RU119408U1 - Borehole PUMP PUMP FOR SMALL-DEVELOPING WELLS - Google Patents

Abstract

1. A downhole sucker rod pump containing a cylinder with a suction valve connected to the pipe string, a plunger with a delivery valve connected by rods with a wellhead drive, characterized in that the delivery valve is located on top of the plunger, which is made with a length greater than the length of the maximum working stroke of the wellhead drive, the cylinder is equipped with a sealed chamber of a larger diameter, in the lower part of which a suction valve is installed, while the valves are made with a capacity not less than the capacity of the plunger. ! 2. The downhole sucker rod pump according to claim 1, wherein the chamber is connected to the bottom of the cylinder. ! 3. The downhole sucker rod pump according to claim 1, wherein the chamber is connected to the top of the cylinder. ! 4. The downhole sucker rod pump according to claim 1, characterized in that the chamber is connected to the cylinder between its upper and lower parts. ! 5. A downhole rod pump according to one of claims 1, 2, 3 or 4, characterized in that the chamber is equipped with at least one additional suction valve installed in series with the suction valve and meeting the same conditions as the other valves. ! 6. A downhole rod pump according to one of claims 1, 2, 3 or 4, characterized in that the plunger is equipped with at least one additional discharge valve installed in series with the discharge valve and meeting the same conditions as the other valves. ! 7. The downhole sucker rod pump according to claim 5, characterized in that the plunger is equipped with at least one additional discharge valve installed in series with the discharge valve and meeting the same conditions as the other valves.

Description

The utility model relates to the oil industry and can be used for the operation of producing low-producing wells, including those with a high gas factor, with flooded and / or highly viscous products.

A well-known deep-well pumping unit (patent RU No. 2361115, F04B 47/02, published July 10, 2009), comprising a sucker rod pump comprising a cylinder, a suction valve, a plunger with a controlled discharge valve, connected to a string of pump rods with centralizers, a packer and a bypass device, characterized in that the downhole pumping unit below the bypass device is equipped with a hollow shank consisting of upper and lower parts, with an additional bypass device, a packer made in the form of self-sealing cuffs with a distance between a number of located self-sealing cuffs that exceed the distance between the ends of the pipes in the coupling joints of the production string and the stop, and below the packer and above the stop, the shank is provided with side openings, and an additional bypass device is made in the form of a cylinder connected to the bottom of the shank with side channels communicating with the inner cavity of the shank, and a hollow piston connected to the upper part of the shank, with the possibility of limited axial movement downward relative to the cylinder with g rmetichnym overlap between the side posts of the cylinder channels and the interior cavity of the shank.

The disadvantages of this pump are the complexity of manufacturing, installation and maintenance due to the presence of a shut-off packer and the need to lower and raise the entire assembly on the rod string, which makes it impossible to use the installation in wells with a depth of more than 1500 m, while the small cross-sections in the valves are significantly which increase the resistance of the fluid flow and, as a result, reduce the coefficient of performance (COP) when producing from low-production wells, especially with highly viscous and / or flooded (more than 80%) products it, as well as with a high gas factor (causing large pressure drops and gas evolution), with a high probability of failure of one of the valves and, as a consequence, the operation of the entire pump.

The closest is a borehole sucker rod pump (patent RU No. 2088805, F04B 47/00, publ. 08.27.1997), containing a cylinder with a suction valve, a plunger with a discharge valve, an coupling device and a drain device, characterized in that the coupling device is provided a centralizer case with an inner conical surface, the circumference of which contains conical dies pressed by a spring and a washer, meshed with a die holder, located in the through hole of a special sub connected to the center case a rotor and rods, and the drain device is provided with a housing with an inner conical surface, within which there are radial holes around the circumference and a conical sleeve placed inside it, the outer surface of which is cylindrical with radial holes placed on it and a conical groove between them, and inside there is a through step hole with grooves on its small diameter.

The disadvantages of this pump are the difficulty in manufacturing a large number of small, complex parts and small throughput sections in the valves, which significantly increase the resistance of the fluid flow and, as a result, reduce the efficiency when producing from low-production wells, especially with highly viscous and / or flooded (over 80%) products , as well as with a high gas factor (causing large pressure drops and gas evolution), while there is a high probability of failure of one of the valves and, as a consequence, the operation of the entire pump.

The technical task of the proposed utility model is to create a borehole sucker rod pump with high efficiency and low resistance for fluid flow in its entire structure, while reducing the likelihood of pump failure due to duplication of valve operation.

The technical problem is solved by a borehole sucker rod pump containing a cylinder with a suction valve connected to a pipe string, a plunger with a discharge valve connected by rods with a wellhead drive.

What is new is that the discharge valve is placed on top of the plunger, which is made longer than the maximum working stroke of the wellhead drive, the cylinder is equipped with a larger diameter hermetic chamber, in the lower part of which a suction valve is installed, while the valves are made with a throughput of at least the plunger throughput.

What is new is that the camera can be connected to the bottom of the cylinder.

What is new is that the camera can be connected to the top of the cylinder.

What is new is that the camera can be attached to the cylinder between its upper and lower parts.

What's new is that the chamber can be equipped with at least one additional suction valve installed in series with the suction valve and meeting the same conditions as other valves.

What's new is that the plunger can be equipped with at least one additional discharge valve installed in series with the discharge valve and meeting the same conditions as other valves.

Figure 1 shows a schematic diagram of a pump with a camera attached to the bottom of the cylinder.

Figure 2 shows a schematic diagram of a pump with a camera attached to the top of the cylinder.

Figure 3 shows a schematic diagram of a pump with a camera attached to the cylinder between its upper and lower parts.

Figure 4 shows a diagram of a chamber with an additional suction valve.

Figure 5 diagram of the plunger with an additional discharge valve.

The downhole sucker rod pump comprises a cylinder 1 (FIG. 1) with a suction valve 2 connected to a pipe string 3, a plunger 4 with a discharge valve 5 connected by a sucker rod 6 to a wellhead drive (not shown in FIG.). The discharge valve 5 is placed on top of the plunger 4, which is made of length L1 of length L (not shown in FIG. 1) —the maximum working stroke of the wellhead drive. The cylinder 1 is equipped with a sealed chamber 7 of a larger diameter, in the lower part of which a suction valve 2 is installed. Valves 2 and 5 are made with a capacity of at least the capacity of the plunger 4 to reduce the resistance to the flow of the pumped liquid.

The chamber 7 can be connected with the lower or upper (figure 2) part of the cylinder 1, as well as between (figure 3) its upper and lower parts of the cylinder 1. Moreover, the connection of the chamber 7 (figure 2) to the upper part of the cylinder 2, which it is connected to the pipe string 3 (FIG. 1), is used to reduce the additional load on the cylinder 1 (FIG. 2), caused by the weight of the chamber 7, during production of products difficult for the pump to operate: high-viscosity oils and / or products with high sulfur content and / or a tendency to form asphalt-paraffin deposits and emulsions. The connection of the chamber 7 (FIG. 1) to the lower part of the cylinder 1 is used at a high gas content in the produced product to prevent its collection in the upper part of the chamber 7. If the product difficult for the pump to produce also has a high gas content, use the connection of the chamber 7 (FIG. .2) to the upper part of the cylinder 1, but in the lower part of the cylinder 1, the space between the cylinder and the chamber 7 is sealed (for example: a sealing sleeve - not shown in Fig. 2) to eliminate additional load on the cylinder 1 and exclude collection Osya gas in the upper part of the chamber 7. The chamber 7 fitting (3) between the upper and lower portions of the cylinder 1 is used in all other cases, if it is necessary to simplify the manufacturing, assembly and maintenance of the pump and connected with the technological features of the design of the cylinder 1.

When mining complex products, especially if there is gas in it, for more reliable operation of the pump, it is necessary to duplicate valves 2 (Fig. 1) and / or 5 with one or more corresponding additional valves 8 (Fig. 4) and 9 (Fig. 5) - this is determined empirically during bench tests of a pump with similar products with which the pump will work. To duplicate the suction valve 2 (Fig. 4), the chamber 7 is equipped with at least one additional suction valve 8 with a throughput of at least the throughput of the plunger 4 (Fig. 1), and an additional suction valve 8 (Fig. 4) is installed in series with the suction valve 2 To duplicate the discharge valve 5 (Fig. 5), the plunger 4 is equipped with at least one additional discharge valve 9 with a throughput of at least the throughput of the plunger 4, with an additional discharge valve 9 are installed in series with discharge valve 5. Additional valves 8 (Fig. 4) and 9 (Fig. 5) operate synchronously with their corresponding valves 2 (Fig. 4) and 5 (Fig. 5), therefore, when describing the principle of pump operation, the valves 8 (FIG. 4) and 9 (FIG. 5) will not be negotiated.

Downhole sucker rod pump operates as follows.

Before the descent, the pump parameters are determined: the inner diameter D _{c of the} cylinder 1 (Fig. 1), which provides a cross-sectional area S _{c of the} cylinder 1 (for small wells, especially with complex production of the formation or layers, to reduce the load on the rods 6 choose cylinders 1 with a minimum S _c and a length L2, it is recommended that at least 1 m), under which a plunger 4 with an inner diameter that provides a cross-sectional area S is selected, productivity, from the well productivity, the working stroke length L of the wellhead drive and the number its reciprocating movements in a period of time. The performance of the pump Q is determined by the following formula:

where Q is the pump capacity per hour, m ³ / hour;

n is the frequency of operation of the wellhead drive, 1 / hour;

η is the efficiency of the pump;

Q _x - pump capacity for one reciprocating movement of the plunger 4, m ³ / n.

The performance of the pump for one reciprocating movement Q _{x of the} plunger 4 is determined by the formula:

where Q _x - pump capacity for one reciprocating movement of the plunger 4, m ³ / n;

n is the frequency of operation of the wellhead drive, 1 / hour;

S _c - the internal cross-sectional area of the cylinder 1, m ² ;

L is the length of the stroke of the wellhead drive, m;

_N D - internal diameter of the cylinder 1, m.

The field of which is selected by the length L1 of the plunger 4, which must be at least the maximum stroke length L of the wellhead drive (L1> L) in order to maintain the pump operability. To maintain the tightness of the connection of the plunger 4 with the cylinder 1 and to eliminate excessive metal consumption of the structure, the length L1 of the plunger 4 is recommended to be taken from the formula:

where L1 is the recommended length of the plunger 4, m;

L _max - the maximum length of the working wellhead drive, m

When the length L1 of the plunger 4 is longer than the length L2 of the cylinder 1 (L1> L2), the length L1 of the plunger 4 can be calculated by the formula:

where L1 is the recommended length of the plunger 4, m;

L _max - the maximum length of the working wellhead drive, m;

L2 - cylinder length 1, m.

The length L3 of the chamber 7 from the lower edge of the cylinder 1 to the suction valve 2 when the length L2 of the cylinder 1 is greater than the length L1 of the plunger 4 (L2> L1) is chosen equal to save materials:

where L3 is the recommended length of the chamber 7 from the lower edge of the cylinder 1 to the suction valve 2, m

When the length L1 of the plunger 4 is longer than the length L2 of the cylinder 1 (L1> L2), the length L3 of the chamber 7 is chosen not less than the length L1 of the plunger 4 without the length L2 of the cylinder 1 (L3≥L1-L2). The length L3 of the chamber 7 is calculated by the formula:

where L3 is the recommended length of the chamber 7 from the lower edge of the cylinder 1 to the suction valve 2, m;

L1 - the length of the plunger 4, m;

L2 - cylinder length 1, m.

To ensure minimal resistance to the flow of fluid pumped through the pump, it is necessary that the flow resistance at all points of the pump be no less than the flow resistance in plunger 4. The main indicator of flow resistance is the cross-sectional area of the product pipeline.

For the base, we take the cross-sectional area S of the plunger 4, determined by the formula:

where S is the cross-sectional area of the inner cavity of the plunger 4, mm ² ;

D _PL - the diameter of the inner cavity of the plunger 4, mm

Based on the cross-sectional area S of the plunger 4, we select the discharge valve 5. For this, the cross-sectional area S2 of the valve seat 5 is determined, which should be at least the cross-sectional area S of the plunger 4:

where S is the cross-sectional area of the inner cavity of the plunger 4, mm ² ;

S2 is the cross-sectional area of the valve seat 5, mm ² ;

D _SNK - diameter of the seat of the discharge valve 5, mm

Based on formulas (7 and 8) that the inner diameter D of the plunger 4 _pl and the diameter of the seat D _SNK valve 5 correspond to the following parameter:

Based on these parameters, a pressure valve 5 is selected, the housing 10 of which through the sub (not shown in Fig.) Is fixed on top to the plunger 4, and the total area S3 of the output channels 11 must be not less than the cross-sectional area S of the inner cavity of the plunger 4:

where S3 is the total area S3 of the output channels 11, mm ² ;

S is the cross-sectional area S of the inner cavity of the plunger 4, mm ² .

Then determine the internal cross-sectional area S _{tr of} the pipe string 3 in the zone of movement of the valve body 5 10, based on their cross-sectional area S _{to the} valve body 5 and the cross-sectional area S of the plunger 4:

where S _Tr - the internal cross-sectional area of the pipe string 3, mm ² ;

S _to - the outer cross-sectional area of the housing 10 of the valve 5, mm ² ;

S is the cross-sectional area of the inner cavity of the plunger 4, mm ² .

The internal cross-sectional area S _{tr of} the pipe string 3 is determined from the formula:

where S _Tr - the internal cross-sectional area of the pipe string 3, mm ² ;

D _Tr - the inner diameter of the pipe string 3, mm

The external cross-sectional area S _{to the} valve body 5 is determined from the formula:

where S _to - the outer cross-sectional area of the housing 10 of the valve 5, mm ² ;

D _to - the outer diameter of the housing 10 of the valve 5, mm

Based on the formulas (6, 7 and 8), we determine the internal diameter D _tr pipe string 3:

where D _Tr - the inner diameter of the pipe string 3, mm

D _to - the outer diameter of the housing 10 of the valve 5, mm

D _PL - the diameter of the inner cavity of the plunger 4, mm

Based on these parameters, choose pipe pipe string 3 to lower the cylinder 1 into the well.

Similarly, a suction valve 2 is selected (valve body 2 in Fig. Not shown) and the inner and outer diameters of chamber 7 of cylinder 1. It is possible that valves 2 and 5 will be taken to the same size as the pipes for pipe string 3 and chamber 7

Having determined the parameters of cylinder 1, plunger 4, valves 2 and 5, chamber 7 and pipe string 3, the pump is assembled. A chamber 7 with a suction valve 2 is attached from below to the cylinder 1 in compliance with the length L3 (for example: using a sub, not shown in Fig. And fixed in the right place outside the cylinder 1). The cylinder 1 on the pipe string 3 is lowered into the well (not shown in Fig.) In the installation interval. After that, the plunger 4 with the discharge valve 5 is attached to the rods 6, on which they are lowered into the pipe string 3, previously fixed at the wellhead, the interaction of the sub of the valve body 10 with the upper edge of the cylinder 1, which is fixed on the wellhead on the weight indicator (on Fig. not shown) in the form of reducing the weight of the rods 6. After which the wellhead is sealed with wellhead fittings (not shown in Fig.), the rod string is lifted (by 5 - 20 cm to exclude shock loads on cylinder 1 from interaction with the housing sub 10 during the reciprocating movement of the rods 6) and connected to the wellhead drive at lowest dead center.

The wellhead drive is launched and it transfers the reciprocating movement to the rods 6 and plunger 4. When the plunger 4 moves up and hermetically moves along cylinder 1, a vacuum is created in chamber 7, pressure valve 5 closes, suction valve 2 opens and fluid flows from the well into the chamber 7. When the plunger 4 moves downward, excessive pressure is created in the chamber, the suction valve 2 closes, the discharge valve 5 opens and the liquid from the chamber 7 flows into the pipe string 3. With a constant reciprocating m moving the plunger 4 relative to the cylinder 1 and the chamber 7, the fluid from the well flows into the pipe string 3, which rises to the surface.

Since cylinder 1 and plunger 4 of small diameter are used in this pump design, and the throughput of valves 2 and 5 is not less than the throughput of plunger 4 (i.e., fluid flow resistance is the minimum possible for a given plunger pair: cylinder 1 - plunger 4), this design allows you to work effectively in low-yield wells with maximum efficiency, including for the production of complex products, waterlogged oil and / and products with a high gas content due to minimal resistance to fluid flow and is duplicated the operation of the valves.

This design allows you to work effectively in low-yield wells with maximum efficiency, including for the production of complex products, waterlogged oil and / and products with a high gas content due to minimal resistance to fluid flow and duplication of valve operation.

Claims (7)

1. A well sucker-rod pump comprising a cylinder with a suction valve connected to a pipe string, a plunger with a discharge valve connected by rods with a wellhead drive, characterized in that the pressure valve is placed on top of the plunger, which is longer than the maximum stroke length of the wellhead drive, the cylinder is equipped with a sealed chamber of larger diameter, in the lower part of which a suction valve is installed, while the valves are made with a throughput of at least a throughput of the plunger a. 2. The well pump according to claim 1, characterized in that the chamber is connected to the lower part of the cylinder. 3. The well pump according to claim 1, characterized in that the chamber is connected to the upper part of the cylinder. 4. The well pump according to claim 1, characterized in that the chamber is connected to the cylinder between its upper and lower parts. 5. A well sucker-rod pump according to one of claims 1, 2, 3 or 4, characterized in that the chamber is equipped with at least one additional suction valve installed in series with the suction valve and meeting the same conditions as other valves. 6. A well sucker-rod pump according to one of claims 1, 2, 3 or 4, characterized in that the plunger is equipped with at least one additional discharge valve installed in series with the discharge valve and meeting the same conditions as other valves. 7. The well pump according to claim 5, characterized in that the plunger is equipped with at least one additional discharge valve installed in series with the discharge valve and meeting the same conditions as other valves.