IMPROVING THE EFFICIENCY OF THE DEVELOPMENT OF OIL DEPOSITS WITH HARD-TO-RECOVER RESERVES IN THE FIELDS OF WESTERN SIBERIA

Abstract

The article proposes well monitoring methods to further improve the efficiency of development and production of hard-to-recover oil reserves (HTR). Various options, on formation of the Lower Cretaceous complex, are considered for example of fields of the Surgut and Nizhnevartovsk vaults. As a result of a detailed study of the geological structure of a number of fields in Western Siberia, mainly considering production wells, the peculiarities of the Jurassic and Cretaceous deposits and their lower parts - the Achimov formation - were formulated, including considered specifics of the previously formed anomalous sections of the Bazhenov formation. Based on the results of the analysis, of structural and total thickness maps, the presence of intensive tectonic movements, during the formation of deposits of the anomalous section of the Bazhenov Formation and the Achimov Formation, was determined. The analysis of the Achimov strata thickness changes in the fields, indicated compensation of the total thicknesses of the Bazhenov Formation and its anomalous section by increasing the thickness of the Achimov deposits, as well as gradual flattening of positive structures as a result of alternate dipping of adjacent blocks along consedimentary faults. All this allows us to consider the Achimov strata as compensatory one. Examples are given on dynamic marker monitoring of flow profiles and composition for horizontal wells in reservoirs with HTR. The feasibility is shown to use monitoring results for optimizing of field development system. Implementation of the proposed approach makes it possible to monitor and optimize the operation of production and injection wells, the field development system, as well as to increase the oil recovery factor due to geological and technical measures, including enhanced oil recovery and oil production stimulation technologies.