摘要
利用有限元软件ABAQUS,建立考虑流固耦合的水力裂缝扩展三维模型。压裂水力裂缝扩展模型采用cohesive单元进行裂缝面的设置,并针对裂缝位置采用变密度进行网格划分,提高压裂水力裂缝扩展计算的精确性。模型计算结果表明,水力裂缝开启和扩展过程中,孔隙压力等值线自裂缝向外以半椭圆形发散,压力值由靠近裂缝的高应力值向外逐渐减小;裂缝高度和宽度在裂缝张开初期快速扩展,到达一定高度后,基本保持不变;而半缝长随注入时间裂缝稳定增长,增长幅度渐渐降低。
By using finite element software ABAQUS, 3D model of hydraulic fracture propagation in consideration of fluid-solid coupling was established. Hydraulic fracture propagation model adopted cohesive unit to set fracture surfaces. And aiming at the fracture position, gridding of variable density was used to improve the accuracy of calculations of hydraulic fracture propagation. The calculated results showed that during hydraulic fracture opening and propagation process, pore pressure contours transpired as semiellipsoid from fracture to the outside, and the pressure value decreased gradually from near the fracture. The fracture height and width expanded rapidly at the early stage when the fracture opened. Once they reached a point, they remained about the same. However, the half fracture length increased steadily with the injecting time while the increasing range reduced gradually.
出处
《油气藏评价与开发》
2014年第5期48-51,共4页
Petroleum Reservoir Evaluation and Development
基金
国家科技重大专项(2011ZX05002-005)资助
关键词
压裂
有限元
起裂
扩展
孔隙压力
ABAQUS
fracture
finite element
ABAQUS
fracture initiation
propagation
pore pressure
