ASSESSMENT OF WELL COMPLETION QUALITY IMPACT ON THE VOLUME OF EXPLORED BALANCE RESERVES OF HYDROCARBONS

Abstract

Link for citation: Katanov Yu.E., Yagafarov A.K., Aristov A.I. Assessment of well completion quality impact on the volume of explored balance reserves of hydrocarbons. Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 9, рр. 91-103. In Rus. The relevance. Traditional methods of hydrodynamics are sufficiently unambiguous to find out how much the actual productivity of the reservoir differs from its potential productivity. Such estimation was not quite satisfied with the production, especially in the conditions of exploration works, where the objectives of achieving the potential productivity of the object, as a rule, are not set during the test. The emergence of requirements of economic nature to the results of the test has further limited the scope of its application. There was an urgent need to create such a methodological approach, which would allow assessing the quality of the activities carried out not by discrete values, but on a continuous scale. For this purpose, the authors proposed to use the «desirability» function, which is widely used for quantitative assessment of the quality of any technological processes. The essence of the approach consists in converting the actual indicators into a dimensionless scale of «desirability», which can be used to assess their qualitative level. The main aim of the work is to develop a primary geological and technological model to assess the impact of well completion quality on the volume of explored balance reserves of hydrocarbons. The objects of the investigation are productive sediments of the Pokurskaya, Vartovskaya, Megionskaya, and Vasyuganskaya formations. Methods. The geological efficiency of exploration works on the basis of retrospective analysis was investigated. The relationship between the productivity factor, complex geophysical parameter, underbalance at development and the depth of the bedrock bedding was investigated through associative analysis and mathematical modeling. Geological and technological modeling was carried out to find the optimal underbalance to cause cost-effective hydrocarbon inflow. Results. The well completion quality estimation scheme was formed. Correlations of optimal underbalance level of significance 0,05 were obtained. The «desirability» function was used to translate the actual productivity coefficient to the «quality level», resulting in a system of equations for the minimum cost-effective productivity coefficient.