高压压汞法结合分形理论分析页岩孔隙结构  

ANALYSIS OF THE SHALE PORE STRUCTURES BY THE COMBINATION OF HIGH-PRESSURE MERCURY INJECTION AND FRACTAL THEORY

作　　者：王欣[1] 齐梅[1] 胡永乐[1] 邱勇松[2] 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]大庆油田有限责任公司,黑龙江大庆163453

出　　处：《大庆石油地质与开发》2015年第2期165-169,共5页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家科技重大专项"全球剩余油气资源研究及油气资产快速评价技术"(2008ZX05028)

摘　　要：在页岩气勘探开发中,储层微观孔隙结构评价具有重要的意义.为了更有效地研究页岩储层微观孔隙结构特征,利用高压压汞实验结合分形理论对孔隙结构进行分析.高压压汞结果显示岩样孔隙半径主要分布在3～50 nm的中孔范围内,其中3～15 nm的孔隙占80％以上,该部分孔隙提供了大部分孔体积.研究岩样中孔的分形维数分析结果表明：页岩岩样中孔的分形分布可明显地分为2段,孔隙半径大于15 nm的孔隙分形维数接近3,说明该部分孔隙非均质性强,孔隙结构分布不均匀;孔隙半径小于15 nm的孔隙分形维数相对较小,该部分孔隙分布较为均匀.高压压汞曲线仅可对中孔和大孔进行分析描述,由于进汞压力大可能导致岩样遭到破坏,不宜利用高压压汞曲线对孔隙半径小于2 nm的微孔进行分析.In the exploration and development of shale gas, the evaluation of the micro-structures of the reservoirs is of great significance. In order to effectively study the structural characteristics, the pore structures are analyzed by the combination of the high-pressure mercury injection experiment and fractal theory. The experiment shows that the pore diameters of the rock samples are mainly in the medium-pore range of 3-50 nm, and moreover more than 80% of them is distributed in 3-15 nm pores, these pores possess a large amount of the volume. The fractal dimen- sion analysis results of the above pores show that the fractal distribution can be obviously divided into two sections： for the pore diameter larger than 15 nm, the value of the fractal dimension is close to 3, this indicates that the het- erogeneity of these samples is rather strong and furthermore the distribution of the pore structures is uneven; The fraetal dimension of the pores with the diameter less than 15 nm is relatively less and the pore distribution is pretty even. The curves of the high-pressure mercury injection can only analyze and characterize those medium and large pores, because of the high pressure, the samples maybe destroyed, so the micro-pores which pore diameters less than 2 nm is not feasible to be analyzed by means of the curves.

关 键 词：页岩气 孔隙结构 压汞实验 分形理论 分形维数 

分 类 号：TE311[石油与天然气工程—油气田开发工程]