页岩气叠后裂缝综合预测技术
——以长宁国家级页岩气示范区为例

Post-stack fracture comprehensive prediction technology for shale gas: taking 
Changning national shale gas demonstration area as an example 

黄浩勇,苟其勇,刘胜军,王乐之,张宗和,钟高,程晓莉

中国石油西南油气田分公司页岩气研究院，四川 成都 610051 安东石油技术（集团）有限公司，北京 100102

基于四川盆地长宁国家级页岩示范区的开发实践，认为天然裂缝（简称裂缝）是影响页岩气开发效果的重要因素。研究区前期裂缝预测大多采用单一技术，预测结果与实钻情况符合率不高，给页岩气钻井及压裂改造等带来一定困难。为此，文中提出了一种页岩气叠后裂缝综合预测技术，即：以叠后地震数据为基础，综合应用构造导向滤波、三维体最大正振幅曲率属性提取和蚂蚁体追踪技术，实现天然裂缝预测。研究结果表明：研究区断层、裂缝发育程度高，大断裂主要发育在北西部，断层走向主要为北东—南西向，延伸距离长；向斜区发育大量微裂缝，以网状缝为主，裂缝倾角较大，呈近直立状。采用该技术进行天然裂缝预测，预测结果分辨率高、裂缝分布合理。利用微地震检测、成像测井、钻井等资料验证了该技术的可靠性，预测结果与实钻情况平均符合率达80.6%。文中研究成果可以指导研究区后续页岩气开发，规避钻井风险，提高压裂效率。

Based on the development practice of the Changning National Shale Demonstration Area in the Sichuan Basin, it is believed that natural fractures are an important factor affecting the effect of shale gas development. Preliminary fracture prediction mostly uses a single technology, and the prediction results are not in good agreement with actual drilling, which brings certain difficulties to shale gas drilling and fracturing in the study area. In this paper, a comprehensive prediction method for shale fractures is proposed, that is, structure-oriented filtering, maximum 3D positive amplitude curvature attribute and ant tracking technology are combined to realize natural fracture prediction based on post-stack seismic data. The results show that the study area has a high degree of development of faults and fractures. The large faults are mainly developed in the northwest of the study area, and the faults are mainly northeast-southwest with a long extension. A large number of micro-fractures mainly in network shape are developed in the syncline area. The dip angles of fractures are large, which are almost upright. This method is used to predict natural fractures in the study area. The prediction results are high in resolution and reasonable in fracture distribution. The reliability of prediction methods are verified by using microseismic monitoring, imaging logging, drilling data and others, which the average coincidence rate between the prediction results and the actual drilling situation is 80.6%. The research results can guide subsequent shale gas development in study area and avoid drilling risks, improve fracturing efficiency.

10.6056/dkyqt202202013