“西气东输”探明天然气的地球化学特征及资源潜势

"西气东输"是西部大开发宏伟工程之一.第一期输气目标为120×108m3.供气基地主要为西部四大盆地, 特别是其中的塔里木盆地.塔里木盆地剩余可采储量3397×108m3,基本满足了第一期工程对资源储备的要求.但随着西气东输工程的完善和全国对天然气需求的增大,提供更充分的资源保证是地学工作者光荣而艰巨的任务.研究四大盆地主要大中型气田地球化学特征,对此有积极意义.研究表明:塔里木盆地以几个前陆盆地的煤型气为主,四川盆地以川东为过成熟油型为主,鄂尔多斯盆地以台盆型煤型气和高-过熟油型与煤型复合气为主,柴达木盆地则以低演化煤型气为主.特别是前三个盆地,其资源潜势很大,都可能在短期内成为探明储量突破万亿立方米的大气区.它们不仅会为西气东输,而且将我国在今后5至15年间,天然气产能达500×108m3和1000×108m3作出重大贡献。

Geochemical Characteristics of the Proved Natural Gas for the Project "West Gas Transporting to the East"and Its Resource Potential

West gases transporting to the east China is one of huge proj ects related to the development on the west China.The amount of first transportation gas that is 120 billion m3 will be provi ded by four basins in the western China especially Tari m basin.The remnant gas excavated in the basin is 3 397 > 108m3, basically satisf y the demand reCuired by the first phase of the proj ect.To provi de such enor mous resources is still in need of arduous assignment of geologists.The geochemical study on four basins,mainly including large- mi ddle basins,is very significant for reaching this goal. The results showthat the nat ural gas fromcoal was mostly generated in several foreland basins in Tarimin basin,China ;and the gas from high rank oil of Chuandong region existed mainly in Sichuan basin,China ;the natural gases of platform basin are the gas fromcoal and the composite gas from high-excessive rank oil gas and coal in Ordos basin China ;the gas of the Gai dam basin mainly came fromthe lowrank gas from coal.The resource potential is optimistic in the first three basins where may be found more than trillion cubic meter natural gas in the near furure.They will contribute to not only the west gases transporting to east region project, but also to our natural gas industry,and the amount of natural gas will be increased more than 500 billion m3 and 1000 billion m3 in the future five and fifteen years,respectively.