Research On Current In-situ Stress Of Yi 176 Block Of Bonan Oilfield

By studying the stratum in the third section of Shahejie Formation of Block Yiyi 176 in Funan Oil Field,it was found that the study area showed strong heterogeneity.Using the previous homogenous model parameters to analyze the study area obviously did not meet the actual situation.Based on triaxial rock mechanics,paleomagnetism,acoustic velocity anisotropy,acoustic emission,and differential strain experiments combined with well logging data,using finite element numerical simulation methods as a means,and through a self-adaptive program,the Yiyang 176 block of Bonan Oilfield was developed.Nowadays,stress is used to simulate the stress field,revealing the distribution law of the stress field,and analyzing the stress field differences under homogeneous and heterogeneous geological conditions,thus providing a theoretical basis for the development after the study area.By analyzing the results of the homogeneity and non-homogeneity numerical simulation of Block 176,it is known that the minimum principal stress is between 46-63 MPa,the maximum principal stress is between 58-80 Mpa,and the vertical principal stress is between 78-102 Mpa.The direction of stress is near the east-west direction,which is basically consistent with the measured ground stress in the study area.Under homogeneous conditions,the distribution of stress field has a clear trend of strip distribution.However,non-homogeneous strata result in non-uniform stress distribution due to different mechanical parameters,leading to the occurrence of simulated results in the stain area.The structure of the field study area is high in the northwest and low in the south.The stress distributions of the two models are analyzed.The stress distributions of the homogeneous and inhomogeneous are basically similar.The high stress areas appear in the eastern part of the study area,and the regional stress around the faults.The value is lower,and the internal stress value of the fault is the smallest.The direction of maximum principal stress is near the east-west direction,and the direction of the minimum principal stress is near-south-north direction.However,in combination with the actual formation conditions,it is obviously unreasonable to use homogeneous formation parameters.Obviously,the heterogeneity is more in line with the needs of our subsequent work.