Study of Hydro-Sand-Blast Perforation Characteristics of Wells on Depleted Gas and Gas Condensate Fields

Abstract

The causes and nature of the well bottom-hole zone contamination on depleted gas and gas condensate fields were characterized. It is shown that under conditions of reduced formation pressure it is not possible to ensure cleaning of the formation bottom-hole zone using the formation gas flow. The application of hydro-sand-blast perforation as one of the most effective methods to improve the hydrodynamic connection of the well and formation was grounded. The types, nature and technology of hydro-sand-blast perforation of wells were described. The
analysis of hydro-sand-blast perforation efficiency and its impact on wells within the terms of natural, technological and technical factors (rock strength in compression, diameter and spatial arrangement of nozzles in the perforator, differential pressure in the nozzles, flow rate) was performed. It was shown that the conventional technology of hydro-sand-blast perforation of wells, using SAS water solutions as sand carrier agents, a significant amount of fluid is absorbed by the formation. The absorbed fluid is quite difficult to remove from the formation during further
well development. As a result, after the well development, it often works with a smaller gas flow rate, than before perforation. Possible types of sand carrier agents for hydro-sand-blast perforation (SAS water solutions and polymers, various types of emulsions, water-gas mixtures, foam systems, liquefied gas). The analysis of experimental studies of water-gas mixtures for well hydro-sand-blast perforation. The application of nitrogen foam for hydro-sand-blast perforation of wells was justified, perforation technology using foam was described. The calculation results and parameters of hydro-sand-blast perforation and gas hydro-sand-blast perforation of well 812-P of Monastyrchanske condensate field was presented, indicating a greater technological efficiency of well gas hydro-sand-blast perforation.