基于积分数学-地质模型定量评价伸展断层侧向封闭性  

Quantitative evaluation of lateral sealing of extensional fault by an integral mathematical-geological model

作　　者：吕延防[1] 胡欣蕾 金凤鸣[2] 肖敦清[2] 罗佳智 蒲秀刚[2] 姜文亚[2] 董雄英[2] LYU Yanfang;HU Xinlei;JIN Fengming;XIAO Dunqing;LUO Jiazhi;PU Xiugang;JIANG Wenya;DONG Xiongying(College of Earth Sciences,Northeast Petroleum University,Daqing 163318,China;PetroChina Dagang Oilfield Company,Tianjin 300280,China;No.4 Oil Production Plant,PetroChina Daqing Oilfield Company,Daqing 163511,China)

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]中国石油大港油田公司,天津300280 [3]中国石油大庆油田公司第四采油厂,黑龙江大庆163511

出　　处：《石油勘探与开发》2021年第3期488-497,共10页Petroleum Exploration and Development

基　　金：国家自然科学基金项目“碎屑岩地层中不同结构断层岩封闭能力定量评价”(41872153);东北石油大学科研启动基金“断层停止活动后对油气形成封闭时间的确定”(1305021839)。

摘　　要：基于断-储排替压力差评价伸展断层侧向封闭机理,考虑成岩时间对断层岩成岩压力及成岩程度的作用效果,建立成岩时间对成岩压力的积分数学-地质模型,定量计算伸展断层的侧向封闭能力。通过对断层岩和围岩地层承受垂向应力及水平地应力的时间积分计算,确定具有与断点断层岩相同泥质含量和成岩程度的围岩的埋深,结合研究区所建立的岩石泥质含量、埋藏深度和排替压力的相关关系,定量计算出断点断层岩的排替压力;用目的盘储集层排替压力与之比较,定量评价伸展断层的侧向封闭性及封闭能力大小。通过渤海湾盆地南堡凹陷1号构造区内断层油气藏实际资料的验证,以及与未考虑或简单考虑成岩时间的断-储排替压力差法断层侧向封闭性评价结果进行对比,显示积分数学-地质模型计算得到的结果与地下实际情况最为接近,预测烃柱高度与实际烃柱高度误差仅0~8 m,可行性最高。To evaluate the lateral sealing mechanism of extensional fault based on the pressure difference between fault and reservoir,an integral mathematical-geological model of diagenetic time on diagenetic pressure considering the influence of diagenetic time on the diagenetic pressure and diagenetic degree of fault rock has been established to quantitatively calculate the lateral sealing ability of extensional fault.By calculating the time integral of the vertical stress and horizontal in-situ stress on the fault rock and surrounding rock,the burial depth of the surrounding rock with the same shale content and diagenesis degree as the target fault rock was worked out.In combination with the statistical correlation of clay content,burial depth and displacement pressure of rock in the study area,the displacement pressure of target fault rock was calculated quantitatively.The calculated displacement pressure was compared with that of the target reservoir to quantitatively evaluate lateral sealing state and ability of the extensional fault.The method presented in this work was used to evaluate the sealing of F1,F2 and F3 faults in No.1 structure of Nanpu Sag,and the results were compared with those from fault-reservoir displacement pressure differential methods without considering the diagenetic time and simple considering the diagenetic time.It is found that the results calculated by the integral mathematical-geological model are the closest to the actual underground situation,the errors between the hydrocarbon column height predicted by this method and the actual column height were 0-8 m only,proving that this model is more feasible and credible.

关 键 词：伸展断层侧向封闭性 积分数学-地质模型 成岩时间 成岩压力 排替压力 南堡凹陷 

分 类 号：TE122.1[石油与天然气工程—油气勘探]