Magnetic mapping and soil magnetometry of hydrocarbon prospective areas in western Ukraine

Abstract

Magnetic measurements in a number of hydrocarbon structures suggest the existence of local magnetic anomalies with certain nT amplitude reflecting the structure contours of the oil and gas deposits, which could therefore be used as a criterion for identifying hydrocarbon traps. Hydrocarbon migration and the microseepage effect changing the composition of magnetic minerals and reaching as high as the near-surface areas and soils cause local magnetic anomalies and changes in the magnetic properties of soils. Magnetic studies on the Orchovychi oil and gas field, Carpathian Foredeep, Western Ukraine, revealed specific features of the local magnetic field and the magnetic properties of soil. A local magnetic anomaly with amplitude of 6-8 nT and a width of about 4 km was detected in the structure of the magnetic field within the Outer zone of the Carpathian Foredeep. The anomaly relates to hydrocarbon deposit areas with complex morphology. Magnetic susceptibility (MS) of soils in the Orhovychi oil and gas field showed a close correlation with landscape changes. Soils were found to show magnetic susceptibility anomalies in close proximity to productive hydrocarbon areas.