影响泥岩盖层质量的主要因素及评价新思路

利用突破压力、盖层物性、排驱压力、扩散系数、中值压力等实验室定量参数,结合泥岩微观组构、岩矿组成、伊利石结晶度等沉积成岩定性参数,综合评价莺歌海盆地东方区和乐东区泥岩盖层的封闭性.结果表明,不同质量泥岩盖层的沉积成岩特征存在差异.质量好的泥岩盖层岩性为黏土粉砂质泥岩,黏土含量较高,碳酸盐含量中等,长石和石英含量较低,伊...

The main factors affecting the quality of mudstone caprock and a new idea for its evaluation

Based on laboratory quantitative parameters,such as breakthrough pressure,physical property of caprock,displacement pressure,diffusion coefficient and median pressure,combined with sedimentary diagenesis qualitative parameters,such as mudstone microstructure,rock composition and illite crystallinity,the sealing property of mudstone caprock in Dongfang-Ledong area of Yinggehai Basin was comprehensively evaluated.It shows that the sedimentary diagenetic characteristics of mudstone cover of different quality are different.The lithology of the mudstone caprock with good quality is composed of relatively compacted clay silty mudstone with high clay content,medium carbonate content,low feldspar and quartz content,low crystallinity of illite.Micro-pores,macro-pores and meso-pores were poorly developed and most cracks were filled in the mudstone.The mudstone caprock was less affected by gravity flow and traction flow with good homogeneity.From the perspective of deposition and diagenesis,a new way of thinking for the evaluation of mudstone caprock is proposed,which effectively solved the uncertainty caused by artificial influence of samples in the evaluation of mudstone caprock based only on test data,such as breakthrough pressure and diffusion coefficient.