CA1232194A - Downhole well pump - Google Patents
Downhole well pumpInfo
- Publication number
- CA1232194A CA1232194A CA000434704A CA434704A CA1232194A CA 1232194 A CA1232194 A CA 1232194A CA 000434704 A CA000434704 A CA 000434704A CA 434704 A CA434704 A CA 434704A CA 1232194 A CA1232194 A CA 1232194A
- Authority
- CA
- Canada
- Prior art keywords
- plunger
- pump
- tubular member
- chamber
- tubes
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B47/00—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps
- F04B47/06—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps having motor-pump units situated at great depth
- F04B47/08—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps having motor-pump units situated at great depth the motors being actuated by fluid
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Reciprocating Pumps (AREA)
- Details Of Reciprocating Pumps (AREA)
Abstract
Abstract of the Invention Methods and means wherein a downhole reciprocating oil well pump powered by a source of pressurized fluid located at the wellhead receives fluid power via one tubing string and pumps liquid from the well through another tubing string, the downhole pump having internal means to vent gas and vapor from the pump chamber and to cause a pump stroke only when the pump chamber becomes filled with liquid. Means are provided to expel sediment from the pump chamber prior to a pump stroke and a method to independently vary the speed of the pump and return strokes and disclosed so as to conserve energy and reduce maintenance.
Description
~232~
Donnelly Well Pump Technical Field .
This invention relates generally to methods and means 05 for pumping oil and water from deep wells and more particularly to the use of reciprocating pumps powered by pressurized fluids such as gas, oil or water. Although fluid power has long been used to power such pumps, severe difficulties still exist in the pumps now available such as sand cutting, sand fouling, vapor locking, excessive use of energy, excessive downtime, excessive replacement of Donnelly tubing and other equipment, pumping at too fast a rate, pumping at too slow a rate, damage to producing formations, to name a few.
Although the use of sucker rods to operate a Donnelly reciprocating pump is the oldest and most wide spread method, the well known high first cost and endless maintenance problems inherent in sucker rod systems have almost become accepted by many operators as inevitable which unfortunately, drives up the cost of oil and was and many "crooked holes" cannot be pumped at all with the use of sucker rods. The practice of "gasliftin~" liquids from wells by injecting pressurized gas into a column of liquid within a tubing is well known to be an inefficient system when compressors are required to compress the gas before injection, and it cannot be used at all in most deep wells of today.
Therefore, particularly with regard to such wells as offshore wells which are generally both deep and directionally drilled, a more reliable and efficient method and means for pumping is needed by the industry to gain many millions of barrels of oil and billions of cubic feet of gas, as the present invention provides.
Baclcqround Art US Patents 2,362,777 and 3,123,007 disclose early systems for hydraulically driving a reciprocating well I
pump by hydrostatic end elevated pressures respectively but neither have bearing on the present invention. Many similar patents exist, some having fluid motors for attachment to conventional pumps or to operate a string of sucker rods which in turn operate a conventional Donnelly pump.
Soberly US. Patent 2,952,212 issued September 13, 1960 operates by co-mingling spent power fluid with produced liquid from the well which requires separation and purification of the power fluid before recirculation to the Donnelly pump.
A later Soberly US. patent 3,005,414 issued October 24, 19~1 employs a power fluid string and a separate string to return spent power fluid and a production string to convey produced liquid to the surface so as to maintain the power fluid clean, in a closed circuit. The present invention may be operated by either method or by a reciprocation of power fluid within one string, the production tubing being used only for produced liquid and other conduit such as an annuls being used to convey gas to the Waldo, as disclosed by the first mentioned patent.
Ryder US. patent 4,268,227 issued May I 1981 provides a "free type" pump that may be removed from the well without removal of the tubing. Cop ending Canadian Patent application 414,084 filed October 25, 1982, bears the closest physical resemblance to the apparatus of the present invention.
The above referenced application provides highly desirable features such as the venting of gas and vapor from the pump chamber before start of a pump stroke and filling of the pump chamber with liquid before start of the pump stroke but controlled from the well head. For some well conditions, it may cause considerable difficulties to cry ~32~9~
communicate between -the pump and -the power unit a-t the jell head and therefore, the present invention comprises all intelligence in the Donnelly pump, to thereby eliminate the need for communication with the Waldo in order to function.
Whereas the referenced application requires a reciprocating column of fluid to power the Donnelly pump, -the present invention may be opera-ted by a reciprocating column or a non-reciprocating column of fluid. The above application provides a float valve to trigger a pump cycle whereas the present invention uses a flow restructure sensitive to a difference in mass flow rate of a vapor as compared to a liquid. Also, the present invention may operate without a pressure buildup of power fluid above -the normal operating pressure to cause a return stroke of the plunger, which therefore allows the use of lower pressure rated equipment and even further reduction of power usage.
All of the prior art known -to the inventor, takes for granted: sand cutting of the pump and early replacement thereof; the pumping of all sediment that enters the pump chamber; no difference in speed between the pinup and return strokes which often requires excessive energy usage because of a pump stroke faster than is required to pump at the rate that the well will produce. Said prior art has no provision within the Donnelly pump to sense when the pump chamber is full of liquid an to trigger a pump or return stroke but requires extensive communication equipment with the surface or worse still, it must often operate with an empty or partially empty pump chamber which wastes energy and causes premature pump failure because enough liquid is not present to carry heat of friction from the pump. Said prior art has no provision to make sliding seals resistant or immune to sand cutting and has no provision to prevent the pumping of sediment that enters the pump chamber which may cause excessive wear of standing valves or may fill the production tubing cry ~;~32~
(4) sufficiently to stop flow to the Waldo. Therefore, it is clear that the industry is in need of novel features afforded by the present invention Disclosure of the Invention 05 The present invention provides novel methods and means within a Donnelly well pump to accept a pressurized power fluid f rum an external source and to operate the Donnelly pump such that: no pump stroke occurs until gas is vented from the pump chamber and the pump chamber is filled with liquid to be pumped, the pump chamber is sensed to be filled with liquid by a flow sensitive flow restructure which monitors the venting of gas and vapor from the pump chamber and causes the vent to close when liquid flows past the restructure; a power valve may be caused to open when the vent is closed, so as to allow the flow OX Power fluid as required -to cause a pump stroke; the inclusion of sand particles or the like in the liquid to be pumped do not adversely affect operation or life ox the pump; the pump may operate freely without lockup of the plunger under rugged oil~ield conditions; the pump stroke speed can be adjusted independently of the return stroke speed so as to allow for pumping at optimum flow rates and consume the least energy; the pump may operate automatically as desired when a proper supply of pressurized power fluid is furnished to the pump; power fluid furnished at a constant pressure may cause proper operation of the pump; a reciprocating column of power fluid may cause proper operation of the pump; sediment at the bottom of the pump chamber may be removed from the pump and not pumped to the Waldo; column members yin the pump may be reloaded in tension so as to prevent buckling during operation of the pump; means to power return strokes of the pump are efficient, reliable and may be automatic.
All necessary intelligence is within a Donnelly pump constructed and installed in accord with the present I
invention such that the pump may automatically in sequence:
receive liquid, gas and vapor into the pump chamber; vent gas and vapor from the pump chamber and up the well bore;
sense when the pump chamber is filled with liquid; admit power fluid to the pump as required to cause a pump stroke at a predetermined speed best suited to the particular well conditions; stop the flow of power fluid to the pump near the end of the pump stroke, allow return of spent power fluid from the pump so as to allow a return stroke; use stored energy to cause a return stroke at an optimum predetermined speed; position all members of the pump as required to begin a subsequent pump cycle. The present invention may provide within the Donnelly pump: a lower wall of the pump chamber contoured so as to direct sediment out of the pump chamber prior to the pump chamber being pressured so as to begin a pump stroke; sliding sealing surfaces wetted by the produced liquid that are harder than sand particles entrained in the produced liquid; means to power a return stroke of the pump comprising a compressed gas-over-oil system with provision to bleed gas from the chambers requiring the presence of oil; quick acting valve monsieur controlling the flow of power fluid to and from the pump.
In summary, therefore, the present invention broadly provides means for pumping liquid from a well comprising; a tubular member formed around a pump chamber;
an upper centrally disposed tube within the pump chamber . .
sealably.attached to an upper end of a centrally disposed -I
mixed piston; a-lower centrally disposed tube sealable LCM/pg - pa _ ~32~
attached to a lower end of the fixed piston; an annular plunger positioned within the pump chamber so as to allow for slid able sealing means between the outer surface of the plunger and an inner surface of the tubular member; the fixed piston having an outer diameter larger than the outer diameters of the tubes; the fixed pistons' outer periphery having means for slid able sealing contact with an inner diameter of the plunger; the plunger having a reduced bore near each end thereof provided with means for slid able sealing contact with the tubes; means to inject fluid pressure alternately above and below the fixed piston within the plunger so as Jo selectively reciprocate the plunger up and down within the pump chamber so as to cause the pump to operate.
Other features and advantages of my invention will become obvious to those skilled in the art after review of these disclosures and review of the attached drawings.
Brief Description of awns Figure 1 depicts a Donnelly pump constructed in accord with the present invention, assembled and suspended in liquid to be pumped.
Figure 2 and 5 illustrate an arrangement for cooperation with a reciprocating column of power fluid and are vertical sections of Figure 1, taken 90 degrees apart.
Figures 3 and 4, when placed below Figure I
illustrate a vertical sectional view of Figure 1 in the same plane as Figure 2.
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- -LCM/pg - -I
I
(6) Figure 5 is a vertical sectional view taken along line 5-5 of Figure 2.
Figure 6 is a horizontal sectional view taken along line 6-6 of Figure 2.
05 Figure 7 is a horizontal sectional view taken along line 7-7 of Figure 4.
Figure 8 illustrates an alternate arrangement to that shown in Figure 2, wherein fully automatic operations of the pump is effected without need to reciprocate the column of power fluid.
Figure 9 is a sectional view taken along line 9-9 of Figure 8.
Best Mode For Carrying Out the Invention he assembled pump depicted generally by 20 in Figure lo 1 is shown suspended in the liquid to be pumped, such that intake ports 22 are below the liquid surface 24 and such that the upper end 26 of vent pipe 28 is above surface 24.
The pump 20 is shown suspended from tubing 30 which conveys produced liquid to the Waldo, and from tubing 32 which conveys power fluid from the Waldo to the pump. Surge chamber 34 may be attached at wits lower end with tubing 30 for communications therewith as at 35. At its upper end, head 38 is sealable attached with tubing 30, tubing 32 and vent pipe 28 for communication with each as is later described Other major members attached in sequence below head 38 are tubular upper jacket 40, tubular middle jacket 42, connector 44, tubular lower jacket 46 and foot 48, all preferably having the same outside diameter as the head.
Now referring to Figures 2 and 3, the upper end of centrally disposed tube 50 may be sealable connected with the lower end of head 38 so as to form annular pump chamber 52 between jacket 40 and tube 50, the lower end of head 38 defining the upper wall of chamber 52. The lower end of jacket 40 may be bored to receive seal rings 56 alternately with spacer rings 58 for purposes to be (7) described below. Lantern ring 60 may retain rings 56 and 58 against downward axial movement and may be aligned such that ports 62 formed through the wall of ring 60, allow communication through ports 22 and 62, between chamber 52 05 and the producing formation.
The periphery of rings 58 and 60 may be formed to receive seal rings as at I suitable to maintain a seal with the end bore of jacket 40. The end surfaces of rings 56 and $8 are formed flat and smooth such that an effective seal is maintained between said surfaces when held in contact by ring 60~ Threaded tube 66 may cooperate with mating threads wormed within jacket 40 to move zings 56, 58 and 60 into intimate sealing contact with one another being retained against upward movement by shoulder 69 formed within jacket 40. Cooperating threads within the upper end of jacket 42 may be attached to threaded tube 66 so as to cause jacket 42 to abut jacket 40 and firmly secure the jackets together. The lower end of tube 50 may be sealable attached to fixed piston 68 having a maximum diameter greater than that of tube 50 Tube 70, having a maximum diameter less than that of piston 68 may be attached to the lower end thereof and project downwardly through connector 44 as shown in Figures 3 and 4 so as to allow for nut 72 to be tightened on the lower threaded end of tube 70 against connector 44 through gland 140 and thereby reload tube 50, tube 70 and piston 68 in tension so as to preclude buckling of tubes 50 and 70. Annular plunger shown generally at 74, may be formed with bore 76 for slid able sealing cooperation with seals 78 positioned around fixed piston 68 to prevent flow around piston 68 within bore 76. Plunger 74 may be provided with end caps 80 which have end bores as at 82 so as to position seals 84 for slid able sealing cooperation against the periphery ox tubes 50 and 70. Bore 86 of tube 50 may convey power fluid to ports 88 through the wall of I
tube 50 just above piston 68 to act within chamber 89 upwardly against the upper cap 80 and cause plunger 74 to move upwardly. Bore 90 of tube 70 may convey return oil to ports 92 and within chamber 93 Jo act downwardly against 05 the lower cap and tend to cause plunger 74 to move downwardly.
The outer cylindrical surface 94 of plunger 74 may be of material harder than sand or foreign particles that may be entrained in the liquid to be pumped and the inner surface 96 of seal rings 56 may be sufficiently harder than surface 94 such that both sand cutting and gauging of the surfaces is precluded. For instance, surface 94 may be - of chromium oxide and surface 96 may be of tungsten carbide which will provide such harnesses and will also preclude corrosion of the seals.
The vertical motion of plunger 74 is limited when the lower cap abuts connector 44 and when the upper cap abuts head 38. Lateral movement of plunger 74 is limited by the sliding fit between surface 94 and surfaces 96 as well as by the contact of bores 82 with the outer surface of tubes 50 and 70. Surfaces 96 guide the portion of the plunger near piston 68 while tubes 50 and 70 guide the ends of plunger 74 near head 38 or connector 44f such that surface 94 it not allowed to contact the inner wall of jackets 40 or 42, even under normal flexing of the jackets during transport or operation of the pump The top of upper cap 80 is contoured so as to direct any sediment from chamber 52 outwardly through ports 22 when plunger 74 is near the lowermost position as shown in Figure 3.
Rings 98 may be provided within the ends of caps 80 so as to scrape tubes 50 and 70 and thereby preclude sand from entering bore 82 and cause excessive wear of seals 84. The outer surface of tubes 50 and 70 may be made similar to surface 94 and the inner surface of ring 98 may ~;~32~
(9) be made similar to surface 96 for reasons already described.
The lowermost ring 55 positioned immediately above member 66, prevents sediment from passing from chamber 52 05 into jacket 42 which if allowed to collect, could settle on the upper end of connector 44 and prevent movement of plunger 74 to its lowermost position. Ports 100 positioned within connector 44 to drain fluid from within jacket 42 may be provided with check valves so as to prevent inflow of fluid from the well bore upon upstroke of the plunger.
Referring now to Figure 4, jacket yo-yo the lower end of connector 44 and the upper end of foot 48 define gas chamber 102 for containing pressurized gas such as nitrogen for use as a spring to store energy so as to power a return stroke of the plunger. Near the lower end of the gas chamber, oil surface 104 is maintained above the lower end of snorkel tube 106 so as to prevent entry of gas into tube 106. During a return stroke of the plunger, the compressed gas in chamber 102 acts on surface 104 and forces pressurized oil up tube 106, through ports 92 to act within the loden portion of plunger 74 against fixed piston Ç8 and against lower cap 80 to thereby force plunger 74 downwardly. Surface 104 is lowered during a return stroke and is raised during a pump stroke as shown at 105, to again further compress the gas within chamber 102 which in turn stores energy for the next return stroke. Should gas enter tube 106 or plunger 74 through ports 92 sized for oil, the plunger action may become less controllable and therefore means to bleed gas is desirable. Tube 108 may be mounted within tube 106, tube 108 having an open upper end positioned near the upper end of tube 106 and having its lower end connected with conventional vent valve 110 such that when valve 110 is opened, gas acting on surface 104 forces oil up tube 106 us which in turn forces gas trapped in the upper end of tube 106, into the top of tube 108 and out valve loo To I
( 10 ) prevent gas from entering tube 106 during transport of the pump, oil valve 112 may be provided to seal the lower end of tube 106. Rotation of valve 112 within foot 48 may advance valve 112 by means of cooperating screw threads as 05 at 114 until seal 116 mounted around the upper circumference of valve 112 engages the inner diameter 118 of the lower end of tube 106 and effects a seal between them. With valve 112 closed, the pump may be laid horizontally without gas entering tube 106. To prevent leakage around valve 112 to atmosphere, annular seal 120 may be provided around the lower end of valve 120 for sealing cooperation with bore 122 of foot 48. Should it be desired to add or remove oil from chamber 10~, conventional valve 124 may be provided within toot 48.
Should it be desired to add or remove gas from chamber 102, conventional valve 126 may be provided within connector I Figure 7 illustrates a configuration for both valves 124 and i26 wherein plug 128 may be replaced with a pressure connection to a pump or to a bleed line, after which needle 130 is partially screwed out to allow fluid to pass seat 13,~ from or to chamber 102 while no slow is allowed to pass by seal 134 positioned around needle 1300 Packing 136 is retained in centrally disposed bore 138 within connector 44 by gland 140 so as to slid ably seal between tube 70 and connector 44 such that nut 72 may be sufficiently tightened on tube 70 and against gland 140 so as to reload tubes 50 and 70 against buckling and reversal of stresses during operation of the pump.
Now referring to Figure 2, tubing 30 is sealable connected with the upper end of head 38 and in communication with production flow path 142 from pup chamber 52~ Located within path 142 are conventional standing valves 144 which allow upward flow from chamber 52 into tubing 30 but allow no return. Power fluid tubing 32 is sealable connected with the upper end of head 38 and (11) in communication with power fluid flow path 146 between tubing 32 and chamber 89, in which power valve 148 is positioned to control the flow. Differential piston 150 has: on its large end a first pressure area 152; on its 05 small end, a second pressure area 154, on the annular surface between said first pressure area no said second pressure area, a third pressure area 156; around the cylindrical surface toward of the small end of piston 150, a fourth pressure area 158. Area 154 is exposed to thy power fluid pressure within tubing 32, area 158 is exposed to the fluid pressure within path 146 which is always in communication with tube 50; area 156 is always in communication with open vent 158 shown in Figure 6; area 152 is in communication with flow path 16Q which is opened and closed by valve 162 shown in Figure 5 and Figure 6.
Piston 150 is shown in its uppermost position for closure of flow path 146 but may be moved downwardly such that seal 164 around pressure area 154 disengages cooperating sealing surface on annular piston 166 to allow flow between areas 154 and 158. Annular piston 166 may be provided with a sliding seal 167 around its periphery for cooperating with bore 168 within which it is mounted such that a pressure below, will cause piston 166 to move upwardly compressing spring 170 and allow slow between area 158 and area 154. When pressure above piston 166 is equal or greater than the pressure below it, piston 166 will remain in its lowermost position as shown, to allow for sealing contact with seal 164 when piston 150 is in an uppermost position and thereby-stop flow between areas 154 and 158~
Differential piston 150 will remain in the closed upward position as shown as long as the force on area 152 exceeds the force on area 154 and conversely, it will move to the open lower position when the force on area 152 is less than the force on area 154.
I
(12) As best viewed in Figure 5, vent valve 162 may comprise recess 174 formed around stem 176 slid ably mounted within bore 178 formed axially within valve body 180. In the lowermost position shown, recess 174 provides 05 for communication between flow path 172 which is in communication with power fluid tubing 32, and flow path 160 in communication with pressure are 152; vent 182 then being closed by the upper portion of stem 176 when in the position shown. In such position, it is clear that power fluid pressure from tubing 32 acts on both ends of piston 150 which causes piston 150 to close power valve 148 because area 15~ is greater than area 154, resulting in a net upward force on piston 150.
Flow restructure 184 may comprise disc 1$6 mounted on the lower portion of stem 176, disc 186 being of such diameter and configuration as required to cause a suitable differential pressure across the disc when gas, vapor or liquid flows around the disc within vent path 188, formed axially within and through head 380 Compression coil spring 190 may be mounted around stem 176 below body 180 such that nut 186 may be adjusted along a threaded portion of stem 176 so as to create a desired compression load upon spring 190 and thereby prevent upward movement of stem 176 until a predetermined upward force on stem 176 is exceeded. Toe predetermined force must be greater than the differential force created across disc 184 by anticipated flowing gas through vent path 188 but less than the force caused by anticipated flowing liquid. Thus, as gas and vapor are vented from pump chamber 52 through path lS8, stem 176 remains in the lower position but when chamber 52 becomes filled with liquid, liquid ken flows upward through path 188 around disc 185 and creates an upward force on stem 176 sufficient to overcome the reload on spring 190 which in turn, causes stem 176 to move upwardly. As an alternate, selected weights may be used in place of spring 190 to provide the desired force. Plug 194 ~13) ~L232~
may be mounted on the upper end of stem 176 for cooperation with vent valve seat 196 formed concentrically within body 180, such that the contact of plug 194 with seat 196 limits the upward movement owe stem 176 and closes 05 vent path 188. The spacing of flow paths 160, '72 and 182, together with the length of recess 174, are such that when stem 176 is in the lowermost position, paths 160 and 172 communicate and path 182 is closed and when stem 176 is in the uppermost position, paths 160 and 182 COrQmUniCate and 10 path 172 is closed. Cylindrical body 180 may have flats cut on opposite sides as shown in Figure 6 from the - lowermost end of body 180 up to just below the level of seat 196 so as to allow the flow of gas and vapor to flow through seat 196 and out vent pipe 28 to the Waldo, 15 when stem 176 is in the lower position. Body 180 has no flats above seat 196 so as to font a seal around body 180 against the bore of path 188.
It can now be understood that a downward acting reload suitable or a given well condition may be 20 provided such that stern 176 remains in the lower possession dllring venting of gas and vapor from chamber 52, maintaining vent path lB8 open and maintaining pressure area 152 in communication with power fluid tubing 32 which in turn maintains power valve 148 closed as previously 25 explained. It can also now be understood that when pump chamber So fills with liquid, liquid begins to flow around disc 186 to create the differential force required to overcome the downwardly acting reload and thereby move stem 176 to its uppermost position which in turn closes 30 vent path 188 and flow path 172 while allowing pressure area 152 to vent through paths 160 and 182 which in turn causes power valve 148 to move down to the open position.
After assembly and installation of the invention as 35 illustrated in Figure 1, operation may be described as follows. Beginning with the configuration as depicted in I
(14) the drawings, power fluid is maintained under pressure within tubing 32 by a suitable fluid power source near the Waldo (not shown) as is well known in the art. Because the Donnelly pump is suspended below the liquid level 24 05 in the well bore, the liquid together with entrained gas and vapor may flow into pump chamber 52 through intake ports 22, the liquid level rising in chamber 52 while gas and vapor escape through vent path 188, through open seat 196 and up vent pipe 28 toward the Waldo. Immediately after chamber 52 becomes filled with liquid, liquid flows around disc 186 which causes stem 176 to rise and move plug 194 against seat 196 to thereby close vent path l88 as before explained. The upward movement of stem 176 also vents pressure area 152~ allowing power valve 148 to open and admit a flow of pressurized power fluid from tubing 32 through pressure area 158, flow path 146, tube 50, ports 88 and into chamber 89 to act against upper cap 80 in sufficient force to move plunger 74 upwardly against the force of liquid within chamber 52 and against the oil pressure within chamber 93 so as to cause liquid from chamber 52 to rise through path 142 past conventional.
standing valves 144 and upwardly to the Waldo through tubing 30. As upper cap 80 rises to contact the lower wall of head 38, the upward movement of plunger 74 is stopped which causes an increase of pressure within tubing 32 above the pressure necessary to raise the plunger Upon a conventional pressure switch mounted with tubing 32 at the Waldo sensing such pressure increase, the pressure within tubing 32 may be automatically vented by a motor valve which serves to reduce the pressure within chamber 83 to hydrostatic pressure only. Gas within chamber 102 having been recharged to a pressure suitable for given well conditions, is further compressed as plunger 74 moves upwardly, forcing oil from chamber 93, through ports 92, tube 70 and into the bottom of chamber 102 to cause liquid surface 104 to rise.
~15) Now, after reduction of pressure within chamber 89 to hydrostatic only, the oil pressure within chamber 93 driven by compressed gas within chamber 102 is sufficient to overcome hydrostatic pressure within chamber 89 and 05 return plunger 74 to the lowermost position which in turn reverses the flow of the power fluid and returns gas pressure within chamber 102 to the recharge pressure.
Power fluid returning upwardly through power valve 148 will move annular piston 166 upwardly against spring 170 to allow free return of power fluid regardless of the position of piston 150, until pressures above and below piston 166 are substantially equal at which time, spring 170 will force piston 166 to a lowermost position and thereby allow sealing contact with piston 150 to allow closure of valve 148.
As plunger 74 begins to descend from the uppermost position, a partial vacuum it created within chamber 52 which causes a downward differential pressure across plug 194 which acts together with said downwardly acting force to move stem 176 to its lowermost position and thereby reopen vent path 188, close vent 182 and admit power fluid prom tubing 32 through paths 172 and 160 to act against pressure area 152 to move piston 150 upwardly to effect closure of valve 148 and thereby return the pump to the first configuration, ready to begin another pump cycle.
A conventional flow sensor mounted with tubing 32 at the Waldo may be used to signal the motor valve to close and to cause repressurization of tubing 32, after return of the power fluid upon the return stroke of plunger OWE
As the pump stroke begins, sealing surface 94 of plunger 74 is not in contact with any of the seal rings 56 that serve to seal chamber 52 from the well bore. sediment that may settle from the liquid while chamber 52 is being filled will fall on the contoured upper surface of cap 80 to be directed towards ports 62. As plunger 74 begins to rise, a predetermined amount of liquid is forced out ~L~32~
116) through ports I so as to return such sediment to the well bore and down below the pump. Upon surface 94 rising high enough to contact the seal ring immediately above lantern ring 60, such flow through ports 60 ceases and liquid ox within chamber I becomes pressurized sufficiently to force it toward the Waldo. Surface 96 of seal rings 56 may be of a slightly smaller diameter than surface 94 so as to maintain sealing contact, rings 56 being cut at one part of its periphery so as to allow minute expansion of lo the ring and intimate contact ox sealing surfaces 94 and 96. Because both surfaces are harder than sand no sand cutting will occur, causing a higher efficiency and longer operating fife of the pump In some installations the pump may be operating with such a fast pump stroke that an excessive pressure buildup tends to occur within the pump chamber before flow to the surface within the production tubing begins due to the inertia of liquid within the production tubing. To prevent such a pressure buildup and to maintain a more constant Zoo rate of flow within the production tubing, surge chamber 34 may be provided, being suitably recharged with was above piston 35, to a pressure near the hydrostatic pressure within the production tubing Then as a pump stroke starts and a pressure surge tends to build up before the column of liquid begins to rise, liquid flows into conduit 36 to act upwardly on piston 35 and further compress the gas above it. us the column of liquid begins to rise, the pressure surge reduces and the compressed gas forces piston 35 back down to help continue the flow, even after standing valves 144 have closed. Surge chamber 34 may be rotated inwardly from the position shown so as to pass within the same size pipe that the Donnelly pump will pass. Surge chamber 35 may be assembled from conventional oilily tubing such that any required length may be readily assembled.
(17) ~32~
For slow stroking pump installations, surge control may be accomplished by controlling the pump stroke speed as described below, so as to start slow and increase the stroke speed as the column of liquid begins to rise.
05 Wells bored into the earth have infinite combinations of conditions such as depth, pipe diameter, pressures, fluid characteristics, temperature, pressure ratings of tubing joints and other equipment Therefore, it may be desirable under some well conditions to furnish fluid 10 power to the Donnelly pump at a constant pressure and to return spent power fluid from the pump up the production string, tubing 30, or up a separate return string, tubing 200 as depicted in Figure 9, both methods of return well known in the art. To operate the present invention by such 15 a method, alternate head 20~ may be provided to replace head 38~
Referring to Figure 8, conventional standing valves 144 are positioned to relieve produced liquid from pump chamber 52, through flow path 122 and to convey it to 20 tubing 30 as described above for Foggier. Tubing 32 is sealable attached Jo the upper end of head 202 so as to supply power fluid at a substantially constant pressure to flow path 204 formed axially within head 202 concentric with and below tubing 32. Now referring to Figure 9, 25 switching valve 206 may be positioned within bore 208 formed axially within head 202 and parallel to flow path 204 so as to protrude into chamber 52 as shown at 210 when in the looniest position, and reversibly movable to an uppermost position 212 as depicted by solid lines. When 30 valve 206 is in the uppermost position, recess 214 formed around a portion of valve stem 216 is positioned such that spent power fluid may return from tube 50 up through axially disposed flow path 218, through laterally disposed flow path 220 into path 208 via recess 214, thence into 35 flow path 222 in communication with return tubing 200.
Should it be desired to return power fluid through (18) I
production tubing 30, flow path 222 may be furnished with a suitable check valve not shown, and connected so as to communicate with tubing 30 instead of with tubing 200 to thereby allow flow from path 222 into tubing 30 but no 05 return flow. While chamber 52 is filling with liquid, valve 206 is held in the uppermost position by the hydrostatic pressure of spent power fluid acting against an upper enlarged end of stem 216 as at shoulder 224, the top end 226 of stem 216 being vented at that time. When fluid force acting against end 226 exceeds the fluid force acting against shoulder 224, valve 206 must move to the lowermost position such that shoulder 224 abuts shoulder 228 and recess 214 connects flow path 230 with path 220 and path 222 is sealed by stem 216 above recess 214.
Valve 232 is constructed the same as valve 162 previously described except that valve 232 vents pressure J
when in the lowermost position and repressurize when in the uppermost position. When valve 232 is in the lowermost position as depicted in Figure 9, fluid pressure acting against end 226 may be vented through lateral flow path 234 into valve 232 through recess 236 and thence out vent 238 to the well bore. check valve may be installed in vent 238 to prevent well fluid from entering the vent path. When valve 232 is shifted to the uppermost position, I vent path 238 is closed by the valve stem and recess 236 places flow path 234 in communication with flow path 240 which in turn is in communication with pressurized fluid flow path aye.
Operation of alternate head 202 may now be described, the remainder of the pump operating as described above. As gas and vapor are vented through valve 232, liquid rises within pump chamber 52 until it is filled whereupon it causes valve 232 to move to the uppermost position as described above for valve 162, thence causing power fluid to flow from path 204 through path 240, recess 236 and path 234 into chamber 225 to act against end 226 of valve I
stem 216 to overcome hydrostatic pressure against shoulder 224 and to cause stem 216 to move to the lowermost position such that path 222 is sealed by stem 216 and simultaneously paths 220 and 230 are placed in 05 communication via recess 214. Then pressurized power fluid may flow from path 204 into tube I so as to actuate the plunger as described above. As upper cap 80 approaches the top of the stroke, the cap contacts the lower end of stem 216 as at 210 and pushes the stem to the uppermost 10 position as at 212, whereupon, power fluid is allowed to return from tube 50 through recess 214 and path 222 and up the tubing to the Waldo As the plunger starts to descend, a vacuum is created in chamber I which causes valve 23~ to return to the lowermost position which causes recess 236 to vent pressure from chamber 225 through paths 234 and 238 such that hydrostatic pressure of spent power fluid may once again act on shoulder 224 to maintain valve 206 in the uppermost position in preparation for a subsequent pump cycle Because the pressure area against cap 80 is far greater than the pressure area against end 226 of stem 206, plunger 74 will easily move stem 216 upwardly and expel fluid prom chamber 225 through path 234, recess 236, path 240 and back into path 204 The return stroke speed of the plunger may be adjusted to the fastest reasonable speed consistent with proper operation by sizing ports 92 to restrict the flow of oil or by regulating the return flow of spent power fluid as by sizing ports-88 or by placing a flow restructure at any point along the spent power fluid return path including placing flow restructures at the source of pressurized power fluid. For some well conditions it may be desired to use only a gas chamber with no oil, for powering the return stroke of the plunger. Any suitable conventional flow restructures may be utilized, depending upon the position of installation and the flow and fluid (20) requirements The pump stroke speed may be independently regulated by adjusting the volume output at the source of fluid pressure mounted near the Waldo The pump stroke need be no faster Han is necessary to pump liquid from 05 the well at the rate the well is capable of producing to thereby reduce the size of the power unit required and to reduce the amount of power consumed to pump the well It may therefore be understood how to regulate the pump and return strokes independently of one another so as to use the minimum energy required to pump a given well.
New and timely methods, means and apparatus for pumping liquids from deep oil wells and the like may now be understood by study of these disclosures and review of the attached drawings.
It is now obvious that the present invention is well suited to attain the desired objectives and provide novel advantages for pumping oil and water from deep wells so as to conserve energy, to reduce maintenance requirements, to reduce costs, to extend equipment life and to recover 20- hydrocarbon deposits otherwise not feasible to recover.
Donnelly Well Pump Technical Field .
This invention relates generally to methods and means 05 for pumping oil and water from deep wells and more particularly to the use of reciprocating pumps powered by pressurized fluids such as gas, oil or water. Although fluid power has long been used to power such pumps, severe difficulties still exist in the pumps now available such as sand cutting, sand fouling, vapor locking, excessive use of energy, excessive downtime, excessive replacement of Donnelly tubing and other equipment, pumping at too fast a rate, pumping at too slow a rate, damage to producing formations, to name a few.
Although the use of sucker rods to operate a Donnelly reciprocating pump is the oldest and most wide spread method, the well known high first cost and endless maintenance problems inherent in sucker rod systems have almost become accepted by many operators as inevitable which unfortunately, drives up the cost of oil and was and many "crooked holes" cannot be pumped at all with the use of sucker rods. The practice of "gasliftin~" liquids from wells by injecting pressurized gas into a column of liquid within a tubing is well known to be an inefficient system when compressors are required to compress the gas before injection, and it cannot be used at all in most deep wells of today.
Therefore, particularly with regard to such wells as offshore wells which are generally both deep and directionally drilled, a more reliable and efficient method and means for pumping is needed by the industry to gain many millions of barrels of oil and billions of cubic feet of gas, as the present invention provides.
Baclcqround Art US Patents 2,362,777 and 3,123,007 disclose early systems for hydraulically driving a reciprocating well I
pump by hydrostatic end elevated pressures respectively but neither have bearing on the present invention. Many similar patents exist, some having fluid motors for attachment to conventional pumps or to operate a string of sucker rods which in turn operate a conventional Donnelly pump.
Soberly US. Patent 2,952,212 issued September 13, 1960 operates by co-mingling spent power fluid with produced liquid from the well which requires separation and purification of the power fluid before recirculation to the Donnelly pump.
A later Soberly US. patent 3,005,414 issued October 24, 19~1 employs a power fluid string and a separate string to return spent power fluid and a production string to convey produced liquid to the surface so as to maintain the power fluid clean, in a closed circuit. The present invention may be operated by either method or by a reciprocation of power fluid within one string, the production tubing being used only for produced liquid and other conduit such as an annuls being used to convey gas to the Waldo, as disclosed by the first mentioned patent.
Ryder US. patent 4,268,227 issued May I 1981 provides a "free type" pump that may be removed from the well without removal of the tubing. Cop ending Canadian Patent application 414,084 filed October 25, 1982, bears the closest physical resemblance to the apparatus of the present invention.
The above referenced application provides highly desirable features such as the venting of gas and vapor from the pump chamber before start of a pump stroke and filling of the pump chamber with liquid before start of the pump stroke but controlled from the well head. For some well conditions, it may cause considerable difficulties to cry ~32~9~
communicate between -the pump and -the power unit a-t the jell head and therefore, the present invention comprises all intelligence in the Donnelly pump, to thereby eliminate the need for communication with the Waldo in order to function.
Whereas the referenced application requires a reciprocating column of fluid to power the Donnelly pump, -the present invention may be opera-ted by a reciprocating column or a non-reciprocating column of fluid. The above application provides a float valve to trigger a pump cycle whereas the present invention uses a flow restructure sensitive to a difference in mass flow rate of a vapor as compared to a liquid. Also, the present invention may operate without a pressure buildup of power fluid above -the normal operating pressure to cause a return stroke of the plunger, which therefore allows the use of lower pressure rated equipment and even further reduction of power usage.
All of the prior art known -to the inventor, takes for granted: sand cutting of the pump and early replacement thereof; the pumping of all sediment that enters the pump chamber; no difference in speed between the pinup and return strokes which often requires excessive energy usage because of a pump stroke faster than is required to pump at the rate that the well will produce. Said prior art has no provision within the Donnelly pump to sense when the pump chamber is full of liquid an to trigger a pump or return stroke but requires extensive communication equipment with the surface or worse still, it must often operate with an empty or partially empty pump chamber which wastes energy and causes premature pump failure because enough liquid is not present to carry heat of friction from the pump. Said prior art has no provision to make sliding seals resistant or immune to sand cutting and has no provision to prevent the pumping of sediment that enters the pump chamber which may cause excessive wear of standing valves or may fill the production tubing cry ~;~32~
(4) sufficiently to stop flow to the Waldo. Therefore, it is clear that the industry is in need of novel features afforded by the present invention Disclosure of the Invention 05 The present invention provides novel methods and means within a Donnelly well pump to accept a pressurized power fluid f rum an external source and to operate the Donnelly pump such that: no pump stroke occurs until gas is vented from the pump chamber and the pump chamber is filled with liquid to be pumped, the pump chamber is sensed to be filled with liquid by a flow sensitive flow restructure which monitors the venting of gas and vapor from the pump chamber and causes the vent to close when liquid flows past the restructure; a power valve may be caused to open when the vent is closed, so as to allow the flow OX Power fluid as required -to cause a pump stroke; the inclusion of sand particles or the like in the liquid to be pumped do not adversely affect operation or life ox the pump; the pump may operate freely without lockup of the plunger under rugged oil~ield conditions; the pump stroke speed can be adjusted independently of the return stroke speed so as to allow for pumping at optimum flow rates and consume the least energy; the pump may operate automatically as desired when a proper supply of pressurized power fluid is furnished to the pump; power fluid furnished at a constant pressure may cause proper operation of the pump; a reciprocating column of power fluid may cause proper operation of the pump; sediment at the bottom of the pump chamber may be removed from the pump and not pumped to the Waldo; column members yin the pump may be reloaded in tension so as to prevent buckling during operation of the pump; means to power return strokes of the pump are efficient, reliable and may be automatic.
All necessary intelligence is within a Donnelly pump constructed and installed in accord with the present I
invention such that the pump may automatically in sequence:
receive liquid, gas and vapor into the pump chamber; vent gas and vapor from the pump chamber and up the well bore;
sense when the pump chamber is filled with liquid; admit power fluid to the pump as required to cause a pump stroke at a predetermined speed best suited to the particular well conditions; stop the flow of power fluid to the pump near the end of the pump stroke, allow return of spent power fluid from the pump so as to allow a return stroke; use stored energy to cause a return stroke at an optimum predetermined speed; position all members of the pump as required to begin a subsequent pump cycle. The present invention may provide within the Donnelly pump: a lower wall of the pump chamber contoured so as to direct sediment out of the pump chamber prior to the pump chamber being pressured so as to begin a pump stroke; sliding sealing surfaces wetted by the produced liquid that are harder than sand particles entrained in the produced liquid; means to power a return stroke of the pump comprising a compressed gas-over-oil system with provision to bleed gas from the chambers requiring the presence of oil; quick acting valve monsieur controlling the flow of power fluid to and from the pump.
In summary, therefore, the present invention broadly provides means for pumping liquid from a well comprising; a tubular member formed around a pump chamber;
an upper centrally disposed tube within the pump chamber . .
sealably.attached to an upper end of a centrally disposed -I
mixed piston; a-lower centrally disposed tube sealable LCM/pg - pa _ ~32~
attached to a lower end of the fixed piston; an annular plunger positioned within the pump chamber so as to allow for slid able sealing means between the outer surface of the plunger and an inner surface of the tubular member; the fixed piston having an outer diameter larger than the outer diameters of the tubes; the fixed pistons' outer periphery having means for slid able sealing contact with an inner diameter of the plunger; the plunger having a reduced bore near each end thereof provided with means for slid able sealing contact with the tubes; means to inject fluid pressure alternately above and below the fixed piston within the plunger so as Jo selectively reciprocate the plunger up and down within the pump chamber so as to cause the pump to operate.
Other features and advantages of my invention will become obvious to those skilled in the art after review of these disclosures and review of the attached drawings.
Brief Description of awns Figure 1 depicts a Donnelly pump constructed in accord with the present invention, assembled and suspended in liquid to be pumped.
Figure 2 and 5 illustrate an arrangement for cooperation with a reciprocating column of power fluid and are vertical sections of Figure 1, taken 90 degrees apart.
Figures 3 and 4, when placed below Figure I
illustrate a vertical sectional view of Figure 1 in the same plane as Figure 2.
. .
- -LCM/pg - -I
I
(6) Figure 5 is a vertical sectional view taken along line 5-5 of Figure 2.
Figure 6 is a horizontal sectional view taken along line 6-6 of Figure 2.
05 Figure 7 is a horizontal sectional view taken along line 7-7 of Figure 4.
Figure 8 illustrates an alternate arrangement to that shown in Figure 2, wherein fully automatic operations of the pump is effected without need to reciprocate the column of power fluid.
Figure 9 is a sectional view taken along line 9-9 of Figure 8.
Best Mode For Carrying Out the Invention he assembled pump depicted generally by 20 in Figure lo 1 is shown suspended in the liquid to be pumped, such that intake ports 22 are below the liquid surface 24 and such that the upper end 26 of vent pipe 28 is above surface 24.
The pump 20 is shown suspended from tubing 30 which conveys produced liquid to the Waldo, and from tubing 32 which conveys power fluid from the Waldo to the pump. Surge chamber 34 may be attached at wits lower end with tubing 30 for communications therewith as at 35. At its upper end, head 38 is sealable attached with tubing 30, tubing 32 and vent pipe 28 for communication with each as is later described Other major members attached in sequence below head 38 are tubular upper jacket 40, tubular middle jacket 42, connector 44, tubular lower jacket 46 and foot 48, all preferably having the same outside diameter as the head.
Now referring to Figures 2 and 3, the upper end of centrally disposed tube 50 may be sealable connected with the lower end of head 38 so as to form annular pump chamber 52 between jacket 40 and tube 50, the lower end of head 38 defining the upper wall of chamber 52. The lower end of jacket 40 may be bored to receive seal rings 56 alternately with spacer rings 58 for purposes to be (7) described below. Lantern ring 60 may retain rings 56 and 58 against downward axial movement and may be aligned such that ports 62 formed through the wall of ring 60, allow communication through ports 22 and 62, between chamber 52 05 and the producing formation.
The periphery of rings 58 and 60 may be formed to receive seal rings as at I suitable to maintain a seal with the end bore of jacket 40. The end surfaces of rings 56 and $8 are formed flat and smooth such that an effective seal is maintained between said surfaces when held in contact by ring 60~ Threaded tube 66 may cooperate with mating threads wormed within jacket 40 to move zings 56, 58 and 60 into intimate sealing contact with one another being retained against upward movement by shoulder 69 formed within jacket 40. Cooperating threads within the upper end of jacket 42 may be attached to threaded tube 66 so as to cause jacket 42 to abut jacket 40 and firmly secure the jackets together. The lower end of tube 50 may be sealable attached to fixed piston 68 having a maximum diameter greater than that of tube 50 Tube 70, having a maximum diameter less than that of piston 68 may be attached to the lower end thereof and project downwardly through connector 44 as shown in Figures 3 and 4 so as to allow for nut 72 to be tightened on the lower threaded end of tube 70 against connector 44 through gland 140 and thereby reload tube 50, tube 70 and piston 68 in tension so as to preclude buckling of tubes 50 and 70. Annular plunger shown generally at 74, may be formed with bore 76 for slid able sealing cooperation with seals 78 positioned around fixed piston 68 to prevent flow around piston 68 within bore 76. Plunger 74 may be provided with end caps 80 which have end bores as at 82 so as to position seals 84 for slid able sealing cooperation against the periphery ox tubes 50 and 70. Bore 86 of tube 50 may convey power fluid to ports 88 through the wall of I
tube 50 just above piston 68 to act within chamber 89 upwardly against the upper cap 80 and cause plunger 74 to move upwardly. Bore 90 of tube 70 may convey return oil to ports 92 and within chamber 93 Jo act downwardly against 05 the lower cap and tend to cause plunger 74 to move downwardly.
The outer cylindrical surface 94 of plunger 74 may be of material harder than sand or foreign particles that may be entrained in the liquid to be pumped and the inner surface 96 of seal rings 56 may be sufficiently harder than surface 94 such that both sand cutting and gauging of the surfaces is precluded. For instance, surface 94 may be - of chromium oxide and surface 96 may be of tungsten carbide which will provide such harnesses and will also preclude corrosion of the seals.
The vertical motion of plunger 74 is limited when the lower cap abuts connector 44 and when the upper cap abuts head 38. Lateral movement of plunger 74 is limited by the sliding fit between surface 94 and surfaces 96 as well as by the contact of bores 82 with the outer surface of tubes 50 and 70. Surfaces 96 guide the portion of the plunger near piston 68 while tubes 50 and 70 guide the ends of plunger 74 near head 38 or connector 44f such that surface 94 it not allowed to contact the inner wall of jackets 40 or 42, even under normal flexing of the jackets during transport or operation of the pump The top of upper cap 80 is contoured so as to direct any sediment from chamber 52 outwardly through ports 22 when plunger 74 is near the lowermost position as shown in Figure 3.
Rings 98 may be provided within the ends of caps 80 so as to scrape tubes 50 and 70 and thereby preclude sand from entering bore 82 and cause excessive wear of seals 84. The outer surface of tubes 50 and 70 may be made similar to surface 94 and the inner surface of ring 98 may ~;~32~
(9) be made similar to surface 96 for reasons already described.
The lowermost ring 55 positioned immediately above member 66, prevents sediment from passing from chamber 52 05 into jacket 42 which if allowed to collect, could settle on the upper end of connector 44 and prevent movement of plunger 74 to its lowermost position. Ports 100 positioned within connector 44 to drain fluid from within jacket 42 may be provided with check valves so as to prevent inflow of fluid from the well bore upon upstroke of the plunger.
Referring now to Figure 4, jacket yo-yo the lower end of connector 44 and the upper end of foot 48 define gas chamber 102 for containing pressurized gas such as nitrogen for use as a spring to store energy so as to power a return stroke of the plunger. Near the lower end of the gas chamber, oil surface 104 is maintained above the lower end of snorkel tube 106 so as to prevent entry of gas into tube 106. During a return stroke of the plunger, the compressed gas in chamber 102 acts on surface 104 and forces pressurized oil up tube 106, through ports 92 to act within the loden portion of plunger 74 against fixed piston Ç8 and against lower cap 80 to thereby force plunger 74 downwardly. Surface 104 is lowered during a return stroke and is raised during a pump stroke as shown at 105, to again further compress the gas within chamber 102 which in turn stores energy for the next return stroke. Should gas enter tube 106 or plunger 74 through ports 92 sized for oil, the plunger action may become less controllable and therefore means to bleed gas is desirable. Tube 108 may be mounted within tube 106, tube 108 having an open upper end positioned near the upper end of tube 106 and having its lower end connected with conventional vent valve 110 such that when valve 110 is opened, gas acting on surface 104 forces oil up tube 106 us which in turn forces gas trapped in the upper end of tube 106, into the top of tube 108 and out valve loo To I
( 10 ) prevent gas from entering tube 106 during transport of the pump, oil valve 112 may be provided to seal the lower end of tube 106. Rotation of valve 112 within foot 48 may advance valve 112 by means of cooperating screw threads as 05 at 114 until seal 116 mounted around the upper circumference of valve 112 engages the inner diameter 118 of the lower end of tube 106 and effects a seal between them. With valve 112 closed, the pump may be laid horizontally without gas entering tube 106. To prevent leakage around valve 112 to atmosphere, annular seal 120 may be provided around the lower end of valve 120 for sealing cooperation with bore 122 of foot 48. Should it be desired to add or remove oil from chamber 10~, conventional valve 124 may be provided within toot 48.
Should it be desired to add or remove gas from chamber 102, conventional valve 126 may be provided within connector I Figure 7 illustrates a configuration for both valves 124 and i26 wherein plug 128 may be replaced with a pressure connection to a pump or to a bleed line, after which needle 130 is partially screwed out to allow fluid to pass seat 13,~ from or to chamber 102 while no slow is allowed to pass by seal 134 positioned around needle 1300 Packing 136 is retained in centrally disposed bore 138 within connector 44 by gland 140 so as to slid ably seal between tube 70 and connector 44 such that nut 72 may be sufficiently tightened on tube 70 and against gland 140 so as to reload tubes 50 and 70 against buckling and reversal of stresses during operation of the pump.
Now referring to Figure 2, tubing 30 is sealable connected with the upper end of head 38 and in communication with production flow path 142 from pup chamber 52~ Located within path 142 are conventional standing valves 144 which allow upward flow from chamber 52 into tubing 30 but allow no return. Power fluid tubing 32 is sealable connected with the upper end of head 38 and (11) in communication with power fluid flow path 146 between tubing 32 and chamber 89, in which power valve 148 is positioned to control the flow. Differential piston 150 has: on its large end a first pressure area 152; on its 05 small end, a second pressure area 154, on the annular surface between said first pressure area no said second pressure area, a third pressure area 156; around the cylindrical surface toward of the small end of piston 150, a fourth pressure area 158. Area 154 is exposed to thy power fluid pressure within tubing 32, area 158 is exposed to the fluid pressure within path 146 which is always in communication with tube 50; area 156 is always in communication with open vent 158 shown in Figure 6; area 152 is in communication with flow path 16Q which is opened and closed by valve 162 shown in Figure 5 and Figure 6.
Piston 150 is shown in its uppermost position for closure of flow path 146 but may be moved downwardly such that seal 164 around pressure area 154 disengages cooperating sealing surface on annular piston 166 to allow flow between areas 154 and 158. Annular piston 166 may be provided with a sliding seal 167 around its periphery for cooperating with bore 168 within which it is mounted such that a pressure below, will cause piston 166 to move upwardly compressing spring 170 and allow slow between area 158 and area 154. When pressure above piston 166 is equal or greater than the pressure below it, piston 166 will remain in its lowermost position as shown, to allow for sealing contact with seal 164 when piston 150 is in an uppermost position and thereby-stop flow between areas 154 and 158~
Differential piston 150 will remain in the closed upward position as shown as long as the force on area 152 exceeds the force on area 154 and conversely, it will move to the open lower position when the force on area 152 is less than the force on area 154.
I
(12) As best viewed in Figure 5, vent valve 162 may comprise recess 174 formed around stem 176 slid ably mounted within bore 178 formed axially within valve body 180. In the lowermost position shown, recess 174 provides 05 for communication between flow path 172 which is in communication with power fluid tubing 32, and flow path 160 in communication with pressure are 152; vent 182 then being closed by the upper portion of stem 176 when in the position shown. In such position, it is clear that power fluid pressure from tubing 32 acts on both ends of piston 150 which causes piston 150 to close power valve 148 because area 15~ is greater than area 154, resulting in a net upward force on piston 150.
Flow restructure 184 may comprise disc 1$6 mounted on the lower portion of stem 176, disc 186 being of such diameter and configuration as required to cause a suitable differential pressure across the disc when gas, vapor or liquid flows around the disc within vent path 188, formed axially within and through head 380 Compression coil spring 190 may be mounted around stem 176 below body 180 such that nut 186 may be adjusted along a threaded portion of stem 176 so as to create a desired compression load upon spring 190 and thereby prevent upward movement of stem 176 until a predetermined upward force on stem 176 is exceeded. Toe predetermined force must be greater than the differential force created across disc 184 by anticipated flowing gas through vent path 188 but less than the force caused by anticipated flowing liquid. Thus, as gas and vapor are vented from pump chamber 52 through path lS8, stem 176 remains in the lower position but when chamber 52 becomes filled with liquid, liquid ken flows upward through path 188 around disc 185 and creates an upward force on stem 176 sufficient to overcome the reload on spring 190 which in turn, causes stem 176 to move upwardly. As an alternate, selected weights may be used in place of spring 190 to provide the desired force. Plug 194 ~13) ~L232~
may be mounted on the upper end of stem 176 for cooperation with vent valve seat 196 formed concentrically within body 180, such that the contact of plug 194 with seat 196 limits the upward movement owe stem 176 and closes 05 vent path 188. The spacing of flow paths 160, '72 and 182, together with the length of recess 174, are such that when stem 176 is in the lowermost position, paths 160 and 172 communicate and path 182 is closed and when stem 176 is in the uppermost position, paths 160 and 182 COrQmUniCate and 10 path 172 is closed. Cylindrical body 180 may have flats cut on opposite sides as shown in Figure 6 from the - lowermost end of body 180 up to just below the level of seat 196 so as to allow the flow of gas and vapor to flow through seat 196 and out vent pipe 28 to the Waldo, 15 when stem 176 is in the lower position. Body 180 has no flats above seat 196 so as to font a seal around body 180 against the bore of path 188.
It can now be understood that a downward acting reload suitable or a given well condition may be 20 provided such that stern 176 remains in the lower possession dllring venting of gas and vapor from chamber 52, maintaining vent path lB8 open and maintaining pressure area 152 in communication with power fluid tubing 32 which in turn maintains power valve 148 closed as previously 25 explained. It can also now be understood that when pump chamber So fills with liquid, liquid begins to flow around disc 186 to create the differential force required to overcome the downwardly acting reload and thereby move stem 176 to its uppermost position which in turn closes 30 vent path 188 and flow path 172 while allowing pressure area 152 to vent through paths 160 and 182 which in turn causes power valve 148 to move down to the open position.
After assembly and installation of the invention as 35 illustrated in Figure 1, operation may be described as follows. Beginning with the configuration as depicted in I
(14) the drawings, power fluid is maintained under pressure within tubing 32 by a suitable fluid power source near the Waldo (not shown) as is well known in the art. Because the Donnelly pump is suspended below the liquid level 24 05 in the well bore, the liquid together with entrained gas and vapor may flow into pump chamber 52 through intake ports 22, the liquid level rising in chamber 52 while gas and vapor escape through vent path 188, through open seat 196 and up vent pipe 28 toward the Waldo. Immediately after chamber 52 becomes filled with liquid, liquid flows around disc 186 which causes stem 176 to rise and move plug 194 against seat 196 to thereby close vent path l88 as before explained. The upward movement of stem 176 also vents pressure area 152~ allowing power valve 148 to open and admit a flow of pressurized power fluid from tubing 32 through pressure area 158, flow path 146, tube 50, ports 88 and into chamber 89 to act against upper cap 80 in sufficient force to move plunger 74 upwardly against the force of liquid within chamber 52 and against the oil pressure within chamber 93 so as to cause liquid from chamber 52 to rise through path 142 past conventional.
standing valves 144 and upwardly to the Waldo through tubing 30. As upper cap 80 rises to contact the lower wall of head 38, the upward movement of plunger 74 is stopped which causes an increase of pressure within tubing 32 above the pressure necessary to raise the plunger Upon a conventional pressure switch mounted with tubing 32 at the Waldo sensing such pressure increase, the pressure within tubing 32 may be automatically vented by a motor valve which serves to reduce the pressure within chamber 83 to hydrostatic pressure only. Gas within chamber 102 having been recharged to a pressure suitable for given well conditions, is further compressed as plunger 74 moves upwardly, forcing oil from chamber 93, through ports 92, tube 70 and into the bottom of chamber 102 to cause liquid surface 104 to rise.
~15) Now, after reduction of pressure within chamber 89 to hydrostatic only, the oil pressure within chamber 93 driven by compressed gas within chamber 102 is sufficient to overcome hydrostatic pressure within chamber 89 and 05 return plunger 74 to the lowermost position which in turn reverses the flow of the power fluid and returns gas pressure within chamber 102 to the recharge pressure.
Power fluid returning upwardly through power valve 148 will move annular piston 166 upwardly against spring 170 to allow free return of power fluid regardless of the position of piston 150, until pressures above and below piston 166 are substantially equal at which time, spring 170 will force piston 166 to a lowermost position and thereby allow sealing contact with piston 150 to allow closure of valve 148.
As plunger 74 begins to descend from the uppermost position, a partial vacuum it created within chamber 52 which causes a downward differential pressure across plug 194 which acts together with said downwardly acting force to move stem 176 to its lowermost position and thereby reopen vent path 188, close vent 182 and admit power fluid prom tubing 32 through paths 172 and 160 to act against pressure area 152 to move piston 150 upwardly to effect closure of valve 148 and thereby return the pump to the first configuration, ready to begin another pump cycle.
A conventional flow sensor mounted with tubing 32 at the Waldo may be used to signal the motor valve to close and to cause repressurization of tubing 32, after return of the power fluid upon the return stroke of plunger OWE
As the pump stroke begins, sealing surface 94 of plunger 74 is not in contact with any of the seal rings 56 that serve to seal chamber 52 from the well bore. sediment that may settle from the liquid while chamber 52 is being filled will fall on the contoured upper surface of cap 80 to be directed towards ports 62. As plunger 74 begins to rise, a predetermined amount of liquid is forced out ~L~32~
116) through ports I so as to return such sediment to the well bore and down below the pump. Upon surface 94 rising high enough to contact the seal ring immediately above lantern ring 60, such flow through ports 60 ceases and liquid ox within chamber I becomes pressurized sufficiently to force it toward the Waldo. Surface 96 of seal rings 56 may be of a slightly smaller diameter than surface 94 so as to maintain sealing contact, rings 56 being cut at one part of its periphery so as to allow minute expansion of lo the ring and intimate contact ox sealing surfaces 94 and 96. Because both surfaces are harder than sand no sand cutting will occur, causing a higher efficiency and longer operating fife of the pump In some installations the pump may be operating with such a fast pump stroke that an excessive pressure buildup tends to occur within the pump chamber before flow to the surface within the production tubing begins due to the inertia of liquid within the production tubing. To prevent such a pressure buildup and to maintain a more constant Zoo rate of flow within the production tubing, surge chamber 34 may be provided, being suitably recharged with was above piston 35, to a pressure near the hydrostatic pressure within the production tubing Then as a pump stroke starts and a pressure surge tends to build up before the column of liquid begins to rise, liquid flows into conduit 36 to act upwardly on piston 35 and further compress the gas above it. us the column of liquid begins to rise, the pressure surge reduces and the compressed gas forces piston 35 back down to help continue the flow, even after standing valves 144 have closed. Surge chamber 34 may be rotated inwardly from the position shown so as to pass within the same size pipe that the Donnelly pump will pass. Surge chamber 35 may be assembled from conventional oilily tubing such that any required length may be readily assembled.
(17) ~32~
For slow stroking pump installations, surge control may be accomplished by controlling the pump stroke speed as described below, so as to start slow and increase the stroke speed as the column of liquid begins to rise.
05 Wells bored into the earth have infinite combinations of conditions such as depth, pipe diameter, pressures, fluid characteristics, temperature, pressure ratings of tubing joints and other equipment Therefore, it may be desirable under some well conditions to furnish fluid 10 power to the Donnelly pump at a constant pressure and to return spent power fluid from the pump up the production string, tubing 30, or up a separate return string, tubing 200 as depicted in Figure 9, both methods of return well known in the art. To operate the present invention by such 15 a method, alternate head 20~ may be provided to replace head 38~
Referring to Figure 8, conventional standing valves 144 are positioned to relieve produced liquid from pump chamber 52, through flow path 122 and to convey it to 20 tubing 30 as described above for Foggier. Tubing 32 is sealable attached Jo the upper end of head 202 so as to supply power fluid at a substantially constant pressure to flow path 204 formed axially within head 202 concentric with and below tubing 32. Now referring to Figure 9, 25 switching valve 206 may be positioned within bore 208 formed axially within head 202 and parallel to flow path 204 so as to protrude into chamber 52 as shown at 210 when in the looniest position, and reversibly movable to an uppermost position 212 as depicted by solid lines. When 30 valve 206 is in the uppermost position, recess 214 formed around a portion of valve stem 216 is positioned such that spent power fluid may return from tube 50 up through axially disposed flow path 218, through laterally disposed flow path 220 into path 208 via recess 214, thence into 35 flow path 222 in communication with return tubing 200.
Should it be desired to return power fluid through (18) I
production tubing 30, flow path 222 may be furnished with a suitable check valve not shown, and connected so as to communicate with tubing 30 instead of with tubing 200 to thereby allow flow from path 222 into tubing 30 but no 05 return flow. While chamber 52 is filling with liquid, valve 206 is held in the uppermost position by the hydrostatic pressure of spent power fluid acting against an upper enlarged end of stem 216 as at shoulder 224, the top end 226 of stem 216 being vented at that time. When fluid force acting against end 226 exceeds the fluid force acting against shoulder 224, valve 206 must move to the lowermost position such that shoulder 224 abuts shoulder 228 and recess 214 connects flow path 230 with path 220 and path 222 is sealed by stem 216 above recess 214.
Valve 232 is constructed the same as valve 162 previously described except that valve 232 vents pressure J
when in the lowermost position and repressurize when in the uppermost position. When valve 232 is in the lowermost position as depicted in Figure 9, fluid pressure acting against end 226 may be vented through lateral flow path 234 into valve 232 through recess 236 and thence out vent 238 to the well bore. check valve may be installed in vent 238 to prevent well fluid from entering the vent path. When valve 232 is shifted to the uppermost position, I vent path 238 is closed by the valve stem and recess 236 places flow path 234 in communication with flow path 240 which in turn is in communication with pressurized fluid flow path aye.
Operation of alternate head 202 may now be described, the remainder of the pump operating as described above. As gas and vapor are vented through valve 232, liquid rises within pump chamber 52 until it is filled whereupon it causes valve 232 to move to the uppermost position as described above for valve 162, thence causing power fluid to flow from path 204 through path 240, recess 236 and path 234 into chamber 225 to act against end 226 of valve I
stem 216 to overcome hydrostatic pressure against shoulder 224 and to cause stem 216 to move to the lowermost position such that path 222 is sealed by stem 216 and simultaneously paths 220 and 230 are placed in 05 communication via recess 214. Then pressurized power fluid may flow from path 204 into tube I so as to actuate the plunger as described above. As upper cap 80 approaches the top of the stroke, the cap contacts the lower end of stem 216 as at 210 and pushes the stem to the uppermost 10 position as at 212, whereupon, power fluid is allowed to return from tube 50 through recess 214 and path 222 and up the tubing to the Waldo As the plunger starts to descend, a vacuum is created in chamber I which causes valve 23~ to return to the lowermost position which causes recess 236 to vent pressure from chamber 225 through paths 234 and 238 such that hydrostatic pressure of spent power fluid may once again act on shoulder 224 to maintain valve 206 in the uppermost position in preparation for a subsequent pump cycle Because the pressure area against cap 80 is far greater than the pressure area against end 226 of stem 206, plunger 74 will easily move stem 216 upwardly and expel fluid prom chamber 225 through path 234, recess 236, path 240 and back into path 204 The return stroke speed of the plunger may be adjusted to the fastest reasonable speed consistent with proper operation by sizing ports 92 to restrict the flow of oil or by regulating the return flow of spent power fluid as by sizing ports-88 or by placing a flow restructure at any point along the spent power fluid return path including placing flow restructures at the source of pressurized power fluid. For some well conditions it may be desired to use only a gas chamber with no oil, for powering the return stroke of the plunger. Any suitable conventional flow restructures may be utilized, depending upon the position of installation and the flow and fluid (20) requirements The pump stroke speed may be independently regulated by adjusting the volume output at the source of fluid pressure mounted near the Waldo The pump stroke need be no faster Han is necessary to pump liquid from 05 the well at the rate the well is capable of producing to thereby reduce the size of the power unit required and to reduce the amount of power consumed to pump the well It may therefore be understood how to regulate the pump and return strokes independently of one another so as to use the minimum energy required to pump a given well.
New and timely methods, means and apparatus for pumping liquids from deep oil wells and the like may now be understood by study of these disclosures and review of the attached drawings.
It is now obvious that the present invention is well suited to attain the desired objectives and provide novel advantages for pumping oil and water from deep wells so as to conserve energy, to reduce maintenance requirements, to reduce costs, to extend equipment life and to recover 20- hydrocarbon deposits otherwise not feasible to recover.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Means for pumping liquid from a well comprising; a tubular member formed around a pump chamber;
an upper centrally disposed tube within the pump chamber sealably attached to an upper end of a centrally disposed fixed piston; a lower centrally disposed tube sealably attached to a lower end of said fixed piston; an annular plunger positioned within the pump chamber so as to allow for slidable sealing means between the outer surface of the plunger and an inner surface of the tubular member; the fixed piston having an outer diameter larger than the outer diameters of the tubes; the fixed pistons' outer periphery having means for slidable sealing contact with an inner diameter of the plunger the plunger having a reduced bore near each end thereof provided with means for slidable sealing contact with the tubes; means to inject fluid pressure alternately above and below the fixed piston within the plunger so as to selectively reciprocate the plunger up and down within the pump chamber so as to cause the pump to operate.
an upper centrally disposed tube within the pump chamber sealably attached to an upper end of a centrally disposed fixed piston; a lower centrally disposed tube sealably attached to a lower end of said fixed piston; an annular plunger positioned within the pump chamber so as to allow for slidable sealing means between the outer surface of the plunger and an inner surface of the tubular member; the fixed piston having an outer diameter larger than the outer diameters of the tubes; the fixed pistons' outer periphery having means for slidable sealing contact with an inner diameter of the plunger the plunger having a reduced bore near each end thereof provided with means for slidable sealing contact with the tubes; means to inject fluid pressure alternately above and below the fixed piston within the plunger so as to selectively reciprocate the plunger up and down within the pump chamber so as to cause the pump to operate.
2. The invention of Claim 1 wherein:
cooperating sealing surfaces between the plunger and the tubular member are harder than any particles contained in the fluid to be pumped; the sealing surface cooperating with the plunger sealing surface being harder than the plunger sealing surface.
cooperating sealing surfaces between the plunger and the tubular member are harder than any particles contained in the fluid to be pumped; the sealing surface cooperating with the plunger sealing surface being harder than the plunger sealing surface.
3. The invention of Claim 1 wherein: the sealing surfaces between the plunger and the tubular member are not in sealing engagement when the plunger is near a lowermost position of the plunger so as to allow for communication between the well bore and the pump chamber.
4. The invention of Claim 3 wherein:
cooperating sealing surfaces between the plunger and the centrally disposed tube are harder than any particles contained in the fluid to be pumped and one of said surfaces is harder than the other.
cooperating sealing surfaces between the plunger and the centrally disposed tube are harder than any particles contained in the fluid to be pumped and one of said surfaces is harder than the other.
5. The invention of Claim 1 further comprising:
the fixed piston and the tubes attached to the ends thereof being preloaded in tension so as to prevent buckling of the tubes upon operation of the pump.
the fixed piston and the tubes attached to the ends thereof being preloaded in tension so as to prevent buckling of the tubes upon operation of the pump.
6. The invention of Claim 1 further comprising:
at least one of said tubes being utilized to convey fluid to within the plunger.
at least one of said tubes being utilized to convey fluid to within the plunger.
7. The invention of Claim 1 further comprising:
clearance between the outer surface of the plunger and the inner surface of the tubular member being sufficient to prevent contact between the plunger and the tubular member upon operation of the pump.
clearance between the outer surface of the plunger and the inner surface of the tubular member being sufficient to prevent contact between the plunger and the tubular member upon operation of the pump.
8. The invention of Claim 1 or 7 wherein: the slidable sealing means between the plunger and the tubular member is sufficiently flexible to allow for limited eccentric movement of the plunger with respect to the tubular member such that normal flexing of the tubular member during installation or operation will not prevent normal operation of the pump
9. The invention of Claim 1 or 7 further comprising: radial clearance between the plunger and the tubular member sufficiently greater than clearance between the tubes and the plunger ends such that the tubes serve to guide the plunger ends without allowing contact between the plunger and the tubular member.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000556179A CA1249964A (en) | 1982-09-22 | 1988-01-08 | Downhole well pump |
| CA000556180A CA1249965A (en) | 1982-09-22 | 1988-01-08 | Downhole well pump |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US42150382A | 1982-09-22 | 1982-09-22 | |
| US06/421,503 | 1982-09-22 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000556179A Division CA1249964A (en) | 1982-09-22 | 1988-01-08 | Downhole well pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1232194A true CA1232194A (en) | 1988-02-02 |
Family
ID=23670795
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000434704A Expired CA1232194A (en) | 1982-09-22 | 1983-08-16 | Downhole well pump |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0119210A4 (en) |
| CA (1) | CA1232194A (en) |
| WO (1) | WO1984001191A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103883503B (en) * | 2014-04-15 | 2015-11-11 | 西安石油大学 | A kind of annular plunger small displacement rod-type pumping unit |
| US20180014878A1 (en) | 2016-07-13 | 2018-01-18 | Biosense Webster (Israel) Ltd. | Diaphragm pumps for medical applications |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE319487C (en) * | 1920-03-09 | Motorenbau Ges M B H Deutsche | Valveless pump, especially for pumping lubricating oil | |
| US2787225A (en) * | 1957-04-02 | rotter | ||
| US1448486A (en) * | 1921-09-15 | 1923-03-13 | George C Garraway | Pump |
| US1488987A (en) * | 1923-07-30 | 1924-04-01 | Earl W Hulsey | Oil-well pump |
| FR1067031A (en) * | 1952-11-21 | 1954-06-11 | Ateliers Et Chantiers Loire Sa | Improvements to reciprocating compressors |
| US2744469A (en) * | 1953-06-05 | 1956-05-08 | Edward J Schaefer | Valve structure for preventing air lock in pumps |
| US2862448A (en) * | 1957-07-29 | 1958-12-02 | Howard F Belding | Fluid operated well pumps |
| US3035609A (en) * | 1958-01-02 | 1962-05-22 | Phillips Petroleum Co | Fluid handling structure |
| US3632234A (en) * | 1969-11-04 | 1972-01-04 | Pump Specialties Inc | Method and apparatus for actuating a subsurface reciprocal well pump |
| DK151077C (en) * | 1974-10-11 | 1988-04-05 | Dansk Ind Syndikat | FLUIDUM VALVE VALVE |
| US4029442A (en) * | 1975-08-19 | 1977-06-14 | Edward Bleiweiss | High pressure piston pump and wiper, sealing, valving structure |
| US4120612A (en) * | 1976-01-22 | 1978-10-17 | Brown Kenard D | Automatic pump for deep wells |
-
1983
- 1983-08-11 WO PCT/US1983/001233 patent/WO1984001191A1/en not_active Application Discontinuation
- 1983-08-11 EP EP19830902739 patent/EP0119210A4/en not_active Withdrawn
- 1983-08-16 CA CA000434704A patent/CA1232194A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| WO1984001191A1 (en) | 1984-03-29 |
| EP0119210A1 (en) | 1984-09-26 |
| EP0119210A4 (en) | 1985-09-26 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |