EXCAVATION METHOD OF BITUMINIC DEPOSITS WITH GAS CAP Russian patent published in 2017 - IPC E21B43/24 E21B7/04 

FIELD: oil and gas industry.

SUBSTANCE: in the excavation method of bituminic deposits with gas cap, which includes the drilling of horizontal wells with the rising profile of horizontal shafts, the steam and gas injecting into the productive formation of the deposit in the cyclic mode, warming up of the formation, selection of products from the indicated horizontal wells, according to the drilling data of the indicated horizontal wells determine the presence of gas cap and clarify the structure of deposits, in the deposit dome part the vertical production well is drilled and it is punched in the formation roof, through this well the gas is selected from the gas cap and sent to the container for gas collecting. After warming up of the formation the horizontal wells is operated in the cyclic mode, at that each cycle consisting of the following stages: injection of the steam - mixture injection consists of steam and gas extracted from the gas caps - the selection of products. The ratio of steam P and gas G in the injected mixture is taken as P:G = 5-50:1, and the steam-gas injection cycle time - not less than 10 days, in order to maintain the given ratio of working agents, its mixing and injection frequency of the produced gas from the mentioned container, and the steam from the steam generator is supplied to the booster unit from which the mixture is pumped directly into the horizontal wells. After the start of the cyclic mode of deposit excavation the injection ratio of the liquid and gas amount by injection in the amount of steam and steam-gas is maintained at the deposit at the level of 40-100% per one cycle. After breaking into the gas cap of the injected steam and/or steam-gas, the gas selection from the vertical well is transferred to the periodic mode, determined by the time required for the gas in the gas cap redistribution into the dome part of the deposit, thus developing the deposit in steam-gas-cyclic drainage mode.

EFFECT: increase of field bituminic oil recovery with a gas cap.

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