摘要:
The vertical conformance of a steam drive process is improved and steam override reduced by penetrating the zone between one injection well and one producing well, with an infill well which is in fluid communication with the bottom half or less of the formation, and producing petroleum from the infill well after steam channeling has occurred at the production well; then converting the infill well from a producer to an injector and injecting steam into the lower portion of the formation via the infill well and recovering fluids from the production well. Two separate communication paths are established, one between the surface and the upper half or less of the formation, and one between the bottom half or less of the formation in the producing well, or in the infill well, or injection well, or combination of two or more thereof. A fluid having lower mobility than steam is injected into the upper part of the formation via one or more of the communication means after steam override has begun, to resaturate the steam swept zone with the low mobility fluid to prevent further steam flow therethrough and force steam to flow into unswept portions of the formation.
摘要:
Polymer flooding is an effective means of increasing the sweep efficiency of a displacement process for recovering petroleum from a subterranean, petroleum containing formation; however, most polymers suitable for use in flooding operations hydrolyze or otherwise decompose at temperatures above about 150.degree. F to 200.degree. F, and the temperature of many subterranean petroleum-containing formations is in excess of 150.degree. F-200.degree. F. Polymers may be employed in tertiary recovery in formations whose temperatures are greater than the temperature stability limit of the polymer if the formation temperature is first reduced by introducing an aqueous fluid such as water at a temperature substantially below the temperature limit of the polymer into the formation for a period of time sufficient to reduce the formation temperature to a value at or below the temperature tolerance level of the polymer.
摘要:
A method is disclosed for recovering hydrocarbons from heavy oil and tar sand formations by a series of sequenced steps, wherein the production wells are initially steam stimulated. Thereafter, about 0.6 to about 1.2 pore volumes of steam of a relatively high steam quality are injected into the formation through the injection wells. An additional quantity of steam is then injected wherein the steam quality is decreased to a relatively low quality. Water injection and wet in situ combustion conclude the method.
摘要:
Method for producing viscous hydrocarbon products such as heavy crude oil or bitumen from tar sands, which products must be thermally converted into flowable condition. A discrete vertical subsection of a productive subterranean layer is marginated by a pair of spaced apart vertical wells and a horizontal well that lies substantially horizontal to the vertical wells. Controlled, pressurized flows of a heating medium such as steam are introduced to one of the vertical wells and to the horizontal well, whereby to establish a controlled thermal front. The latter is progressively urged by the pressurized steam, through the discrete vertical subsection and toward the other of the vertical wells at which hydrocarbon emulsion is produced.
摘要:
Steam breakthrough at the updip outcrop of a steeply dipping heavy oil reservoir is prevented by the injection of a hot water bank above the point at which the steam is injected into the heavy oil reservoir.
摘要:
The disclosed invention is a method of producing horizontal wells in the most efficient manner at an optimum fluid production rate, which is the maximum rate at which fluids may be produced from a horizontal well while maintaining the downward velocity of formation fluids towards the horizontal well at a velocity which will avoid fingering of the fluids through the formation.
摘要:
A well completion and the method therefor for a wellbore which extends generally horizontally of a subterranean layer comprised primarily of unconsolidated sand particles which hold a viscous hydrocarbon. The completion includes an elongated perforated liner which is positioned in the wellbore. The liner is substantially surrounded by a gravel pack which functions to limit the amount of sand particles which are carried from the subterranean layer into the liner in response to the introduction of a flow of a hot stimulating fluid into the substrate.
摘要:
Method for forming a gravel pack in-situ about a horizontal well in a sandy formation. The gravel pack is formed in two separate steps so that part of the pack will function as a foundation for slidably inserting and supporting the well liner. Thereafter, the remainder of the pack is completed about the liner by introducing a gravel slurry that accumulates on the foundation and about the liner.
摘要:
The disclosed invention is a group of steam foaming agents for injection with steam and a non-condensable gas to decrease permeability in steam swept zones and increase oil recovery. The foaming agents have the general formula:RO(R'O).sub.n R"SO.sub.3 Mwhere R is an alkyl radical, branched or linear, or an alkylbenzene, alkyltoluene or alkylxylene group, having from about 8 to about 24 carbon atoms in the alkyl chain, R' is ethyl, propyl or a mixture of ethyl and propyl, n has an average value of about 1 to about 20, R" is ethyl, propyl, hydroxypropyl or butyl and M is an alkali metal or ammonium ion.
摘要:
The invention is a method of recovering hydrocarbons from an underground hydrocarbon formation which comprises drilling and completing at least three substantially parallel horizontal wells to form a substantially triangular well pattern within a hydrocarbon formation. The first well is placed relatively near the top of a hydrocarbon interval and the second and third wells are placed near the bottom of the interval on each side of the first well. A recovery fluid is injected into the formation through the second and third wells and hydrocarbons and other fluids are recovered through the first well.