FR3064314A1 - PUMP WITH DOUBLE TRAY AND DOUBLE BARREL - Google Patents

Abstract

The present invention relates to a pump (1) comprising two pump assemblies distributed symmetrically with respect to a plane perpendicular to the axis of a drive shaft (12), each pump assembly comprising a cylinder (4, 5 ), a plate (2, 3), an intake pipe (8, 9) and a discharge pipe (10, 11), the plates (2, 3) of each assembly being interconnected at the plane of symmetry.

Description

® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number: 3,064,314 (to be used only for reproduction orders)

©) National registration number: 17 52410

COURBEVOIE

©) Int Cl ⁸ : F 04 B 23/06 (2017.01), F 04 B 1/16, 1/22, 15/00

A1 PATENT APPLICATION

©) Date of filing: 23.03.17. © Applicant (s): IFP ENERGIES NOUVELLES Etablis- (30) Priority: public education - FR. ©) Inventor (s): PAGNIER PHILIPPE, TROST JULIEN and AVERBUCH DANIEL. (43) Date of public availability of the request: 28.09.18 Bulletin 18/39. (56) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ©) Holder (s): IFP ENERGIES NOUVELLES Etablisse- related: public. ©) Extension request (s): @) Agent (s): IFP ENERGIES NOUVELLES.

DOUBLE TRAY AND DOUBLE BARREL PUMP.

The present invention relates to a pump (1) comprising two pumping assemblies distributed symmetrically with respect to a plane perpendicular to the axis of a drive shaft (12), each pumping assembly comprising a barrel (4 , 5), a plate (2, 3), an intake pipe (8, 9) and a discharge pipe (10,11), the plates (2, 3) of each assembly being interconnected at the level of the plane of symmetry.

FR 3 064 314 - A1

The present invention relates to the field of pumps, in particular for high pressure and high flow pumping, in particular for drilling operations ranging from a few hundred meters to a few kilometers.

In the field of hydrocarbon production, it is currently observed that the boreholes must reach increasingly deeper depths, which implies working with ever higher injection pressures. Oil companies and service companies in the petroleum sector therefore need very high pressure pumps (for example for injection of drilling muds) to reach the required depths. They must also be reliable, economical, flexible and compact, in order to meet the increasingly demanding demands of the energy sector.

In general, crankshaft pumps are the most widespread in all sectors of industry: capital goods, the oil, gas and food industries, the automotive sector, construction (heating, wells, air conditioning, water pumps, etc.) and more specifically for water and waste treatment (water and sanitation network). To date, pumps of this type have a limited number of pistons (of the order of 5), due to the limitations of the size of the crankshaft which is also subjected to high stresses and sudden pressure variations which can intervene in the refoulement. These pumps therefore have limits in terms of power, pressure / flow torque (limited by "water hammer" generated by the sinusoidal pressure of the crankshaft), weight, efficiency and service life. In addition, they do not allow to have a variable displacement and therefore lack flexibility of use.

Another positive displacement pump technology is the barrel pump, also called a platter pump. For this type of pump, the pistons are distributed on a circle, unlike crankshaft pumps for which the pistons are aligned. Pumps designed with a barrel, operate using a plate system or a rotating barrel, which actuates the different pistons one after the other. When a piston is in the intake phase, the opposite piston is in discharge mode, which provides a constant flow upstream and downstream of the pump. The distribution of the positions of the pistons with guidance by the barrel ensures progressive distribution of the forces during the rotation of the shaft driven by the motor.

Mainly intended for pumping at lower pressure and flow (they are mainly used in the pumping of hydraulic oils), they offer many advantages:

Excellent weight / power ratio - Very good value for money

Interesting mechanical and volumetric yields Possibility of variable displacement by adjusting the inclination of the plate.

Generally speaking, there are three main barrel pump architectures:

Fixed barrel pumps (Figure 1): in this pump configuration 1, where the barrel is fixed, it is the inclined plate 2 which rotates (driven by the shaft 5) in order to generate the movement of the pistons 3 in their shirts 4. The connection between the pistons 3 and the plate 2 is then ensured by swivel shoes which rub on the plate 2. The advantage here is to have a very low inertia of the rotating parts. Rotary barrel pumps (Figure 2): within pump 1, the plate 2 is fixed and the barrel 6 carrying the pistons 3 is in rotation, thus ensuring the movement of the pistons 3 in their liners 4. The piston 3 - plate 2 connection is provided in the same way as for the first configuration. The advantage of this architecture is that one can easily make the plate adjustable in inclination and thus have the possibility of variable displacement. On the other hand, the inertia of the rotating parts increases significantly since the barrel and the set of pistons are rotated.

Barrel pumps with swash plate: the barrel is fixed in this architecture and there are two plates, a first inclined plate is in rotation and transfers to the second plate only the oscillation movement. Thus, the pistons can be linked to the second swash plate without the need for rubbing elements, for example with a connecting rod linked to the piston and to the plate by ball joints. It is the only architecture suitable for high pressure pumping due to the absence of friction elements (there are some of them on the geothermal market). It also offers excellent mechanical performance.

In the case of such barrel pumps, the number and diameter of the pistons, as well as the inclination of the plate, determine the desired flow rate for the pump. In fact, when the latter is operating, the pistons are in turn under high pressure, then at atmospheric pressure, so that the barrel / piston assembly prints a load on the plate, the module of which is spatially heterogeneous. Indeed, with regard to the intake pipe (atmospheric pressure) the load is relatively low, while with regard to the discharge pipe, the load is maximum.

Furthermore, when barrel pumps, whether rotary barrel, rotary plate or oscillating, are used in the field of very deep drilling combining high pressure and high flow, the forces applied by a large number of pistons can generate considerable efforts on the plate and the mechanical connections between the constituents which, in extreme conditions can generate a deformation of the plate or the breakage of a connection. In addition, the connections between the pistons and the plate provided, for example, by swivel pads, must be designed with a minimum of friction.

This load imbalance applied to the plate can induce significant forces on the plate and on the mechanical connections of the system, which leads to more bulky and more massive parts making the pump more energy-consuming. In addition, the connections between the pistons and the plate, for example by swivel shoes, can be inconceivable if the applied load is too great.

Also known is patent CN 103696920 which describes a hydraulic pump comprising two plates and two barrels each with a set of pistons. According to this design, the plates are placed at the opposite ends of the pump and the barrels are in the center, the pump then having only one inlet and only one delivery. However, such a pump involves independently dimensioning each of the plates, which can prove difficult in high pressure and high flow applications. In addition, such a configuration of the various elements of the pump does not allow a common adjustment of the inclination of the plates.

To overcome these drawbacks, the present invention relates to a double barrel, double plate and double inlet / outlet pump, the elements of each of the barrel-tray-inlet-outlet assembly being distributed along a drive shaft so as to reduce the stresses on the plates and the various mechanical connections, and thus reduce the risk of breakage.

The device according to the invention

The invention relates to a barrel pump comprising at least one drive shaft, a first pumping assembly and a second pumping assembly, each pumping assembly being formed of elements comprising at least one plate, a cylinder block, a pipe. inlet and discharge pipe, said cylinder block comprising at least two compression chambers distributed circumferentially, at least two pistons being in translation respectively in said compression chambers of said cylinder block of each of said assemblies, said plate of each of said two assemblies being inclined relative to the axis of rotation of said drive shaft, said drive shaft generating a relative movement in rotation between said plate and said cylinder block of each of said two assemblies.

According to the invention, said elements of said second set are distributed symmetrically with respect to said elements of said first set in a plane perpendicular to the axis of rotation of said drive shaft, and said plates of said two sets are interconnected at said plane of symmetry.

Advantageously, said inlet and outlet pipes of the same assembly can be placed in symmetry with respect to the axis of said drive shaft,

According to an implementation of the invention, said plates of said two assemblies can be formed in a single block.

According to an embodiment option, said plates of said two assemblies can be interconnected by connecting means passing through said plane of symmetry.

According to one implementation, said connecting means can comprise a pivot link arranged at a point situated substantially on the periphery of said two plates.

In accordance with a variant implementation of the invention, said relative movement in rotation may be a movement in rotation of said plate of each of said assemblies.

According to another variant of the invention, each of said assemblies may additionally comprise a swash plate, said swash plate of each of said assemblies being in pivot connection with said rotating plate of said same assembly.

According to another implementation option of the invention, said relative movement in rotation may be a movement in rotation of said cylinder block of each of said assemblies.

According to one implementation, the angle of inclination of said plate of each of said assemblies with respect to the axis of said drive shaft can be between 70 and 90 ° in absolute value.

Advantageously, said pump may include means for controlling the inclination of said plate of each of said assemblies relative to the axis of said drive shaft.

Furthermore, the invention relates to a use of said barrel pump for a drilling operation, in particular for the injection of drilling mud into a wellbore.

Brief presentation of the figures

Other characteristics and advantages of the device according to the invention will appear on reading the description below of nonlimiting examples of embodiments, with reference to the appended figures and described below.

FIG. 1, already described, illustrates a fixed barrel pump according to the prior art.

FIG. 2, already described, illustrates a rotary barrel pump according to the prior art.

FIG. 3 illustrates a pump according to a first embodiment of the invention.

Figure 4 illustrates a pump according to a second embodiment of the invention.

Detailed description of the invention

The present invention relates to a barrel pump. The purpose of the barrel pump is to pump a fluid (for example: water, oil, gas, drilling mud, etc.) by means of a linear displacement of several pistons. This type of pump has the advantage of being compact, having interesting mechanical and volumetric yields, an excellent weight / power ratio. The barrel pump according to the invention can be a fixed barrel, a rotary barrel, or a swash plate.

The barrel pump according to the invention generally comprises a casing, and within a casing comprises:

- a drive shaft: this is driven in rotation, relative to the casing by an external source of energy, in particular a driving machine (for example thermal or electric), in particular by means of a transmission (for example a gearbox);

- a first set of pumping elements, comprising at least one plate, a cylinder block (called barrel), an intake pipe and a discharge pipe and a second set of pumping elements, comprising at least the same elements as the first pumping assembly, the elements of each of these assemblies being distributed along the drive shaft. Conventionally, a cylinder block comprises at least two compression chambers (also called liners) distributed circumferentially (in other words the compression chambers are distributed in a circle), and at least two pistons in translation respectively in the compression chambers compression, the translation of the pistons within the compression chambers pump the fluid. The plates of each set can have substantially the shape of a disc. However, the trays can have any shape. Only the compression chambers (and the pistons) are distributed on a circle. Furthermore, conventionally, the fluid to be pumped passes through the intake pipe of one of the assemblies, enters a compression chamber of this assembly, is compressed and then discharged from the pump by the discharge pipe of this assembly.

Furthermore, according to the invention:

- the plate of each of the two sets is inclined relative to the axis of rotation of said drive shaft. The inclination of the plates influences the stroke of the pistons in the compression chambers and thus determines the displacement of the pump;

said drive shaft induces a relative rotational movement between said plate and said cylinder block of each of said two assemblies. Thus, according to the invention, the drive shaft can just as well rotate the plate as the barrel;

the distribution of the elements of the second set is symmetrical with respect to that of the elements of the first set along a plane perpendicular to the axis of rotation of the drive shaft, the plates of the two sets being interconnected at the level of the plane of symmetry. Thus, the barrel pump according to the invention comprises, from one end to another, first inlet and outlet pipes, a first barrel, a first plate, a second plate, a second barrel, and second lines inlet and outlet, all of which is traversed by a drive shaft.

Thus, according to the invention, the plates of each of the pumping assemblies are inclined at the same angle, in absolute value, and face each other. The forces applied to each of the plates by the translational movement of the pistons in each of the compression chambers of each of the cylinder blocks have the same standard but are of opposite direction. The plates of the two assemblies being interconnected, this configuration makes it possible to reduce the axial loads borne by the plates and by the mechanical plate-piston connections.

Advantageously, the intake pipe and the discharge pipe of each of the pumping assemblies can be placed in symmetry with respect to the axis of the drive shaft, or in other words the intake and discharge pipes of the same assembly face each other with respect to the drive shaft. Thus, the balance of axial forces at the level of the plate can be balanced more easily.

According to a first implementation variant of the invention, the drive shaft rotates the plates of each of the two assemblies, the rotational movement being considered relative to the pump housing. Thus, this first variant describes a fixed barrel pump. According to this variant, the rotary plate of a given assembly is inclined relative to the drive shaft at the same angle of inclination as the plate of the other assembly, each of the plates being moreover driven in rotation by the 'training tree.

According to a second implementation variant of the invention, the drive shaft rotates the cylinder block or barrel of each of the two pumping assemblies, the rotational movement being considered relative to the pump casing. Thus, this second variant describes a rotating barrel pump. According to this variant, the plates of each pumping assembly are fixed and inclined by the same angle of inclination in absolute value. For this variant, the rotating barrel of each pumping assembly induces a translational movement of the pistons in their respective compression chamber, via the connection of the pistons with the plate of their respective pumping assembly.

According to a third variant embodiment of the invention, each of the two pumping assemblies comprises at least two plates which are parallel to each other (and therefore both are inclined at the same angle at the same instant): a driven rotary plate in rotation by the drive shaft, and an oscillating plate driven in oscillation by the rotary plate, the oscillating plate being in pivot connection along the axis of the rotary plate relative to the rotary plate. Thus, according to this variant, the rotary plate transmits only the oscillating movement to the oscillating plate and does not transmit the rotary movement. According to this design, the pistons of each of the compression chambers of a given pumping assembly are driven by the swash plate of this assembly, for example by means of connecting rods (the connecting rods connect, by means of ball joints, the swash plate and the pistons so as to transform the oscillation movement into the translational movement of the pistons), and the translation of the pistons within the compression chambers pump the fluid. According to this variant of the invention, the rotary plate can be driven by the drive shaft by means of a finger ball joint, the position of the finger ball joint determining the inclination of the two plates (rotary and oscillating) by compared to the drive shaft. Recall that a ball-and-socket connection is a connection between two elements (here the drive shaft and the turntable), which has four degrees of connection and two degrees of relative movement; only two relative rotations are possible, the three translations and the last rotation being linked. Generally speaking, it is a ball joint with a finger preventing it from rotating.

According to an embodiment of the invention which can be applied for any of the variants described above, the plates of the two assemblies are formed in one piece. This reduces the fragility of the contact between the two plates, and therefore improves the reliability of the pump according to the invention.

According to an embodiment of the invention which can be applied for any one of the variants described above, the plates of the two assemblies are connected together by connecting means. Advantageously, the means for connecting the plates of the two assemblies comprise a pivot connection placed at a point situated substantially on the periphery of the two plates. Conventionally, the pivot connections are formed by bearings or bearings, promoting the relative movement of the elements. This pivot link allows adjustment of the inclination of the plates of each pumping assembly. Preferably, the means of connecting the plates of the two assemblies comprise, in addition to a pivot connection, at least one spacer element of variable length placed so as to reinforce the assembly formed by the two inclined plates and connected together by the pivot link.

Advantageously, the inclination of the plate or plates of each of the assemblies is continuously adjustable by means of control of the inclination of the plates, which allows a variable displacement. Indeed, the inclination of the plates influences the stroke of the pistons. Thus, the pump according to this variant allows good flexibility thanks to the continuous variation of the unit displacement. In addition, the pump according to this fourth variant allows a gradual start-up of the pump: for example, during start-up, the angle of inclination can be small, and subsequently, it can be increased according to the desired conditions. (fluid flow and pressure). This increases the reliability of the pump. According to an exemplary embodiment, the means for controlling the inclination of the plates interact with the connecting means connecting the plates of the two pumping assemblies. According to an embodiment of the invention in which the connection means comprise a pivot connection and a variable-height spacer element as described above, the means for controlling the inclination of the plates cooperate with the means for adjustment of the height of the spacer, so as to increase or reduce the spacing between the plates. According to an embodiment of the invention, the means for controlling the inclination of the plates is ensured by an endless screw.

According to an implementation of the invention, the pump according to the invention may comprise, in each cylinder block, a number of pistons of between three and fifteen, preferably between five and eleven. Thus, a high number of pistons provides a continuous flow upstream and downstream of the pump.

According to an embodiment of the invention which can be applied to any one of the variants described above, the angle of inclination of the plate or plates (a rotary plate in the case of the first variant, a fixed plate in the case of the second variant, or a rotary plate and an oscillating plate in the case of the third variant) of each set of pumping elements is between 70 ° and 90 ° in absolute value relative to the axis of l 'training tree. In other words, the plate or plates of one of the sets is inclined between 0 and 20 ° relative to the plane of symmetry of the first and second pumping sets, and the plate or plates of the other set is inclined between -20 ° and 0 with respect to this same plane of symmetry.

FIG. 3 shows, in an illustrative and nonlimiting manner, a section passing through the axis of rotation of the drive shaft of a barrel pump according to an embodiment of the invention. The pump 1 according to this illustrated embodiment is a pump of the rotating barrel type. This pump comprises a drive shaft 12, which is rotatably mounted in a casing (not shown). The drive shaft 12 is rotated by an external source, not shown, for example an electric machine and a gearbox. Pump 1 comprises two pumping assemblies distributed symmetrically with respect to one another along a plane of symmetry perpendicular to the axis of rotation of the shaft. The first (respectively second) assembly comprises a fixed plate 2 (respectively 3), a rotating barrel (or cylinder block) 4 (respectively 5), an intake pipe 8 (respectively 9), a discharge pipe 10 (respectively 11 ). In this figure, two pistons 6, 7 are shown per cylinder block, these pistons being arranged within their respective compression chamber and being connected to their respective plate by a swivel pad. The drive shaft 12 drives the barrel 4, 5 of each pumping assembly. The plates of each of the pumping assemblies are inclined relative to a plane perpendicular to the axis of rotation of the drive shaft at the same angle of inclination in absolute value. According to this implementation of the invention, the fixed plates 2, 3 of each set of pumping elements are linked together by a pivot link 13 and by a spacer element 14 the length of which can be variable. Thus, the plates facing directly and undergoing the same stress but in opposite directions, it is clear that the axial loads on the plate and on the mechanical plate-piston connections are reduced.

FIG. 4 shows a variant of the pump as shown in FIG. 3. In fact, the pump according to this nonlimiting example of embodiment of the pump according to the invention comprises, in addition, means for controlling the inclination of the plates 15 of each pumping assembly, in the form of an endless screw controlling the spacer element with variable length.

The invention also relates to the use of the pump according to the invention for a drilling operation, in particular for the injection of drilling mud into a wellbore. Indeed, the pump according to the invention making it possible to balance the distribution of the axial loads, it is possible to dimension a pump according to the invention so as to withstand high pressures and high flow rates. In fact, this improvement in the distribution of axial loads can make it possible to multiply the number of pistons in order to achieve the desired flow, and this, with a smaller radial size (pistons in greater number and smaller diameter). For example, the pump according to the invention can be dimensioned to operate up to pressures of the order of 1500 bars, that is to say 150 MPa. In addition, the pump according to the invention can be dimensioned to operate at flow rates varying from 30 to 600 m ³ / h.

Claims (11)

Claims 1) Barrel pump (1) comprising at least one drive shaft (12), a first pumping assembly and a second pumping assembly, each pumping assembly being formed of elements comprising at least one plate (2, 3 ), a cylinder block (4, 5), an intake pipe (8, 9) and a discharge pipe (10, 11), said cylinder block (4, 5) comprising at least two compression chambers distributed circumferentially, at least two pistons (6, 7) being in translation respectively in said compression chambers of said cylinder block (4, 5) of each of said assemblies, said plate (2, 3) of each of said two assemblies being inclined relative to the axis of rotation of said drive shaft (12), said drive shaft (12) generating a relative rotational movement between said plate (2, 3) and said cylinder block (4, 5) of each of said two assemblies, characterized in that said elements of said second set are distributed symmetrically with respect to said elements of said first set in a plane perpendicular to the axis of rotation of said drive shaft (12), and in that said plates (2, 3) of said two sets are interconnected at said plane of symmetry. 2) Pump according to claim 1, wherein said intake (8, 9) and discharge (10, 11) pipes of the same assembly are placed in symmetry with respect to the axis of said drive shaft (12 ). 3) Pump according to one of the preceding claims, wherein said pump (1) comprises control means (15) of the inclination of said plate (2, 3) of each of said assemblies relative to the axis of said shaft d drive (12). 4) Pump according to one of claims 1 or 2, wherein said plates (2, 3) of said two sets are formed in one block. 5) Pump according to one of claims 1 to 3, wherein said plates (2, 3) of said two assemblies are interconnected by connecting means (13, 14) passing through said plane of symmetry. 6) Pump according to claim 5, wherein said connecting means (13, 14) comprises a pivot connection (13) disposed at a point located substantially at the periphery of said two plates (2, 3). 7) Pump according to one of the preceding claims, wherein said relative rotary movement is a rotary movement of said plate (2, 3) of each of said assemblies. 5 8) Pump according to claim 7, wherein each of said assemblies further comprises a swash plate, said swash plate of each of said sets being in pivot connection with said rotating plate (2, 3) of said same assembly. 9) Pump according to one of claims 1 to 6, wherein said relative movement in 10 rotation is a rotational movement of said cylinder block (4, 5) of each of said assemblies. 10) Pump according to one of the preceding claims, wherein the angle of inclination of said plate (2, 3) of each of said assemblies relative to the axis of said shaft 15 drive (12) is between 70 and 90 ^e in absolute value. 11) Use of said barrel pump according to one of the preceding claims for a drilling operation / in particular for the injection of drilling muds into a wellbore. 1/3 Prior art Figure 2 2/3