Development of an Integrated Approach to Laboratory Research of Filtration, Fracture and Sand Production Processes in Arctic Shelf Gas Reservoirs to Identify Optimal Well Operation Parameters

The paper presents the results of a comprehensive study of fracture, filtration and sand production processes in weakly cemented reservoirs of one of the gas condensate fields of the Arctic shelf of Russia. A modified multidisciplinary scientific method was developed and implemented to solve the problems of ensuring safe operation of wells, validating effective modes of their operation and reducing the risks of sand production. The research methods are based on multilateral study of core material properties by means of geomechanical modeling of mechanical and filtration processes in the vicinity of wells, Thick-walled cylinder type tests to study sand production processes in wells, scanning electron microscopy, micromineralogy, computed tomography and digital core analysis. Special emphasis was placed on the analysis of changes in reservoir structure as a result of sand production processes, taking into account the mineral composition of the matrix and the dislodged sand. Experimental results allowed to determine for the considered field: a) evolution of deformation and filtration properties of rocks in the near-wellbore zone; b) values of critical stresses leading to wellbore wall failure; c) type and nature of rock failure; d) parameters of sand production processes and mechanisms of associated reservoir matrix failure; e) reservoir properties of rocks. Based on the research results, the optimal parameters for safe and efficient well operation have been determined, including allowable drawdown to reduce the sand production risks and maintain wellbore stability; the nature of well contour failure and the risks of damage to downhole equipment; and the optimal characteristics of downhole filters. The results of this research are intended to contribute to the development of technologies for creating new solutions aimed at improving the efficiency of hydrocarbon production, reducing the risks of sand production and wellbore wall failure, deterioration and breakdown of downhole equipment.