METHOD OF COMPLETION OF WELL WITH FORMATION FLUID LEVEL BELOW TUBING SHOE UNDER CONDITIONS OF ABNORMALLY LOW FORMATION PRESSURES Russian patent published in 1998 - IPC

FIELD: development of gas and gas-condensate fields at the final stage of well operation; may be used in completion of well with high stage of gas presence (300-500 m). SUBSTANCE: method includes injection into well of anionic or nonionic surfactant or their mixture in the amount sufficient for formation of stable foam of formation fluid. Well is closed and excessive pressure is built up at wellhead meeting the conditions specified in the invention description. Introduced into pipe space successively are gas-forming agent, for instance, ammonium carbonate and acid, for instance, 24-% hydrochloric acid solution in stoichiometric quantities. Annular space is communicated with high-pressure gas main line, and pipe space is connected with flare line up to ceasing of foam flowing out. Efficiency of removal of formation fluid from self-killing wells is increased due to water encroachment under conditions of abnormally low formation pressures (below 0.5 of hydrostatic pressure) when formation fluid level is below tubing shoe and tubings are above interval of perforation of producing formation. EFFECT: higher efficiency.