叠前方位AVO裂缝预测技术在茅口组储层中的应用

Application of pre-stack azimuthal AVO fracture prediction technology in Maokou Reservoir

川东南南川地区茅口组储层横向非均质性强、天然气产量差别大,裂缝控制储层的孔渗性,影响其产量。针对茅口组裂缝型储层,采用叠前纵波方位AVO反演的方法对裂缝发育强度和方向进行了预测。预测结果显示,茅口组地震反射具有明显的振幅随方位角变化特征,南川地区平桥背斜、东胜背斜裂缝发育程度高,裂缝发育强度在0~30之间。通过现有的生产测试资料分析,水平井测试产气量与裂缝发育强度呈正相关性,高产气井对应的裂缝发育强度大于16。水平段方位与裂缝方向夹角越大,单井产量越高,裂缝预测结果有利于指导高产井部署。

The reservoir of Maokou Formation in Nanchuan area of Southeastern Sichuan has strong lateral heterogeneity and large difference in natural gas production.Fractures control the porosity and permeability of reservoir and affect gas production.For the fractured reservoir of Maokou Formation,the pre-stack P-wave azimuth AVO inversion method was used to predict the strength and direction of fracture.The results show that the reflection of target layer has obvious characteristics of amplitude changing with azimuth.The fracture development degree of Pingqiao anticline and Dongsheng anticline in Nanchuan area is high,and the fracture development strength is between 0 and 30.Through the analysis of production test data,the horizontal well test gas production is positively correlated with the fracture development strength,and the fracture development strength of high-yield gas wells are greater than 16.The larger the angle between the horizontal well orientation and the fracture direction is,the higher the gas production is.The fracture prediction results are helpful to guide the deployment of high production wells.