合肥盆地重磁资料处理及重磁震联合反演

合肥盆地自1958年开始历经3次区域普查,近年来胜利油田又加大了对该盆地的投资力度,投入了大量资金开展地震、非地震勘探——覆盖全盆地的高精度重磁、化探及纵横贯穿全区的8km×8km二维地震测网与8条电法剖面。作者针对该盆地的勘探现状,利用丰富的重磁电资料,打破以往常规处理的模式,重点进行了重磁资料的目标处理,快速准确地提取了该区区域构造、局部构造及断裂的重磁异常信息和电性特征,并绘制了相关图件,为合肥盆地的油气综合评价提供了可靠而翔实的依据,并总结归纳了一套适合新区勘探的重磁处理新思路;同时,针对合肥盆地物性数据欠缺但物探资料丰富的特点,创立了不依赖物性参数的统计推断反演方法,综合全区31条地震测线资料和全区重磁数据建立起统计关系式,反演计算出其印支面埋藏深度,成功地绘制了重磁震联合反演印支面构造图,细致刻画了地震测网未涉及区域的构造分布形态;另外,应用LCT软件对HF-700、HF-340进行了重磁电震的联合解释,取得了较好的地质效果。

THE GRAVITY AND MAGNETIC DATA PROCESSING AND THE INTEGRATED GRAVITY, MAGNETIC AND SEISMIC INVERSION OF THE HEFEI BASIN

The Hefei Basin has experinced three regional reconnaissance survey since 1958. In recent years, Shengli oilfield increased investment to the basin and threw in a large amount of funds to carry out seismic and nonseismic exploration, including the high-precision gravity, magnetic and geochemical prospecting covering the whole basin, a 8km×8km 2-D seismic measuring network running through the whole area in length and breadth and eight electrical profiles. In view of the exploration situation of the basin, a wealth of gravity, magnetic and electrical data were used to focus on the target processing of gravity and magnetic data instead of routine processing models.The gravity and magnetic anomaly information and electrical characteristics of regional tectonics, local structures and faults in this area were obtained rapidly and correctly, and the related graphs were drew. This provided reliable, full and accurate bases for the comprehensive hydrocarbon assessment of the Hefei Basin, and resulted in a new set of thinking about gravity and magnetic processing suitable to new area prospecting. Meanwhile, as the Hefei Basin was short of physical property data and rich in geophysical data, a statistical deduction inversion methoel which did not rely upon physical property parameters was proposed. Combined with the 31 seismic traverse data and the gravity and magnetic data of the whole area, a statistical relationship formula was established, the burial depth of the Indosinian discontinuity was calculated by inversion, the integrated gravity, magnetic and seismic inversed Indosinian discontinuity structural mep was drew successfully, and the structural distribution patterns of the areas not involved by the seismic measuring network were depicted in detail. Basides, HF-700 and HF-340 two sections were subjected to integrated gravity, magnetic, electrical and seismic interpretation, and well geological effects were obtained.