PROCEDURE FOR REPLACEMENT OF OIL FROM HORIZONTAL WELL Russian patent published in 2011 - IPC E21B43/24 

FIELD: oil and gas production.

SUBSTANCE: perforated flow string is lowered into drilled borehole. Annular space is isolated up to a horizontal borehole. Oil-well tubing is installed into the flow string. Annular space is sealed with an insulation unit. Replacing agent is supplied into an end portion of the flow string behind the insulation unit; production is withdrawn at the beginning of a horizontal section of the flow string. According to the invention before the flow string is lowered into the borehole up to the horizontal section there is lowered a casing string which is successively cemented. Before lowering the flow string is outside equipped with an inflatable packer between the beginning of the horizontal section and the end section. The packer is communicated inside with the flow string by means of overflow orifices on the side of a wellhead from the insulation unit. Working substance is pumped via inter-tubular space via a process valve with its outlet of the end portion communicated with the flow string. Production is withdrawn via the production string communicated with annular space of the flow string by means of radial channels.

EFFECT: raised efficiency of reservoir heating facilitating flow of heated production via production string; simplified repair of well due to possibility to extract casing string in case of necessity.

1 dwg