摘要
承压堵漏是解决裂缝性地层井漏问题的重要方法,准确预测地层封堵承压能力是科学利用承压堵漏技术的核心基础。为此,在分析非均匀地应力状态下裂缝宽度变化特征的基础上,基于叠加原理推导了任意封堵位置处裂缝尖端应力强度因子计算公式,建立了裂缝性地层封堵承压能力解析预测模型。与传统模型相比,新模型的预测结果具有更高的精度和可靠性。最后,分析了不同工程地质参数对裂缝封堵承压效果的影响规律。结果表明,增加裂缝尖端长度,同时降低裂缝尖端流体压力,有利于提高地层的封堵承压能力;当在井壁附近形成低渗透封堵层时,有必要对封堵层长度进行优化,以最大化地提高地层的封堵承压能力;当地层渗透率确定时,裂缝封堵承压效果随着地应力比的增加而降低,随着弹性模量、泊松比以及断裂韧性的增加而增大。
Pressure-bearing plugging is an important method to solve the problem of lost circulation in fractured formation.Accurate prediction of pressure-bearing capacity of leakage formation is the core basis of scientific application of pressurebearing plugging technology.For this purpose,on the basis of analyzing the variation of fracture width under non-uniform insitu stress,the crack tip stress intensity factor when considering in-fracture plugging is derived based on superposition principle,and an analytical model for predicting the pressure-bearing capacity of plugged fractured formation is established.Compared with the traditional model,the prediction results of this model have higher accuracy and reliability.Finally,the influence of different engineering and geological parameters on the pressure-bearing capacity of plugged fracture is analyzed.The results show that increasing the fracture tip length and reducing the fluid pressure at the fracture tip during plugging treatment are beneficial to improving pressure-bearing capacity of fractured formation.When a low-permeable plugging zone is formed in the vicinity of borehole wall,it is necessary to optimize the length of the plugging zone to maximize the pressure-bearing capacity of plugged fracture.When the formation permeability is determined,pressure-bearing capacity of plugged fracture decreases with the increase of the ratio of in-situ stresses,and increases with the increase of elastic modulus,Poisson′s ratio and fracture toughness.
作者
刘阳
张沛
马琪
王俊力
马天寿
LIU Yang;ZHANG Pei;MA Qi;WANG Junli;MA Tianshou(School of Mechanical Engineering,Southwest Petroleum University,Chengdu,Sichuan 610500,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China;No.1 Gas Production Plant,PetroChina Changqing Oilfield Company,Jingbian,Shaanxi 718500,China;Shu′nan Division,PetroChina Southwest Oil&Gasfield Company,Luzhou,Sichuan 646000,China)
出处
《西南石油大学学报(自然科学版)》
北大核心
2025年第6期119-128,共10页
Journal of Southwest Petroleum University(Science & Technology Edition)
基金
四川省国际科技创新合作项目(2021YFH0047)
中国博士后科学基金(2022T150543)。
关键词
裂缝性地层
井漏
裂缝宽度预测
承压堵漏
参数化分析
fractured formation
lost circulation
fracture width prediction
pressure-bearing plugging
parametric analysis
