液相高压脉冲放电致裂岩石技术研究进展

致密砂岩和页岩油气藏因其岩性致密、孔隙度和渗透率极低等特点给勘探开发带来了挑战。针对低渗油气资源,液相高压脉冲放电致裂岩石技术是提高开发效果的重要手段之一。分析总结液相高压脉冲放电致裂岩石技术的实验装置研发、影响因素和岩石裂缝规律,明确当前面临的问题以及发展方向。结果表明:液相介质电导率的提高有助于提高脉冲放电冲击波强度;放电电压越高、放电能量越大,致裂岩石效果越好;岩石裂缝的起裂主要受张剪性应力影响,裂缝扩展存在对称性,有转向、分叉和波形特征。该文可为液相高压脉冲放电致裂岩石技术相关研究工作提供参考,对非常规油气藏开发工作具有重要意义。

Study Progress of Rock Fracturing Technology with High-voltage Pulse Discharge in Liquid

There are much more challenges in the exploration and development of tight sandstone and shale oil and gas reservoirs due to their tight lithology and extremely low porosity and permeability. For low-permeability oil and gas resources, rock fracturing technology with high-voltage pulse discharge in liquid is one of the important means to improve the effect of development. In this paper, the experimental device development, influencing factors and rock fracture law of the rock fracturing technology with high-voltage pulse discharge in liquid were analyzed and summarized, and the existing problems and development direction were determined. The results showed that the improvement of the conductivity of the liquid medium was helpful to increase the intensity of the pulse discharge shock wave; the higher the discharge voltage and the greater the discharge energy, the better the rock fracturing effect; the rock fracturing was mainly affected by tensile and shear stress, the fracture progress was symmetric, with turning, bifurcation and waveform characteristics. This paper provides a reference for the studies on rock fracturing technology with high-voltage pulse discharge in liquid, with great significance for the development of unconventional oil and gas reservoirs.