Stairs. Entry group. Materials. Doors. Locks. Design

Two thirds of the stock (66%) of operating wells in the CIS countries (approximately 16.3% of the total oil production) are operated by SHSNU. The flow rate of wells ranges from tens of kilograms per day to several tons. Pumps are lowered to a depth of several tens of meters to 3000 m, and in some wells to 3200 ¸ 3400 m.

Rice. 3.12. Scheme of installation of a sucker-rod pump

SHSNU includes:

1. Ground equipment: pumping unit (SK), equipment mouth.

2. Underground equipment: tubing (tubing), pumping rods (NSh), rod borehole pump(SHSN) and various protective devices, improving the operation of the installation in complicated conditions.

A distinctive feature of SHSNU is that a plunger (piston) pump is installed in the well, which is driven by a surface drive through a rod string (Fig. 3.12).

Rod deep pumping unit (Fig. 3.12) consists of a borehole pump 2 of plug-in or non-plug type, pump rods 4 tubing 3, suspended on a faceplate or in a pipe suspension 8, stuffing box 6, stuffing rod 7, pumping unit 9, foundation 10 and tee 5. protective device as gas or sand filter 1.

3.3.2 ROD DRIVE PUMPS

ShSN provide pumping out of wells of liquid, water cut up to 99%, absolute viscosity up to 100 mPa s, content of solid mechanical impurities up to 0.5%, free gas at the reception up to 25%, hydrogen sulfide volume content up to 0.1%, water salinity up to 10 g/l and temperature up to 1300C.

According to the method of attachment to the tubing string, plug-in (NSV) and non-insertion (NSN) borehole pumps are distinguished (Fig. 3.13, 3.14). For non-inserted (pipe) pumps, a cylinder with a suction valve seat is lowered into the well on the tubing. A plunger with a discharge and suction valve is lowered into the well on rods and inserted into the cylinder. The plunger is connected to the suction valve ball by means of a special rod. The disadvantage of HSN is the complexity of its assembly in the well, the complexity and duration of extracting the pump to the surface to eliminate any malfunction. Plug-in pumps are entirely assembled on the surface of the earth and lowered into the well inside the tubing on rods. The NSV consists of three main units: a cylinder, a plunger and a cylinder lock support.

In tubular pumps, to extract the cylinder from the well, it is necessary to lift the entire equipment(rods with valves, plunger and tubing). This is the fundamental difference between NSN and NSV. When using plug-in pumps, round-trip operations during well repair are accelerated by 2 ¸ 2.5 times and the work of workers is significantly facilitated. However, the flow of an insertion pump with pipes of a given diameter is always less than the flow of a non-insertion one.

The NSV-1 pump is a plug-in single-stage, plunger pump with a sleeve cylinder and a lock at the top, discharge, suction and anti-sand valves (Fig. 3.13).

Rice. 3.13. Plug-in borehole pumps

1 - inlet valve; 2 - cylinder; 3 - discharge valve;

4 - plunger; 5 - rod; 6 - lock.

Rice. 3.14. Non-inserted borehole pumps:

1 - suction valve; 2 - cylinder; 3 - discharge valve;

4 - plunger; 5 - gripping rod; 6 - catcher

The NSV pump is lowered on the rods. Fastening (compacting by landings) takes place on the interlock support, which is previously lowered onto the tubing. The pump is removed from the well when only the rod string is lifted. Therefore, it is advisable to use NSV in wells with a small flow rate and at large depths of descent.

The non-inserted (pipe) pump is a cylinder connected to the tubing and lowered into the well together with them, and the plunger is lowered and raised on the rods. NSN are appropriate in wells with a large flow rate, a small depth of descent and a long overhaul period.

Depending on the size of the gap between the plunger and the cylinder, pumps of the following groups of landings are manufactured (version "C" - i.e. with a compound cylinder):

The higher the viscosity of the liquid, the higher the landing group.

The conditional size of the pumps (according to the plunger diameter) and the plunger stroke length, respectively, are taken within the limits:

for NSV 29 - 57 mm and 1.2 ÷ 6 m;

HSN 32 - 95 mm and 0.6 ¸ 4.5 m.

Designation HSN2-32-30-12-0:

0 - landing group;

12x100 - the greatest depth of pump descent, m;

30x100 - plunger stroke length, mm;

32 – plunger diameter, mm.

The sucker rod is designed to transmit the reciprocating motion of the pump plunger. The bar is a rod round section with thickened heads at the ends. Rods are produced from alloy steels with a diameter (along the body) of 16, 19, 22, 25 mm and a length of 8 m - for normal conditions exploitation.

To regulate the length of the rod columns in order to properly fit the plunger into the pump cylinder, there are also shortened rods (feet) with a length of 1; 1.2; 1.5; 2 and 3 m.

The rods are connected by couplings. There are also tubular ( outside diameter 42 mm, thickness 3.5 mm).

Started to produce sucker rods made of fiberglass (JSC "Ocher Machine-Building Plant"), which are characterized by greater corrosion resistance and reduce energy consumption by up to 20%.

Continuous rods "Korod" are used (continuous on drums, the section is semi-elliptical).

A special rod is a wellhead rod connecting the rod string with a rope suspension. Its surface is polished (polished stem). It is made without heads, and has a standard thread at the ends.

To protect against corrosion, painting, galvanizing, etc. are carried out, and inhibitors are also used.

Estuary equipment pumping wells is designed for sealing the annular space, the internal cavity of the tubing, the removal of well products and hanging the tubing string.

Estuary equipment type OU includes wellhead stuffing box, tee, cross, stopcocks and check valves.

The wellhead stuffing box seals the outlet of the wellhead stem with a stuffing box head and ensures product diversion through the tee. The tee is screwed into the tubing sleeve. Availability ball joint ensures self-alignment of the stuffing box head in case of misalignment of the stuffing box with the tubing axis, eliminates one-sided wear of the sealing packing and facilitates packing change.

The tubing string is suspended on a cone in the cross and is located eccentrically relative to the axis of the well, which makes it possible to lower the instruments into the annulus through a special wellhead branch pipe with a valve.

Pumping units - individual mechanical drive SHSN (Tables 3.2, 3.3).

Table 3.2

In the code of the machine - rocking chairs of the SKD type, for example SKD78-3-4000, it is indicated: letters - the rocking machine is deaxial, 8 - the maximum allowable load Pmax on the balancer head at the point of suspension of the rods in tons (1t = 10 kN); 3- maximum length wellhead stroke in m; 4000 - the highest permissible torque M kr max on the driven shaft of the gearbox in kgf / m (1 kgf / m \u003d 10-2 kN m).

The pumping unit (Fig. 3.15) is an individual drive of the borehole pump.

Table 3.3

The main components of the pumping unit are a frame, a rack in the form of a truncated tetrahedral pyramid, a balance beam with a swivel head, a traverse with connecting rods hinged to the balance beam, a gearbox with cranks and counterweights. The SC is completed with a set of interchangeable pulleys for changing the number of swings, i.e. discrete regulation. For quick change and tension of belts, the electric motor is mounted on a swivel skid frame.

The pumping unit is mounted on a frame mounted on a reinforced concrete base (foundation). The fixation of the balancer in the required (uppermost) position of the head is carried out with the help of a brake drum (pulley). The head of the balancer is hinged or swivel for an unhindered passage of downhill and deep equipment at underground repair wells. Since the head of the balance bar moves along an arc, there is a flexible rope suspension 17 to articulate it with the wellhead rod and rods (Fig. 3.15). It allows you to adjust the fit of the plunger into the pump cylinder or the exit of the plunger from the cylinder, as well as install a dynamograph to study the work. equipment.

The amplitude of movement of the head of the balancer (stroke length of the wellhead rod - 7 in Fig. 3.12) is regulated by changing the place of articulation of the crank with the connecting rod relative to the axis of rotation (relocation of the crank pin to another hole).

For one double stroke of the balancer, the load on the SC is uneven. To balance the work of the pumping unit, weights (counterweights) are placed on the balancer, crank or on the balancer and crank. Then the balancing is called, respectively, balancing, crank (rotor) or combined.

The control unit provides control of the SC electric motor in emergency situations(breakage of rods, breakdown of a gearbox, pump, pipeline rupture, etc.), as well as self-starting of the SC after a power outage.

They produce SC with a load capacity on the head of the balancer from 2 to 20 tons.

Rice. 3.15. Pumping unit type SKD:

1 - wellhead rod suspension; 2 - balancer with support; 3 - rack; 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 electric motors for the SC are short-circuited asynchronous three-phase electric motors of the AO series and AO2 electric motors and their modifications AOP2 in moisture and frost-resistant design.

The frequency of rotation of electric motors is 1500 and 500 min -1.

Currently, Russian factories have mastered and are producing new modifications of pumping units: SKDR and SKR (a unified range of 13 options with a lifting capacity from 3 to 12 tons), SKB, SKS, PF, OM, PShGN, LP-114.00.000 (hydroficated) . Pumping units for temporary prey can be mobile (pneumatic) with a car engine.

Topic 7

Scheme of rod well pumping unit.

2. Pumping units.

Wellhead equipment.

Pump rods (ShN).

Rod borehole pumps ShSN.

Conventions borehole rod pumps.

7. Design of borehole pumps.

8. Castle support.

pump performance.

Safety rules for the operation of wells with rod pumps.

Scheme of a rod well pumping unit

The cessation or absence of flowing led to the use of other methods of lifting oil to the surface, for example, by means of sucker-rod pumps. Most wells are currently equipped with these pumps. The flow rate of wells is from tens of kilograms per day to several tons. Pumps are lowered to a depth of several tens of meters to 3000 m, sometimes up to 3200 - 3400 m.

SHSNU includes:

a) ground equipment - pumping unit (SK), wellhead equipment, control unit;

b) underground equipment - tubing (tubing), pumping rods (SHN), sucker rod pump (SHSN) and various protective devices that improve the operation of the installation in difficult conditions.

Rod deep pumping unit (Figure 7.1) consists of a borehole pump 2 plug-in or non-plug type, sucker rods 4 , tubing 3 suspended on a faceplate or in a pipe hanger 8 wellhead fittings, stuffing box seal 6 , stuffing box 7 , rocking machine 9 , foundation 10 and tee 5 . A protective device in the form of a gas or sand filter is installed at the well pump intake. 1 .

Rice. 7.1. Scheme of a rod pumping unit

1 - shank; 2 - downhole pump; 3 - tubing; 4 – sucker rods; 5 - wellhead fittings; 6 - wellhead gland; 7 - polished rod; 8 - rope suspension; 9 - rack; 10 - foundation.

2. Pumping units

The pumping unit (Figure 7.2) is an individual drive of the borehole pump.

Figure 7.2 - Pumping unit type SKD

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

The main components of the pumping unit are a frame, a rack in the form of a truncated tetrahedral pyramid, a balance beam with a swivel head, a traverse with connecting rods hinged to the balance beam, a gearbox with cranks and counterweights. The SC is completed with a set of interchangeable pulleys for changing the number of swings, i.e. the regulation is discrete.

For quick change and tension of belts, the electric motor is mounted on a swivel sled.

The pumping unit is mounted on a frame mounted on a reinforced concrete base (foundation). The fixation of the balancer in the required (uppermost) position of the head is carried out with the help of a brake drum (pulley). The head of the balancer is hinged or swivel for unimpeded passage of tripping and downhole equipment during underground well workover. Since the head of the balance bar moves along an arc, there is a flexible rope suspension for its articulation with the wellhead rod and rods. 17 . It allows you to adjust the fit of the plunger in the pump cylinder to prevent the plunger from hitting the suction valve or the plunger leaving the cylinder, as well as to install a dynamograph to study the operation of the equipment.

The amplitude of movement of the head of the balancer (stroke length of the wellhead rod - 7) is regulated by changing the place of articulation of the crank by the connecting rod relative to the axis of rotation (relocation of the crank pin to another hole). For one double stroke of the balancer, the load on the SC is uneven. To balance the work of the pumping unit, weights (counterweights) are placed on the balancer, crank or on the balancer and crank. Then the balancing is called, respectively, balancing, crank (rotor) or combined.

The control unit provides control of the SC electric motor in emergency situations (breakage of rods, breakdown of the gearbox, pump, pipeline break, etc.), as well as self-starting of the SC after a power outage.

For a long time, our industry produced pumping units of standard sizes SK. Currently, according to OST 26-16-08-87, six standard sizes of pumping units of the SKD type are produced, the main characteristics are given in table 4.

1. Types of SRP, description, decoding of standard sizes, design features, specifications, determination of the performance of the USP. Deep rod pumps (hereinafter referred to as pumps) are vertical structure single acting with ball valves, fixed cylinder and metal plug. Designed for pumping out from oil wells liquid having the following parameters: temperature - no more than 130 0 C, water cut - no more than 99% by volume, viscosity - no more than 0.3 Pa * s, water salinity - up to 10 g / l, water content mechanical impurities - up to 1.3 g / l, the volume content of free gas at the pump intake - no more than 10%, hydrogen sulfide - no more than 200 mg / l and the concentration of hydrogen ions - pH = 4 - 8. There are separate types of pumps made to order , with operating parameters higher than typical, for example, pumps with a chrome-plated inner cylinder coating.

According to TU 26-16-06-86, rod pumps of the following types are manufactured:

HB1 - plug-in with a lock at the top,

HB2 - plug-in with a lock at the bottom,

NN - non-inserted (pipe) with a knock-off valve,

HH2 - non-inserted with catcher.

NV1B-32-30-15-2 is a sucker rod pump with the following characteristics:

Plug-in with a lock at the top,

One-piece thick-walled cylinder,

Nominal plunger diameter – 32mm,

Plunger stroke - 3000m,

Landing group - 2.

2. The main reasons for the failures of USP.

Bar break

Leaks through leaks in tubing couplings, which are constantly subjected to variable loads
- decrease useful move of the plunger in comparison with the descent of the suspension point of the rod due to elastic deformations

pump rods

Leaks between the cylinder and the plunger, which depend on the degree of wear of the pump and the presence of abrasive

impurities in the pumped liquid

Leaks in the pump valves due to their slow closing and opening and mainly due to their wear and

corrosion

-great content sand of pumped liquid (sand, getting into the deep pump, leads To wear and tear

pairs of friction "cylinder-plunger", valves, in some cases causes jamming of the plunger in the cylinder and

breakage of rods. In addition, an excessive amount of sand in the production leads to the deposition of part of it at the bottom of the wells, the formation of sand plugs, and a decrease in productivity. Various filters are applied

screwed to the pump foot valve., sand anchors. In the sand anchor, the liquid changes direction by 180", the sand separates and accumulates in a special pocket at the bottom of the anchor.

When filling the pocket with sand, the anchor is removed to the surface and cleaned. Condition effective work sand anchor is the existence of an anchor at the rate of the upward flow of liquid, less than the rate of settling of sand particles.

Salt deposits on the IVNKT pump units;

Asphalten-resin-paraffin deposits in tubing and sucker rods;

Strong curvature of wells

Corrosion of oilfield equipment.

High Viscosity and High Waxy Oils

In short, two main processes take place inside:
separation of gas from liquid- Ingress of gas into the pump may impair its operation. For this, gas separators are used (or a gas separator-dispersant, or simply a disperser, or a double gas separator, or even a double gas separator-disperser). In addition, for the normal operation of the pump, it is necessary to filter out the sand and solid impurities that are contained in the liquid.
rise of liquid to the surface- the pump consists of many impellers or impellers, which, while rotating, impart acceleration to the liquid.

As I already wrote, electric centrifugal submersible pumps can be used in deep and inclined oil wells (and even in horizontal ones), in heavily watered wells, in wells with iodine-bromide waters, with high salinity of formation waters, for lifting salt and acid solutions. In addition, electric centrifugal pumps have been developed and are being produced for the simultaneous-separate operation of several horizons in one well. Sometimes electric centrifugal pumps are also used to pump saline formation water into an oil reservoir in order to maintain reservoir pressure.

The assembled ESP looks like this:

After the liquid is raised to the surface, it must be prepared for transfer to the pipeline. The products coming from oil and gas wells are not, respectively, pure oil and gas. Formation water, associated (petroleum) gas, solid particles of mechanical impurities ( rocks, hardened cement).
Produced water is a highly mineralized medium with a salt content of up to 300 g/l. The formation water content in oil can reach 80%. Mineral water causes increased corrosion destruction of pipes, tanks; solid particles coming from the flow of oil from the well cause wear on pipelines and equipment. Associated (petroleum) gas is used as raw material and fuel. It is technically and economically expedient to subject oil to special treatment before it is fed into the main oil pipeline in order to desalt it, dehydrate it, degas it, and remove solid particles.

First, oil enters automated group metering units (AGZU). From each well, through an individual pipeline, oil is supplied to the AGZU along with gas and formation water. The AGZU records the exact amount of oil coming from each well, as well as primary separation for the partial separation of formation water, oil gas and mechanical impurities with the direction of the separated gas through the gas pipeline to the GPP (gas processing plant).

All data on production - daily flow rate, pressure, etc. are recorded by operators in the cult house. Then these data are analyzed and taken into account when choosing a production mode.
By the way, readers, does anyone know why the cult house is called that?

Further, the oil partially separated from water and impurities is sent to the complex oil treatment unit (UKPN) for final purification and delivery to the main pipeline. However, in our case, the oil first passes to the booster pumping station(DNS).

As a rule, BPS are used in remote fields. The need to use booster pumping stations is due to the fact that often in such fields the energy of the oil and gas reservoir is not enough to transport the oil and gas mixture to the UKPN.
Booster pumping stations also perform the functions of separating oil from gas, cleaning gas from dropping liquid and subsequent separate transportation of hydrocarbons. In this case, oil is pumped by a centrifugal pump, and gas is pumped under separation pressure. DNS differ in types depending on the ability to pass through themselves various liquids. A full-cycle booster pumping station consists of a buffer tank, an oil leakage collection and pumping unit, a pumping unit itself, and a group of candles for emergency gas discharge.

In the oil fields, after passing through group metering units, oil is taken into buffer tanks and, after separation, enters the buffer tank in order to ensure a uniform flow of oil to the transfer pump.

UKPN is a small plant where oil undergoes final preparation:

• Degassing(final separation of gas from oil)
• Dehydration(destruction of the water-oil emulsion formed during the lifting of products from the well and its transport to the UKPN)
• Desalting(removal of salts by adding fresh water and re-dehydration)
• stabilization(removal of light fractions in order to reduce oil losses during its further transportation)

For more effective training often used chemical, thermochemical methods, as well as electrical dehydration and desalination.
Prepared (commercial) oil is sent to the commodity park, which includes tanks of various capacities: from 1,000 m³ to 50,000 m³. Further, the oil is fed through the main pumping station to the main oil pipeline and sent for processing. But we'll talk about that in the next post :)

In previous releases:
How to drill your well? The Basics of Oil and Gas Drilling in One Post -

The SRP in its simplest form consists of a plunger moving up and down a well-fitting cylinder. The plunger is equipped with a check valve that allows fluid to flow upwards but not downwards. A non-return valve, also called a pressure valve, in modern pumps usually a ball-seat valve. The second suction valve is a ball valve at the bottom of the cylinder and, like a non-return valve, allows liquid to flow upwards but not downwards. Initially, the plunger is in a stationary state at the bottom of the stroke. At this point, both the suction and discharge valves are closed. The liquid column in the tubing creates hydrostatic pressure above the suction valve. The load on the gland rod (upper rod of the sucker rod string) is only the weight of the sucker rod string. When the plunger moves up check valve remains closed and the sucker rod string takes on the weight of the liquid in the tubing - the weight of the sucker rod string and the weight of the liquid column. With minimal leakage between the plunger and the pump cylinder, the pressure between the discharge and suction valves is reduced so that the suction valve opens and fluid from the wellbore enters the pump cylinder.

At the top of the stroke, the plunger stops and both valves close again, with the weight of the fluid back on the plunger and delivery valve. Let us assume that the pump cylinder is now filled with liquid and the liquid is incompressible. When the plunger starts to move down, the discharge valve will open. The weight of the liquid column in the tubing string will be transferred to the suction valve and workstring, and the load on the stuffing box and the pumping unit will again consist only of the weight of the rods.

Further downward movement of the plunger will cause fluid to flow from the cylinder into the plunger through the check valve. Returning the plunger to the bottom of the stroke will end the cycle (figure 1.8).

When automating the operation of downhole sucker rod pumps, the methods of wattmetering, barography and dynamometers are used. The first method allows you to control, mainly, the operation of ground equipment, the second and third - deep.

Barography allows you to determine the pressure in the suction valve and at the pump outlet, the pressure drop in the valves, the nature of the leaks, etc. The pressure is recorded by a depth gauge lowered on a wire through the annulus. The barography method is quite complicated and time-consuming and cannot be used for operational control over the operation of pumping units.

1 - discharge valve; 2 - suction valve

Figure 1.8 - The principle of operation of a sucker rod pump

The advantages of wattmetering include factors such as ease of measurement (only measuring current and voltage transformers are required on the motor phases) and the ability to keep records of the electricity consumed by the drive (control stations can be integrated into commercial and technical electricity metering systems - ASKUE and ASTUE).

The wattmeter diagram is a curve of the power consumption of the electric motor of the pumping unit. According to the wattmeter diagram, first of all, such important indicator, as the imbalance of the SKN (Figure 1.9).

Wattmetering allows you to get information about the operation of surface equipment, while it is most important to have an idea about the state and mode of operation of the downhole pump and the rod and pipe string. The dynamometer method helps to solve this problem, the result of which is a graph of the dependence of the force at the suspension point of the rods on the movement of this point, called the wellhead dynamometer chart.

a) balanced rocking machine

b) unbalanced rocking machine

Figure 1.9 - Wattmetergrams of the SC

In practice, the following concepts are used: theoretical, practical (measured, real) dynamometer chart (Figure 1.10). The simplest theoretical dynamometer chart for the normal operation of a pump has the shape of a parallelogram (Figure 1.10, line 1). It is built for the condition when the pump is serviceable and tight, the cylinder is filled with an incompressible liquid, the pump submersion under the dynamic level is equal to zero, there are no dynamic loads, the filling factor of the pump is equal to unity.

A practical wellhead dynamogram reflects the real change in the load on the polished rod for a full swing cycle.

The real graph differs from the theoretical one, mainly due to the influence of inertia forces and oscillatory processes in the rod string (Figure 1.10, line 2). Due to the influence of the inertia force, the dynamometer turns out to be rotated by a certain angle clockwise, and the longitudinal oscillations in the rod string cause undulating changes in the load on the wellhead rod.

1 - theoretical; 2 - practical

Figure 0.10 - Graphs of wellhead dynamometer charts

The dimensions and shape of a real dynamometer chart are determined by the stroke length of the polished rod and the forces acting on it, which, in turn, depend on the depth of the descent and the diameter of the pump, the frequency of oscillations and the nature of disturbances in underground equipment or the hydrostatic load on the plunger.

We can formulate the following characteristics practical dynamometer charts, which together give the right to conclude on the normal operation of the pump:

The lines of perception (Figure 1.10, line AB) and removal (Figure 1.10, line CD) of the load can practically be taken as straight lines;

The lines of acceptance and unloading of the practical dynamometer chart are parallel to the corresponding lines of the theoretical dynamometer chart, and, therefore, are parallel to each other;

The lower left and upper right corners of the dynamogram are sharp.

Conclusion: with the help of dynamometer, which is the simplest, most accessible, and, therefore, the most common method of field research and operational control over the operation of the SHNU, the following tasks are solved:

1) certain parameters of the formation and wells are determined, and the operating mode of the pumping unit is checked: pump flow, productivity factor, pump filling and delivery factors, pump intake pressure, pipe and rod deformation;

2) the correct operation of the SRP is checked and mechanical malfunctions of individual units of underground equipment are detected: leakage of the suction and discharge valves of the pump, stuck plunger, breakage of rods, incorrect installation of the pump, leakage of pipes, etc.