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Publication numberUS3128719 A
Publication typeGrant
Publication dateApr 14, 1964
Filing dateMay 5, 1961
Priority dateJun 13, 1960
Publication numberUS 3128719 A, US 3128719A, US-A-3128719, US3128719 A, US3128719A
InventorsSchmit Jongbloed Lodewijk J, Vos Eduard A
Original AssigneeShell Oil Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Gas anchor
US 3128719 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

Ap 14, 1964 L. J. s. JONGBLOED ETAL 3, 28,719

GAS ANCHOR Filed May 5. 1961 INVENTORS: L J SCHMIT JONGBLOED E. A. vos BY:H,h Q-|/&

THEIR AGENT United States Patent Ofi ice 3,128,719 Patented Apr. 14, 1964 3,128,719 GAS ANCHOR Lotlewijk J. Schmit Jonghloed and Eduard A. Vos, Delft,

Netherlands, assignors to Shell Oil Company, New

York, N.Y., a corporation of Delaware Filed May 5, 1961, Ser. No. 108,113 Claims priority, application Netherlands June 13, 1960 4 Claims. (Cl. 103-203) This invention relates to gas anchors and pertains more particularly to gas anchors and separators adapted for use in the pumping of oil wells.

A pumping well is normally equipped with a string of easing, a string of tubing depending within the casing, a pump attached to the lower end of the tubing string and a gas anchor attached to the pump over the suction inlet of the pump, the object of the gas anchor being to promote better separation of gas from the oil by providing a long and tortuous path to the suction end of the pump.

Oil flowing into the bottom of a well often contains large quantities of gas which, unless separated from the oil, are drawn into the pump. The displacement capacity devoted to the compression of this gas in a pump reduces its liquid capacity. Also, the power required to compress any free gas entrained with the oil drawn into an oil well pump is largely wasted. It is therefore necessary, insofar as is practical, to exclude the entry of gas from the pump in order to minimize the size and initial cost of the pumping system as well as the operating and maintenance costs.

Since pump eificiencies and capacities are adversely affected by the depth of the well, the trend toward deeper wells increases the need for better gas-liquid separation at the pump. Furthermore, the trend toward drilling wells of smaller diameter adds emphasis to the need for better separation of the oil and gas by means of a gas anchor, as it is well known that the performance of gas anchors in present use is directly related to the hydraulic radius of the gas anchor down-pass which is limited by the oil well bore. In modern oil well pumping, liquid displacement efliciencies of less than 60 percent are by no means uncommon, even though attention has been given to securing gas anchors of the best available types.

It is therefore an object of this invention to provide an improved gas anchor or separating device of simple and rugged design adapted to separate gas from oil that is to be pumped.

Another object of this invention is to provide an eflicient gas anchor of large capacity for a given diameter which can be readily attached to a well pump to be located near the bottom of a well.

A further object of this invention is to provide a gas anchor of such design that high separation efficiency is maintained when anchors of small diameter are used. It is apparent that the greater the amount of gas separated from an oil-gas mixture by means of a gas anchor prior to passing the mixture in a well pump, the greater amount of oil which can be pumped per unit time by the well pump.

These and other objects of this invention will be understood from the following description of the preferred embodiment of the invention when taken with reference to the drawing, wherein a diagrammatic view of the gas anchor of the present invention is illustrated as being connected to the bottom of a pump and positioned in a well casing.

The present invention relates to a gas anchor consisting of a cylindrical housing sealed at the bottom, at least one sheet metal helix accommodated in the housing, and a tube, one side of which communicates with the space underneath the sheet metal helix. According to the invention, a gas discharge conduit is centrally positioned in the housing, which conduit is provided with openings, preferably near the side of the sheet metal helix facing the bottom of the housing. Preferably the top of the helical channel between the housing, the gas discharge conduit and the sheet, communicates with the outside of the housing.

Referring to the drawing, a Well pump 10 is shown as having attached thereto the housing 11 of a gas anchor and positioned in a production well provided, for example, with a casing 12. This casing communicates, in a manner not further shown, with the pore space of an oilbearing formation traversed by the well. An oil discharge conduit 14 leads from the space 13 at the bottom of the housing 11, the conduit communicating at its other end with the suction side of the well pump 10. Of this pump only the suction valve 16 is shown. It is not necessary to arrange the conduit 14 centrally in the housing 11, as shown in the embodiment in the drawing; if necessary the conduit can be led along the outside of the housing 11.

The gas discharge tube 17 is arranged round the oil discharge conduit 14. If desired, the gas conduit may be sealed at the bottom. Between the housing 11 and the conduit 17 are arranged one or more, for example, two sheet metal helices 18a and 18b in such a way that between the inner wall of the housing 11, the outer Wall of the conduit 17 and the sheet metal helices 18a and 18b two helical channels are formed, the bottoms of which communicate with the space 13 at the bottom of the housing 11. Openings 19 are arranged in the conduit 17 under the sides of the sheet metal helices 18a and 18b facing the bottom of the housing 11. These openings 19, of which only a few are shown in the drawing, are arranged in the conduit 17 in the part over which the sheet metal helices 18a and 181) are arranged.

On a level above the sheet metal helices 18a and 18b, supply openings 20 are provided in the wall of the housing 11, via which openings the outside of the housing 11 communicates with the top part of the helical channels. The gas discharge conduit 17 runs sideways into the wall of the housing 11, preferably at the point 21 on a level located above the supply openings 20.

The apparatus according to the invention operates as follows:

A mixture of oil and gas flows upward from the formation through the annular space 22 between the inner wall of the casing 12 and the outer wall of the housing 11.

A great portion of the gas in the mixture escapes from this mixture in the area where the openings 20 are arranged. This gas fiows via the annular space 15 between the tubing (not shown) and the casing 12 to the wellhead. The mixture entering the housing 11 via the openings 20 contains a considerably smaller, but still undesirable amount of gas. After flowing through the openings 20 the mixture passes downwardly through the helical channels between the sheet metal helices 18a and 18b to the bottom of the housing 11; thence the oil is sucked up by the pump 10 through the conduit 14.

During the passage of the mixture through the helical channels the heavy component of the mixture (the oil) is forced towards the inner wall of the housing 11, and the light component (the gas) moves to the center line of the housing 11. The light component (the gas) escapes through the openings 19 to the space between the conduits 14 and 17, and flows upward through it to the opening 21 which opens into a zone 15 where the gas already separated from the mixture at the openings 20 flows upwards. The oblique position, shown in the drawing, of the sheet metal helices 18a and 18b is adjusted to the movement of the gas bubbles insofar as it is caused by the co-action of centrifugal force and gravity, and thus favors 3 the removal of the gas from the mixture. The amount of gas in the mixture decreases with increasing downward flow of mixture, until the latter is sucked up by the pump 10 from the bottom space 13 of the housing 11 through the conduit 14. The invention is not restricted to gas/ oil separators provided with two sheet metal helices.

In an experimental arrangement in which the outside diameter of the helical channels was 7.5 cm., mixtures of varying gas/ oil ratios were supplied to a gas anchor according to the invention. The quantity of oil passing the separator per hour was from 1 to 1 /2 cu. meters,

When dispersions having gas-oil ratios of between 5 and 20 were supplied, the gas/oil ratio of the mixture flowing through conduit 4 was less than 0.01.

Gas/ oil mixtures of the same composition and quantity were supplied to a separator of similar dimensions but of different design. The gas/oil ratios of the mixtures passing through the conduit 14 were between 0.06 and 0.3.

We claim as our invention:

1. For use with a well pump having fluid inlet means thereto, a gas anchor comprising: a tubular housing member closed at the lower end and having fiuid port means through the side Wall thereof; gas conduit means fixedly secured to and axially disposed within said housing member, the upper end of said conduit means being directed to and through the side wall of said housing member above the port means therein; downwardly opening spirally trough channel means formed on the outside of said gas conduit means throughout a substantial portion of the length thereof, said channel means extending substantially to the inner wall of said housing member; fluid openings through the wall of said gas conduit means at locations near the top of said trough channel means; and, an imperforate delivery tube carried by said housing member, said delivery tube extending axially through said gas conduit means in spaced relationship therewith, said delivery tube having its lower end open to the space within the housing member near the lower closed end thereof and having its upper end in open communication with the fluid inlet means of a well pump.

2. A gas anchor for use in wells, said gas anchor comprising: a cylindrical housing having a closed lower end and having fluid port means through the side walls thereof; at least one helical member carried within said housing and extending over a substantial length thereof to form an inverted troughlike fluid flow channel; a gas discharge tube centrally positioned within said housing, said gas discharge tube extending through and in contact with said helical member, the upper end of said gas discharge tube extending through the wall of said housing above the helical member therein and being in open communication with the space outside the housing; said helical member sloping upwardly from the housing wall with the bottom surface of the helical member at all times forming an acute angle with the longitudinal axis of said discharge tube; a plurality of openings through the wall of said discharge tube at levels just below the points where the buttom surface of said helical member contacts the discharge tube; and, an imperforate delivery tube carried by said cylindrical housing, said delivery tube having its lower end open to the space within said housing near the closed lower end thereof and having its upper end in open communication with the fluid inlet means of a well pump.

3. The apparatus of claim 2 wherein said fluid port means includes a plurality of fluid ports through the wall of said housing above the helical member carried therein and below the point at which the upper end of said gas discharge tube extends through the wall of said housing.

4. The apparatus of claim 3 wherein said delivery tube extends axially through said gas discharge tube and is in spaced relationship therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,628,900 Neilsen May 17, 1927 2,104,339 Arutunoff Ian. 4, 1938 2,147,671 Pratt Feb. 21, 1939 2,398,339 Watts Apr. 9, 1946 2,652,130 Ferguson Sept. 15, 1953 2,843,053 Carle July 15, 1958 2,993,480 Huet July 25, 1961

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1628900 *May 13, 1926May 17, 1927Neilsen Karl PDeep-well gas and oil separator
US2104339 *Aug 7, 1933Jan 4, 1938Armals ArutunoffGas separator for pumps
US2147671 *Jul 15, 1937Feb 21, 1939Motor Power IncCentrifugal gas separator
US2398339 *Apr 3, 1945Apr 9, 1946Socony Vacuum Oil Co IncGas anchor
US2652130 *Jun 26, 1950Sep 15, 1953California Research CorpGas-oil separator
US2843053 *Mar 26, 1956Jul 15, 1958Carle Joseph TGas anchor
US2993480 *Jul 18, 1958Jul 25, 1961Huet AndreTubular evaporator
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3377779 *Feb 16, 1966Apr 16, 1968Gen ElectricAir separation device and liquid delivery system incorporating same
US4074763 *Dec 17, 1976Feb 21, 1978Chevron Research CompanyBottom-hole gas-liquid separator
US4376676 *Oct 19, 1981Mar 15, 1983Gill Carl LIn-line separator for crude oil
US4515608 *Mar 4, 1982May 7, 1985Shell Oil CompanyMulti-chamber gas anchor
US4531584 *Feb 6, 1984Jul 30, 1985Blue Water, Ltd.Downhole oil/gas separator and method of separating oil and gas downhole
US5113937 *Dec 28, 1990May 19, 1992Institut Francais De PetroleDevice for separating a mixture of free gas and liquid at the intake of a pump at the bottom of a drilled well
US5240073 *Apr 3, 1992Aug 31, 1993Corpoven, S.A.Down-hole concentric chamber gas separator and method
US5314018 *Jul 30, 1992May 24, 1994Cobb Delwin EApparatus and method for separating solid particles from liquids
US5431228 *Nov 28, 1994Jul 11, 1995Atlantic Richfield CompanyDownhole gas-liquid separator for wells
US5474601 *Aug 2, 1994Dec 12, 1995Conoco Inc.Integrated floating platform vertical annular separation and pumping system for production of hydrocarbons
US5482117 *Dec 13, 1994Jan 9, 1996Atlantic Richfield CompanyGas-liquid separator for well pumps
US5570744 *May 17, 1995Nov 5, 1996Atlantic Richfield CompanySeparator systems for well production fluids
US5653286 *May 12, 1995Aug 5, 1997Mccoy; James N.Downhole gas separator
US5902378 *Aug 12, 1997May 11, 1999Obrejanu; MarcelContinuous flow downhole gas separator for processing cavity pumps
US6382317May 8, 2000May 7, 2002Delwin E. CobbApparatus and method for separating gas and solids from well fluids
US6554066 *Jan 24, 2001Apr 29, 2003Petroleo Brasileiro S.A.-PetrobrasGas separator with automatic level control
US6755250 *Aug 16, 2002Jun 29, 2004Marathon Oil CompanyGas-liquid separator positionable down hole in a well bore
US7290607 *Apr 4, 2005Nov 6, 2007Innovative Engineering Systems Ltd.Device for the separation of the gas phase from a mixture of fluid/gas for use in hydrocarbons producing and injection wells
US7703509 *Mar 2, 2007Apr 27, 2010Michael Brent FordGas anchor and solids separator assembly for use with sucker rod pump
US7883570Oct 1, 2007Feb 8, 2011Star Oil Tools Inc.Spiral gas separator
US8136600May 2, 2006Mar 20, 2012Exxonmobil Upstream Research CompanyVertical annular separation and pumping system with integrated pump shroud and baffle
US8322434 *May 2, 2006Dec 4, 2012Exxonmobil Upstream Research CompanyVertical annular separation and pumping system with outer annulus liquid discharge arrangement
US9022106Jun 22, 2012May 5, 2015James N. McCoyDownhole diverter gas separator
US9045979 *Dec 11, 2012Jun 2, 2015Delwin E. CobbDownhole gas separator and method
US9366127Feb 14, 2013Jun 14, 2016James N. McCoyGas separator with integral pump seating nipple
US20050217489 *Apr 4, 2005Oct 6, 2005Innovative Engineering Systems Ltd.Device for the separation of the gas phase from a mixture of fluid/gas for use in hydrocarbons producing and injection wells
US20080210417 *Mar 2, 2007Sep 4, 2008Michael Brent FordGas anchor and solids separator assembly for use with sucker rod pump
US20090084263 *Oct 1, 2007Apr 2, 2009Star Oil Tools Inc.Spiral gas separator
US20090211763 *May 2, 2006Aug 27, 2009Exxonmobil Upstream Research CompanyVertical Annular Separation and Pumping System with Integrated Pump Shroud and Baffle
US20090211764 *May 2, 2006Aug 27, 2009Brian J FieldingVertical Annular Separation and Pumping System With Outer Annulus Liquid Discharge Arrangement
US20140158343 *Dec 11, 2012Jun 12, 2014Delwin E. CobbDownhole gas separator and method
USRE35454 *Jun 8, 1995Feb 18, 1997Cobb; Delwin E.Apparatus and method for separating solid particles from liquids
EP0699270A1 *Apr 20, 1994Mar 6, 1996Atlantic Richfield CompanyDownhole gas-liquid separator for wells
WO2004016335A2 *Aug 15, 2003Feb 26, 2004Marathon Oil CompanyA gas-liquid separator positionable down hole in a well bore
WO2004016335A3 *Aug 15, 2003Jul 29, 2004Marathon Oil CoA gas-liquid separator positionable down hole in a well bore
WO2013151864A3 *Mar 28, 2013Sep 12, 2014Saudi Arabian Oil CompanyElectrical submersible pump assembly for separating gas and oil
WO2014093468A3 *Dec 11, 2013Dec 11, 2014Cobb Delwin EDownhole gas separator and method
Classifications
U.S. Classification166/105.5, 55/456
International ClassificationE21B43/38, E21B43/34
Cooperative ClassificationE21B43/38
European ClassificationE21B43/38