Land Magnetic Investigation on the West Qarun Oil Field, Western Desert-Egypt

Abstract

In this study we delineate the subsurface structures within an area of about (35 × 25) km2 in the Western part of Qarun Concession, using magnetic method. The main goal is to understand the role of subsurface structures and tectonics in the petroleum processes. Land magnetic survey has been carried out along profiles covering the area under study. The magnetic data set is processed using horizontal Gradient and tilt derivative. Also, 3D Euler deconvolution and 2D power spectrum have been used as fast techniques for depth estimation. The results indicate that the most predominant tectonic trends are generally aligned in NE-SW for the major structures, while the minor structures are aligned in NW-SE. The depth to the regional basement estimated range around 3900 m, and the shallower structures range around 750 m. The obtained results are in good agreement with the data from drilling wells in the area under study. The RTP magnetic anomalies range between -116 nT and 145 nT. The high values strongly suggest that the near structures (ferromagnetic minerals) accompany the basement along the West Qarun concession. There is good correlation between the structures deduced from the magnetic analysis and the known geological information. Most of these oil accumulations are restricted to the major tectonic trends with a NW-SE and NW-SE directions. We conclude that oil accumulation is structurally controlled by faulting, probably as a result of tectonic regimes during Cretaceous and Jurassic periods.