页岩储层层间暂堵转向工艺技术研究

Research on inter-layer temporary plugging steering process technology for shale reservoirs

摘要:

针对大庆古龙页岩油储集层页理发育丰富，水平渗透率低，垂向无法流动等特点，需通过暂堵转向压裂技术增大净压力，利用暂堵颗粒封堵炮眼迫使压裂液转向，进一步提高裂缝复杂程度。本文通过分析暂堵颗粒在井筒以及炮眼附近的受力与暂堵前后压力变化，提出暂堵颗粒运动方程，建立评价暂堵颗粒坐封效果的两个参数，制定暂堵转向评价标准，形成了暂堵颗粒用量设计方法，研究页岩油试验区水平井压裂施工中暂堵颗粒的封堵效果。现场试验结果显示暂堵有效率达到66.7%，坐封效率达到74%，暂堵颗粒效率达到34%，暂堵后裂缝起裂位置或延伸方向明显不同，炮眼封堵有效，实现了压裂转向的目的，为今后页岩油储集层压裂改造提供理论支撑。

关键词:页岩油;水平井分段压裂;暂堵颗粒;暂堵转向;坐封效果

Abstract:

In response to the characteristics of Daqing Gulong Shale-type reservoirs such as rich phyllite， low horizontal permeability and inability to flow in the vertical direction， it is necessary to increase the pure pressure by temporary plugging steering fracturing technology. The degree of fracture complexity is further increased using the temporary particles to seal the borehole and force the fracturing fluid to turn. This paper analyzes the force and pressure changes of temporary plugging particles in the wellbore and near the shot-holes before and after temporary plugging， proposes the equation of motion of the temporary plugging particles， establishs two parameters to evaluate the setting effect of temporary plugging particles， sets the standard to evaluate the temporary plugging steering， develops the dosage design method of temporary plugging particles， and studies the sealing effect of temporary plugging particles in the process of fracturing construction for horizontal wells in shale oil test area. The field test results show that the efficiency of temporary plugging reached 66.7%， the setting efficiency reached 74% and the temporary plugging particle efficiency reached 34%. The fracture initiation position or extensive direction is obviously different after temporary plugging， the shot-hole sealing is effective， and the purpose of fracture steering is realized， which provides theoretical support for the future work of fracturing for shale oil reservoirs.

Key words:shale oil;segmentation fracturing for horizontal well;temporary plugging particles;temporary plugging steering;setting effect