FORMULA FOR THE DURABILITY OF OIL AND GAS FIELDS

Abstract

The article is concerned with the issues of the status and results of long-term development of oil and gas fields, with consideration and justification of the factors that influence the extension of their further cost-effective development. To evaluate the potential factors of “plant life extension” of hydrocarbon reservoirs, the Munaily field in above-salt deposits of the southeastern part of the PreCaspian Depression has been designated as a pilot option. Pursuant thereto, the sequence of the major stages in the study and development, as well as the specific features of this field are provided. The forecast made by the authors for the longevity of field production is based on the factor of natural replenishment of reserves, which can be achieved through the establishment of certain restrictive measures and observance of the optimum operation mode appropriate for the conditions of each particular field. This refers to the setting of optimal oil withdrawals, the average daily flow rate of the well, etc. Determination of this pattern and its use in practical terms has favorable historical prerequisites, which is confirmed by the example of numerous objects under development in Russia and Kazakhstan. When substantiating this forecast, the main features of the geological structure of the Munaily field have also been taken into account, among which considerable importance in evaluating the mode of occurrence and productivity of above-salt deposits in the Pre-Caspian Depression is given to the presence and impact of underlying complexes of sediments. This concerns the salt-bearing section of the Kungurian age, the subsalt Paleozoic strata, and the influence of fault tectonics, which contributes to the development in the field section of certain oil and gas feed channels due to disturbances of various order, zones of decompaction, and fracture porosity of the rock formations. Following the results of the analysis, the necessity of compliance with the rehabilitation cycle of 10-15 years has been substantiated, which allows restoring the internal indicators of the energy state and the volume of hydrocarbons in line with the existing model of the reservoir (trap) of the field to the level at which the continuation of further cost-effective development is possible.