摘要
本文在实验室里对老爷庙油田馆陶组(Ng)油气贮层砂岩岩芯的孔隙度φ、空气渗透率κ、骨架密度ρ_(ma)、岩石密度ρ_b和不同有效覆盖压力△P下岩芯的声波时差△t,做了精确测量,用回归分析拟合了φ-K、φ-ρ_b、φ-△t和V-△p(△t-△p)的经验关系式;保持原始孔隙结构不变的前提下,在岩芯饱和各种矿化度的孔隙流体时测定了声波时差△t与孔隙度φ的关系.研究结果表明,当贮层的φ-K、φ-ρ_b和φ-△t相关时,可用声波时差△t或波速V解释贮层的岩性,并可反演求出贮层的φ、K和ρ_b;地层有效覆盖压力对贮层的孔隙度和波速具有明显的影响.根据V-△p曲线的变化规律,可以评价贮层的岩性和埋藏地质体的油、气储集能力.这些结果对油田地震勘探和石油测井资料的解释具有重要的参考价值,并为预测储油有利地区和评价贮层提供了一种新的途径.
In this study, the porosity φ, permeability to air K, skeleton density ρma, bulk density ρb and sound wave time difference At under different effective overburden pressure Δp of sandstone cores collected from the oil/gas reservoir in the Guantao formation (Ng), Laoyemiao Oil Field are measured in laboratory; empirical relationships of φ vs. K, φ vs. ρb, φ vs. Δt and V vs. Δp(Δt vs. Δ6p) are fitted by regression analysis; and the variation of sound wave time difference Δt with porosity (?) are measured when the cores are saturated with pore fluid of different salinity under the prerequisite of keeping the initial pore structure undisturbed. The results of study suggest that when the relations of φ-K, φ-ρb and φ-Δt are correlative with one another, the data of sound wave time difference Δt and wave velocity V can be used to explain the lithological character of reservoirs and thus to inverse the values of φ, K and ρb of the reservoir; the effective onverburden pressure of strata has significant effects on the porosity and wave velocity of the reservoir and thus it is possible to evaluate the lithological characters and oil/gas storage capacity of reservoirs from the regularities of variation of velocity-pressure curves. These results are of important referential value for the data explanation of seismological exploration and well-logging of oil fields, and provide a new tool for predicting favorable areas of oil storage and evaluating the capacity of reservoirs.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
1990年第2期212-219,共8页
Chinese Journal of Geophysics
关键词
波速
压力
岩性
物性
声波
时差
Porosity, Permeability to air, Skeleton density, Bulk density, Sound wave time difference, Effective overburden pressure.
