砂岩气藏压裂定向井优化射孔工艺研究

On Optimizing Perforating Technology for Orientation Well in Sandstones Reservoir Fracturing

定向井作为砂岩气藏开发的重要技术手段,在压裂改造过程中普遍体现出了较直井高效压裂更为困难的现象。基于真三轴水力压裂模拟实验,模拟了定向井压裂过程,基于实验结果,分析认为定向井压裂时明显的近井筒效应是定向井较直井高效压裂更为困难的重要因素。同时基于模拟实验,研究了孔深、孔径、孔密对定向井压裂改造的影响规律,提出了射孔参数优化原则。基于方位定向现场试验,给出了外定向、内自定向2种方式的推荐应用范围。通过9个层次的定向射孔工艺现场试验,均有效地提高了定向井压裂效果,降低了地层破裂压力及近井筒效应,提高了单井产能。为砂岩气藏定向井高效压裂改造提供了可靠的技术措施,具有推广应用价值。

In sandstones gas reservoir development, orientation well is an important technology means, but practices show that the effect of most fractured orientation well is worse than vertical well. In this paper, based on the three-axle hydraulic fracturing modeling, simulated is the process of inclined well fracturing. The experiment results show that the near well-bore effect is the important effect factor of fracturing in the orientation well. Based on the simulation experiment, researched are the effects of hole depth, diameter and shooting density on the orientation well fracturing modification. Proposed are optimization principles of perforation parameter design. In-situ orientation tests give the range of Outer orientation perforation and inner auto-orientation perforation. Nine field applications show that this technique effectively improves the fracturing transformation effect of orientation well, reduces the formation fracture pressure and nearwell bore effect, and increases the output of single well. These optimization perforation parameters provide new technical support for the orientation well fracturing, and have the wide application value.