残留盆地油气系统研究方法——以中国南方中、古生界海相地层为例

通过对南方中、古生界油气地质综合研究及勘探成果总结,初步提出一套改造型残留盆地或叠合盆地的油气系统研究方法,其核心思路是强调进行油气地质的“动态演化”研究,主要通过拟三维盆地模拟反演主要烃源岩的时空演化、生烃过程及其不同地质阶段中的生烃强度、资源量,结合古今油气藏解剖分析油气成藏—破坏规律及古构造分析研究油气运聚指向,结合主要构造运动期对南方中、古生界主要油气系统进行了分阶段的动态演化研究,认为南方中、古生界油气勘探的现实对象是次生油气系统及再生烃油气系统,现存的原生油气系统很少,提出南方中、古生界油气勘探有利区为川东北大巴山前缘及石柱复向斜西侧高陡背斜带、苏北盆地阜宁—盐城—海安—兴化—宝应地区、江汉盆地沉湖地区南部潜江—仙桃—牌州—汊参1井地区、江西南鄱阳盆地及云南楚雄盆地北部凹陷,这一认识已经得到苏北盆地盐城凹陷朱家墩气田及江汉盆地沉湖地区南部开先台西含油构造勘探发现的证实。

Methods for the Study of the Petroleum System in Remnant Basins-A Case Study of Mesozoic and Paleozoic Marine Strata in Southern China

Through an integrated study of Mesozoic and Paleozoic petroleum geology in southern China and summing-up of the exploration results, the authors put forward a set of methods for the study of petroleum systems in re-worked remnant basins or superposed basins. Its main concept is emphasizing the study of the "dynamic evolu-tion" of petroleum systems. The spatio-temporal evolution, hydrocarbon-generating process and hydrocarbon-generating intensity and resource amount in different geological stages of chief hydrocarbon source rocks are de-duced by performing 3-D basin modeling. The regularities of formation and destruction of oil-gas deposits are summarized by analyzing the old and existing oil-gas deposits. The migration and accumulation orientations are studied by the analysis of paleo-structures. The dynamic evolution of chief Mesozoic and Paleozoic petroleum systems in southern China during main tectonic movements is studied. The authors suggest that the realistic ex-ploration targets of Mesozoic and Paleozoic petroleum systems in southern China are secondary petroleum sys-tems and regenerated petroleum systems. As the existing primary petroleum systems are scarce, the authors suggest that the favorable perspective exploration areas of Mesozoic and Paleozoic petroleum systems in southern China are the high and steep anticlinal belt in the front of the Daba Mountains and on the western side of the Shizhu synclinorium, northeastern Sichuan, the Funin - Yancheng - Hai'an - Xinhua - Baoyin area in the Shubei basin, the Qianjiang - Xiantao -Paizhou - well Chacan 1 area in the southern part of the Jianghan basin,the Poyang basin in southern Jiangxi and the northern depression of the Chuxiong basin in Yunnan. This view has been supported by the exploration of the Zhujiadun gas field in the Yancheng depression of the Shubei basin and the Kaixiantaixi oil-bearing structure in the southern part of the Jianghan basin.