重力、地震联合反演方法确定深层油气藏的分布——以锡林凹陷石炭系分布为例

DECIDING ON THE DISTRIBUTION OF DEEP RESERVOIR BY THE JOINT INVERSION METHOD OF GRAVITY AND SEISMIC DATA ——TAKING THE CARBONIFEROUS IN XILIN SAG AS A N EXAMPLE

文章以内蒙巴彦浩特盆地锡林凹陷为例,说明重力、地震联合反演方法在确定深部生油目的层石炭纪地层的应用效果。巴彦浩特盆地多期构造影响,造成逆冲、剥蚀及断块作用十分显著;在地震资料解释中,同相轴难以追踪或会误追踪。采用2 D重力模型反演与地震走时反演的联合反演对x5,x6线高精度重力与地震资料进行处理,指出了原根据地震资料确定的局部高隆起不是目的层石炭系而是剥蚀殆尽的寒武系;同时还给出了锡林凹陷石炭系的分布范围,避免了勘探风险。

By taking the Xilin Sag in Bayanhaote Basin, Inner Mongolia, as an example, the result of deciding on the deep target zone (Carboniferous) by applying the joint inversion method of gravity and seismic data is introduced in the paper. The thrusting, denudation and fault-block action are very obvious in Bayanhaote Basin owing to the influence of multiphase tectonic movements, so that the event tracing is very difficult or incorrect in seismic data interpretation. Through-processing the high resolution gravity and seismic data of Lines x5 and x6 by applying the joint inversion of the 2 1/5 D gravity data and seismic travel-time data, it was considered that the formation confirmed initially by seismic data at the local uplift is not the Carboniferous, but the completely denudated Cambrian, Meanwhile, the distribution of the Carboniferous in the sag was delimited, thus decreasing the exploration risk.