川南东部地区阳新统的地层破裂压力预测

碳酸盐岩裂缝性地层破裂压力定量预测目前仍是一道非常复杂的难题。文章应用水力压裂力学原理，紧密结合川南东部地区阳新统碳酸公岩地层特征，探讨了该地区的地层破裂压力机理，认为该区大部分压裂酸化井人工压裂缝是在自然垂缝上延伸扩展，破裂压力近似等于其垂缝延伸压力。在水平挤压应力和扭剪应力作用下，岩体抗张强度主要受地层破碎系数和应力强度指数控制，文章建立了预测地层破裂压力的物理一数学模型，确定岩体视抗张强度，进而对地层破裂压力进行预测。经实际破裂压力资料验证，绝对误差最大５．０ＭＰａ，一般小于３．０ＭＰａ；相对误差最大５．０％，一般小于２．０％。

FORECASTING FRACTURE PRESSURE IN STRATA OF YANGXIN SERIES IN THE EAST-ERN AREA OF SOUTH SICHUAN

Quantitive forecasting the break down pressure in carbonatite fractured strata is still a knotty problem. Hydraulic stimulation mechanics is used while it is taken into account of the characteristic of carbonatite formation in Yangxin series in the eastern area of South Sichuan. In this district strata fracture pressure mechanism is discusses on. In most fracture acidizing wells hydraulic fracture extends through natural verticle fracture,with its extension pressure be approximately equal to fracture pressure. As the actions of horizontal extrusion, torsion and shear stresses. the rock tensile stress is affected by formation crush coeifficient and stress intensity exponent. A physicsmathematics model is for forecasting formation fracture pressure to determine the apparent tensile stress of rocks. With data of actual fracturing pressure.the prediction pressure is proved that the absolute error is generally less than 3. 0 MPa. 5. 0 MPa of the maximum;the fractional error is generally less than 2. 0%, 5. 0% of the maximum.