A comprehensive analysis of geophysical well logging data in the study of low-resistivity thin beds

Based on Geophysical Well Logging (GWL) data, the study of thin beds promotes the significance of efficiency improvement in the interpretation results of geophysical materials, at the stages of both prospecting and exploration and development of oil-gas fields. One of the primary objectives in evaluating hydrocarbon reservoirs is to build a detailed reservoir model. A case study was carried out using GWL, Core Sample Analysis (CSA) and complex geological-geophysical data from several fields. Based on a novel methodical approach for analyzing and interpreting the geological-geophysical data referred to the heterogeneous thin beds with low-resistivity in the studied areas, the key factors affecting indicator parameters of layers were determined and their hydrocarbon saturation was estimated. A comparison of interpretation results of GWL based on a novel methodical approach with Perforation Inflow Test Analysis was carried out to assess the determining reliability in terms of saturation of heterogeneous thin beds in well sections. As illustrated in the correlation scheme derived from wells in a few reservoirs, layer alternations in the lower part of the NKG were identified through self-potential and gamma ray log responses. In certain wells, these variations appeared to be minimal. It is important to mention that resistivity curves are influenced by numerous factors, including measurement conditions within the borehole—such as temperature, pressure, and borehole size—as well as the properties of the formation water. The obtained results will allow for increased efficiency in the comprehensive analysis of GWL data and in general, effective field development. Keywords: Geophysical Well Logging; heterogeneous; thin beds; low resistivity; a novel approach; saturation; evaluation; Perforation Inflow Test Analysis.