柴达木盆地冷湖七号构造成藏分析及勘探意义

应用成藏系统论的的研究思路,从成藏条件、成藏过程及它们之间的组合关系对冷湖七号构造的油气分布规律进行了深入探索。深层不可能形成规模岩性油气藏,是因为油气在大量生成及运移时,砂体上倾方向没有遮挡,不具备储集功能;深层不可能形成构造圈闭油气藏,是因为油气在大量生成及运移时构造圈闭还未发育而成;浅层形成次生规模天然气藏的可能性不大,是因为在浅层圈闭形成后烃源岩的供烃能力衰竭,而且油气再次分配时缺乏深层来源。圈闭的有效性是该区油气成藏的主控因素,有利构造圈闭在马海大红沟隆起区和昆北斜坡带,有利岩性圈闭在赛什腾凹陷,潜伏地区是首选目标。

Hydrocarbon Accumulation Analysis and Exploration Significance of No.7 Lenghu Structure in Qaidam Basin

The reservoir forming theory is used to deeply study the reservoir forming conditions,its rules and the relations,combination between them and effects on the hydrocarbon distributional rules,lithologic reservoirs can not be formed in deep strata because the up-dip sandbodies could not be sheltered as hydrocarbon is generated and migrated at a large scale,of which accumulation functions are not available;structural trap reservoirs can not created in deep strata,this is because the structural traps are not formed as the hydrocarbon is generated and migrated at a large scale,it is not highly possible for forming a secondary scale of gas reservoirs in shallow strata,because of depletion of hydrocarbon supply capacity of the source rocks after the shallow traps formation, and deep resources are lacked as hydrocarbon is reallocated.The effectiveness of the traps is the major constraining factor of reservoir forming in the area.The beneficial structural traps are in Mahai-Dahonggon uplift area and Kunbei slope belt,while the beneficial traps are in Saishiteng Depression,thus the potential area is the major target.