Rod borehole pumping units (shsnu). Rod pumps

Oil production with rod pumps is the most common method of artificially lifting oil, which is explained by their simplicity, efficiency and reliability. At least two thirds of the existing production wells are operated by SRP units.

Concrete pumps have the following advantages over other mechanized methods of oil production:

• have a high efficiency;
• repair is possible directly at the fields;
• different drives can be used for prime movers;
• SRP units can be used in complicated operating conditions - in sand-producing wells, in the presence of paraffin in the produced oil, with a high GOR, when pumping out a corrosive liquid.

Rod pumps also have disadvantages. The main disadvantages include:

• limitation on the depth of the pump descent (the deeper, the higher the probability of rod breakage);
• low pump flow;
• restriction on the inclination of the wellbore and the intensity of its curvature (not applicable in deviated and horizontal wells, as well as in highly deviated vertical ones)

A deep-well rod pump in its simplest form (see figure on the right) consists of a plunger moving up and down a well-fitting cylinder. The plunger is provided check valve, which allows the liquid to flow up but not down. The non-return valve, also called a poppet valve, in modern pumps is usually a ball-and-seat valve. The second suction valve is a ball valve located at the bottom of the cylinder and also allows liquid to flow upwards but not downwards.

Rod pump refers to a positive displacement pump, the operation of which is provided by the reciprocating movement of the plunger with the help of a ground drive through a connecting body (rod string). The top bar is called polished stem, it passes through the stuffing box at the wellhead and is connected to the balance head of the pumping unit using a traverse and a flexible rope suspension.

The main units of the USHGN drive (pumping unit): frame, stand in the form of a truncated tetrahedral pyramid, 6 balancer with a swivel head, a traverse with connecting rods hinged to the balance bar, a gearbox with cranks and counterweights, are equipped with a set of interchangeable pulleys to change the number of swings. For quick change and tension of belts, the electric motor is mounted on a rotary slide.

Rod pumps are plug-in (NSV) And non-inserted (NSN).

Plug-in rod pumps are lowered into the well in assembled form. First, a special locking device is lowered into the well on the tubing, and the pump on the rods is lowered into the already lowered tubing. Accordingly, to change such a pump, it is not necessary to once again lower and raise the pipes.

Non-insert pumps are lowered semi-disassembled. First, the pump cylinder is lowered onto the tubing. And then a plunger with a check valve is lowered on the rods. Therefore, if it is necessary to replace such a pump, it is necessary to lift the plunger on the rods from the well first, and then the tubing with the cylinder.

Both types of pumps have their advantages and disadvantages. For each specific condition, the most suitable type is used. For example, subject to the content in oil a large number paraffin, it is preferable to use non-inserted pumps. Paraffin deposited on the tubing walls can block the possibility of lifting the plug pump plunger. For deep wells, it is preferable to use an insert pump to reduce the time required to trip the tubing when changing the pump.

Installation and descent of USHGN

For lowering into the well, a revised (repaired) SRP with an operational certificate is imported. Disassembly of the pump on the well is prohibited.

The pump is exposed visual inspection: the stroke of the plunger in the cylinder is checked, the marking of the pump is checked against passport details,

the plunger stroke is checked, the condition threaded connections, extension pipe, filter or HPU.

Before carrying out a trip, the working platform and receiving walkways must be cleaned of dirt.

The SRP is lowered into the well according to the layout specified in the work plan (work order).

Before descent, the length of pipes and rods is measured, and a measure is drawn up.

When descending pipe pump first you need to lower the protective device (HPJ, filter, etc.), then the cylinder with a suction valve, with a branch pipe and a coupling for the elevator and tubing to the required depth.

Tubing, lowered into the well for inner surface must be free of salt deposits, paraffin, scale and dirt. To check the condition of the inner surface, as well as to confirm the flow area (especially when running NN2B - 57 and plug-in SRPs of all sizes), tubing is templated with a template:

After lowering the tubing, check and, if necessary, replace the hanger pipe on the faceplate, and after working out the SRP for more than one year, the hanger pipe must be changed without fail.

After landing the faceplate on the flange of the column head, the plunger is lowered on the rods. Without allowing the last three rods, flush the pump with a killing liquid, in a volume of at least 16 m 3, to clean the pump from possible mechanical impurities, scale, etc. When completing the assembly with an automatic coupler, the plunger is lowered in the cylinder, having previously screwed on the coupler assembly (spike or grip), and then the rod string is lowered.

The insertion pump is lowered in the following sequence:

Protective device (gas anchor, sand anchor, filter, etc.);

Castle support;

After landing the faceplate on the flange of the casing head, the insertion pump is lowered into the tubing string on the sucker rods.

Sucker rods lowered into the well must be straight and clean (without any deposits and damage). outer surface rod bodies, their threaded connections and couplings).

The last three rods should be lowered at low speed, in order to avoid a sharp landing of the plunger into the pump or the plug-in pump into

lock seat, otherwise it may lead to galling of the plunger or damage to the seat of the lock seat.

When tripping rods with scrapers-centrators, it is necessary to use a guide cone-shaped funnel to prevent chipping of scrapers-centrators. The speed of descent of the rods is 0.25 m/s, while it is necessary to make visual control over the integrity of all centralizer scrapers.

After lowering the pump into the well to the required depth, it is necessary to adjust the pump rod string to ensure normal operation rod pump.

Plunger seating is the most critical operation. When the plunger is admitted to the cylinder, the last rod is lowered slowly to prevent it from hitting the cylinder. lower part pump.

Turning the entire string of sucker rods with a circular wrench clockwise (no more than two turns), slowly insert the plunger into the cylinder.

When the landing is made, make a mark on the rods, raise them and plant them again. If the mark on the upper (control) rod remains in the same place, then the plunger is in the pump.

After that, the stroke of the plunger is adjusted using the lifting unit.

The rods are carefully raised until the IVE-50 - an electronic indicator - weights fixes the weight of the entire column of rods, after which a second mark is made on the upper (control) rod. To the distance between the first and second marks, the correction for the extension of the rods during the operation of the SRP is added, and the total distance will be 350-400 mm.

In addition to the total distance, the distance corresponding to the height of the SUSG and the lower position of the head of the balancer of the pumping unit is marked on the upper (control) bar.

Raise the upper (control) rod, unscrew and measure the polished rod with this rod, if the upper (control) rod corresponds to the length of the polished rod, then it is replaced with a polished rod. Polished rods are produced with a diameter of 32 mm and a length of 2600-4600 mm. The length of the polished rod is chosen depending on the stroke length of the pumping unit.

If the length of the upper (control) rod does not match the length

polished rod, adjustment (selection) of the length of the replaced upper (control) rod is carried out by adjusting rods (half rods) of various lengths. The diameter of the adjusting rods (half rods) must correspond to the diameter of the upper part of the rod column.

The selection of the length of the replaced upper (control) rod must be made so that the connection of the column of rods or adjusting rods (when choosing the length of the replaceable control rod) with the polished rod, even at the highest position of the plunger, does not touch the SUSG.

After completing the work on adjusting the plunger stroke, assemble the wellhead equipment and, using a lifting unit, by moving the rod string, make at least 6-8 plunger strokes and start the feed (if the static level is low, add the well to the wellhead).

Conduct an audit of the SUSG, change the lower stuffing box seal, in case of detection of defects in the SUSG - submit an application to the oil field for the delivery of a new one and replace it.

2 hours before the start of the well, the team confirms the application to call the representative of the oil field. The application is transferred to the dispatcher or oil field technologist.

In the presence of a representative of the TsDNG, call for the supply and pressurize the tubing with a pump with drawing up an act of acceptance of the well from repair, then, by means of a cable suspension, bring the string of rods to the head of the balancer and put the pumping unit into operation.

The foreman of the PRS brigade (KRS) fills operational passport SRP with indication of all layout parameters of the lowered underground equipment (diameter of tubing, rods, presence and number of centralizers, filter, HJP, etc.).

The act of handing over the well from repair is signed, after 72 hours of non-failure operation of the SRP, by a representative of the oil field. The basis for signing the act on the delivery of the well from the repair is a dynamogram taken after the well was launched. The operating certificate of the SRP is attached to the well repair certificate, which must be kept together with the certificate, and during subsequent repairs, be transferred to the TsPRS with filling in the data on the operation of the pump.

Rod pump installation equipment (UShGN)

Oil extraction with rod pumps is the most common method of artificially lifting oil. Distinctive feature SHSNU consists in the fact that a plunger (piston) pump is installed in the well, which is driven by a surface drive through a string of rods.

Concrete pumps have the following advantages over other mechanized methods of oil production:

having a high efficiency;

repair is possible directly at the fields;

different drives can be used for prime movers;

SRP units can be used in complicated operating conditions - in sand-producing wells, in the presence of paraffin in the produced oil, with a high GOR, when pumping out a corrosive liquid.

Rod pumps also have disadvantages. The main disadvantages include: limitation on the depth of pump descent (the deeper, the higher the probability of rod breakage); low pump flow; restriction on the inclination of the wellbore and the intensity of its curvature (not applicable in deviated and horizontal wells, as well as in highly deviated vertical ones)

Structurally, USHGN equipment includes ground and underground parts.

Ground equipment includes:

drive (pumping machine) - is an individual drive of a sucker-rod pump, lowered into the well and connected to the drive by a flexible mechanical connection - a string of rods;

· wellhead fittings with polished rod glands are designed for rod sealing and wellhead sealing.

Underground equipment includes:

tubing (tubing), which is a channel through which the produced fluid flows from the pump to the day surface.

deep well pump designed for pumping out of the well fluid watered up to 99% with a temperature of not more than 130 ° C of plug-in or non-plug type

rods - designed to transfer reciprocating motion to the plunger of the deep pump from the machine - rocking chair and is a kind of piston pump rod.

Figure 1 shows a diagram of a rod well-pumping unit (USHPU).

Figure 1. Scheme of a rod well-pumping unit (USHPU)

1 - production string; 2 - suction valve; 3 - pump cylinder; 4 - plunger; 5 - delivery valve; 6 - tubing; 7 - sucker rods; 8 - cross; 9 - wellhead branch pipe; 10 - check valve for bypassing gas; 11 - tee; 12 - wellhead gland; 13 - wellhead stock; 14 - rope suspension; 15 - balancer head; 16 - balancer; 17 - stand; 18 - balance weight; 19 - connecting rod; 20 - crank load; 21 - crank; 22 - gearbox; 23 - driven pulley; 24 - V-belt transmission; 25 - electric motor on a rotary slide; 26 - drive pulley; 27 - frame; 28 - control unit.

Installation works in the following way. plunger pump is powered by a pumping unit, where the rotational motion received from the engine using a gearbox, a crank mechanism and a balancer is converted into a reciprocating motion transmitted to the rod pump plunger through the rod string. When the plunger moves upwards, the pressure in the pump cylinder decreases and the lower (suction) valve rises, opening up fluid access (suction process). At the same time, the liquid column located above the plunger presses the upper (discharge) valve to the seat, rises up and is ejected from the tubing into the working manifold (injection process).

When the plunger moves down, the upper valve opens, the lower valve is closed by fluid pressure, and the fluid in the cylinder flows through the hollow plunger into the tubing.

Figure 2. Pumping unit type SKD

1 - wellhead rod suspension; 2 - balancer with support; 3 - rack (pyramid); 4 - connecting rod; 5 - crank; 6 - gearbox; 7 - driven pulley; 8 - belt; 9 - electric motor; 10 - drive pulley; 11 - fence; 12 - rotary plate; 13 - frame; 14 - counterweight; 15 - traverse; 16 - brake; 17 - rope suspension.

The pumping unit (Figure 2) is an individual drive of the borehole pump.

The pumping unit informs the rods of a reciprocating motion close to sinusoidal. The SC has a flexible rope suspension of the wellhead rod and a folding or swivel head of the balancer for unimpeded passage of tripping mechanisms (travel block, hook, elevator) during underground repairs.

The balancer swings on transverse axis, mounted in bearings, and articulated with two massive cranks using two connecting rods located on both sides of the gearbox. Cranks with movable counterweights can move relative to the axis of rotation of the main shaft of the gearbox for a certain distance along the cranks. Counterweights are needed to balance the pumping unit.

All elements of the pumping unit: rack, gearbox, electric motor are attached to a single frame, which is fixed on a concrete foundation.

In addition, all SCs are equipped with a brake device necessary to hold the balancer and cranks in any given position. The point of articulation of the connecting rod with the crank can change its distance relative to the center of rotation by moving the crank pin into one or another hole. This achieves a stepwise change in the swing amplitude of the balance bar, i.e. plunger stroke length.

Since the gearbox has a constant gear ratio, a change in the oscillation frequency is achieved only by changing the gear ratio of the V-belt transmission and changing the pulley on the motor shaft to a larger or smaller diameter.

Downhole rod pumps are positive displacement hydraulic machines, where the seal between the plunger and the cylinder is achieved due to the high accuracy of their working surfaces and regulated clearances.

Structurally everything borehole pumps consist of a cylinder, a plunger, valves, a lock (for plug-in pumps), connecting and mounting parts. When designing pumps, the principle of the maximum possible unification of these components and parts is observed for the convenience of replacing worn parts and reducing the range of required spare parts.

Pumps applied the following types:

non-inserted

inserted.

Non-insert pumps are lowered semi-disassembled. First, the pump cylinder is lowered onto the tubing. And then a plunger with a check valve is lowered on the rods. The non-insert pump is simple in design. The cylinder of a non-inserted pump is mounted directly on the tubing string, usually in its lower part. Below the cylinder there is a lock support in which the suction valve is locked. After the cylinder and the lock support are lowered into the well, the plunger is lowered on the rod string. When the number of rods is lowered into the well, which is necessary for the plunger to enter the cylinder and the suction valve to land on the locking support, final fit plunger suspension height. The suction valve is lowered into the well, fixed at the lower end of the plunger with a gripping rod. When the suction valve actuates the lock support, the latter locks it with mechanical lock or friction cuffs. The plunger is then released from the suction valve by rotating the rod string counterclockwise. The plunger assembly is then lifted away from the suction valve to the height necessary to free the plunger downward.

Therefore, if it is necessary to replace such a pump, it is necessary to lift the plunger on the rods from the well first, and then the tubing with the cylinder.

Plug-in rod pumps are lowered into the well in assembled form. The tool is first lowered into the well at or near the last tubing.

Depending on the conditions in the well, a mechanical lower lock or lower collar type lock is lowered into it, if the pump is with a lock at the bottom, or a mechanical upper lock or upper collar type lock, if the pump is with a lock at the top. Then the entire pumping unit is lowered into the well on a string of rods with a landing unit on the lock support. After fixing the pump on the locking support, adjust the height of the plunger suspension so that it is as close as possible to the lower base of the cylinder. In wells with a high gas content, it is desirable to hang the pump so that the movable pump assembly almost touches the lower base of the cylinder, i.e. Minimize the distance between the suction and discharge valve on the downward stroke of the plunger. Accordingly, to change such a pump, it is not necessary to once again lower and raise the pipes. The plug-in pump works on the same principle as the plug-in pump.

Both types of pumps have their advantages and disadvantages. For each specific condition, the most suitable type is used. For example, if the oil contains a large amount of paraffin, it is preferable to use non-inserted pumps. Paraffin deposited on the tubing walls can block the possibility of lifting the plug pump plunger. For deep wells, it is preferable to use an insert pump to reduce the time required to trip the tubing when changing the pump.

There are the following types of borehole pumps (Figure 3):

HB-1 - plug-in with a lock at the top;

HB-2 - plug-in with a lock at the bottom;

NN - non-inserted without catcher;

HH-1 - non-inserted with a gripping rod;

NN-2S - non-inserted with catcher.

IN symbol pump, for example, NN2BA-44-18-15-2, the first two letters and a number indicate the type of pump, the next letters indicate the design of the cylinder and pump, the first two digits indicate the pump diameter (mm), the subsequent plunger stroke length (mm) and head (m), reduced by 100 times and the last digit - landing group.

Figure 3. Types of borehole rod pumps

The use of HH pumps is preferable in wells with a large flow rate, a small depth of descent and a long overhaul period, and HB pumps in wells with a small flow rate, at large depths of descent. The higher the viscosity of the liquid, the higher the landing group is taken. For pumping liquid from high temperature or high content sand and paraffin, it is recommended to use pumps of the third landing group. With a large depth of descent, it is recommended to use pumps with a smaller clearance.

The pump is selected taking into account the composition of the pumped liquid (presence of sand, gas and water), its properties, flow rate and depth of its descent, and the tubing diameter - depending on the type and conditional size of the pump.

The principle of operation of the pumps is as follows. When the plunger moves upwards, a vacuum is created in the intervalve space of the cylinder, due to which the suction valve opens and the cylinder is filled. With the subsequent downward stroke of the plunger, the intervalve volume is compressed, due to which the discharge valve opens and the liquid that has entered the cylinder flows into the area above the plunger. Periodic up and down movements made by the plunger provide pumping of the formation fluid and its injection to the surface into the pipe cavity. With each subsequent stroke of the plunger, almost the same amount of fluid enters the cylinder, which then passes into the pipes and gradually rises to the wellhead.

SRP types:
HB1 - plug-in with a lock at the top
HB2 - plug-in with a lock at the bottom
NV1B-44-18-12-2-I
HB1 - pump type;
B - execution on the cylinder;
44 - conditional size (plunger diameter) of the pump;


2 - landing group;
And - performance in terms of resistance to the environment.

Types of SHSN:
NN - non-inserted without catcher
HH1 - non-pluggable with a gripping rod
НН2 - non-inserted with catcher
B - sleeveless pump cylinder
C - pump cylinder with bushings
NN2B-57-30-12-1

Types of SHSN:
NN - non-inserted without catcher
HH1 - non-pluggable with a gripping rod
НН2 - non-inserted with catcher
B - sleeveless pump cylinder
C - pump cylinder with bushings

NV1B-44-18-12-2-I
HB1 - pump type;
B - execution on the cylinder;
by design features:
T - with a hollow (tubular) rod, providing
lifting liquid through the channel of the column of hollow rods;
A - with a coupling device (auto coupler) (only
for HH) providing cohesion of the column
rods with a pump plunger;
D1 - single-stage, two-plunger providing the creation of hydraulic
heavy bottom;
D2 - two-stage, two-plunger providing two-stage compression
pumped liquid;
U - with unloaded cylinder (only for HH2)
providing removal from the cylinder of cyclic
load at work.
44 - conditional size (plunger diameter) of the pump;
18 - plunger stroke in mm reduced by 100 times;
12 - pump head in m reduced by 100 times;
2 - landing group;
1I - - lock;
2 - stock;
3 - emphasis;
4 - locknut;
performance
by durability
medium;
5 - plunger cage; 6 - cylinder; 7 - plunger;
8 - discharge valve; 9 - suction
valve

Insertion pumps

Non-insert pumps

NN2B-57-30-12-1
Non-insert (tube) pumps
lowered into the well in parts:
cylinder - on the tubing string,
and the plunger assembly with the suction and
delivery valves - on the rods.
1 - cylinder; 2 - stock; 3 - plunger cage;
4 - plunger; 5 - delivery valve;
6 - catcher rod;
7 - suction valve; 8 - cone seat

The fit of the plunger in the pump cylinder is characterized by the limiting gaps (per diameter) between the plunger and the cylinder. depending

from limit values pumps are available in the following groups
landings:
"1" group - up to 0.063mm.
"2" group - from 0.025 to 0.078mm
"3" group - from 0.050 to 0.113mm
"4" group - from 0.075 to 0.138mm
"5" group - from 0.100 to 0.163mm
Plunger seating groups in the pump cylinder according to the API standard
(American Petroleum Institute).
1 – 0,025-0,088
2 – 0,050-0,113
3 – 0,075-0,138
4 – 0,100-0,163
5 – 0,125-0,188

SHGN cylinders

Sleeveless cylinders:
a - plug-in pumps with a nominal diameter of 29 to 57 mm, with a plunger stroke of 1200 and
3500 mm; b - non-inserted pumps;
c - plug-in pumps with a nominal diameter of 38 to 57 mm, with a plunger stroke of 4500 and
6000 mm.

Composite (sleeve) cylinder:
1 - coupling; 2 - bushing; 3 - casing
Rod pump plunger assembly:
1 - plunger; 2 – discharge valve assembly; 3 - valve cell

Plungers SHR

Valve assemblies
According to OST 26-16-06-86, a saddle-ball pair is made in three versions: K, KB and KI
Valves K and KB (valve with shoulder) complete pumps of conventional design according to
resistance to the environment, and KI valves - abrasive-resistant pumps.
The larger the valve seat bore diameter, the smaller
hydraulic losses on the valve assembly, which is especially important when pumping viscous
liquids. However, in this case, it is possible for the ball to stick in the seat due to
elastic deformation of the latter, so the ratio of the diameter of the saddle hole
dov to the ball diameter dsh is strictly specified by the standard and is set equal to 0.865
The ball is made from high carbon of stainless steel 95X18W with
hardness HRC 65, stainless steel seat 30X13, 95X18 with hardness HRC 45.

Castle supports

LOCK SUPPORT TYPE OM
The lock support is designed for fixing
plug-in pumps in the tubing string at the required
depth. Support type OM consists of two groups
details:
- descending on the tubing (sub, reference
ring, spring anchor, support sleeve, casing,
guide sub;
- on the pump (thrust nipple and cone).
Fixation of the pump is carried out by landing the cone on
support ring and stop the anchor petals in the groove
nipple.
Castle support:
1.6 - subs;
2 - support ring;
3 - spring anchor;
4 - support sleeve;
5 - shirt

Rod deep pumps(SHGN) - these are pumps that are submerged well below the level of the liquid that is planned to be pumped. The depth of immersion in the well allows for not only a stable rise of oil from a great depth, but also excellent cooling of the pump itself. Also, these pumps allow you to lift oil with a high percentage of gas.
Rod pumps differ in that the drive in them is carried out due to an independent engine located on the surface of the liquid, using a mechanical connection, in fact, the rod. If a hydraulic motor is used, then the energy source is the same pumped liquid supplied to the pump under high pressure. An independent engine in this case is installed on the surface. Positive displacement rod pumps are used to lift oil from wells.

Rod pump types

1. Non-insertable. The pump cylinder is lowered into the oil well along pump pipes without plunger. The latter descends to sucker rods , and is introduced into the cylinder together with the suction valve. When replacing such a pump, it is necessary to first lift the plunger on the rods from the well, and then the tubing with the cylinder.
2. Plug-in. A cylinder with a plunger is lowered into an oil well on rods. For such pumps, the plunger diameter must be much smaller than the pipe diameter. Accordingly, if it is necessary to replace such a pump, it is not necessary to once again lower and raise the pipes.

Deep Rod Pumps come with a lower or upper cuff fastening and can be with mechanical fastening at the top or bottom.Rod pumps have a number of advantages, which include: simplicity of design, the ability to pump fluid from oil wells, if other methods of operation are unacceptable. Such pumps are capable of operating at very great depths, and have a simple adjustment process. Also, the mechanization of the pumping process and ease of maintenance of the installation should be attributed to the advantages.

Benefits of sucker rod pumps

• Have a high efficiency;
• A wide variety of drives can be used for prime movers;
• Carrying out repairs directly at the place of pumping oil;
• Downhole rod pumps can be installed in complicated oil production conditions - in wells with fine sand, paraffin in the product, high GOR, pumping various corrosive liquids.

Characteristics of sucker rod pumps

• Water cut - up to 99%;
• Temperature - up to 130 C;
• Work at the content of mechanical impurities up to 1.3 g/liter;
• Work with the content of hydrogen sulfide - up to 50 mg / liter;
• Mineralization of water - up to 10 g / liter;
• pH values ​​are from 4 to 8.

Oil production using downhole rod pumps is one of the most common methods of oil production. This is not surprising, simplicity and efficiency of work are combined in SRP with highest reliability. More than 2/3 of operating wells use installations with SRP.
For order sucker rod pump you need to fill out a questionnaire or contact our specialists by filling out the form on the right side of the page or by calling the specified contact numbers.