Abstract In order to realize the inversion of multi-density interface in complex model, a multi-interface inversion method based on potential field separation and downward continuation was proposed on the basis of previous inversion methods. Firstly, a multi-interface complex inversion model was designed. It was considered that Bouguer gravity anomaly was mainly generated by the undulations of every density interfaces, and the average depth of the top interface of the density layer was set as the datum plane of its bottom interface. Then, the gravity anomaly generated by each density layer on the ground was separated from the Bouguer gravity anomaly using the cutting method. In order to improve the convergence of Parker-Oldenburg inversion method, the method for downward continuation of potential fields with a larger continuation depth was used to extend the anomaly to the datum plane. Finally, Parker-Oldenburg inversion method was used to realize accurate inversion of each interface. The inversion method was proved to be feasible using a model experiment. Through the application of this method in Tuanbo-Dasi area, Tianjin, the potential field separation of Bouguer gravity anomaly, the downward continuation of the separated anomaly and the inversion of each interface were effectively realized with the help of the existing fracture system, drilling holes and the collected physical property data in the area. Virtual boreholes were made using seismic and MT results with high resolution in vertical detection in order to make up for the shortage and uneven distribution of boreholes, and in addition to the existing borehole data, the accuracy of the inversion interface depth was evaluated, which proved that the inversion result and the inversion method were reliable.
This work was supported by Research Projects of Tianjin North China Geological Exploration Bureau (HK2018-B4-4) and Tianjin Municipal Bureau of Planning and Natural Resources (TMBPNR2018-13).
About author: Zheng Guo-Lei, a senior engineer, graduated from Lanzhou Institute of Seismology, China Earthquake Administration in 2010. His main research interests are gravity inversion, signal processing and 3D visual modeling.
Cite this article:
. Research and application of multi-interface inversion based on potential field separation and downward continuation[J]. APPLIED GEOPHYSICS, 2018, 15(3-4（2）): 668-681.
2018, Vol. 15 
