岩性、含油气性、声波动力学特征规律的研究

INTEGRATIVE EXPERIMENTAL STUDY OF LITHOLOGIES,HYDROCARBON-BEARING AND DYNAMIC PKOPERTIES

在正旋回砂砾岩储层中，采集８种不同岩性的典型样品，在五种含油（气）水饱和状态下油饱和（Ｓ＿ｏ＝１００％）、水饱和（Ｓ＿ｗ＝１００％）、气饱和（Ｓ＿ｇ＝１００％）、束缚水（Ｓ＿（ｗｉ））、残余油（Ｓ＿（ｏｒ））测试了不同有效覆盖压力（ΔＰ）下的纵横波速度Ｖ＿ｐ、Ｖ＿ｓ和力学参数（体积模模量Ｋ、扬氏模量Ｅ、切变模量μ、拉梅常数λ、泊松比ｖ和密度ρ）。通过分析表明：（１）弹性模量Ｅ、Ｋ、μ、λ随ΔＰ增加而增加，随ΔＰ变化在低压范围比高压范围更敏感；（２）同一油、气水饱和状态下，同一非均质单层的岩性变化范围控制了弹性模量一有效覆盖压力曲线族的宽度；（３）无论岩样的岩性、物性以及压力条件如何，弹性模量（Ｅ、Ｋ、μ、λ）和泊松比ｖ与饱和度均呈线性关系；（４）在同一非均质单层内，岩石的模理一压力变化曲线族随着含油、气、水饱和状态的不同具有明显的分带性；（５）同一非均质单层内，岩样的动态压缩系数与静态压缩系数之间存在很好的相关关系。

Eight samples with different lithologic characters are collected from sandstone-conglom-erate reservoirs with positive rhythm. Under five kinds of saturation fully saturated states-with water(Sw=100%),oil(So=100%),gas(Sg=100%),irreducible water and residual oil,the velocities of compressional and shear waves(Vp,Vs)and mechanical pararneters(Bulkmodulus K, Young′s modulus E, Lame constant λ, Rigidity modulus μ, Poisson′s ratio v andDensity ρ)are measured precisely under different effective overburden pressure in laboratory. The results of this study suggest that :(1)Elastic moduli E,K,λ,μ of rock increase as pres-sure ΔP increases,variation of E,K,λ,μ with ΔP is more sensitive in low-pressure rangethan in high pressure range. (2)Under the same saturation state,the range of elastic modulivs. effective overburden pressure curves is controlled by lithological variations in the samereservoir. (3)Under the same pressure(surface to subsurface)and in three systems(oil-water,oil-gas,gas-water),elastic modulus in each case is a linear function of saturation. (4)Elasticmodulus vs. pressure curves have evident zonal distribution under different saturation state. (5 ) There is a good correlative relationship between the dynamic and static compressibilitycoefficient in eight samples.