塔里木盆地下古生界成藏控制因素及勘探思路

Controlling Factors and Exploration Idea about Reservoir Formation of Lower Palaeozoic,Tarim Basin

塔里木早古生代时并不是一个统一的盆地,在其后的发展演化历史中,又经历了多期成盆、多期发育与多期改造,从而最终成为叠合型盆地。这样的盆地发育特点造成塔里木盆地下古生界的多源生烃、多期生烃、多期运聚、多期成藏和多期改造。塔里木盆地下古生界油气成藏控制因素可以概括为"源控、隆控、坡控、面控、断控和相控"。与中国东部中、新生代原型盆地的"定洼选带"相比,其勘探思路应该是"定源选带"。在确定有效烃源灶的基础上,通过断层、不整合面以及输导层的研究确定与烃源灶有关系的有利勘探区带,根据烃源岩的热演化程度确定有利区带的勘探战略是以油勘探为主、气勘探为主还是油气并举。

Tarim Basin in Early Palaeozoic was not a uniform one,and after then it underwent multi-stage basin formation,multi-stage development,and multi-stage reconstruction.Finally it evolved into an overlay one.As a result,the Lower Palaeozoic of the Basin was characterized by multi-source hydrocarbon generation,multi-stage hydrocarbon generation,multi-stage migration and accumulation,multi-stage reservoir formation and multi-stage reconstruction.The factors controlling the oil-gas reservoir formation of Lower Palaeozoic could be summarized as òsource control,uplift control,slope control,surface control,fault control,and facies controló.Compared to the exploration idea of òselecting zone by determining bottomó of primary type basins of the Mesozoic and Cenozoic era in East China,the exploration idea of Tarim Basin should be òto select zone by determining sourceó.On the basis of confirming effective hydrocarbon kitchen,through the study and determination of fault,unconformable surface,transport layer,and the favorable exploration zone related to hydrocarbon kitchen,the exploration strategy of favorable zone might be determined as òdominated by exploration for oil,gas,or oil and gas simultaneouslyó,according to the thermal evolution degree of source rocks.