【摘要】 准确计算地层破裂压力是致密油水平井压裂成功的关键,但常用的地层破裂压力计算模型忽略了地层各向异性的影响。利用鄂尔多斯盆地X233区块延长组长7段岩心开展各向异性岩石力学实验,优选适用于该地层的各向异性抗拉强度计算准则。基于最大张应力准则,考虑TIV地层各向异性和井眼方位等影响,建立层理型致密砂岩水平井破裂压力的计算新模型,通过测井数据计算获得连续的水平井破裂压力剖面。计算结果与现场水力压裂得到的地层破裂压力数据的相对误差为5.3%,表明建立的破裂压力预测模型合理可靠,能够提高地层破裂压力的计算精度,可为水平井压裂设计和施工提供重要的决策依据。更多还原

【Abstract】 Accurate calculation of formation fracturing pressure is the key to successful fracturing operation of tight oil horizontal wells. However, the influence of formation anisotropy is often neglected in the conventional model for calculating formation fracturing pressure. Experiments were carried out on the anisotropic mechanics of the Chang 7 member of the Yanchang formation in block X233, and calculations followed the anisotropic tensile strength criterion applicable to the formation; then based on the maximum tensile stress and considering the effects of anisotropy of the TIV formation and borehole orientation, a new model for calculating the fracturing pressure of layered tight sandstone in horizontal wells was established; and finally a continuous fracturing pressure profile was obtained based on logging data. The error between the modeled fracturing pressure and that from field hydraulic fracturing operation is 5.3%, indicating that the fracturing pressure model is reasonable and reliable, and it can improve the calculation accuracy of formation fracturing pressure, and provide an important basis for designing horizontal well fracturing process and field fracturing operation.更多还原