摘要
以往研究单一或成组裂缝的数值模拟,多未考虑孔洞存在对裂缝宽度变化的影响。用断裂力学基本理论及有限元法建立了不同缝洞组合裂缝宽度变化的有限元模型,通过ANSYS有限元软件模拟研究了缝洞型储层中不同缝洞组合:缝—洞、缝—洞—缝、缝—洞—缝—洞3种模型。探讨了不同模型中裂缝宽度变化、裂缝长度、井筒正压差及溶洞发育情况的关系。模拟结果表明,井筒正压差越大,裂缝宽度增量越大;相同井筒正压差下,裂缝长度越大,其缝宽增量越大;溶洞越发育,缝宽增量也越大;随着溶洞直径的逐渐增大,缝宽增量也越大。计算机模拟裂缝宽度变化规律为选取合理粒径的堵漏材料、优化漏失控制技术提供了一定的理论依据。
Computer simulations of a single or set of fractures were conducted previously,and the effects of cavities on fracture width variation were hardly concerned.In this paper,we established a finite element model of fracture width variation for different fracture-cavity groups according to the finite element method of fracture mechanics and computer simulation,and discussed 3 types of fracture-cavity groups models related with fractured/caved carbonate reservoirs in Tahe oilfield.The relationships among the fracture width,length,positive differential pressure and cavity development were probed.The simulation results showed that,the fracture width increment increased with the increasing of the positive differential pressure;under the same positive differential pressure,the fracture width increment increased with the growing of fracture length;and the occurrence of cavities intensified the fracture width variation.The richer the cavities porosity was,the bigger the fracture width increment was;the growing of fracture width increment was coming with the increasing of cavity radius.The computer simulation of fracture width variation can provide a theoretical basis for choosing suitable lost circulation materials and improving lost control technologies.
出处
《天然气地球科学》
EI
CAS
CSCD
北大核心
2011年第2期340-346,共7页
Natural Gas Geoscience
基金
国家"973"计划课题(编号:2010CB226705)
国家科技重大专项(编号:2008ZX05049-003-03
2008ZX05005-006-08HZ)联合资助
关键词
计算机模拟
缝洞型储层
孔洞
裂缝动态宽度
缝宽增量
Computer simulation
Fracture-cavity reservoir
Cavity
Fracture dynamic width
Fracture width increment.
