A method for recovery of oil from a subterranean, viscous oil-containing formation penetrated by one or more wells each of which is provided with at least one separate flow paths, the first flow path in fluid communication with the bottom of the formation from adjacent or below the formation and the second flow path in fluid communication with substantially the full vertical thickness of the formation. Steam is injected into the formation via the second flow path and fluids including oils are recovered from adjacent or below the bottom of the formation via the first flow path at a predetermined rate which is substantially less than the injection rate of steam so as to increase the formation pressure to a desired level. Formation pressure is maintained at the desired level while continuing injection of steam and production of fluids including oil until the fluids recovered contain an unfavorable amount of water. In a preferred embodiment, the tubing providing the first flow path may be progressively withdrawn or lowered into the wellbore to obtain improved steam-oil ratios and/or higher oil production rates. This method provides maximum gravity drive displacement of oil from the formation.
A device for rinsing contaminants from ground comprises a perforated well tube sunk through a well shaft in the ground to ground water. The ground water is received in the well shaft through lower perforations, pumped up the well shaft, and out to upper ground regions through upper perforations, so that it can circulate back down to the ground water level, thus flushing contaminants from the upper ground regions. The circulation is accomplished with a well tube insert assembly placed in the well tube, comprising a seal device intermediate upper and lower well tube portions, a pipe through the seal, and a pump in the pipe to pump water from the lower portion to the upper portion. After circulation is established, the well tube insert assembly may be raised within the well tube to raise the level of circulation in the ground. A filter or cleaning device may be placed in the circulation path to remove contaminants.
A method of influencing a liquid in ground by forming a liquid circulation in ground comprises a shaft arranged in ground and extending to a desired liquid region, a pump arranged in the shaft for producing a liquid circulation, the pump having a feeding power selected so that in a shaft surrounding a liquid peak located above a normal liquid level is produced.
A horizontal well completion apparatus and method for heavy, viscous oil in a producing zone (114) are disclosed using a single well. Hot injection fluid is injected into an injection string (120), and emitted through steam distribution holes (133) in the lower portion (120) of the injection string into the casing (116) near perforations (118). A packer (126) separates the upper well annulus (140) from the lower well annulus (142) Insulation (121) surrounds injection tubing string (120) between the packer (126) and the well head (111). Perforations (118) in the horizontal portion (112) of the well allow heated oil to flow into the lower annulus 42 in the horizontal portion (112) of the well where is picked up by the injected fluid and lifted to the surface of the well by a jet pump (128). Temperature and pressure in the lower well annulus (142) are controlled by the temperature and pressure of the injection fluid, and the pumping rate of the produced fluids.
