崖13-1气田成因浅析

Genetic analysis of YA13-1 gas field

ＴＥ１１２．１ ２００００４０９崖 １３－１气田成因浅析［刊］／崔护社，仝志刚… ／／石油勘探与开发．－２０００，２７（４）．－４５～４８ 崖１３－１气田是迄今中国海域发现的最大气田，有关其天然气来源问题目前仍有争论。结合地质和地球化学研究成果，运用ＰｒｏＢａｓｅｓ盆地数值模拟系统定量模拟气田西侧的莺歌海盆地和东侧的琼东南盆地的构造、地温及孔隙流体压力的演化过程。模拟结果表明：崖１３－１气田区东西两侧盆地（或凹陷）构造演化和温度场、压力场演化的特征都有明显差异；气田区附近的异常超压是莺歌海盆地异常超压流体系统的一部分，因欠压实、水热增压以及黏土矿物脱水的综合作用而产生；１号断层（气田区段）是热流和高压释放带，亦是流体和烃类运移的通道，莺歌海盆地异常高温高压可以驱使烃类及流体由深向浅、自西向东进行大规模的长距离运移。据此得出结论：崖１３－１气田的天然气既来自西侧的莺歌海盆地下第三系烃源岩（早期）与上第三系烃源岩（晚期），也来自东侧的崖南凹陷下第三系陵水组、崖城组烃源岩（晚期），是双向供气形成的混源气田。图７参２（崔护社摘）

Combined the geological and geochemical research results, the genetic analysis of YA13-1 gas field has been done by means of the basin modeling, from that we can obtain the following conclusions: ①The evolution discrepancy of basin structure and the temperature & pressure fields of YA13--1 gas field in Ying-Qiong basin can be seers ②The overpressure of YA13-1 gas field is a part of the Yinggehai' s, which is resulted from Several effects including the undercompaction, aquathermal pressuring and semectite dehydration. ③The No. 1 faulted zone in YA13-1 gas field is a release are for heat flow and overpressure fluid. It is also a migration pathway for fluid and hydrocarbon. ④ The gas of YA13-1 gas field is from mixed sources, and the gas generated from the Neogene formation (late stage) or the Paleogene formation (early stage) in Yinggehai basin and the Paleogene formation (late stage) in Qiongdongnan basin.