水力喷射压裂机理与技术研究进展

Research on hydrajet fracturing mechanisms and technologies

水力喷射压裂是集射孔、压裂、隔离一体化的新型增产改造技术,适用于低渗透油藏直井、水平井的增产改造,是低渗透油藏压裂增产的一种有效方法。介绍了水力喷射射孔和水力射孔裂缝起裂控制机理,分析了影响水力喷砂射孔效果的因素。综述了水力喷射压裂原理,依据Bernou lli原理,射流增压与环空压力叠加超过破裂压力产生裂缝并维持裂缝延伸。介绍了水力喷射辅助压裂、水力喷射环空压裂及水力喷射酸压等多种工艺形式。水力喷射压裂工具是现场应用成功的关键因素之一,连续油管与水力喷射压裂技术联作在油田增产作业中有一定优势。水力喷射压裂工艺在国外现场应用已经取得较好效果,在国内尚属现场试验起步阶段。指出了目前研究的不足,并对未来的研究方向做出了分析展望。

Hydrajet fracturing, which integrates perforation, fracturing, and isolation, is a new stimulation technology for horizontal or vertical wells in low permeability reservoirs. It is feasible and effective for fracturing stimulation in low permeability reservoirs. This paper introduces the mechanisms of hydrajet perforation and hydrajet fracturing control, analyzing the factors that influence hydrajet perforation and summarizing the principle of hydrajet fracturing. According to Bernoulli＇s principle, jet supercharge superimposed upon annulus pressure surpass fracturing pressure, which will generate fractures and maintain fracture extension. Multiple technologies are also introduced including the assistant hydrajet fracturing technology, the annulus hydrajet fracturing technology, and the hydrajet acid - fracturing technology. The hydrajet fracturing tool is critical to realize field application and combination of coiled tubing technology with hydrajet fracturing technology. Hydrajet fracturing technology has been successfully abroad and good results have been obtained. However, it is still in the preliminary stage of field test in China. This paper presents some problems of the technology and discusses the prospect for its further development.