【摘要】 基于复合断裂力学解析方法和能量平衡原理,考虑非常规油气储层岩石高脆性和低渗透性特点,研究水平井分段压裂诱导裂缝间应力相互干扰条件下裂缝扩展的力学机制和缝内变密度支撑剂运移规律。根据水力压裂裂缝扩展的拟三维模型和考虑缝内流体沿缝长、缝高二维流动的全三维模型,分别考虑水平井单井缝网压裂和双井同步压裂形成网状裂缝状态,建立考虑缝间应力干扰的诱导网状裂缝体积压裂优化设计模型,采用Visual Studio 2012开发平台,研制设计软件3D-UGMulti-Fracture。根据断裂力学和渗流力学原理研究水力压裂过程中不同密度支撑剂在网状裂缝内的运移过程。利用微地震技术对同步压裂井实施裂缝监测,检测结果与软件计算结果具有很好的一致性。按照压裂工艺设计要求,优化排液量和砂比等参数,增加裂缝有效支撑长度,提高裂缝导流能力。更多还原

【Abstract】 Based on compound fracture mechanics and energy balance principle,and considering the high brittleness and low permeability of the rock in the unconventional oil and gas reservoirs,the mechanical mechanism of crack propagation under the mutual stress interference between induced fracture of staged fracturing for horizontal wells and the transport regularity of variable density proppant in fractures were studied. Taking into account the forms of the network cracks respectively in the network fracturing of single horizontal well and the sync-fracturing of twin wells,a volume optimal design model of the induced reticular fracture was built considering the mutual stress interference between induced fractures. Meanwhile,the 3DUGMulti-Fracture software was developed with the Visual Studio 2012 development platform,according to the both simulated three-dimensional model of crack extension of the hydraulic fracture and the full three-dimensional model of the two dimensional flows along the crack length and height. The transport process of variable density proppant in the network fracture was studied on the basis of fracture mechanics and fluid mechanics. The fracturing process was monitored by the micro-seismic technology,and it was found that the calculated results via the developed software agree well with the test results. According to the design requirements,the parameters such as liquid discharge and sand ratio are optimized. The effective support length increases and flow capacity of the features is improved.更多还原