摘要
水力压裂作为油气藏增产的重要措施,压裂液的流变性质对裂缝扩展形态起着重要作用。为探寻幂律型压裂液对裂缝扩展的影响,建立了考虑岩石变形和裂缝幂律流体流动的二维非均质油藏水力裂缝扩展数学模型,分别采用扩展有限元和标准有限元法求解应力场和流场,并通过迭代法将两场耦合起来。通过与经典模型计算结果比较,证明了模型能准确地预测裂缝扩展形态。参数敏感性分析表明:岩石弹性模量的非均质越强,越容易形成短、宽型水力裂缝,而泊松比的非均质几乎没有影响;幂律流体流性指数越大,越容易形成短、宽型水力裂缝;幂律流体稠度系数越大,越容易形成短、宽型水力裂缝。该模型可为压裂设计和预测提供理论指导。
Hydraulic fracturing is an important stimulating treatment for oil and gas reservoirs,and the rheological properties of the fracturing fluid play significant role in the fracture propagated configurations.To seek for the influences of the power-law fracturing fluid on the propagation,the mathematical model of 2D hydraulic fracture propagation for the heterogeneous oil reservoir is established in the considerations of the rock deformations and power-law fluid flow in the fractures,the stress and flow fields are solved through the extended and standard finite element methods respectively,and moreover the two fields are coupled by the iterating method.The model is verified to be capable of forecasting the fracture propagation accurately by comparison with the computed results of the classical model.Furthermore,the parameter sensitivity analysis shows that the stronger the heterogeneity of the elastic modulus is,the shorter and wider the fractures will induce;there is almost no influence for the heterogeneity of the Poisson＇s ratio;the larger the liquidity index of the power-law fluid is,the shorter and wider fractures will produce;the larger the consistency index of the power-law fluid is,the shorter and wider the fractures will generate.The model can provide the theoretic guidance for the fracturing design and prediction.
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2015年第3期81-86,共6页
Petroleum Geology & Oilfield Development in Daqing
基金
国家自然科学基金项目(51234007)
长江学者和创新团队发展计划(IRT1294)
中央高校基本科研业务费专项资金(11CX05005A)
关键词
幂律流体
压裂液
非均质性
水力压裂
扩展有限元
裂缝扩展
power-law fluid
fracturing fluid
heterogeneity
hydraulic fracturing
extended finite element
fracture propagation
