝，并探讨了主力含气层段裂缝与产气量的关系，总结了裂缝在平面上的分布规律，分析认为控制单井产气量的主要因素是储层本身物性、岩性、含气性和厚度，裂缝对产气量的作用有限。在岩相分析基础上，对盒8段古水流、沉积相进行了分析，认为盒8上段主要发育低弯度曲流河沉积相，盒8下段主要发育辫状河沉积相，这对于该地区天然气勘探开发有一定的指导意义。