石油地球物理勘探2019，Vol.54Issue(2)：461-471,前插8,12.DOI:10.13810/j.cnki.issn.1000-7210.2019.02.026
渭河盆地基底三维变密度重力反演
Basement depth estimation based on gravity anomalies in Weihe Basin with 3Dvariable density contrast model
摘要
Abstract
The depth estimation of the Precambrian basement of Weihe Basin is of great significance for the Paleozoic hydrocarbon exploration in the basin.Unfortunately, there is lack of understanding of the basement depth. The density of each sedimentary layer varies with depth,and it also changes in the horizontal direction. Therefore,the gravity inversion conducted with a constant density contrast cannot accurately delineate the basement depth.We fit the real density contrast of the sediments with 6different density-depth functions according to 5integrated geophysical sections and 3boreholesinformation, which contains the density of every sedimentary layer in different tectonic units.Fitting-error statistical results of different functions indicate that the exponential density contrast-depth function is more coincide with the real density variation in Weihe Basin.Then the decay factorλand the density contrastΔρ0at the surface are extracted from the fitted exponential density contrast-depth functions,and theλandΔρ0in the whole basin are acquired by gridding the discreteλandΔρ0.Thus,the 3Dvariable density contrast model is obtained by combination the griddedλand Δρ0in the whole area.Finally,this variable density contrast model is applied in Precambrian basement estimation of Weihe Basin,and the result indicates that the 3Ddensity could be adopted to obtain a more accurate basement relief than the constant density contrast.This approach provides a strong basic data support for the hydrocarbon exploration in the basin and can also be very helpful for solving similar problems in other basins.关键词
三维变密度模型/重力勘探/盆地基底/密度界面反演Key words
3Dvariable density contrast model/gravity exploration/basement/density interface inversion分类
天文与地球科学引用本文复制引用
冯旭亮,袁炳强,李玉宏,张瑾爱,张林,郭瑞坤..渭河盆地基底三维变密度重力反演[J].石油地球物理勘探,2019,54(2):461-471,前插8,12.基金项目
本项研究受陕西省自然科学基础研究计划项目"渭河盆地及邻区磁性结构及其与氦气成藏关系研究"(2018JQ4034)和陕西省教育厅科研计划项目"基于L0-范数约束的海沟型密度界面反演技术研究"(17JK0617)联合资助. （2018JQ4034）
