水力破裂机制及其在盖层和断层稳定性评价中的应用

Hydraulic fracturing mechanism and its application in stability evaluation of caprock and fault

水力破裂现象在世界上许多沉积盆地内均有发现,是指由孔隙流体压力增加导致的岩石破裂过程,包括孔隙流体压力增加导致的新裂缝的形成和原有裂缝的张开两方面。由于孔隙流体压力不断地积累和释放,使得水力破裂表现为周期性和瞬时性的特点。水力破裂往往会引起盖层和断层发生油气渗漏,通常以发生水力破裂所需的孔隙流体压力增加量来定量评价水力破裂的风险性。深入研究水力破裂机理及形成条件,对进一步认识岩石中流体活动、油气运移和油气田安全开采等都具有重要的指导作用。文中在调研了大量国内外文献的基础上,系统地阐述了水力破裂准则、地质条件以及水力破裂在盖层和断层稳定性定量评价中的应用,以对以后水力破裂的研究提供参考。

The phenomenon of hydraulic fracturing has been found in many sedimentary basins in the world. Hydraulic fracturing is a kind of rock failure process that is caused by the increase of pore fluid pressure, including both the formation of new fractures and the open of pre-existing fractures. Because pore fluid pressure continually accumulates and releases, hydraulic fracturing is characterized by episodic and transient. Hydraulic fracturing always causes hydrocarbon leakage in caprock and fault and the risk of hydraulic fracturing is evaluated by the increase of pore fluid pressure that is required to cause failure. The research on hydraulic fracturing mechanism and condition has an important implication for deepening insight into fluid dynamics in rock, hydrocarbon migration and oil/gas field safety exploitation. Based on reviewing a large number of literatures at home and abroad, this paper illustrates systematically hydraulic fracturing criteria, geologic condition and applications in quantitative evaluation of caprock and fault stability, which can provide a reference for the future study of hydraulic fracturing.