油源断裂转换带裂缝发育及其对油气控制作用——以冀中坳陷文安斜坡议论堡地区沙二段为例

Fracture Development in Oil-Migrating Fault Transition Zones and Its Control on Hydrocarbon Migration and Accumulation:A Case Study of Es_2 Oil Formation of Yilunpu Structure of Wen'an Slope of Jizhong Depression

在伸展盆地中,油源断裂转换带往往对油气有着重要的控制作用,是油气的有利聚集部位。为了明确油源断裂转换带裂缝发育及其对油气运聚的控制作用,本文利用垂直累积断距-距离曲线法厘定了文安斜坡议论堡构造3条油源断裂的转换带并明确了其分布特征;依据岩心、露头资料、实钻资料和叠前三维地震资料对油源断裂转换带伴生裂缝分布进行了预测模拟;总结了油源断裂转换带对裂缝发育的控制作用,以及二者与油气成藏关系。结果表明:在本研究区油源断裂转换带部位富含砂岩的输导层较发育,应力相对油源断裂其他部位较集中,是裂缝密度高值的发育区,为油气聚集提供优势的运移通道和指向,使油气向低势区汇聚成藏。

Oil-migrating fault transition zones often play an important role on controlling hydrocarbon migration and accumulation,and are the preferential parts for hydrocarbon accumulation in a stretching basin.In order to clarify fracture development in oil-migrating fault transition zones and its control on hydrocarbon migration and accumulation,the evolution of vertical cumulative throw-distancecurve is applied,and 3oil-migrating fault transition zones have been recognized in Yilunpu structure of Wen＇an slope.Fracture distribution in oil-migrating fault transition zones is forecasted based on the data of outcrop,drilling,logging,and pre-stack seismic.The authors summarize the control effect of fracture development in oil-migrating fault transition zones,and the relationship with hydrocarbon accumulation.The results show that,in the oil-migrating fault transition zones,sandstone and fracture is more developed,stress is more concentrated.The fracture is responsible for the path of hydrocarbon migration and accumulation.