摘要
疏松砂岩具有胶结性差，结构疏松及强度小的特征，现场往往采用铅封和冷冻取心，不仅成本高，而且难以获得代表性成型岩心，铅封岩心还存在州试结果不准确的问题，故为此研究了一种弱胶结高渗疏松砂岩岩心制作新技术。在不改变粒度组成及胶结剂用量的条件下，选用与储层粒径分布相似的河沙作为骨架颗粒时，加入一定量的地层水可较好的控制岩心胶结程度，且不需要扩孔，岩心较容易成型，制作岩心的渗透率范围为1000～3700mD，润湿性符合河流沉积砂岩特征。研究认为地层水是制作疏松砂岩岩心的主控因素，通过对比天然岩心和人造岩心的孔隙度、渗透率、胶结方式和胶结指数等参数，添加地层水制作的岩心胶结性和孔渗较好，与天然岩心有较高的相似性，制作的岩心可用于室内实验研究，表明此制作技术可行。
Unconsolidated sandstone has the characteristics of poor cementation, loose structure and low intensity. The field often use lead seal and frozen cores and it not only costs highly but also is difficult to obtain representative molding core, lead seal cores still exist the problem of inaccurate test results, therefore we study a new technology of making weakly cemented and hypertonic artificial cores of unconsolidated sandstone. Under the condition of not change the size composition and the dosage of cementing agent, choose the fluviatile sand which has the similar size distribution to the reservoir as the granule of framework, adding a certain amount of water can control the degree of cores＇ cementation better, and do not need to expand the porosity, the cores are relatively easy to molding, the permeability of manufactured cores range from 1000 mD to 3700 roD, wettability consistent with features of fluvial deposit sandstone. Studies suggest that the formation water is the main factor of making artificial cores of unconsolidated sandstone, by comparing parameters such as the porosity, permeability, cementation mode and cementation exponent between natural cores and artificial cores, the cementation,porosity and permeability of artificial cores which added formation water are better, these cores have high similarity with natural cores. These artificial cores can be used in the indoor experimental study. It indicates that the manufacturing technology is feasible.
出处
《地球物理学进展》
CSCD
北大核心
2015年第3期1474-1479,共6页
Progress in Geophysics
基金
国家科技重大专项项目(2011ZX05024-002-005)部分研究内容
关键词
弱胶结
疏松砂岩
人造岩心
地层水
胶结指数
粒度组成
weakly cemented
unconsolidated sandstone artificial core
formation water
cementation exponent
size composition
