Alberta Oil Sands Technology and Research Authority

Alberta Science and Research Authority

Rangewest Technologies Ltd.

Alberta Oil Sands Technology and Research

Kenneth E Kisman

Boyd Russell

Ben I Nzekwu

William Keith Good

Rick W Luhning

Edmund C Lau

Steam assisted gravity drainage ('SAGD') is practised in a first section of a reservoir containing heavy oil. When steam/oil ratio rises sufficiently, steam injection into the first section is curtailed or terminated. Non-condensible gas is then injected into the section to pressurize it and production of residual oil and steam condensate is continued. Concurrently with pressurization, SAGD is practised in an adjacent reservoir section. As a result, some of the residual oil in the first section is recovered and steam loss from the second section to the first section is ameliorated.

Process for sequentially applying SAGD to adjacent sections of a petroleum reservoir

extending into a hot subterranean hydrocarbon-bearing formation containing water at greater than 100.degree. C. The wellbore is divided into three co-extensive passageways; an annulus, and first and second conduits. The annulus is formed within the wellbore between a block at its bottom above the completion intervals and an outlet at the wellhead. The first conduit extends from the formation, through the bottom of the annulus and to an outlet at an elevation intermediate up the annulus. The first conduit is insulated between the bottom of the annulus and its outlet. A second conduit extends between the bottom of the annulus and an outlet at the wellhead. In operation, by producing fluid from the annulus and the second conduit outlets at the wellhead, formation fluid is induced to rise up the first conduit. While the fluid rises, contained water flashes providing steam-enhanced lift. The now-cooled fluid flows out of the first conduit's outlet and into the annulus, separating into substantially gas-phase and liquid phase fluids which flow up and down the annulus respectively. The gas phase fluid is produced from the top of the annulus. Liquid-phase fluid pools in the bottom of the annulus may be artificially lifted through the second conduit using gas-lift or pumps for production at the wellhead outlet.

Enhanced lift method and apparatus for the production of hydrocarbons

An in-situ combustion method is provided for the recovery of viscous oil from an oil-bearing reservoir. A linear array of vertical air injection wells is drilled into the reservoir; the wells are completed in the upper portion of the reservoir. One or more gas production wells are provided, remote from the row of injection wells, said gas production wells also being completed in the upper portion of the reservoir. A horizontal oil production well is completed in the bottom portion of the reservoir, aligned with and positioned in spaced relation beneath the vertical injection wells. The reservoir is prepared for ignition and combustion is initiated at each of the injection wells. A hot fluid-transmissive chamber is formed around each of the injection wells as combustion proceeds. Combustion gas communication is established with the gas production wells. Heated oil and water, produced by the combustion front in each hot chamber, drains under the effect of gravity and is produced from the horizontal production well. The main features of the process are the implementation of gravity drainage to a basal horizontal well in a combustion process and the splitting of liquid and gas production.

Horizontal well gravity drainage combustion process for oil recovery

The invention has application only to a first oil well producing oil having a high water cut, said oil well being completed in a reservoir having an increased gas saturation, in the vicinity of the first oil well, arising from injection of gas through an adjacent injection well. The first oil well is treated by injecting through it into the reservoir a slug of non-condensible gas in an amount between about 40,000 m.sup.3 and 200,000 m.sup.3. The first well is then placed back on production and its water cut is significantly reduced.

Treatment for reducing water coning in an oil reservoir

An oil well producing water is treated to reduce the water cut by injecting through the well into the reservoir a composite slug comprising:

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Calgary, Canada

Kenneth E Kisman