空-地-井重力异常正则化协同密度反演方法

围绕综合利用空-地-井多源重力异常联合反演提升精度的目标,提出正则化协同密度反演方法,从而有效利用多维数据的横向和纵向变化特征提高反演精度,且无需先验信息的约束.此外,还提出利用奇异值谱和深度分辨率工具评价航空数据观测高度和层数对反演分辨率的影响.通过理论模型试验本文方法在空-地、地-井等不同情况下的应用效果,结果表明空-地-井重力异常正则化协同密度反演方法能获得更高分辨率、高精度的反演结果,且证明不同的钻孔位置对反演结果有较大的影响,从而可指导实际的空-地-井联合勘探.最后,利用文顿盐丘实际勘探数据进行空地和空地井重力数据协同反演,反演结果垂向分辨率明显优于地面观测数据反演结果,盐盖的顶面及中心埋深与前人研究和地质资料解释相吻合,验证了方法正确性及实用性,为推进我国空-地-井立体重磁勘探提供了重要的技术手段.

Joint regularized density inversion method of airborne,surface and borehole gravity anomaly data

In order to comprehensively utilize the joint inversion of airborne-surface-borehole multi-source gravity data anomalies to improve the accuracy, a regularized density inversion method was proposed, so as to effectively utilize the horizontal and vertical variation characteristics of multi-dimensional data to improve the inversion accuracy without the constraint of prior information. In addition, singular value spectrum and depth resolution plot tool were used to evaluate the effect of observation height and flight layer numbers on inversion resolution. Theoretical model was used to test the application effect of the method in airborne-surface, surface-borehole and other conditions. The results showed that joint regularized density inversion of airborne-surface-borehole gravity anomaly can obtain higher resolution and precision, and proved that different drilling positions have a greater influence on inversion results, which can guide the actual airborne-surface-borehole joint exploration. Finally, using actual field data of Vinton salt dome to carry out airborne-surface and airborne-surface-borehole joint inversion, the vertical resolution of inversion result was obviously better than the inversion result of surface data. The top depth and center depth of cap rock was consistent with predecessors' research and geological interpretation, which verifies the correctness and practicability of the method, and provides an important technical means for promoting three-dimensional airborne-surface-borehole gravity and magnetic exploration in China.