四川盆地涪陵焦石坝地区五峰—龙马溪组低序级断层识别技术及应用效果

Low-grade fault recognition technology and its application in Wufeng-Longmaxi formations in Jiaoshiba area,Fuling,Sichuan Basin

四川盆地涪陵页岩气开发工作成效显著,但在页岩气开发实践中,钻井泥浆漏失现象频现,低产低效井时有发生,分析认为这些问题与低序级断层密切相关。北美页岩气开发区构造简单,而涪陵焦石坝区块受多期构造运动叠加,改造构造变形强、断裂复杂。与以往低序级断层的分析大多基于钻测井资料不同,提出了基于井—震、动—静结合研究思路,在综合利用三维地震、钻井、测井、试气等资料的基础上,采用精细层位标定,水平切片、方差体、曲率等方法开展低序级断层的识别研究,为水平井部署与调整、钻井设计、压裂参数优化提供了地质依据。

The development of shale gas in the Fuling area of Sichuan Basin has achieved remarkable results.However,in the practice of shale gas development the phenomenon of drilling mud loss is frequent,and low-productivity and inefficient wells occur from time to time,which is considered to be closely related to low-grade faults.The North American shale gas development zone has a simple structure,while the Fuling Jiaoshiba block is superimposed by multi-stage tectonic movements with strong deformation and complicated faults.The conventional low-grade fault recognition was mainly based on drilling and logging data.A new method combining well data with seismic data uses both dynamic and static aspects.It was based on the comprehensive utilization of 3D seismic,drilling,well logging and gas test data.Fine horizon calibration,horizontal slice,variance body,curvature and other methods were applied to identify low-grade faults,which provided an important geological basis for the deployment and adjustment of horizontal wells,drilling design and the optimization of fracturing parameters.