SEAL CHARACTERISTICS OF K-1d-1 MUDSTONE CAPROCK AND RESEARCH SIGNIFICANCE IN WUERXUN DEPRESSION
乌尔逊凹陷大一段泥岩盖层封闭能力及其研究意义

Based on the study of seal mechanisms of caprock to each phase of oil or gas and their influence factors, this paper sisterly studied seal characteristics of K_1n~1 mudstone caprock to each phase of oil or gas in Wuerxun depression. This paper considered mudstone caprock of K_1n~1 to have best direct ability of capillary seal to oil or gas in free phase, to have best indirect ability of abnormal pore fluid pressure to oil or gas in free phase in the middle of depression and have better and diddle in direct ability of abnormal pore fluid pressure to oil or gas in free in the side of depression. Mudstone caprock of K_1d~1 have best seal ability to gas in water-dissolving phase and diffusion phase in the mast of depression and better seal ability to gas in water-dissolving phase and diffusion phase in the side of depression. The formation period of seal ability of K_1n~1 mudstone caprock is ealier the period of a lot of oil and gas in each phase expelled form K_1n~1 sourcerock. A lot of oil and gas in each phase can be sealed. It is favorable for oil and gas to accumulate and form oil and gas reservoirs. It is the basical cause that there are many oil and gas reservoirs in K_1n~2.