论文部分内容阅读
本文介绍了水平井水力压裂真三维物理模拟实验。其结果表明,初破裂压力及初裂缝形态,与钻孔水平段相对于水平主应力方向的取向明显相关。通过改变水平段取向可以影响初破裂压力和控制初裂缝形态。钻孔水平段与水平主应力方向不相合时,裂缝通常不沿原来的裂缝面扩展。有些裂缝呈现出Ⅰ、Ⅱ型复合裂纹扩展的一些特点,如出现“S”型裂缝面。此类裂缝扩展,裂缝面最终将转向垂直于最小水平主应力方向。套管射孔模拟实验表明,如果钻孔方位和射孔位置、密度合适,则可以形成多裂缝。裂缝面最终也将垂直于最小水平主应力方向。
This paper introduces the true 3D physical simulation of horizontal well hydraulic fracturing. The results show that the initial fracture pressure and the initial fracture morphology are obviously related to the orientation of the horizontal section of the borehole relative to the horizontal principal stress. By changing the horizontal section orientation can affect the initial fracture pressure and control the initial fracture morphology. When the horizontal section of the borehole does not coincide with the horizontal principal stress direction, the fracture usually does not expand along the original fracture surface. Some cracks show some characteristics of the type Ⅰ and type Ⅱ composite cracks, such as “S” type fracture surface. Such cracks extend and the fracture surface will eventually turn perpendicular to the direction of the minimum horizontal principal stress. Casing perforation simulation experiments show that if the drilling position and perforating position, the density is appropriate, you can form multiple cracks. The fracture surface will eventually also be perpendicular to the minimum horizontal principal stress direction.