塔河碳酸盐岩储层地应力实验研究

AN EXPERIMENTAL STUDY OF IN-SITU STRESSES OF CARBONATE RESERVOIRS IN TAHE OILFIELD

对常规差应变实验进行改进,结合波速各向异性和古地磁定向实验,形成一套针对小直径圆柱体岩芯的地应力实验方案。利用新实验方案对塔河油田碳酸盐岩储层进行地应力大小和方向测试,塔河碳酸盐岩储层水平最大主应力方向主要分布为NE45°～90°;垂向主应力梯度为0.025 MPa/m,水平最大主应力梯度为0.020 2 MPa/m,水平最小主应力梯度为0.015 2 MPa/m。室内实验结果与现场监测结果具有很好的一致性,间接印证了新实验方案的可靠性和实用性。

By improving differential strain analysis method, we combine wave velocity anisotropy method and palaeomagnetic core reorientation method to develop a suit of new experimental program on in-situ stresses for small diameter cylindrical cores. Using the new experimental program, we measured magnitude and orientation on in-situ stresses of carbonate cores in the Tahe oilfield in lab. The results show that the orientation of horizontal maximum principle in-situ stress mainly distributes among NE 45 ~ - 90 ~, the gradient of vertical principle in-situ stress is 0.025 MPaJm, the gradient of horizontal maximum principle in-situ stress is 0.020 2 MPa/m, and the gradient of horizontal minimum principle in-situ stress is 0.015 2 MPa/m. The experimental results are fundamentally consistent with oilfield monitored results. It＇s indirectly proved that the new experimental program is reliable and practical.