3D stochastic joint inversion of borehole gravity and gravity gradient data using cokriging

Gravity gradiometry has come to be a useful tool for both the mining and hydrocarbon exploration areas. Given borehole gravity has recently been used in mineral exploration with the advent of slim-hole gravimeters, it is logical to perform joint inversion to fully utilize the information in the newly acquired data. The inversions were carried out using cokriging that is a geostatistical method of estimation that minimizes the error variance by applying cross-correlation between several variables. The example presented demonstrates that the ability of the method to include the geological information and physical property from borehole measurements in the inversion. The results also show that the depth resolution of gravity gradient inversion can be significantly improved by including borehole data. Moreover, compared with inversion using only borehole data, incorporating gravity gradient data increases the lateral resolution of the recovered density model.