Abstract:
Petroleum hydrocarbons are produced from a formation which is in contact and overlays a water-producing formation by a process in which water coning is inhibited. In this process a liquid hydrocarbon at a temperature of about 200* to 500* F is injected via a well bore into the lower portion of the producing formation, the liquid hydrocarbon is withdrawn via the well bore from the upper portion of the producing formation and is continuously injected and withdrawn while at the same time, petroleum hydrocarbons are produced from the upper portion of the said hydrocarbon-bearing formation. Prior to the injection of the hot hydrocarbon liquid, a slug of carbon dioxide or flue gases which can optionally contain a hydrolyzable silane, may be injected into the upper portion of the formation.
Abstract:
A vertical downward gas-driven miscible blanket oil recovery process wherein the spreading rate of the solvent blanket on top of the oil column is increased by adding to the conventional solvent a high density solvent such as carbon disulfide, carbon tetrachloride or certain halogenated hydrocarbons. Sufficient dense solvent is added to the conventional hydrocarbon solvent to increase the density of the injected solvent mixture to a value only slightly less than the density of the formation petroleum being displaced, so that a stable blanket will be maintained with substantially increased rate and extent of spreading of the solvent blanket on top of the oil column. The miscible blanket is displaced downward by injecting gas such as natural gas, methane, or carbon dioxide into the upper portion of the reservoir.
Abstract:
A vertical miscible recovery process for the recovery of oil from an oil-bearing reservoir wherein a miscible slug is established ''''in-situ,'''' at the crest of the oil column or at the gas-oil interface by the separate and simultaneous injection of a stream of the light constituents and a stream of the heavy constituents comprising the miscible slug, followed by the injection of a driving fluid to displace the slug and the reservoir oil downward thru the reservoir.
Abstract:
A solution-mining technique for recovering bitumen from subterranean bitumen-containing deposits such as tar sand deposits having a ratio of overburden thickness to formation thickness of one or less. The overburden is excavated from the deposit and injection and production wells are completed open hole into the tar sand interval, and a solvent for bitumen, said solvent having a density greater than the density of water, is injected into an injection well and a mixture of solvent and bitumen is produced from the remotely located production well. The solvent moves in a horizontal direction across the top portion of the tar sand deposit. Water is used to fill the cavity above the tar sand deposit previously occupied by the overburden. The solvent remains in a thin horizontal layer between the water and the top of the tar sand deposit. As the bitumen is removed from an upper portion of the tar sand interval, water moves down to occupy the area previously occupied by bitumen, and the horizontally moving solvent layer is forced down deeper into the tar sand deposit.
Abstract:
Hot hydrocarbon solvent may be injected into a subterranean hydrocarbon reservoir with little heat loss through the casing walls on the way down to the injection zone by placing tubing inside the casing of an injection well and injecting a hot fluid or vapor into the tubing and a solvent fluid into the annulus between the tubing and casing.
Abstract:
A method for recovering oil from a subterranean oil reservoir which has a finite water saturation and is deficient in energy so that it will not flow by natural means, whereby, first, steam is injected into the reservoir at a faster volumetric rate than production is taken from the reservoir in order to raise the pressure and temperature of the reservoir and then injection is ceased and production of the oil is commenced so that the pressure of the reservoir drops at least to the flash point of the water in the reservoir. Then continuing to produce oil from the reservoir.
Abstract:
A miscible displacement process for the recovery of petroleum from a petroleum-bearing formation is performed in situ by use of a solvent miscible with the petroleum and having a density greater than water followed by a gaseous driving fluid.
Abstract:
A miscible displacement process for the recovery of petroleum from a petroleum bearing formation is performed in situ by the use of a solvent system miscible with the petroleum, the solvent system comprising sequential slugs of carbon disulfide and a hydrocarbon solvent.
Abstract:
A method for the miscible displacement of petroleum from a subterranean reservoir is provided. The method involves injecting two miscible fluids into an injection well and producing petroleum from a production well. A first solvent, more dense than water, is injected into the reservoir near the top of the reservoir, and a second solvent, less dense than water, is injected into the reservoir near or at the bottom of the reservoir. Both solvents are followed by water. The first solvent will tend to flow downward and the second solvent will tend to rise. The solvents will blend and provide piston-like displacement through the reservoir.
Abstract:
A petroleum recovery method employing a mixed solvent for use in subterranean petroleum-containing formations. The mixed solvent density is less than the density of water and greater than the density of the formation petroleum, and preferably has a boiling point less than the boiling point of the formation petroleum. Water is injected into the bottom of the petroleum formation and solvent is injected into the formation above the depth at which water is injected, and a mixture comprising solvent and petroleum is recovered from production wells. The solvent may be separated from the produced petroleum-solvent mixture by distillation and recondensation for reinjection into the formation. The rate of water injection is controlled to force the horizontally moving solvent bank slowly upward so as to sweep the entire formation.