Correlating Core Analysis and Well Logging: The Stezyca Oil and Gas Field

摘要

Core analysis and Well logging are two essential procedures undertaken as part of the formation evaluation process which, when used alongside each other can help to determine fundamental properties of a reservoir and how these properties can affect hydrocarbon production. This report aims to provide an overview of these two procedures by considering the numerous properties which can be measured using data provided as well as considering the various types and methods of coring and well logging. The relationship between core and well log data has also been analysed using a case study (STEZYCA OIL AND GAS FIELD, located in Poland). By studying core and well log data acquired from this field, analysing and correlating both sets of data, it is possible to determine important properties such as porosity, permeability, lithlogy and saturation while also reducing uncertainty within the formation. The analysis was performed was on the basis of well log interpretation and core sample description (micro-photographs and cross-sectional view made available). The well logs analysed consisted of data from a Gamma Ray log, Neutron log, Density log, Sonic log and Resistivity log. Three samples have been analysed from the same well. Using the core samples, performing the required laboratory tests to obtain key parameters such as permeability, porosity, saturation, capillary pressure etc., are essential to fully evaluate the formation, but are not always sufficient. Correlation of core and well log data, is an essential process as is analysing and comparing data for calibration to characterise lithology. This is important in order to calibrate the data, reduce uncertainty and as a result, gain a more complete understanding of what to expect within the formation.