摘要
石炭系是川东的主力产气层，为扩大其勘探领域，寻找更多的大中型气田，开展了开江古隆起石炭系成藏条件及气田分布规律研究。通过研究，建立了石炭系储层孔隙演化、烃源岩生、排烃演变及古地温、古地温梯度三种模型，确定了各地史时期构造对烃类运、聚的控捕范围，并进行聚集量的定量计算，从而得出：开江古隆起自海西期形成，印支期基本定形，燕山期继续发展，是个长期继承性的叠隆起。石炭系自印支期起开始聚集油气，初期以聚油为主，晚侏罗世以聚气为主，至燕山期末在古隆起东西两侧形成了储层尖灭与古构造共同控制的气田。喜山期川东全面褶皱，形成现今构造，天然气重新分配，形成现今气田。这些气田的含气面积往往超出构造圈闭范围，形成地层一构造复合型大气田。因此，开江古隆起的石炭系是大中气田群的分布区。研究认为，目前应把五百梯、龙安场、云龙场－沙河铺及檀木场－沙罐坪等地区作为主要勘探目标。
Carboniferous system is the main gas-producing zone in East Sichuan.In order to expend the exploration areas and find out more large-middle scale gas fields,researches have been done on the forming conditions of reservoir at Carboniferous polaeohgh in Kaijiang and the distribution law of gas fields. Based on the researches,three kinds of model are built,they are the models about pore evolution in Carboniferous reservoir;the form and expulsion of hydrocarbon in source rock;pelaeogeothermal and palaeogeothermal gradient.Through research,the control and trap range of structure of different geologic epoch on hydrocarbon migration and accumulation are determined.By quantitative calculation of accumulation,we get the idea that the kaijiang palaeohigh was formed in Haixi epoch;formed into a pattern in Indosinian epoch;and want on developing in Yanshan epoch,it's a long term succession imbricate rise.The oil-gas accumulation in Carboniferous began from Indosinian epoch. In early period,the main accumlation is oil;at late Jurassic,it's gas.To the end of Yanshan epoch,a gas field controlled by stratal pinch-outs and palaeostrueture was formed on the east-west flanks of the pelaeohigh.During Xishan epoch,folding began in East Sichuan and developed into the present structure,Natural gas was re-distributed too,and formed the gas field today.The gas-bearing areas of these gas fields always exceed the range of structural trap to form the large formation-structure composite system.So,the Carboniferous at kaijiang palaeohigh is the distributive district of large-middle scale gas fields group.At present,we should take Wubeiti,Longanchang,Yulongchang-Shahepu and Tanmuchang-Shaguanping as the main exploration targets.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
1995年第4期1-5,共5页
Natural Gas Industry
关键词
四川盆地
古构造
油气田形成
油气勘探
碳纪
Sichuan basin
East
Carboniferous
Palaeostructure
Large-scale gas field
Form
Exploratory area.
