Cyclic Gas/Steam Well Stimulations: Field Results

Abstract

ABSTRACT The paper is an addition to those presented at and published by the 5th and the 6th European Simposia on Improved Oil Recovery held in Hungary and Norway. Included in the paper are results of laboratory and field studies on cyclic stimulation of bottom-hole formation zones containing high-viscosity oil by gas-steam heat-carrier. The paper presents the last data on performance of the wells after the 1st and the 2nd cycles of stimulation of bottom-hole formation zones. Cyclic stimulations were conducted in a pilot area of Zybza-Gluboky Yar oil field, Krasnodar Territory. Pontian deposits of the field contain oil of 300÷420 cp @ 325K at the depths of up to 500 m. The paper presents results of laboratory studies on oil viscosity variation by dissolving CO2 in the oil for the temperature range of 298-373K at 8 MPa pressure. There are also data on gas-steam generating unit performance under extreme northern conditions in Usinsk oil field (Komi Republic) in the paper. The field contains high-viscosity oil that occurs in carbonate reservoirs at depths of above 1500 m. The paper presents results of field testing of the gas-steam generator and variants of both surface and well-bottom operation. Provided by the paper are analysis and generalization of the obtained results.