油气盆地储层构造裂缝定量预测研究方法及其应用

Methods and applications of quantitative prediction and evaluation of tectonic fracture in reservoir in petroliferous basin

构造裂缝预测研究的基本方法有岩石破裂法、主曲率法、能量法、统计学方法。针对不同类型致密油气(田)藏,可采用不同方法或多方法综合处理。以川西新场气田为例,采用统计法和岩石破裂法相结合,预测了新场晚侏罗统蓬莱镇组中、上砂层组(J3p1、J3p2)、中侏罗统沙溪庙组(J2s)"A"和"C"砂岩层和千佛岩组(J2q)砂砾岩层中裂缝发育状况。结果表明,研究区大部分高产气井和产气井与预测的喜马拉雅期构造运动形成的裂缝发育区-次发育区有很好的对应关系,具有两层以上裂缝发育区的叠合区,是天然气聚集最有利区块。

The authors summarize the research situation, major progresses, and methods of quantitative prediction and evaluation of natural fracture system of such reservoir, and generalizes the basic research methods as four kinds, namely rock cracking, main curvature, deformation energy and statistics, which are suitable for different types of fractured oil-gas pools. Xinchang gas field in the west part of Sichuan basin is taken as an example for illustrating the role of quantitative prediction of tectonic fractures in exploration of oil-gas. Xinchang gas field is characteristic of multiplayer sandstone reservoirs. Main gas-producing layers are made up of sandstone layer(J3p1?J3p2) in Penglazhen group(J3p),'A' and 'C' sandstone layers in Shaximiao group(J2s), and conglomerate layer in Qianfuyan group(J2q). Based on three-dimensional stress field numerical simulation, the main reservoirs were predicted quantitatively by using rock-cracking method. It is clear that a majority of high gas-producing wells or production wells in research area are commendably corresponding to fracture development and hypo-development regions which were formed in Himalayan movement. Superposition regions of fracture-development of different layers are the best location of gas accumulation. This results provide a good basis for farther gas prospecting in western Sichuan basin.