中国大中型气田成藏的主控因素及勘探领域

研究大中型气田成藏的主控因素及勘探领域,对于中国天然气工业的发展有重要意义。中国目前只在西部、中部、东部及近海4个含气区11个盆地有储量大于100×108m3的大中型气田[统计不包括南海南部含气(油)区及台湾省]。结合中国的地质条件,总结了中国大中型气田形成的10条主控因素,其中充足的生气量、较高生气强度的富气凹陷以及大区域良好的封闭保存条件是形成大中型气田诸多地质因素中最为重要的地质因素。据天然气资源的探明程度,今后相当一段时间仍应以四川、鄂尔多斯、塔里木、莺琼、东海、柴达木、准噶尔以及松辽、渤海湾盆地深部为重点,并以中西部前陆盆地、中古生界碳酸盐岩气和煤成气、近海及东部含煤-含气(油)盆地及深部湖相泥岩气、具有二次生气及良好保存条件的中古生界煤系及碳酸盐岩系为重点勘探领域,并要重视广义生物气的勘探与研究工作。

Main control factors of large and medium gas fields and exploration domains in China

Study of the main factors controlling the reservioring of large and medium gas fields and the exploration domain have important significance to development of gas industry in China.Large and medium gas fields with reserves of over 10 BCM have only been discovered in 11 basins in 4 gas-bearing regions in western,central,eastern and offshore China(excluding gas/oil bearing region in southern part of South China Sea and Taiwan province).In combination with the geologic conditions in China,ten main factors controlling the formation of large and medium gas fields are summarized,of which sufficient amount of gas generation,gas-rich sag with high gas generation intensity and good regional sealing and preservation conditions are the most important geologic factors.According to the situation of gas resources having been explored,the deep formations in Sichuan,Ordos,Tarim,Yingqiong,East China Sea,Qaidam,Junggar, Songliao and Bohai Bay basins should still be taken as the key exploration targets for a certain period of time.Gas exploration should be focussed on the foreland basins in west-central China,gas and coal-type gas in Meso-Paleozoic carbonates,(coal-and) gas/oil-bearing basins in eastern and offshore China and gas in deeply buried lacustrine mudstones,and Meso-Paleozoic coal measures and carbonates having the ability of secondary gas generation and good preservation conditions.Importance should also be attached to exploration and research of generalized biogas.