摘要
随着油气勘探不断向深部延伸,储层温度逐渐升高,温度变化引起的热应力对油气储层地应力状态的影响越来越大,已经成为一个不可忽视的重要因素。以川南海坝区块五峰组—龙马溪组页岩气储层为研究对象,利用三维有限元数值模拟方法将构造应力与热应力两者耦合,探究研究区页岩气储层的地应力分布特征。结果 表明:川南海坝区块页岩气储层处于较为复杂的应力状态,断裂发育较多,在断层附近会出现应力值突变现象。整个海坝区块南北两端应力值最高,越往背斜核部、剥蚀面及东西两端埋深越浅,应力值越低。研究区热应力值约为8.3~32.5MPa,构造最大水平主应力约为-13.5~-85.5MPa,热力耦合最大水平主应力约为-5~-83MPa,构造最小水平主应力约为-3~-40MPa,热力耦合最小水平主应力约为-1~-55MPa。热力耦合后的应力值普遍低于构造应力,是由于岩体温度变化产生的拉张热应力会在一定程度上削弱构造挤压应力,使得起主导作用的构造挤压应力值有所下降。
As oil and gas exploration continues to the depth,the reservoir temperature increases gradually,and the thermal stress caused by temperature change has more and more influence on the in-situ stress state of oil and gas reservoirs,which has become an important factor that cannot be ignored.Wufeng Formation-Long-maxi Formation shale gas reservoirs in Haiba block in southern Sichuan are studied.The three-dimensional fi-nite element numerical simulation method is used to couple tectonic stress and thermal stress to explore the distribution characteristics of in-situ stress of shale gas reservoirs in the study area.The results show that the shale gas reservoirs in the Haiba block in southernSichuan are in a relativelycomplex stress state,with many fractures developed,and a sudden jump in stress value will occur near the faults.The stress values at the northern and southern ends of the Haiba block are the highest,and the lower the stress values are when the anticline core,the denudation surface,and the eastern and western ends are buried shallower.In the study area,the thermal stress is about 8.3 to 32.5MPa,the maximum structural horizontal principal stress is about-13.5 to-85.5MPa,the maximum horizontal principal stress of the thermodynamic coupling is about-5 to-83MPa,the minimum structural horizontal principal stress is about-3 to-40MPa,and the minimum horizontal principal stress of thermal coupling is about-1 to-55MPa.The stress value after thermal coupling is gener-ally lower than the tectonic stress.This is because the tensile thermal stress generated by the temperature change of rock mass will weaken the tectonic compression stress to a certain extent,and the dominant tec-tonic compression stress value will decrease.
作者
王胜宇
余仕免
梁明娟
Wang Shengyu;Yu Shimian;Liang Mingjuan(Geological Museum of Guizhou,Guiyang Guizhou 550081)
出处
《中外能源》
CAS
2024年第8期46-53,共8页
Sino-Global Energy
基金
国家岩矿化石标本资源库项目“贵州典型岩矿化石标本资源数字化及共享服务”(编号:NCSTI-RMF20240213)。
关键词
地应力状态
构造应力
热应力
热力耦合
储层温度
页岩气储层
in-situ stress state
tectonicstress
thermalstress
thermalcoupling
reservoir temperature
shale gas reservoir
