重力-地震联合反演解释技术在拉布达林盆地油气资源评价中的应用

内蒙古拉布达林盆地面积大、油气勘探程度很低.由于浅层广泛分布的火山岩的强反射屏蔽作用造成地震勘探对深层成像差，难以评价盆地油气勘探潜力.为了解决盆地主要目的层上库力组底界深度及沉积岩分布不清的问题，对盆地南部二维地震资料开展重力-地震联合反演解释.通过在GM-SYS重磁剖面解释软件中加载地震剖面，建立重力模型，利用地震浅层可靠解释成果做约束条件，消除上覆火山岩的重力干扰，减少了重力反演深层构造界面的多解性，成功地反演了盆地上库力组底界深度、沉积岩厚度，指出巴彦哈达断陷为有利勘探区，在此基础上估算出油气资源量.

APPLICTION OF GRAVITY-SEISMIC INVERSION IN PETROLEUM RESOURCES EVALUATION OF THE LABUDALIN BASIN

The Labudalin basin in Inner Mongolia covers a large area,yet with a low degree of exploration for oil and gas.Due to the poor seismic imaging for deep strata by the strong reflection shielding effect of widely distributed volcanic rocks in the shallow,it is difficult to evaluate the exploration potential of oil and gas in the basin.In order to recognize the distribution of sedimentary rocks and the bottom depth of the Shangkuli Formation of the target strata in the basin,gravity-seismic inversion interpretation of two-dimensional seismic data is carried out in the south of the basin.The gravity and magnetic model is established with embedding seismic profiles in simulated GM-SYS gravity and magnetic software.The gravity interference of overlying volcanic rocks is eliminated by using the reliable interpretation results of shallow seismic strata as constraints.The multiplicity of deep structural interface in gravity inversion is reduced,and the bottom depth and sedimentary rock thickness of the Shangkuli Formation are successfully inverted.On this basis,the petroleum prospects of the basin are estimated and the Bayanhada fault depression is delineated as a favorable exploration area.