真三轴条件下延安蟠龙地区致密砂岩力学特性试验  

Mechanical properties of tight sandstone in Yan’an Panlong area under true triaxial conditions

作　　者：任颖惠 韩进[1,2] REN Yinghui;HAN Jin(School of Petroleum Engineering and Environmental Engineering,Yan’an University,Yan’an 716000,Shaanxi,China;Yan’an Engineering Technology Research Center of Efficient Pipeline Transportation of Oil and Gas and Flow Guarantee,Yan’an 716000,Shaanxi,China)

机构地区：[1]延安大学石油工程与环境工程学院,陕西延安716000 [2]延安市油气高效管输与流动保障工程技术研究中心,陕西延安716000

出　　处：《石油地质与工程》2024年第2期8-12,21,共6页Petroleum Geology and Engineering

基　　金：陕西省教育厅科研计划项目资助(22JK0615);延安大学博士科研启动项目(2003/205040339);延安市重点研发计划项目(SL2022SLGYGG-013);榆林市科技计划项目(CXY-2021-123)。

摘　　要：为了研究不同荷载作用下延安蟠龙地区致密砂岩的强度及变形特征,对致密砂岩开展真三轴试验,研究常规三轴应力下抗压强度与围压的关系,以及真三轴应力下σ_(3)和σ_(2)对致密砂岩强度和变形的影响。研究结果表明,真三轴应力下,σ_(3)和σ_(2)对致密砂岩的强度都起了一定的保护作用,使得岩石的承载能力增强;随着σ_(3)和σ_(2)的增大,岩样的弹性模量和峰值强度均不断增大,峰值应变逐渐减小。σ_(1)-ε_(1)峰值前后曲线陡升陡降,说明研究区致密砂岩具有明显的脆性特征,表明研究区在压裂过程中容易形成压裂缝,有利于非常规油气的开采。该研究对致密砂岩油气开采具有借鉴意义。In order to analyze the strength and deformation of the tight sandstone in Yan’an Panlong area under different loading states,a true triaxial experiment was carried out using YSZS-2000 electro-hydraulic servo rock true triaxial testing machine.In the experiment,the relationship between compressive strength and confining pressure under conventional triaxial stress and the effect ofσ_(3) andσ_(2) on the strength and deformation of tight sandstone under true triaxial stress were studied.The results show that under true triaxial stress bothσ_(3) andσ_(2) protect the strength of tight sandstone,which enhances the bearing capacity of rock.The elastic modulus and peak strength of the rock sample increase with the increase ofσ_(3) andσ_(2),while the peak strain gradually decreases.From the shape ofσ_(1)-ε_(1) curve,it can be seen that the curve rises and falls sharply before and after the peak value,indicating that the tight sandstone in the study area has obvious brittle characteristics.Therefore,the study area is prone to forming fractures during the fracturing process,which is beneficial for unconventional oil and gas and provides a good reference for oil and gas production of tight sandstone.

关 键 词：真三轴试验 非常规油气 致密砂岩 强度 变形 

分 类 号：TE125[石油与天然气工程—油气勘探]