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

作　　者：LYU Yanfang HU Xinlei JIN Fengming XIAO Dunqing LUO Jiazhi PU Xiugang JIANG Wenya DONG Xiongying 

机构地区：[1]College of Earth Sciences,Northeast Petroleum University,Daqing 163318,China [2]PetroChina Dagang Oilfield Company,Tianjin 300280,China [3]No.4 Oil Production Plant,PetroChina Daqing Oilfield Company,Daqing 163511,China

出　　处：《Petroleum Exploration and Development》2021年第3期569-580,共12页石油勘探与开发（英文版）

基　　金：Supported by the China National Science and Technology Major Project(41872153);Northeast Petroleum University Research Startup Fund(1305021839)。

摘　　要：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 clay 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 F_(1), F_(2) and F_(3) 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：lateral sealing of extensional fault integral mathematical–geological model diagenetic time diagenetic pressure Nanpu Sag 

分 类 号：TE319[石油与天然气工程—油气田开发工程]