New unconventional techniques for potential field data inversion and interpretation / Mohamed Abdrabou Radwan Mousa ; Supervised Mohamed Hassan Khalil , Maha Abdelazeem Mohamed

Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Geophysics

Degree: Master of Science in Geophysics Geophysical inversion has been a significant and successful tool in both petroleum and mineral industries. My thesis is focusing on the unconventional techniques of potential field data inversion in Geophysics. Inversion is known as a very powerful tool for parameter estimation of buried objects, however, due to the need for accurate and plausible solution to the inverse problem, the conventional inversion techniques are found to be not enough to meet the present goal. To achieve that, Whale Optimization Algorithm (WOA) was applied to solve the inverse problem of self-potential (SP) data resulted from 2D inclined sheet which is a common model in mineral exploration and shear zones. Single objective function was minimized and also multi-objective functions minimized to find the optimal solution of these problems (i.e. to estimate electrical properties of rocks, their depths and shape from their SP fields and comparison with present techniques). Also, the meta-heuristic algorithm (WOA) was extended for performing stable and plausible inversion of SP data resulted from ideal buried structures such as: sphere, horizontal and vertical cylinders and multiple sources. WOA was extended also for ore and mineral investigation.This proficient algorithm is suggested for the elucidation of magnetic field data resulted from simple shaped subsurface geo-bodies like a thin dike, a dipping dike, and a vertical fault. In addition, a hybrid algorithm merging a bat algorithm (BA) with the preconditioned conjugate gradient (PCG) method is suggested as a mean for inverting surface gravity anomalies to obtain the density distribution in the subsurface. In this thesis, twenty-two real field anomalies are studied

Issued also as CD