水力压裂岩体损伤破裂折迭突变模型研究与应用

STUDY OF DAMAGE TENSOR FOLDING MUTATION MODEL FOR FRACTURING ROCK MASS AND ITS APPLICATION

为准确描述油气田工程中压裂岩体损伤突变裂缝的起裂问题,基于岩体孔隙度的变化,定义岩体损伤变形的损伤变量,并建立岩体形变过程的损伤本构模型。考虑油气藏压裂岩体损伤破坏过程为岩体形变能的积聚增加与突然释放,基于能量守恒原理,建立压裂岩体损伤的张量型折迭突变模型。给出压裂岩体损伤突变平衡方程与岩体损伤突变破坏能量释放量计算模型。计算、分析长庆油田苏里格区块石英砂岩与岩屑砂岩水力压裂岩体损伤突变破坏能量释放量变化规律,为油气田压裂岩体损伤破坏裂缝形成的研究提供新方法。

In order to accurately describe the problems of fracturing rock mass damage mutation cracking up crack in the oil and gas field engineering,based on the changes of rock porosity,the rock mass damage variable is defined and the damage constitutive model in the process of rock mass deformation is established. Considering that the process of reservoir fracturing rock mass damage is the accumulation increasing and suddenly releasing of rock mass deformation energy,the folding mutation model of fracturing rock mass damage tensor type is established based on the principle of conservation of energy. The balance equation of fracturing rock mass damage mutation and the calculation model of energy release quantity of rock mass damage mutational damage are given. Combined with quartz sandstone and lithic sandstone characteristics of Sulige block of Changqing Oilfield,the change rule of energy release quantity of rock damage mutational damage under hydraulic fracturing is calculated,and a new method is provided for the study of the oil and gas field fracturing rock mass damage crack formation.