渤南油田义176区块三维应力场智能预测

为提高应力场数值模拟的运算效率，基于ANSYS中的APDL语言编译自适应边界程序，将边界条件的人为调整过程自动化，并借助Petrel与ANSYS的联合建模技术以及三维非均质岩石力学场的构建技术，开展了渤南油田176区块三维应力场的智能预测。结果表明，自适应边界程序大幅且有效地缩短了人工反复尝试边界条件的时间，提高了应力场模拟的效率，且保证了预测精度。义176区块现今最大水平主应力方向总体呈近EW-SEE向，边界断层对应力方向影响较为显著，引起了约5 °~10 °的偏转。现今地应力数值变化较大，离散性高，平面上呈带状展布，具有北高南低的分布趋势，在目的层范围内属于I_a类地应力，岩石的非均质性是造成应力数值差异的主要原因。在义176区块中部存在一片条带状展布的“应力甜点”，可以作为井位部署和压裂作业的优势区域。

Smart Prediction of the Three-dimensional Stress Field of Block Yi 176 of the Bonan Oilfield

In this study, an intelligent prediction of the three-dimensional stress field of block Yi 176 of Bonan Oilfield is performed by combining the modeling technology of Petrel and ANSYS and using the construction technology of a threedimensional heterogeneous rock mechanics field. To improve the computational efficiency of the numerical simulation of the stress field, the boundary condition, which is traditionally set manually, is now set automatically using the self-adaptive boundary program developed by the APDL program in ANSYS. The results show that the self-adaptive boundary program can greatly reduce the time taken to set the correct boundary conditions by repetitive manual trials. This approach can improve the efficiency of stress field simulation while ensuring prediction accuracy. The maximum horizontal principal stress of block Yi 176 follows an EW-SEE direction in general. The boundary fault has a significant impact to the stress direction, causing a deflection of around 5°~10°. The in-situ current stress value varies substantially with a high level of discreteness and a belt-like distribution in the plane. Furthermore, the stress is found to be higher in the north region and smaller in the south region. In the current formation, the stress belongs to the type I_a in-situ stress. The heterogeneity of the rock is the main cause of the difference in stress values. In general, a belt-like distribution of "stress dessert" is found in the central part of block Yi 176, which can be used as an advantageous area for well location deployment and fracturing operations.