Showing papers on "Steam injection published in 1991"

Thermal Recovery of Oil and Bitumen

Abstract: Introduction to thermal recovery conduction of heat within solids convective heating within reserving steamflooding the displacement of heavy oil cyclic steam stimulation steam-assisted gravity drainage steam recovery in situ combustion. Appendices.

Method and apparatus for improved recovery of oil from porous, subsurface deposits (targevcir oricess)

Abstract: A method and apparatus for the improved recovery of oil from porous sub-surface deposits such as tar sands comprising mining and drilling a well with upper and lower horizontal rectangular grids extending outward into the deposit and applying steam heat or super heated crude oil vapor through the lower grid and hot pressurized flue gas through the upper grid. The flue gas and steam or super heated crude oil vapor are produced in a generation facility that provides electricity for the installation from turbine generators, the crude oil for super heating being provided by an initial production from the deposit following flue gas injection. Steam condensate is recycled from the recovered oil to the generation facility thereby reducing the water requirements and environmental pollution, and, where super heated crude oil vapor is used, a portion of the produced crude is used for this purpose.

Reservoir simulation of cyclic steam stimulation in the Cold Lake oil sands

Abstract: Steam injectivity during cyclic steam stimulation (CSS) as Cold Lake can be achieved only by injecting at pressures high enough to fail the formation mechanically. The reservoir also exhibits water/oil relative permeability hysteresis. This paper describes enhancements made to a thermal reservoir simulator to incorporate these Cold Lake physics. The geomechanical model allows both localized fracturing and global reservoir deformation (dilation and history-dependent recompaction). This representation allows the simulator to match injection and production pressures that are otherwise difficult to reproduce. The history-dependent relative permeability hysteresis model calculates gridlock relative permeabilities that always lie on or between input imbibition and drainage bounding curves. The model makes it possible to use laboratory-derived relative permeabilities in a simulation and still matchmatch field WOR's.

Water spray ejector system for steam injected engine

Abstract: A steam injected engine, including a compressor, a combustor and a turbine in series combination, with a gas flow path passing therethrough. A steam injection system is provided for adding superheated steam to the gas flow path. A water spray and mixer system sprays water into the steam injection system, whereby the water is immediately vaporized and the resultant mixture remains at superheated temperatures but a greater mass flow of steam is provided to the gas engine to thereby produce an increase in the power output from the engine at reduced thermal efficiency. This new system also provides a means for introducing external waste heat or waste steam into current engine steam piping.

Rf in situ heating of heavy oil in combination with steam flooding

Abstract: A subterranean hydrocarbon-bearing formation is preheated by application of RF energy to the formation so that subsequent steam flooding will more effectively sweep the hydrocarbons from the formation without steam override occurring.

Recovering hydrocarbons from tar sand or heavy oil reservoirs

Abstract: Method of recovering hydrocarbons from an underground tar sand reservoir or heavy oil reservoir (5) comprising (a) drilling and completing a first pair (6) of wells and a second pair of wells (7), each pair comprising an injection well (9 and 14) terminating in the reservoir (5) and a production well (13 and 18) terminating in the reservoir (5) below the injection well (9 and 14); (b) circulating steam through the injection wells (9 and 14) and performing alternate steam injection and hydrocarbon production through the production wells (13 and 18); and (c) injecting steam through the injection wells (9 and 14) while producing hydrocarbons through the production wells (13 and 18), wherein the injection pressure of the injection well (9) of the first pair (6) of wells is greater than the injection pressure of the injection well (14) of the second pair (7) of wells.

Effects of CO2 Addition to Steam on Recovery of West Sak Crude Oil

Abstract: This paper reports on a high-pressure 1D laboratory displacement study which evaluated the effects of adding CO{sub 2} to steam on the recovery of West Sak crude oil Results of the laboratory experiments indicate that the simultaneous injection of CO{sub 2} and steam increases recovery, reduces injection temperatures, and reduces the heat input required

Limited entry steam heating method for uniform heat distribution

Abstract: A well completion method is claimed for steam stimulation of a wellbore, either horizontal or vertical, where limited entry perforations are utilized. Limited-entry perforations of specified spacing and size are placed into a closed-end injection tubing. Steam is directed down the tubing and distributed through the perforations which act as steam chokes, under critical flow conditions, thereby causing uniform steam injection and uniform heating along a desired length of a horizontal wellbore.

Evaluation of Key Reservoir Drive Mechanisms in the Early Cycles of Steam Stimulation at Cold Lake

Abstract: Utilization of a history-matched, 2D, single-well numerical model to evaluate the contributions of four key drive mechanisms to early cyclic-steam-stimulation oil recovery at Cold Lake, Alta.: formation compaction, solution gas-drive, fluid expansion and gravity drainage.

Enhanced oil recovery technique using hydrogen precursors

Abstract: In situ hydrogenation in a subterranean formation is readily performed by introducing a non-gaseous hydrogen precursor into steam to form a composition. The composition is injected into the oil-bearing subterranean formation to enhance the recovery of the oil from the formation.

An evaluation of field projects of steam with additives

Abstract: The use of additives to improve both steamdrive and cyclic steam injection in field projects has been tested under a variety of conditions. This technique attempts to reduce gravity override and channeling of the steam by foam generation. Another mechanism appears to be detergent cleaning near wellbores by surface-active agents. When successful, this technology seems to be economic even at a low oil price. The results, however, have ranged from excellent to negative. In this paper, the authors attempt toe valuate the field projects published to date. The results of this study show that the use of additives with steam can provide significant benefits over the use of steam alone. Indeed, addition of surfactant to the steam has proved to be both technically and economically successful when the proper products and procedures were used. Caustics have given mixed results but seem to have been effective in at least one cyclic-steam project.

Single horizontal well conduction assisted steam drive process for removing viscous hydrocarbonaceous fluids

Abstract: A conduction assisted steam flooding process is described where heavy oil is recovered from reservoirs with limited native injectivity and a high water saturated bottom zone. A horizontal well is placed above the water saturated zone. This well is perforated on its top side at selected intervals. An uninsulated tubing having a circumference smaller than the well is inserted therein to its furthest end thereby making a first and second conduit. Steam is injected into the second conduit and formation fluids are removed by the first conduit or tubing until steam communication is established between the two intervals. Once steam communication is established between the intervals, steam injection is ceased and a thermal packer is placed around the tubing so as to form two separated, spaced-apart, perforated intervals. Thereafter, steam is injected into the reservoir via one interval and hydrocarbonaceous fluids are removed at the other interval.

In-situ reduction of oil viscosity during steam injection process in EOR

Abstract: A method for lowering the viscosity of a heavy hydrocarbon in situ in a well formation so as to improve well production wherein the heavy hydrocarbon has an API gravity in the range between 6° and 12° and a dynamic viscosity in the range between 300 and 900 centipoises @ 195° F. comprising lowering the viscosity of a virgin heavy hydrocarbon outside of a well formation wherein said heavy hydrocarbon has an API gravity in the range between 6 and 12 degrees and a dynamic viscosity above 300 centipoises @ 195° F. so as to make pumpable with conventional pumping equipment comprising mixing said hyrdocarbon at a temperature range between 400° and 500° F. with steam and an additive selected.

Foam/steam injection into a horizontal wellbore for multiple fracture creation

Abstract: A foam/steam injection method for forming fractures is a for reservoir penetrated by a horizontal wellbore. Steam is injected into said wellbore at a pressure sufficient to fracture the formation. Water which is used to make the steam contains a foamable composition in an amount sufficient to make a foam upon contact with steam. Steam and foam enter the wellbore and create a fracture in an oil-rich zone. Thereafter, foam blocks further steam entry into the created fracture which causes another fracture to form at a second interval along the horizontal wellbore. These steps are repeated until a fracture system is made along the length of the wellbore.

Enhanced Recovery of Bitumen by Steam with Chemical Additives

Abstract: Enhanced recovery of bitumen by a combination of steam and caustic chemicals with and without alcohol has been investigated using both static and dynamic techniques. Static experiments were conducted on the basis of information derived from a previous investigation to define the alcoholic caustic formulations potentially effective for bitumen mobilization. The aliphatic alcohol that gave increased bitumen emulsification with a further indication of a more favorable condition for bitumen microemulsion displacement was then selected for the dynamic tests, in which a caustic concentration level up to 0.4 wt% was propagated by a saturated steam at 400 kPa through oil-bearing sand packs. Data obtained from these tests revealed a better bitumen displacement and greater sweep efficiency in steamfloods with caustic and 50% octanolic-caustic additives than in steam drive. In addition, bitumen production began earliest in the alcohol system and was accompanied by increased production rate, leading to more ...

Improved Steam-Foam Formulations: Concepts and Laboratory Results

Abstract: Methodology used at Kern River pilot to evaluate foam formulation that ideally result in improved performance. Steam-foam formulation based on an alpha olefin sulfonate (AOS) containing 16 to 18 carbon atoms in the HC chain improves sweep efficiency and oil recovery of the steamdrive but propagates relatively slowly and leaves the same residual oil saturation (ROS) as steam. Research has identified potentially superior formulations that form stronger foams, propagate faster, and/or reduce ROS below that to steam in the laboratory

Method for improving the steam splits in a multiple steam injection process

Abstract: A method for enhancing the uniformity of steam quality, i.e., steam quality equalization, in a multiple steam injection system having a steam generator, a primary steam header, at least one secondary steam header, a primary steam line connecting the generator to the primary header, at least one secondary steam line connecting the primary header to a secondary steam header, and a plurality of tertiary steam lines connecting the secondary steam header to a tertiary steam header or one of a plurality of steam injections wells involves the introduction of a surfactant at a point subsequent to the steam generator. The surfactant preferably includes those alkyl aromatic sulfonates which include at least one alkyl group comprising 12-30 carbon atoms, more preferably, 20-24 carbon atoms with the preferred concentration of surfactant being about 100 to about 250 ppm, based on the total cold water equivalent of the steam flow.

Steam-foam drive

Abstract: The time delay experienced between the commencement of the steam-foam drive and the subsequent incremental increase in oil production rate is reduced by simultaneously (a) injecting steam into the lower level of a subterranean oil-bearing formation and (b) injecting foam into the upper elevation of the formation. Preferably, the elevation where the foam is injected is gradually lowered while maintaining the steam injection elevation substantially constant. The accelerated response rate improves the economics of the steam-foam drive.

Steam-Soak Performance in South Oman

Abstract: With about 2 {times} 10{sup 9} stock-tank m{sup 3} (12.6 {times} 10{sup 9} STB) of medium/heavy oil originally in place (OOIP) in south Oman, considerable scope exists for increasing oil recovery by thermal methods. The viability of thermal recovery in south Oman was tested with a steamflood pilot in the Al Khlata sands of the Marmul field and a 2-year steam-soak project to test the applicability of steam soak in five south Oman oil fields producing heavy oil. This paper describes the performance of the latter project. The wells selected for the test program included a wide range of south Oman reservoir and oil characteristics i.e., the main reservoir drive mechanisms of depletion, solution-gas, and edge- and bottomwater drive, the reservoir sandbody types, and oil viscosities from 80 to 4000 mPa {center dot} s (80 to 4,000 cp). Steam-soak operations were successful, and oil production accelerated significantly, with an average stimulate production rate twice that before stimulation. Acceleration was less marked in wells where reservoir energy is limited or where the primary (cold) water cut is more than 30%. At primary (cold) water cuts {gt}50%, no increase in oil production rate was observed. The process was simulated numerically for severalmore » wells, with the results in close agreement with performance. Improved understanding of the process resulting from the simulation allowed the most important factors influencing performance to be identified and aided process optimization in the field test. Two small-scale steam-soak projects currently are being assessed for implementatioimplementation in the early 1990's.« less

Enhanced oil recovery method using an inverted nine-spot pattern

Abstract: In an inverted nine-spot pattern in an areally homogeneous reservoir, oil recovery is enhanced when the completion of the sidewells is restricted to the lower 20% of the reservoir. An inverted nine-spot pattern has a steam injection well at the center of the pattern and production wells at each of the four corners of the pattern and at the center of each side of the pattern. Steam is injected at the center well, and oil is produced from sidewells and corner wells.

Sweep in thermal eor using emulsions

Abstract: Water-in-oil emulsions are injected into subterranean formations to divert steam from steam-swept zones around cyclic steam stimulation wells or between injection and production wells in steam floods. The emulsions divert hot fluids to cold unswept zones containing high oil saturations, thereby increasing the net oil recovery.

Wellbore heating process for initiation of below fracture pressure steam stimulation from a horizontal well located in an initially immobile tar sand

Abstract: A steam stimulation process for removing viscous hydrocarbonaceous fluids from a reservoir penetrated by a horizontal wellbore. Steam is injected into the wellbore slightly above the reservoir pressure. Injection is continued so as to allow the steam to heat the reservoir by conductance. once thermal-stimulation is obtained to the extent desired, steam injection is stopped and hydrocarbonaceous fluids are produced to the surface. A void is created in the area adjacent the wellbore and hydrocarbonaceous fluids removed therefrom. Steam in an amount sufficient to fill the void is injected into the formation at pressures slightly above the reservoir pressure but below its fracture pressure. Afterwards, the steps are repeated.

Seismic reflection amplitude versus angle variations over a thermally enhanced oil recovery site

Abstract: In recent years it has become increasingly important to develop a capability for monitoring enhanced oil recovery (EOR) processes as they are occurring within any reservoir. An amplitude‐versus‐angle (AVA) analysis over a steam injection location showed encouraging results and established that seismic reflection methods, when well designed and carefully processed, can be used to map the invaded steam zones in steam stimulation EOR operations. The results are imaged on a new type of display called ARPA (amplitude‐ratio for partial angle), which illustrates reflection zones with low or high Poisson’s ratio or equivalently high or low gas saturation with a CMP stack section plotted as the background. A seismic experiment consisting of three reflection lines was carried out by Esso Resources in February, 1984 over a steam injection site near Cold Lake, Alberta. Analysis of the field data showed that large variations in reflected scattered energy were a function of angle of incidence in areas affected by the s...

Steam injection and mixing apparatus

Abstract: A device for the injection and mixing of steam into a fluid stream. A conduit which is cylindrically-shaped is provided for carrying a fluid such as water. A tubular conduit is then provided for discharging steam in the vicinity of a material mixing apparatus which possesses a plug for intermittently blocking steam discharge within the cylindrically-shaped conduit. A material mixing apparatus is positioned with the cylindrically-shaped conduit for mixing steam with the fluid stream, the material mixing apparatus being in the shape of the conduit and having openings containing mixing elements each of which induce a rotational angular velocity of the same sign to the fluid.

Cleaning device for semiconductor substrate

Abstract: PURPOSE:To shorten a water-washing time and to prevent the reattachment of dust, etc., due to stirring of a water-washing tank by making the constitution of the title device a two-tank constitution of a steam tank equipped with a high-pressure steam injection nozzle and the water-washing tank equipped with a feed water port and water injection nozzle. CONSTITUTION:The title device is a two-tank type one combining a steam tank 7 with a water-washing tank 1 provided with a feed water port 2 and a water injection nozzle 3. At the time of cleaning a wafer, the wafer 5 after a chemical processing by means of phosphoric acid is put in a rack 4 and the rack 4 is first thrown into a steam tank 7. Then, steam is injected from an injection nozzle 8 to remove most of the phosphoric acid and dust attached to the wafer 5. Subsequently, the rack 4 is transferred to the water-washing tank 1 for the purpose of conducting rinsing by the injection of water from a nozzle 3 and continuously by the supply of water from the feed water port 2. Thus, it is possible to contrive to shorten the water-washing time of the wafer and to prevent the reattachment of dust.

Thermal expansion packer

Abstract: The utility model relates to a thermal expansion type metal thermal recovery packer used for a steam injection well of a high-viscosity oil field, which is composed of a thermal expansion body 1, a central pipe 2, a bearing pad 3, a sealing piece 4, a supporting sleeve 5 and a joint 6. The thermal expansion packer is lifted and lowered with a steam injecting pipe column. The packer is sealed automatically after expanded by that the heat energy of steam has action on expansion agent filled in the thermal expansion body 1. Thereby, compared with the other thermal packers, the thermal expansion packer is easy to operate and control construction quality. The utility model has the advantages of novel structure and favorable performance. By utilizing the thermal expansion packer, the long-term seal and the normal steam injection of the steam injecting pipe column can be ensured under the condition that the pressure difference is 25 MPa and the temperature is 360 DEG.