涠西南凹陷二号断裂带断裂控藏研究及应用

The research and application of the reservoir controlling mechanism for the No.2 Fracture Zone, Weixi’nan Sag

涠西南凹陷是勘探开发一体化研究重点区,本文以二号断裂带为研究对象,综合断裂动力学特征、运动学特征、几何学特征等研究,将中段“坡坪式”断裂体系、两侧“铲式”断裂体系等差异性断裂体系内部划分为3级雁列式主断裂、4级分支断裂、5级分支断裂。中段“坡坪式”断裂体系受到更高强度地应力作用,主断裂与分支断裂更为发育,二号断裂带绝大多数油气分布于此。综合分析二号断裂带差异性断裂体系内部断裂系统与油气展布规律之间的关系,得到3方面断裂控藏规律及4种优势断裂控藏模式。在断裂控藏规律及断裂控藏模式的指导下,搜索、优选二号断裂带中段北1块、北3块、北4块潜力目标进行评价、实施。3个潜力区块均实施成功,达到地质油藏目的,断裂控藏规律、断裂控藏模式在涠西南凹陷二号断裂带潜力区块应用效果好。

The Weixi’nan Sag is the important research area of exploration and development integration. This study takes the Weizhou Formation of the No.2 Fracture Zone as the research object. By analyzing the geometry, kinematics, and dynamics characteristics of fracture, the "slope-flat" fault system in the middle section and the "shoveltype" fault system on both sides are divided into the level 3 en-echelon main fracture zone, the level 4 branch fracture zone, and the level 5 branch fracture zone. The "slope-flat" fault system in the middle section is subjected to higher in-situ stress, and the main and branch faults are more developed. The vast majority of oil and gas are distributed in the "slope-flat" fault system. A comprehensive analysis of the relationship between the internal fracture system of the differential fault system in the No.2 Fracture Zone and the oil-gas distribution law is made, and obtains the corresponding regular of 3 aspects of fracture reservoir controlling mechanism and 8 types of fracture reservoir controlling patterns. Under the regular of fracture reservoir controlling mechanism and patterns, the search and evaluation of targets are carried out around the inner or surrounding oil fields of the No.2 Fracture Zone, and good results are obtained. Based on the field production, the potential targets of North 1, North 3 and North 4 in the middle part of the No.2 Fracture Zone are searched and optimized. The three blocks have been successfully drilled, and the purpose of the geological reservoir has been achieved. The regular of fracture reservoir controlling mechanism and patterns which have been applied to the potential zone of the No.2 Fracture Zone in the southwest depression play very good effect.