WO2006091640A2 - Dispositif de surveillance de la pression utilisant un tubage capillaire - Google Patents

Dispositif de surveillance de la pression utilisant un tubage capillaire Download PDF

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Publication number
WO2006091640A2
WO2006091640A2 PCT/US2006/006208 US2006006208W WO2006091640A2 WO 2006091640 A2 WO2006091640 A2 WO 2006091640A2 US 2006006208 W US2006006208 W US 2006006208W WO 2006091640 A2 WO2006091640 A2 WO 2006091640A2
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WIPO (PCT)
Prior art keywords
gas
production
tube
pressure
capillary tube
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Application number
PCT/US2006/006208
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English (en)
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WO2006091640A3 (fr
Inventor
Greg Allen Conrad
Original Assignee
Greg Allen Conrad
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Filing date
Publication date
Application filed by Greg Allen Conrad filed Critical Greg Allen Conrad
Publication of WO2006091640A2 publication Critical patent/WO2006091640A2/fr
Publication of WO2006091640A3 publication Critical patent/WO2006091640A3/fr

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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B47/00—Survey of boreholes or wells
    • E21B47/06—Measuring temperature or pressure

Definitions

  • the present invention relates to pressure monitoring systems for gas wells, and in particular to an apparatus for monitoring the pressure at the bottom of a gas well by means of a capillary tube external of the well's production tube.
  • coalbeds often contain combustible gaseous hydrocarbons that are trapped within the coal seam.
  • Methane the major combustible component of natural gas, accounts for roughly 95% of these gaseous hydrocarbons.
  • Coal beds may also contain smaller amounts of higher molecular weight gaseous hydrocarbons, such as ethane and propane. These gases attach to the porous surface of the coal at the molecular level, and are held in place by the hydrostatic pressure exerted by groundwater surrounding the coal bed.
  • the methane trapped in a coalbed seam will desorb when the pressure on the coalbed is sufficiently reduced. This occurs, for example, when the groundwater in the area is removed either by mining or drilling.
  • the release of methane during coal mining is a well-known danger in the coal extraction process. Methane is highly flammable and may explode in the presence of a spark or flame. For this reason, much effort has been expended in the past to vent this gas away as a part of a coal mining operation.
  • CBM extractable coal-bed methane
  • CBM has been commercially extracted in the Arkoma Basin (comprising western Arkansas and eastern Oklahoma) since 1988. As of March 2000, the Arkoma Basin contained 377 producing CBM wells, with an average yield of 80,000 cubic feet of methane per day. Today, CBM accounts for about 7% of the total production of natural gas in the United States.
  • This approach involves the determination of the physical size of a reservoir, pore volume within the mineral matrix of the field, and the gas content within the matrix. A recovery factor is then applied, based on experience with the type of field in question, against the total hydrocarbons-in-place estimate. All of the factors used in these calculations involve estimated values, that when multiplied together create significant uncertainties in the gas reserve estimation process. As production data from a field or well become available over an initial period of operation, more accurate techniques for gas reserve estimation may be used. Such methods include decline analysis and material balance calculations. These methods are generally more accurate in oil fields, where bottom-hole pressures are typically fixed, and less accurate in gas fields where wellhead back-pressures tend to fluctuate significantly. Nevertheless, these approaches may represent the best available approaches to the pursuit of good gas reserve estimates.
  • the principle behind decline analysis is the fitting of empirically derived curves to daily or monthly production data in order to forecast future production and predict recoverable reserves.
  • Earlier decline analysis techniques depended only upon flow information, but, as explained more fully below, more sophisticated techniques in use today may also take into account the flowing pressure of gas. Flowing pressure is most accurately measured at the downhole end of the production tube, just above the location of the packer.
  • the most common decline curve analysis is the exponential decline.
  • hyperbolic and harmonic curves may also be used in specific cases where these curves are known to produce better results.
  • the hyperbolic curve in particular, has been used to model the later stages of production from CBM wells, where significant reserves may remain but the remaining gas is produced at very low pressure levels.
  • the deterministic calculation procedure is far more common.
  • a single value for each parameter is input into an appropriate equation to obtain a single answer.
  • a distribution curve is employed for each parameter and, through the use, for example, of a Monte Carlo simulation, a distribution curve for the answer can be developed.
  • Statistical techniques can then be applied to this distribution curve to determine, for example, the minimum and maximum estimated gas reserve values, the mean value, the medial value, the mode value, and the standard deviation. All of this data may prove helpful in the ultimate calculation of expected gas reserves on a continuing basis.
  • Gas wells and, as already noted, particularly unconventional wells, create special problems with any of these gas reserve calculation approaches.
  • gas wells usually do not flow at a constant bottom hole pressure throughout their lives.
  • CBM wells in particular may actually exhibit a negative decline during their early production phase due to the dewatering effect, particularly when additional wells are added in a high permeability region.
  • These issues make gas reserve calculation in unconventional wells particularly difficult.
  • gas flowing pressure may be used as part of a decline analysis. Since production rates vary proportionally with the flowing pressure drop, dividing the production rates by the associated drop in flowing pressure is an effective method for normalizing production data.
  • This normalized rate may be plotted against a function defined as the amount of time it would take to produce the current cumulative production at the current rate.
  • the rate is thus defined as cumulative production divided by flow rate.
  • gas compressibility is a very strong function of reservoir pressure. Compressibility describes the amount of volume of a fluid that may be moved with a given change in pressure. This is critical to a determination concerning gas reserves, because it describes the energy in the gas that allows it to be driven from the reservoir in the first place. As already explained, unconventional gas wells tend to produce at very low pressure, particularly in the later stages of their lifetimes. Gas compressibility increases as pressure decreases, and thus there are increasing amounts of reservoir energy available as the reservoir is depleted. Iterative calculations are necessary in order to track this effect as a well produces.
  • the present invention is directed to an apparatus for continuously monitoring the flowing bottom hole pressure of a gas well.
  • the invention is particularly well suited to use in CBM and other unconventional gas well configurations.
  • the invention utilizes a capillary tube that runs along the exterior of the production tubing for the well. In this manner the delicate instrumentation associated with the measurement may be located at the other end of the capillary tube, preferably at the well head. This reduces the likelihood of damage or loss to sensitive instrumentation during use. It also simplifies maintenance with respect to the invention, since the tubing need not be removed if there is a need to replace or calibrate instrumentation.
  • a monitor tip serves to protect the end of the tubing during insertion and operation. Even though the monitor tip and capillary tube are located to the exterior of the production tube, the gas pressure is still taken at the interior of the downhole end of the production tube by means of a passage between the interior of the production tube and the monitor tip. In this way the most accurate downhole pressure reading may be made available.
  • an apparatus for monitoring downhole pressure in a well comprising a production tube comprising a downhole end, and further comprising an exterior and interior; a capillary tube comprising a wellhead end and a downhole end, wherein said capillary tube is positioned to said exterior of said production tube; a monitor tip adjacent to said exterior of said production tube, said monitor tip positioned near said downhole end of said production tube and in communication with said downhole end of said capillary tube; and a pressure gauge in communication with said wellhead end of said capillary tube. It is therefore an object of the present invention to provide for a pressure monitoring apparatus and method that directly detects pressure at the bottom of a gas well.
  • FIG. 1 is an elevational view of a downhole tube assembly and production tubing segment according to a preferred embodiment of the present invention.
  • Fig. 2 is an elevational, partial cut-away, partial exploded view of a downhole tube assembly according to a preferred embodiment of the present invention.
  • Fig. 3 is an elevational view of a well head assembly according to a preferred embodiment of the present invention.
  • downhole subassembly 10 of a preferred embodiment of the present invention may be described.
  • Downhole subassembly 10 is preferably designed for deployment at or near the end of a production tube for placement in a well, just above the position for placement of the borehole packer.
  • Downhole subassembly 10 is composed of production tube segment 12 and monitor tip 14.
  • production tube segment 12 is a tube constructed of steel or other appropriately strong material, threaded to fit into other segments of the well production tube (shown in dotted lines in Fig. 1).
  • production tube segment 10 is sized to fit either of the most common 2 3/8 inch or 2 7/8 inch production tube sizes used in CBM extraction. In alternative embodiments, other sizes may be accommodated.
  • the hollow interior of production tube segment 12 is kept clear in order to minimize blockage and facilitate periodic swabbing and cleaning.
  • monitor tip 14 Attached to production tube segment 12 by welding or other appropriate means is monitor tip 14.
  • Monitor tip 14 protects the downhole entry point for gas in order to facilitate an accurate reading, as will be described more fully herein.
  • monitor tip 14 may be constructed of steel or another appropriately strong material.
  • Monitor tip 14 is, however, preferably of solid construction for strength.
  • the tip of monitor tip 14 is tapered or otherwise beveled or pointed, thereby forming an angled edge that eases insertion of the production tube/monitor tip combination into a well.
  • Filter 18 is mounted within an appropriately-sized opening in monitor tip 14.
  • Filter 18 serves to prevent dirt or other foreign material from traveling into the capillary tube.
  • filter 18 fits into a cylindrically-shaped opening at the top end of monitor tip 14, and is threaded to receive fitting 22 as described below.
  • the operator need merely to remove fitting 22 and then physically replace the used filter 18 with a new filter 18.
  • production tube segment orifice 17 is an opening by which gas may pass out from the interior of production tube segment 12.
  • monitor tip passage 19 allows gas to flow from the outside of monitor tip 14 through filter 18 and into fitting 22.
  • gas may pass from within the production tube ultimately up capillary tube 24.
  • the pressure of the gas within the production tube may be measured. More specifically, the pressure is measured within production tube segment 12 at the point where production tube segment orifice 17 intersects the wall of production tube segment 12.
  • production tube segment orifice 17 should be located near, but just above, the location of the packer in the wellbore. This placement allows the best downhole pressure reading to be acquired.
  • the size of this opening formed by production tube segment orifice 17 and monitor tip passage 19 is roughly one- fourth of an inch in diameter in the preferred embodiment, although other sizes may be employed in other embodiments.
  • Fitting 22 is used to connect monitor tip 14 to capillary tube 24, allowing gas that passes through filter 18 to enter capillary tube 24.
  • fitting 22 connects to canister 18 using pipe threads, and connects to capillary tube 24 using a compression, flare, or other tube-type fitting.
  • fitting 22 may be omitted if monitor tip 14 is configured so as to connect directly to capillary tube 24.
  • capillary tube 24 is a one-fourth inch diameter tube, and therefore fitting 22 should be sized for one-fourth inch tubing.
  • Capillary tube 24 preferably extends from fitting 22 along the entire upper length of the production tube.
  • Banding (not shown) is preferably used to hold capillary tube 24 in place against the production tube along its length, thereby preventing damage to capillary tube 24 during insertion of the production tube and during the operational life of the well.
  • the banding is preferably thin stainless steel, such as three-quarter inch stainless steel banding, for strength and corrosion-resistance, but other appropriate flexible and strong materials may be substituted.
  • the banding is placed along capillary tube 24 roughly every sixty feet along its length. The configuration of that portion of a preferred embodiment of the invention located at the wellhead may now be described with reference to Fig. 3.
  • Capillary tube 24 extends upward at the wellhead and is fitted through a wing valve 26 at wellhead 25.
  • Bull plug 27 is then fitted over capillary tube 24 and is tightened into wellhead 25.
  • bull plug 27 is a one-fourth inch by two inch high-pressure bull plug, intended to fit the one-fourth inch diameter capillary tube 24.
  • Packing device 29 is then attached over the free end of capillary tube 24.
  • Packing device 29 is preferably a one-fourth inch tube fitting to one-fourth inch pipe thread fitting. Packing device 29 is drawn over capillary tube 24 in order to seal off the pressure within capillary tube 24.
  • Pipe fitting 31 is then connected to capillary tube 24 at its free end.
  • Pipe fitting 31 is preferably a one- fourth inch tube fitting by one-fourth inch pipe thread fitting.
  • pipe tee 33 Connected to pipe fitting 31 is pipe tee 33, which is preferably of the one-fourth inch high pressure type.
  • high-pressure gauge 35 On the vertical port of tee 33 is mounted high-pressure gauge 35, as shown in Fig. 3.
  • satellite up-linked pressure monitoring device 37 On the horizontal port of tee 33 is mounted a satellite up-linked pressure monitoring device 37.
  • CBM wells are generally lined with a casing as drilled to protect the well from collapse.
  • the most common casing sizes are 4 1/2 inches and 5 1/2 inches. Since the most common production tubing sizes are 2 3/8 inches and 2 7/8 inches, this size disparity leaves sufficient room for the production tube to be easily inserted and removed from casing 44.
  • the size disparity also allows additional room for capillary tube 24 to be mounted to the exterior of production tube 42, with periodic banding as described above.
  • Subassembly 10 is preferably fitted to the production tubing at a point just above the packer in the production string. This allows subassembly 10 to be positioned where the downhole gas pressure can be most accurately measured during operation of the well.
  • capillary tube 24 is preferably provided on a large roll, such that it may be fed forward as the production tube is fed into the casing. At regular intervals, preferably approximately every 60 feet or so, capillary tube 24 is fastened to production tube 42 using banding as already described. This banding operation continues until the production tube is fully inserted into the well, and is properly situated at the mineral formation of interest for gas recovery.
  • capillary tube 24 and other parts described herein with respect to the preferred embodiment provides for a production tube that is free of all obstacles, allowing unrestricted outflow of gas through the production tube to the surface.
  • This feature is particularly important for gas production in "dirty" wells such as those drilled into coal formations for CBM recovery, although the invention is not so limited. In such environments, an unusually high number of contaminants will enter the well. It will thus be necessary to periodically swab the production tube and to remove coal plugs from the production tube. With the production tube remaining otherwise open, it is a simple matter to run a swab the length of the production tube in order to clear obstacles. Otherwise, it would often be necessary to remove the production tube from the casing in order to perform maintenance. Removal of the production tube increases the equipment maintenance cost associated with the CBM extraction operation, and further causes significant downtime during CBM extraction.
  • the capillary tube 24 material should be cut such that preferably about ten feet of excess material remains at the wellhead end of the production tube.
  • the production tubing string should be positioned at least ten feet below the point at which the packer is to be set.
  • the wellhead end of capillary tube 24 is then fed through wing valve 26, while picking up about five feet of the production tubing string.
  • the production packer is then set and the normal flange-up operation at the wellhead is performed as with any gas well.
  • tee 31 feeds both to a mechanical pressure gauge 35 with a visual analog readout, and the satellite-linked pressure monitoring device 37.
  • gas recovery may begin in the traditional manner. It may be seen as gas recovery proceeds, gas will pass from within the production tube into filter 18 through the passage formed by production tube segment orifice 17 and monitor tip passage 19. This gas then passes through filter 18 and passes up capillary tube 24, eventually reaching the wellhead. The pressure of this gas may be read at the wellhead visually by means of mechanical pressure gauge 35. This pressure may also be measured by satellite-linked pressure monitoring device 37, such that pressure data may be transmitted by satellite to any remote location desired. In a preferred embodiment, the pressure of many gas wells in a field, or even several different fields, may be remotely monitored in this manner. Since some algorithms for calculating gas reserves will include data concerning multiple wells operating in the same field, the ability to easy integrate this data from multiple wells serves to further increase the accuracy of gas well reserve calculations.

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  • Physics & Mathematics (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Geology (AREA)
  • Mining & Mineral Resources (AREA)
  • Geophysics (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Measuring Fluid Pressure (AREA)

Abstract

L'invention concerne un dispositif permettant de surveiller la pression d'un puits de gaz à un emplacement de fond. Le dispositif utilise un tube capillaire qui relie un ensemble surveillance de fond de trou à un ou plusieurs manomètres en tête de puits. L'ensemble surveillance de fond de trou et le tube capillaire sont externes par rapport au tube de production, afin d'éviter de bloquer le tube de production à des fins de nettoyage, entre autres. Un passage, partant de l'intérieur du tube de production, laisse passer le gaz vers le tube capillaire pour permettre de mesurer la pression à l'extrémité de fond du tube de production.
PCT/US2006/006208 2005-02-23 2006-02-22 Dispositif de surveillance de la pression utilisant un tubage capillaire WO2006091640A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US65585405P 2005-02-23 2005-02-23
US60/655,854 2005-02-23

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WO2006091640A2 true WO2006091640A2 (fr) 2006-08-31
WO2006091640A3 WO2006091640A3 (fr) 2007-11-22

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WO (1) WO2006091640A2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103742128A (zh) * 2013-12-18 2014-04-23 中国科学院力学研究所 一种煤层气的毛细管压力测试系统
WO2016200266A1 (fr) * 2015-06-09 2016-12-15 Wellguard As Appareil permettant de surveiller au moins une partie d'un puits de forage
US10858928B2 (en) 2018-08-21 2020-12-08 Baker Hughes, A Ge Company, Llc Gauge assembly and method of delivering a gauge assembly into a wellbore

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7954547B2 (en) * 2008-09-03 2011-06-07 Encana Corporation Gas flow system
CN103726833A (zh) * 2013-12-10 2014-04-16 中国科学院力学研究所 一种毛细管测试的地面数据采集系统
IT201900012879A1 (it) * 2019-07-25 2021-01-25 Dab Pumps Spa Dispositivo per la rilevazione del livello di un pozzo/serbatoio ed elettropompa ad immersione con tale dispositivo
US20220220818A1 (en) 2021-01-14 2022-07-14 Halliburton Energy Services, Inc. Gauge sensor for downhole pressure/temperature monitoring of esp intake pressure and discharge temperature

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6257332B1 (en) * 1999-09-14 2001-07-10 Halliburton Energy Services, Inc. Well management system
US6464004B1 (en) * 1997-05-09 2002-10-15 Mark S. Crawford Retrievable well monitor/controller system

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2620740A (en) * 1949-09-24 1952-12-09 Garrett Oil Tools Inc Valve
US2832566A (en) * 1953-04-10 1958-04-29 Exxon Research Engineering Co Method for maintaining level of drilling fluid
US3096819A (en) * 1959-05-22 1963-07-09 Champion Chemicals Inc Method and composition for preventing corrosion
US3712129A (en) * 1970-06-02 1973-01-23 Cities Service Oil Co Simplified wellbore pressure testing apparatus
US3895527A (en) * 1973-11-08 1975-07-22 Sperry Sun Well Surveying Co Method and apparatus for measuring pressure related parameters in a borehole
US3980136A (en) * 1974-04-05 1976-09-14 Big Three Industries, Inc. Fracturing well formations using foam
US4414846A (en) * 1982-02-09 1983-11-15 Jack Schrenkel Gas well monitoring device
US5033550A (en) * 1990-04-16 1991-07-23 Otis Engineering Corporation Well production method
US5152343A (en) * 1991-05-29 1992-10-06 Otis Engineering Corporation Reeled tubing gas lift mandrel
US5339905B1 (en) * 1992-11-25 1995-05-16 Subzone Lift System Gas injection dewatering process and apparatus
US5706892A (en) * 1995-02-09 1998-01-13 Baker Hughes Incorporated Downhole tools for production well control
US5535767A (en) * 1995-03-14 1996-07-16 Halliburton Company Remotely actuated adjustable choke valve and method for using same
US5775425A (en) * 1995-03-29 1998-07-07 Halliburton Energy Services, Inc. Control of fine particulate flowback in subterranean wells
US6619402B1 (en) * 1999-09-15 2003-09-16 Shell Oil Company System for enhancing fluid flow in a well
US6873267B1 (en) * 1999-09-29 2005-03-29 Weatherford/Lamb, Inc. Methods and apparatus for monitoring and controlling oil and gas production wells from a remote location
OA12225A (en) * 2000-03-02 2006-05-10 Shell Int Research Controlled downhole chemical injection.
US6405803B1 (en) * 2000-04-14 2002-06-18 Weatherford/Lamb, Inc. Differential flow control valve
US20040253734A1 (en) * 2001-11-13 2004-12-16 Cully Firmin Down-hole pressure monitoring system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6464004B1 (en) * 1997-05-09 2002-10-15 Mark S. Crawford Retrievable well monitor/controller system
US6257332B1 (en) * 1999-09-14 2001-07-10 Halliburton Energy Services, Inc. Well management system

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103742128A (zh) * 2013-12-18 2014-04-23 中国科学院力学研究所 一种煤层气的毛细管压力测试系统
WO2016200266A1 (fr) * 2015-06-09 2016-12-15 Wellguard As Appareil permettant de surveiller au moins une partie d'un puits de forage
GB2557040A (en) * 2015-06-09 2018-06-13 Wellguard As Apparatus for monitoring at least a portion of a wellbore
GB2557040B (en) * 2015-06-09 2020-01-08 Wellguard As Apparatus for monitoring at least a portion of a wellbore
US10655456B2 (en) 2015-06-09 2020-05-19 Wellguard As Apparatus for monitoring at least a portion of a wellbore
US10858928B2 (en) 2018-08-21 2020-12-08 Baker Hughes, A Ge Company, Llc Gauge assembly and method of delivering a gauge assembly into a wellbore

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WO2006091640A3 (fr) 2007-11-22
US20060185840A1 (en) 2006-08-24

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