Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
  • E21B43/121—Lifting well fluids
  • E21B43/126—Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
  • E21B43/121—Lifting well fluids
  • E21B43/126—Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive
  • E21B43/127—Adaptations of walking-beam pump systems
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/34—Arrangements for separating materials produced by the well
  • E21B43/38—Arrangements for separating materials produced by the well in the well
• • 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
  • F04B47/02—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps the driving mechanisms being situated at ground level
• • 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
  • F04B47/02—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps the driving mechanisms being situated at ground level
  • F04B47/026—Pull rods, full rod component parts
• • 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
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/10—Valves; Arrangement of valves
• • 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
  • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
  • F04B53/14—Pistons, piston-rods or piston-rod connections
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B2200/00—Special features related to earth drilling for obtaining oil, gas or water
  • E21B2200/04—Ball valves

Definitions

• the present invention relates to downhole pumps (also known as bottom-hole pumps). More specifically, the present invention relates to downhole pumps comprising means for preventing gas lock.
• the sucker-rod string is connected to a device known as a pumping unit, whose function is to convert the rotary motion of a conventional motor into a reciprocating motion with slow rotation to the sucker rod, which in its turn transfers it to the pump installed at the bottom of the well.
• a pumping unit whose function is to convert the rotary motion of a conventional motor into a reciprocating motion with slow rotation to the sucker rod, which in its turn transfers it to the pump installed at the bottom of the well.
• bottom checking which consists of repositioning the travel of the pump so that at the end of the descending cycle, the piston collides with the barrel, causing maximum reduction of the dead space between piston and standing valve, which reduces the possibility of accumulation of gas and helps to ensure that the maximum amount of gas is expelled.
• Document W02008153698A1 discloses a downhole pump for removing volumes of liquids, such as oil, gases and production water, from oil wells.
• the pump described in that document comprises, among other elements: a chamber for gas separation, with a standing valve; a piston with a travelling valve; and an actuator of the travelling valve.
• the actuator of the travelling valve consists of a pin that actuates the ball of the valve, opening the travelling valve, in order to equalize the pressure between the interior of the piston and the separating chamber, preventing blocking by gas.
• WO2008153698A1 makes use of a pin for actuating the ball valve of the travelling chamber, so that, owing to the repeated movements of the valve, the pin is subjected to a high mechanical force, making it very susceptible to fractures.
• Document US3215085A discloses a configuration of standing valve for a downhole plunger pump. This document specifically envisages that, fixed to the standing valve, a means is provided for actuating the ball of the travelling valve fixed to the piston, when the piston is at the lowest point of its travel. In the configuration presented in this document, a pin is adopted for actuating the ball of the travelling valve. Thus, it makes it possible for gas trapped in the stationary assembly (separating chamber) to be directed to the interior of the piston, preventing blocking of the pump by gas.
• the downhole pump disclosed in document US3215085A makes use of a pin for actuating the ball valve of the travelling chamber, so that, owing to the repeated movements of the valve, the pin is subjected to a high mechanical force, which makes it very susceptible to fractures.
• Document US7909589B2 discloses a downhole pump that comprises a separating chamber, with a standing valve, and a piston, with a travelling valve, in which the piston is divided into two parts.
• a chamber for trapping sand is provided between the two parts of the piston, to prevent sand present in the pumped fluid entering the piston.
• orifices are also provided between the two parts of the piston, which allow fluid communication between the interior of the piston and the separating chamber (balancing).
• these orifices allow the internal pressure of the piston and the pressure of the separating chamber to be equalized, thus preventing blocking of the pump by gas.
• a channel is maintained between the piston and the inside wall of the separating chamber, via which a fluid (such as gas) can drain away.
• the oil being pumped comprises a number of impurities such as sand and mud
• the channel maintained between the piston and the inside wall of the separating chamber is liable to obstruction, which could cause blocking of the pump by gas.
• Document US8858187B2 discloses a downhole pump that comprises a filter provided in the piston adapted for separating the interior of the piston from the separating chamber.
• the filter comprises openings that allow passage of fluid with the aim of balancing the pressure inside the piston and in the separating chamber, thus preventing blocking of the pump by gas.
• the oil being pumped comprises a number of impurities such as sand and mud
• the channel maintained between the piston and the inside wall of the separating chamber is liable to obstruction, which could cause blocking of the pump by gas.
• Document US6273690B1 discloses a downhole pump that comprises a piston and a separating chamber, with standing and travelling valves, in which a channel is provided between the piston and the separating chamber so as to provide communication around the piston.
• the channel is kept open when the piston is in the highest position of its travel, and is kept closed when the piston is in the lowest position of its travel.
• the object described ensures that the internal pressure of the piston is equalized with the pressure of the separating chamber.
• the oil being pumped comprises a number of impurities such as sand and mud
• the channel maintained between the piston and the separating chamber is liable to obstruction, which could cause blocking of the pump by gas.
• the present disclosure aims to solve the problems of the prior art described above in a practical and efficient manner.
• the present disclosure aims to provide a downhole pump for onshore oil production capable of substantially minimizing the gas lock effect.
• a downhole pump comprising at least one of an extension wall; a barrel that extends vertically to the interior of the extension wall; a gas separating chamber delimited by the barrel and the interior surface of the extension wall; and a piston comprising a travelling valve in its lower portion, wherein the piston is configured to slide vertically in the barrel to the interior of the separating chamber between an upper end of stroke position and a lower end of stroke position; wherein the piston comprises at least one venting orifice, wherein the at least one venting orifice is configured to provide communication between the interior of the piston and the gas separating chamber when the piston reaches the lower end of stroke position, wherein, in the lower end of stroke position, the venting orifice is positioned below the barrel.
• the piston comprises a plurality of venting orifices.
• the venting orifices are located at the same horizontal position on the piston.
• venting orifices have different dimensions.
• the at least one venting orifice provides fluid communication between the interior of the piston and the separating chamber in the uppermost region of the separating chamber
• the pump further comprises a nipple configured to be connected to a lower end of a production pipe between the barrel and the production pipe
• the pump further comprises an end-of-stroke sleeve configured to be connected to the sucker rod, wherein the nipple is adapted to interrupt the descending motion of the end-of-stroke sleeve when the piston reaches the lower end of stroke position.
• the end-of stroke sleeve is configured to be connected at an end of the sucker rod, wherein the pump further comprises a connecting rod which connects the end-of-stroke sleeve to the piston
• the end-of-stroke sleeve is configured to be adjustably connected to the sucker rod.
• the extension wall is an extension of the barrel, the interior of the extension wall having a larger diameter than the interior of the barrel.
• the gas separating chamber comprises a standing valve.
• the piston is configured to be driven by a sucker rod.
• venting orifice is configured not to provide communication between the interior of the piston and the gas separating chamber when the piston is away from the lower end of stroke position.
• a bottom-hole pump with gas separator and anti-gas lock orifice comprising: a nipple (5) connected to a lower end of a production pipe (2), and comprising a barrel (6) that extends vertically to the interior of an extension wall (10) of the pump; a gas separating chamber (11 ) comprising a standing valve (9), wherein the gas separating chamber (11 ) is delimited by the barrel (6) and the extension wall (10) of the pump; and a piston (7) comprising a travelling valve (8) in its lower portion, wherein the piston (7) is driven by the sucker rod (3), and adapted to slide vertically in the barrel (6) to the interior of the separating chamber, the bottom-hole pump being characterized in that the piston (7) comprises at least one venting orifice (12), wherein the at least one venting orifice (12) is adapted for providing communication between the interior of the piston (7) and the gas separating chamber (11 ) when the piston (7) reaches an end of stroke position,
• the piston (7) comprises a plurality of venting orifices, wherein the venting orifices are positioned in one and the same horizontal line.
• the venting orifices comprise different dimensions.
• the at least one venting orifice (12) provides fluid communication between the interior of the piston (7) and the separating chamber (11 ) in the uppermost region (110) of the separating chamber (11 ).
• the pump comprises an end-of-stroke sleeve (4) fixed to the sucker rod (3), wherein the nipple (5) is adapted to interrupt the descending motion of the end-of-stroke sleeve (4) when the piston (7) reaches a lowest position of travel.
• the end-of-stroke sleeve (4) is fixed in a final position of the sucker rod (3), wherein a connecting rod (13) is adopted, connecting the end- of-stroke sleeve (4) to the piston (7).
• end-of-stroke sleeve (4) is connected adjustably to the sucker rod (3).
• Fig. 1 illustrates a schematic view of the downhole pump with gas separator and anti-gas lock orifice according to an optional configuration of the present disclosure.
• Fig. 2 illustrates a schematic view of the detail of the operation of the venting orifice of the piston illustrated in Fig. 1.
• Fig. 3a illustrates a schematic view of the downhole pump with gas separator and anti-gas lock orifice from Fig. 1 in the initial position of the cycle.
• Fig. 3b illustrates a schematic view of the downhole pump with gas separator and anti-gas lock orifice from Fig. 1 in an initial position of the ascending cycle.
• Fig. 3c illustrates a schematic view of the downhole pump with gas separator and anti-gas lock orifice from Fig. 1 in an initial position of the descending cycle.
• Fig. 3d illustrates a schematic view of the downhole pump with gas separator and anti-gas lock orifice from Fig. 1 in the final position of the cycle.
• the present disclosure relates to a downhole pump preferably for onshore use.
• a pump of this type is usually installed at the bottom of a production well.
• Such a pump can be connected to a sucker-rod string of sufficient length so that the other end reaches the surface.
• the sucker-rod string can be connected to a device known as a pumping unit.
• the function of the pumping unit is to convert the rotary motion of a conventional motor into a reciprocating motion and slow rotation for the sucker rod.
• the sucker rod can in turn transfer the motion to the pump installed at the bottom of the well.
• a downhole pump as illustrated schematically in Fig. 1 , which illustrates an optional configuration of the bottom-hole pump with gas separator and anti-gas lock orifice, comprising:
• a nipple 5 connected to a lower end of a production pipe 2, and comprising a barrel 6 that extends vertically to the interior of an extension wall 10 of the pump;
• a chamber for gas separation comprising a standing valve 9, wherein the separating chamber is delimited by the barrel 6 and the extension wall
• a piston 7 (also known as a plunger) comprising a travelling valve 8 in its lower portion, wherein the piston 7 is driven by the sucker rod 3, and adapted for sliding vertically in the barrel 6 to the interior of the separating chamber.
• a downhole pump comprising one or more of an extension wall 10; a barrel 6 that extends vertically to the interior of the extension wall 10; a gas separating chamber 11 comprising a standing valve 9, wherein the gas separating chamber 9 is delimited by the barrel 6 and the interior surface of the extension wall 10; and a piston 7 comprising a travelling valve 8 in its lower portion, wherein the piston is configured to slide vertically in the barrel 6 to the interior of the separating chamber between an upper end of stroke position and a lower end of stroke position; wherein the piston 7 comprises at least one venting orifice 12, wherein the at least one venting orifice 12 is configured to provide communication (i.e. fluid communication) between the interior of the piston and the gas separating chamber
• the piston 7 may be configured to be driven by a sucker rod 7.
• the extension wall 10 may take the form of a cylindrical wall.
• the cylindrical wall may have a side portion and a bottom portion.
• the standing valve 9 may be disposed in the bottom portion.
• the interior of the pump defines a volume formed by the interior of the barrel 6 and the extension wall 10.
• the barrel 6 has a smaller interior diameter than the extension wall 10.
• the extension wall 10 may be thought of as an extension of the barrel, with a larger interior diameter.
• the exterior diameters of the barrel 6 and the extension wall 10 may be substantially the same, as shown in Figure 1.
• a nipple 5 (also known as a seating nipple) may be provided above the barrel 6.
• the nipple 5 may be positioned at the top of the pump to allow a connection to a production pipe 2.
• the barrel 6 may be considered as part of the nipple 5, or alternatively, the barrel 6 can be considered as a separate part, with the nipple being positioned between the production pipe 2 and the barrel 6.
• the extension wall 10, barrel 6, and, where present, the nipple 5 may be considered to form a main body of the pump.
• the gas separating chamber 11 is defined by the space between the side and bottom walls of the extension wall 10, and the boundary between the extension wall and the barrel 6.
• the gas separating chamber 11 may comprise a standing valve 9.
• the standing valve 9 may be located at the bottom of the gas separating chamber 11 (i.e. in the bottom wall of the extension wall 10).
• the oil extracted from the well consists of a mixture of molecules, some of which are in a gas phase and some of which are in a liquid phase.
• the separating chamber 11 promotes phase separation of the mixture extracted from the well, wherein the gas phase tends to be displaced and to accumulate in the upper portion 110 of the separating chamber 11 , and the liquid phases are displaced and accumulate in the lower portion 111 of the separating chamber 11.
• the piston 7 of the downhole pump of the present disclosure comprises at least one venting orifice 12.
• the venting orifice 12 is adapted for providing fluid communication between the interior of the piston 7 and the gas separating chamber 11 when the piston 7 reaches the lower end of stroke position.
• the venting orifice 12 is positioned below the barrel 6.
• the venting orifice 12 is an opening in the wall of the piston which allows gas to pass from the gas separating chamber 11 to the interior of the piston 7 when the piston 7 is at its lowest position.
• the venting orifice 12 is configured not to provide communication between the interior of the piston 7 and the gas separating chamber 11. This may be because the orifice 12 can be blocked by the inner wall of the barrel 6. This may occur because the inner diameter of the barrel 6 may be smaller than the inner diameter of the extension wall 10.
• the state in which the piston 7 is considered to be away from the lower end of stroke position may be, for example, when the piston 7 is in the upper 90% of its travel. Any other suitable proportion of the stroke may also be chosen.
• Fig. 2 illustrates a schematic view of the detail of the operation of the venting orifice 12 of the piston 7 illustrated in Fig. 1.
• this chamber is expected to have a pressure greater than that of the interior of the piston 7, but the pressure difference between the separating chamber 11 and the piston 7 is not sufficient to actuate (i.e. open) the travelling valve 8.
• Figs. 3a, 3b, 3c, and 3d illustrate, respectively, the pump from Fig.
• the initial and final positions represent the same position of the pump, or of the piston 7, since at the end of a cycle, the pump begins a new cycle immediately.
• the initial position of the piston 7 represents the point where the piston 7 reaches the lower end of stroke position, i.e. the lowest position of its travel.
• the upper end of stroke position is the position of the piston 7 at which the piston stops ascending (as shown in in Figure 3b) and starts descending again. It will be understood that in each cycle, the piston 7 travels from the lower end of stroke position, to the upper end of stroke position, and back down to the lower end of stroke position.
• the piston 7 comprises only one venting orifice 12
• a plurality of venting orifices may optionally be provided in the piston 7.
• these orifices are positioned on one and the same horizontal line.
• the orifices may comprise different sizes (i.e. be of different dimensions).
• others can provide fluid communication between the interior of the piston 7 and the separating chamber 11.
• the varying sizes of orifices 12 may allow at least one orifice to remain clear of obstructions if the obstruction is made up of particles of a particular size, because those particles may block an orifice of a certain size, but pass through an orifice of a different size.
• venting orifice 12 remains obstructed by the barrel 6 of the pump, so that the venting orifice 12 is only in communication with the separating chamber 11 when the piston 7 is closer to its lower end of stroke.
• venting orifice 12 only provides communication between the interior of the piston 7 and the separating chamber 11 in the uppermost region 110 of the separating chamber 11 , which normally is only filled with the gas phase.
• an end-of-stroke sleeve 4 connected (or fixed) to the sucker rod 3.
• the nipple 5 may be adapted to interrupt the descending motion of the end-of-stroke sleeve 4 when the piston 7 reaches a lowest position of travel.
• the lowest position of travel is such that the venting orifice 12 is positioned below the barrel 6. This can allow fluid communication between the interior of the piston 7 and the separating chamber 11.
• “fixed” need not mean“permanently fixed” and that any suitable attachment or connection may be used.
• the end-of-stroke sleeve 4 may be fixed at the end of the sucker rod 3, wherein a connecting rod 13 is adopted, connecting the end-of- stroke sleeve 4 to the piston 7.
• the pump may comprise a connecting rod 13 between the end-of-stroke sleeve 4 and the piston 7 to provide a connection between the sucker rod 3, end-of stroke sleeve 4 and piston 7.
• a connecting rod 13 need not be provided, and the end-of-stroke sleeve 4 may be directly connected to the piston or connected to the piston using an arrangement other than a connecting rod 13.
• the end-of-stroke sleeve 4 may be connected adjustably to the sucker rod 3.
• the limit position of end of stroke defined by the position of the sleeve 4 may be adjustable.
• the standing and travelling valves 8,9 may be any that are known from the prior art, so that this feature does not limit the scope of protection of the invention.

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• Engineering & Computer Science (AREA)
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• Life Sciences & Earth Sciences (AREA)
• Mining & Mineral Resources (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
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• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Details Of Reciprocating Pumps (AREA)
• Reciprocating Pumps (AREA)
• Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

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Citations (10)

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• 2018
  • 2018-02-19 BR BR102018003152-0A patent/BR102018003152B1/pt active IP Right Grant
• 2019
  • 2019-02-19 CA CA3091553A patent/CA3091553A1/en active Pending
  • 2019-02-19 WO PCT/GB2019/050445 patent/WO2019158952A1/en unknown
  • 2019-02-19 CN CN201980026724.4A patent/CN112105794B/zh active Active
  • 2019-02-19 MX MX2020008621A patent/MX2020008621A/es unknown
  • 2019-02-19 AU AU2019221823A patent/AU2019221823A1/en active Pending
  • 2019-02-19 EP EP19707097.2A patent/EP3755877B1/en active Active
  • 2019-02-19 US US16/970,905 patent/US20200386087A1/en active Pending

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