页岩储层多缝应力干扰下裂缝起裂角计算新模型

, PP. 30-35

Keywords: 页岩气,位移不连续法,应力干扰,应力强度因子,起裂角

Full-Text   Cite this paper   Add to My Lib

Abstract:

页岩储层具有低孔、低渗的物性特征。对页岩储层进行增产改造形成复杂裂缝网络是高效开采页岩气的有效手段,但改造过程中多裂缝同时扩展时产生的干扰应力会对裂缝走向产生影响。考虑远场地应力、多缝扩展应力干扰条件下,结合不同起裂理论,建立了水力裂缝被天然裂缝捕获后在天然裂缝端部重新起裂时起裂角计算模型。分析得到,考虑多缝应力干扰条件下,水力裂缝和天然裂缝长度对该情况下的起裂角影响较小,但随着裂缝间距的增大,干扰应力减小,起裂角先增大后减小;且在高逼近角条件下,由于多缝干扰应力的影响,随缝内净压力增大,裂缝起裂角变化不大。而在低逼近角条件下,起裂角随净压力变化,净压力越大,起裂角越小。

References

[1]	贾承造,郑民,张永峰. 中国非常规油气资源与勘探开发前景[J]. 石油勘探与开发,2012,39 (2):129~136.
[2]	赵靖周. 非常规油气有关概念、分类及资源潜力[J]. 天然气地球科学,2012,23 (3):393~406.
[3]	吴奇,胥云,王晓泉,等. 非常规油气藏体积改造技术:内涵、优化设计与实现[J]. 石油勘探与开发,2012,39 (3):352~358.
[4]	赵金洲,李勇明,王松,等. 天然裂缝影响下的复杂压裂裂缝网络模拟[J]. 天然气工业,2014,34 (1):68~73.
[5]	张旭,蒋廷学,贾长贵,等. 页岩气储层水力压裂物理模拟试验研究[J]. 石油钻探技术,2013,41 (2):70~74.
[6]	Daneshy A A. Hydraulic fracture propagation in the presence of planes of weakness [J] . SPE 4852, 1974.
[7]	Blanton T L. An experimental study of interaction between hydraulically induced and pre-existing fractures [J] . SPE10847, 1982.
[8]	Palaniswamy K, Knauss W G. On the problem of crack extension in brittle solids under general loading [J] . Mechanics Today,1978, 4 (30): 87~148.
[9]	Erdogan F, Sih G C. On the crack extension in plates under plane loading and transverse shear [J] . Journal of Basic Engineering, 1963, 85 (4): 519~525.
[10]	Sih G C. Some basic problems in fracture mechanics and new concepts [J] . Engineering Fracture Mechanics, 1973, 5 (2): 365~377.
[11]	Gu H, Weng X.. Criterion for fractures crossing frictional interfaces at nonorthogonal angles [A] . 44th US Rock Mechanics Symposium and 5 th US– Canada Rock Mechanics Symposium [C] . Salt Lake City, Utah, US, 2010-06-27~30.
[12]	程远方,常鑫,孙元伟,等. 基于断裂力学的页岩储层缝网延伸形态研究[J]. 天然气地球科学,2014,25 (4):603~611.
[13]	邵尚奇,田守嶒,李根生,等. 泥质页岩地层水力裂缝延伸方位研究[J]. 石油钻探技术,2014,42 (3):28~31.
[14]	曾凡辉,郭建春,刘恒,等. 致密砂岩气藏水平井分段压裂优化设计与应用[J]. 石油学报,2013,34 (5):959~968.
[15]	陈作,薛承瑾,蒋廷学,等. 页岩气井体积压裂技术在我国的应用建议[J]. 天然气工业,2010,30 (10):30~32.
[16]	Crouch S L, Starfield A M. Boundary element methods in solid mechanics [M] . London: George Allen & Unwin, Ltd, 1983.
[17]	Olson J E, Arash D T. Modeling simultaneous growth of multiple hydraulic fractures and their interaction with natural fractures [J] . SPE119739, 2009.
[18]	程万,金衍,陈勉,等. 三维空间中水力裂缝穿透天然裂缝的判别准则[J]. 石油勘探与开发,2014,41 (3):336~340.

Full-Text