CAJ | 학술논문

在细观尺度上对孔隙流体对岩石力学性质的影响进行定量化研究.将孔隙流体带来的非线性应变的影响分为经典应变的影响和非经典弹性单元(NCU)对非经典应变的影响.分析低饱和度和高饱和度时微细观机制的作用,以此分别讨论流体对岩石非线性力学行为和岩石介质宏观刚度的影响.为适应不同饱和度下岩石力学行为,提出一种新的固液相互作用函数关系,对试验数据进行非线性反演,获得不同饱和度时的PM空间图像,分析孔隙流体对PM空间密度(NCU数目)的影响.首次反演杨氏模量、压缩波速度随饱和度变化完整过程.饱和度为0%～20%时,由于液体的激活作用,对于经典部分,动态杨氏模量随饱和度增加而减小;对于非经典部分,随饱和度增大PM空间NCU密度增大,NCU数目增多,非线性增强,杨氏模量下降.当饱和度为20%～80%时,动态杨氏模量不随饱和度变化,PM空间NCU密度也基本保持不变.当饱和度由80%以上增大到全饱和时,杨氏模量、弹性波速度反而随饱和度增加而增大,PM空间NCU数目有所减小,非线性程度下降.饱和岩石的经典和非经典非线性应变比干燥岩石有显著的增长,与模拟的PM空间NCU密度分布结果是一致的.这些数值分析结果与试验结果的规律性基本吻合.该项研究对于储层预测、油藏描述、斜坡附近建筑的安全性、核仓库性能及地球物理反演、资料解释都具有潜在的应用前景.
재세관척도상대공극류체대암석역학성질적영향진행정양화연구.장공극류체대래적비선성응변적영향분위경전응변적영향화비경전탄성단원(NCU)대비경전응변적영향.분석저포화도화고포화도시미세관궤제적작용,이차분별토론류체대암석비선성역학행위화암석개질굉관강도적영향.위괄응불동포화도하암석역학행위,제출일충신적고액상호작용함수관계,대시험수거진행비선성반연,획득불동포화도시적PM공간도상,분석공극류체대PM공간밀도(NCU수목)적영향.수차반연양씨모량、압축파속도수포화도변화완정과정.포화도위0%～20%시,유우액체적격활작용,대우경전부분,동태양씨모량수포화도증가이감소;대우비경전부분,수포화도증대PM공간NCU밀도증대,NCU수목증다,비선성증강,양씨모량하강.당포화도위20%～80%시,동태양씨모량불수포화도변화,PM공간NCU밀도야기본보지불변.당포화도유80%이상증대도전포화시,양씨모량、탄성파속도반이수포화도증가이증대,PM공간NCU수목유소감소,비선성정도하강.포화암석적경전화비경전비선성응변비간조암석유현저적증장,여모의적PM공간NCU밀도분포결과시일치적.저사수치분석결과여시험결과적규률성기본문합.해항연구대우저층예측、유장묘술、사파부근건축적안전성、핵창고성능급지구물리반연、자료해석도구유잠재적응용전경.
Quantitative studies of pore fluid influence on the mechanical properties of rocks are carried out on mesoscopic scale. The nonlinear strain is decomposed into a classical part and a nonclassical contribution which is described by nonclassical elastic units(NCU). Based on the analysis of the mechanism on mesoscopic scale,fluid influences on rock mechanical behavior and stiffness under various saturations are discussed. Introducing new forms of macroscopic solid-fluid interaction functions,Preisach-Mayergoyz(PM) space under different saturations are obtained from the inversion of experimental data;and the influences of fluid saturation on PM space density are investigated. The entire variation between Young's modulus and compressional wave velocity with saturation is studied. When saturation increases from 0% to 20%,the dynamic modulus decreases for classical part,and the PM space density increases for nonclassical part,respectively. Whereas saturation is between 20% and 80%,the dynamic modulus and PM space density barely changes. As saturation increases from 80% to 100%,the dynamic modulus increases and the PM space density decreases,contrary to the low saturation condition. The classical and nonclassical nonlinear strains of saturated rocks are obviously larger than those of dry rocks in accord with the PM space density distribution. These numerical results are generally consistent with the experimental results. This simulation research has potential prospects for the problems such as reservoir prediction and description,safety of constructions near slope area,nuclear storehouse properties,geophysical inversion,and data interpretations.