摘要
天然气水合物特殊的赋存环境决定着其储层为双相或多相孔隙介质。利用双相孔隙流体介质理论可以充分地考虑介质的结构、流体与固体的特殊性质、局部特性与整体效应的关系,能更准确地描述实际地层结构、地层性质以及地层对地震波的动态响应。根据天然气水合物的固态属性及其赋存地质条件,针对水合物储层构建了双相固体介质的岩石物理模型;提出正向、逆向、双向线性回归密度计算公式。以ODP 164航次991 A、995 A站位为例,基于此模型应用岩石的整体密度信息反演求取水合物和骨架介质的密度参数,水合物密度计算值分布在0.858 2～1.055 6 g/cm3之间;并对所得密度值进行修正计算,得到不同深度域孔隙内介质的密度值,根据计算结果进行了水合物有利储层的识别。为利用岩石物理方法研究水合物提供新的思路。
The occurrence of gas hydrate reservoirs is a special environment that belongs to the multiple phases.The use of two-phase porous medium theory can fully take into account the structure of the medium,the special nature of the fluid and gas that fill the pores among the mineral framework,the relationship between the properties of the parts and the entirety,which can accurately describe the actual stratigraphic structure,the attributes of strata,and the dynamic response of seismic waves in the rock.This study proposed a rock physics model based on the solid property of gas hydrate and the characteristics of the geological conditions,and constructed the equations of forward,reverse and bidirectional linear regression to calculate density.Taking sites of 991 A,995 A in ODP Leg 164 as examples,the densities of gas hydrate and framework were calculated with rock density based on this model.The calculated values of the density of gas hydrates are from 0.858,2 to 1.055,6 g/cm3.After the calculated values were corrected,the framework densities in different depths were derived,and the distribution of favorable hydrate reservoir was identified.This study provides a new rock physics model for the research on gas hydrates.
出处
《现代地质》
CAS
CSCD
北大核心
2011年第6期1180-1186,共7页
Geoscience
基金
国家自然科学基金项目(40874052)
关键词
天然气水合物
双相介质理论
反演
数值计算
gas hydrate
two-phase medium theory
inversion
numerical calculation
