METHOD OF CAUSING FLUID INTRUSION FROM WELL Russian patent published in 2012 - IPC E21B43/25 E21B43/18 E21B47/06 

FIELD: oil and gas industry.

SUBSTANCE: invention may be used in development of wells with bed pressure of 0.8-1.0 of water column hydrostatic pressure in well. Proposed method comprises running-in of tubing into well, decreasing pressure on productive bed by replacing water column with gas-fluid mix by forcing it with the help of booster unit, and providing required ratio of mix components to reach required pressure on productive bed. Note here that at bed pressure of 0.8-1.0 of water column hydrostatic pressure in well, remote-control depth gage is fitted on tubing bottom end prior to running in. Tubing run-in in well, water column is replaced with gas-fluid mix be injecting it by booster unit, said mix representing higher-density foam including surfactant with minor aeration of 5 to 7 m³/m³. Then, fluid intrusion is initiated by injecting gas-fluid mix in well annular space while higher-density foam is replaced with lower-density foam. Aeration is gradually increased control pressure on production bed to preset magnitude to be controlled by said depth gage. Reached pressure is maintained by varying injection pressure of booster unit to circular foam in volume equal to that of the well. If fluid intrusion occurs, foam in well is replaced by process fluid with density that allows maintaining bed collecting properties. Note here that in case fluid intrusion does occur, foam circulation is terminated to define acidity of well fluid by sampling bed fluid for pH-factor. Thereafter, acid composition is injected and forced into bed via tubing. Then, pause is made for 2-3 h to open tubing gate valve to repeat abode described jobs.

EFFECT: higher quality and efficiency.

2 dwg