陕北地区中生界石油补偿成藏规律研究

陕北地区是鄂尔多斯盆地石油的主要产地,分布有中生界三叠系和侏罗系油藏.研究结果表明,陕北地区中生界油藏的形成和分布受补偿成藏规律控制.油藏的形成是不同成藏要素相互补偿作用的结果,不同层位油藏之间的成藏条件有补偿关系,长6、长2以及侏罗系油藏在平面分布上具有相互补偿规律.长6油藏主要分布在油源岩有利区,在封、盖良好的地区油藏可连片发育,以岩性圈闭为主.长2油藏受长4+5盖层、长1盖层的共同控制,在一定程度上还受鼻状隆起控制,油藏平面分布密度变小.侏罗系油藏的分布除了受下伏地层中盖层的控制外,受到构造控制的程度更高,油藏规模小,并呈零星分布.

Compensatory petroleum accumulation rules in the Mesozoic of Shaanbei area

The main source rocks and reservoirs of Ordos Basin are located in Shaanbei area, where developed Triassic and Jurassic petroleum pools of the Mesozoic. The forming of oil pool depended on the compensation of those accumulation factors and was also controlled by the compensation of oil deposits in different formations. The locations of Chang 6 Member, Chang 2 Member and Jurassic reservoirs were compensated in section. Most oil-bearing intervals in Chang 6 Member are lithologic traps, which developed in the favorable areas of source rocks. The oil-bearing interval of Chang 2 Member was controlled by the cap rocks of Chang 4-Chang 5 Member and Chang 1 Member,and also controlled by the nose-type uplift to an extent. The distribution of the Jurassic reservoirs was controlled by the underlying cap rock and structures.