STRUCTURAL FEATURES OF PARFENOVSKY HORIZON RESERVOIR FORMATIONS OF THE KOVYKTA GAS CONDENSATE FIELD BY WELL LOGGING DATA AND WELL TESTING RESULTS

Purpose. The research is aimed at studying the geological structure of the Kovykta gas condensate field in the Irkutsk region, identifying and outlining of the zones of heterogeneous structure of the productive deposits of the Parfenovsky horizon of the Chorsky formation of the Vendian period as well as the assessment of the need for a revi-sion of the reservoir petrophysical model presented in 2013 when the hydrocarbon reserves of the Parfenovsky horizon of the Kovykta gas condensate field were calculated. Methods. The analysis of calculated parameters distribution (ef-fective thickness, open porosity coefficient) and field characteristics (delivery) of the Parfenovsky horizon reservoirs is performed by the field area and by the section. The differential distributions of effective thicknesses and reservoir po-rosity are compared before and after the division of the Kovykta gas condensate field into the zones with a different type of the Parfenovsky horizon section. Results. The data on the structural features of the Parfenovsky horizon reservoir rocks of the Kovykta gas condensate field are provided. Three types of the Parfenovsky horizon section have been identified. The wells of the Kovykta gas condensate field have been ranked by the type of the Parfenovsky horizon sec-tion and its test results in the open borehole and/or in the drill string. The directions of further study of the structural fea-tures of the Parfenovsky horizon reservoirs have been determined. Conclusions. The Parfenovsky horizon features the presence of reservoirs with improved and degraded porosity and permeability. The presence of the reservoirs different in properties and composition in the Parfenovsky horizon deposits has revealed the need for the revision of the petro-physical model and the methodic base of the integrated interpretation of well geophysical research data presented by the recalculation of hydrocarbon reserves of the Kovykta gas condensate field in 2013.

Parfenovsky horizon, reservoir, test results, well logging

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