RU2762640C1 - Method for removing and preventing salt deposition in a well operated by a sucker rod pump - Google Patents

Abstract

FIELD: oil production.

SUBSTANCE: invention relates to oil production. A method for removing and preventing salt deposition in a well operated by a sucker rod pump includes lowering a string of pipes with a sucker rod pump inserted into the key support of the pipe string into a production well, pumping a scale inhibitor into the bottomhole zone of a production well, holding the well and then withdrawing oil from the producing well. Before pumping the inhibitor, the sucker rod pump drive is stopped, the pump unit, the flow switch, tank trucks with acid, anticorrosive liquid and scale inhibitor, as well as a gutter tank are installed and hydraulically connected. After that, the well is examined by beating the liquid level in the annulus of the well. Scale inhibitor is injected in a volume of 0.2 m³ into the annular space of the well, not exceeding the injection pressure of 3.0 MPa. Exposure is carried out for 2 hours, a decrease in the liquid level in the annulus of the well is expected. After that, the well is examined by repeated beating of the liquid level in the annulus of the well. Then the linear valve is closed and the sucker rod pump drive is turned on, then for 12 hours the well fluid mixed with the scale inhibitor is circulated between the wellhead and the bottom of the well. Then the drive of the sucker rod pump is stopped, the sucker rod pump is removed from the lock support of the pipe string. Further, hydrochloric acid is injected into the annulus of the well. Then, by pumping an anti-corrosive liquid into the annulus of the well, hydrochloric acid is brought to the intervals of perforation of the formation and the well is left for technological exposure for 1 hour. Then, in 3 cycles, every 0.5 hours, alternately, 0.5 m³ of process fluid is injected into the pipe string, then into the annulus of the well. After the end of the holding time, a sucker rod pump is installed in the lock support of the pipe string, the drive of the sucker rod pump is started, and the sucker rod pump is pumped out of the reservoir into a trough container until the pH is neutral. After that, oil is withdrawn from the producing well.

EFFECT: improving the efficiency of removing and preventing salt deposition in the well, improving the quality of treatment of downhole equipment, reducing the turnaround time of the well, eliminating environmental pollution while reducing costs.

1 cl, 5 dwg

Description

The invention relates to oil production, in particular to methods for removing and preventing salt deposits in a well, as well as on downhole equipment operated by a sucker rod pump. The fallout of salts (gypsum, anhydride, calcium carbonate) in the well is associated with the extraction of formation water together with oil, as well as the mixing of formation waters of various types with each other (alkaline with hard).

There is a known method for preventing salt deposition in oilfield equipment, which is carried out as follows (patent RU No. 2320852, publ. 03/27/2008). including the extraction of production equipment (pipe string, pump) from the well, lowering the production string of pipes with a packer into the well, planting the packer in the well above the formation, sequential injection along the pipe string of the solvent slug, inhibiting solution slug, alkali slug and hydrophilic squeezing fluid slug. In this case, the following are used as a solvent: aliphatic, aromatic hydrocarbons (hexane, petroleum ether, nefras), organic solvents (benzene, toluene fractions). The composition of the inhibitory solution includes, wt%:

- organophosphorus compounds 1 ÷ 15 - hydrochloric acid 6 ÷ 23 - hydrofluoric acid 0.1 ÷ 5 - water 57 ÷ 92.9

As organophosphorus compounds are used: nitrilotrimethylphosphonic acid (NTF), hydroxyethylidene diphosphonic acid (OEDP), sodium salts of nitrilomethylenephosphonic acids, polyaminomethylenephosphonates, sodium hexametaphosphate, fusion salts. As an alkali, a universal reagent for oil production (RDN-U) is used. Hydrophilic displacement fluid is an aqueous solution of reagents based on alkyl sulfonates or reagents based on polyethylene glycol monoalkylphenyl ether.

Disadvantages of the method:

- firstly, the use of a similar composition of an inhibiting solution due to the presence of acidic reagents in it can cause an increase in corrosion processes in wells;

- secondly, the presence of hydrofluoric acid in the composition can lead to the formation of sparingly soluble calcium fluoride upon possible contact of the composition with formation waters and formation rocks containing calcium ions;

- thirdly, due to the fact that a pre-stop of a hydrocarbon solvent is used, there is a risk of introducing an inhibiting solution into oil-saturated intervals and changing the phase permeabilities for oil and water, which can lead to watering of the produced product;

- fourthly, environmental pollution due to the outflow at the wellhead of sequentially injected chemical reagents through the pipe string during the installation and dismantling of equipment (open system) in the process of implementing the method;

- Fifthly, high costs, since the implementation of the method requires the involvement of a well workover team to extract the production equipment (pipe string and pump) from the production well, run the technological pipe string into the well, and after processing the bottomhole zone of the production well for extraction from production wells, installation of production equipment in a production well;

- sixth, a long process of processing the bottomhole zone of a production well, since it is necessary to mount and dismantle equipment at the wellhead several times, depending on the technological operation (extraction of production equipment (pump, pipe string) from the well, lowering the production pipe string with a packer, landing a packer in the well above the formation, sequential injection of a solvent slug, an inhibitor slug, an alkali slug and a slug of a hydrophilic squeezing fluid into the bottomhole zone of the well, unpacking and extraction of the process pipe string with a packer, running production equipment into the well).

A known method of removing the removal of salt deposits in a well operated by a sucker rod pump, including preparing the wellhead for circulation of the solution in a closed cycle, pumping a process solution into the well in a closed loop, flushing the well with a process solution at a variable speed (patent RU No. 2003783, publ. 30.11 .1993). Determine the degree of flushing of the tubing by the current of the electric motor of the pumping unit. When it reaches the nominal value, the flushing is stopped.

The disadvantages of this method are:

- firstly, low efficiency of dissolution and removal of salt deposits by injection of chemical solutions, low turnaround time of the well, due to insufficient dissolution of salt deposits, insufficient washout of salt dissolution products that remain in the pores of the bottomhole formation zone and on the equipment, which leads to a decrease in filtration, and as a result, a decrease in the productivity of a production well;

- secondly, high corrosive wear of downhole equipment during the implementation of the method, since acid-containing solutions have a negative effect, both on the elements of the sucker rod pump and on the pipe string;

- thirdly, environmental pollution due to the outflow of chemical reagents, including acid-containing ones, sequentially pumped through the pipe string at the wellhead, during the installation and dismantling of equipment (open system) during the implementation of the method;

- fourthly, the complexity of the implementation of the process associated with the need to install a separator at the wellhead, as well as high costs of process fluid for flushing the well.

The closest in technical essence and the achieved result is a method for preventing the deposition of inorganic salts in oil and gas field equipment (RF patent No. 2484238, publ. with a packer, planting a packer in the well above the formation, sequential injection of solvent rims, a scale inhibitor solution and a hydrophilic squeezing fluid along the pipe string into the bottomhole formation zone, and a mutual solvent is pumped in as a solvent, a scale inhibitor is pumped in an aqueous solution of potassium chloride and as a hydrophilic squeezing liquids, the specified aqueous solution of potassium chloride is injected, and as a mutual solvent, butyl cellosol or a mixture of solvents is injected, and a 1-2% solution of potassium chloride in fresh water is injected as a hydrophilic displacement fluid, as an inhibitor and scaling uses an organophosphorus type inhibitor.

Disadvantages of the method:

- firstly, the low efficiency of preventing salt deposition by pumping chemical reagents (solutions) specified in the method. This is due to the fact that the products of salt dissolution remain in the pores of the bottomhole formation zone, which leads to a decrease in filtration, and, as a consequence, to a decrease in the productivity of the production well;

- secondly, the low quality of treatment of downhole equipment. This is due to the fact that the products of salt dissolution and chemical reagents injected into the well, which are in the well after the end of treatment, are not extracted to the surface;

- thirdly, environmental pollution due to the outflow of chemicals at the wellhead sequentially injected through the pipe string during the installation and dismantling of equipment (open system) in the process of implementing the method;

- fourthly, high costs, since the implementation of the method requires the involvement of a well workover team to extract the production equipment (pipe string and pump) from the production well, run the production string into the well, and after processing the bottomhole zone of the production well to extract from production wells, installation of production equipment in a production well;

- fifth, a long process of processing the bottomhole zone of a production well, since it is necessary to mount and dismantle equipment at the wellhead several times, depending on the technological operation (extraction of production equipment (pump, pipe string) from the well, lowering the production pipe string with a packer, landing a packer in the well above the formation, sequential injection of chemical reagents into the bottomhole zone of the well: a solvent which is used as butyl cellosol or a mixture of solvents, a scale inhibitor solution, as well as a hydrophilic squeezing fluid, unpacking and extraction of the production string of pipes with a packer, lowering of production equipment into the well) ...

The technical objectives of the proposed invention are to improve the efficiency of the implementation of the method for removing and preventing salt deposition in the well and improving the quality of treatment of downhole equipment, reducing the turnaround time of the well, eliminating environmental pollution due to the outflow of acid at the wellhead during installation and dismantling of equipment at the wellhead , as well as reducing the cost of implementing the method and reducing the duration of the process of preventing salt deposition in the production well.

The set technical tasks are solved by the method of removing and preventing salt deposition in a well operated by a sucker rod pump, including lowering a string of pipes with a sucker rod pump inserted into the key support of the pipe string into a production well, pumping a scale inhibitor into the bottomhole zone of a production well, holding the well and subsequent extraction of oil from a production well.

What is new is that, before pumping in the inhibitor, the sucker rod pump drive is stopped, the pumping unit, the flow switch, tank trucks with acid, anticorrosive liquid and scale inhibitor are installed and hydraulically connected to each other, as well as a trough tank, after which the well is examined by beating the liquid level in the annular space of the well, the injection of the scale inhibitor is carried out in a volume of 0.2 m ³ into the annular space of the well without exceeding the injection pressure of 3.0 MPa, holding is carried out for 2 hours, and a decrease in the liquid level in the annular space of the well is expected, after which the well is examined by repeated striking liquid level in the annulus of the well, then close the linear valve and turn on the sucker rod pump drive, then circulate the well fluid mixed with the scale inhibitor between the wellhead and the bottom of the well for 12 hours, then stop the rod depth drive of the pump, the sucker rod pump is removed from the key support of the pipe string, then hydrochloric acid is injected into the annulus of the well, then by pumping an anti-corrosive liquid into the annulus of the well, hydrochloric acid is brought to the intervals of perforation of the formation and the well is left for technological exposure for 1 hour, after which in 3 cycles every 0.5 hours alternately, then into the pipe string, then into the annulus of the well, 0.5 m ^{3 of} process fluid is injected, after the end of the holding time, a sucker rod pump is installed in the key support of the pipe string, the sucker rod pump drive is started and pumping out the waste fluid from the formation into a trough tank to a neutral pH is carried out by a sucker rod pump, after which oil is withdrawn from the production well.

FIG. 1-5 schematically and sequentially depicts a method for removing and preventing salt deposition in a well operated by a sucker rod pump.

The fallout of salts (gypsum, anhydride, calcium carbonate) in the well is associated with the extraction of formation water together with oil, as well as the mixing of formation waters of various types with each other (alkaline with hard).

In production wells, serious complications are caused by the deposition of salts: solid calcium sulfate - gypsum CaSO ₄ 2H ₂ O and anhydrite - CaSO ₄ · 0.5H ₂ O. Gypsum deposits prevail at temperatures of 40 degrees and below, at higher temperatures anhydrite can precipitate.

The proposed method is based on the chemical method of removing and preventing the formation of salts in the well and production equipment by transforming sediments using a scale inhibitor and then dissolving the reaction products with hydrochloric acid and removing them from the well by flushing with a process fluid. The implementation of this method 3-4 times a year prevents the formation of salts in the well.

The proposed method is implemented as follows.

A production well 1 (see Fig. 1-5) is operated at the oil field, equipped with a pipe string 2 with a sucker rod pump (SUP) 3 installed in the key support 4 of the pipe string 2. During the operation of production well 1, salt deposits are formed in it (gypsum, anhydride) and during the subsequent operation of production well 1, this leads to overlap of the perforation intervals 5 of the productive formation 6 of the production well 1. As a result, the production rate of the well decreases and the water cut of the production of production well 1 increases. In addition, salts are deposited on the production equipment: casing pipes, pump, narrowing the flow area of the operational equipment. Linear 7 and annular 8 valves are installed at the wellhead of the production well.

In order to clean the well 1 from salts already formed in it and prevent further salt formation, the sucker rod pump 3 drive is stopped, then installed at the wellhead of the production well 1 and the pump unit 9 is hydraulically connected to each other (see Fig. 2-5), the fluid flow switch 10 , tank truck with scale inhibitor 11, tank truck with acid 12, tank truck with anticorrosive liquid (ACL) 13, tank truck with process fluid 14 and gutter tank 15, process valves 16, 17, 18, 19, 20, 21, 22 are also installed in the hydraulic piping , 23. Technological valves 16, 17, 18, 19, 20, 21, 22, 23 are closed.

As a pumping unit 9 is used, for example, the pumping unit SIN35.64 manufactured by OOO Plant Synergy, RF, Perm Territory, Chermoz.

As a flow switch 10 liquid used, for example, a flow switch manufactured by OOO "OZNA" Measuring systems of the Russian Federation, Republic of Bashkortostan, Oktyabrsky.

As tank trucks, for example, acid trucks of the SIN37.51 brand on the basis of the NEFAZ trailer, produced by Synergy Plant LLC, Russia, Perm Territory, Chermoz, are used.

As a gutter container 15, for example, a technological container is used on a tractor chassis trailer ET 18. KSHP "UNIKOM" acid-resistant performance, produced by ZAO ZNPO "UNIKOM" RF, Sverdlovsk region, Pervouralsk.

As a scale inhibitor, any known scale inhibitor is used, for example, a scale inhibitor SNPKh-5314, according to TU 2458-262-05765670-2007. produced by the Russian Federation, the Republic of Tatarstan, Kazan. Purpose - the scale inhibitor has complexing and crystal-breaking properties. Scale inhibitor SNPKh-5314 is delivered to the well in a tanker truck 11.

As an acid, for example, inhibited synthetic technical 12% hydrochloric acid is used, obtained from hydrochloric acid of technical grade A according to GOST 857-95 by adding, for example, waste water with a density of 1100 kg / m3. 12% inhibited synthetic technical salt is delivered to well 1 by tanker truck 12.

An acid corrosion inhibitor is used as an ACL, for example, TATOL / TATOL 1-10 m2 according to TU 20.59.42-007-48694360-2017, manufactured by the Russian Federation, Republic of Tatarstan, Kazan. AKZH is prepared on the basis of production services and delivered to the well in a tank truck 13.

As a process fluid used, for example, waste water with a density of 1050 kg / m ³ . Waste water of the specified density is prepared on the basis of production services and delivered to the well in a tanker truck 14.

Set the fluid flow switch 10 to position "a". The casing 8 and process valves 16 and 20 are opened. Using the pumping unit 9 from the tank truck 11 through the fluid flow switch 10, the scale inhibitor is injected in a volume of 0.2 m ³ into the annulus 24 of the well 1 without exceeding the injection pressure of 3.0 MPa, so as not to transfer the sucker rod pump 3 located in the key support 4 pipe strings 2.

Next, the well 1 is examined by a beating of the liquid level 25 'in the annulus 24 of the well 1. The beating of the level is performed using an echo sounder (not shown in Figs. 1-5). For example, they use an echo sounder of the MIKON-811-02 brand, manufactured by LLC Mikon, RF, Republic of Tatarstan, Naberezhnye Chelny.

For example, according to the results of the studies carried out, the level - L _{1 of the} fluid in the annulus 24 (see Fig. 2) of well 1 is 900 m.

Exposure is carried out for 2 hours to mix the scale inhibitor with the well fluid in the annulus 24 of well 1, while the scale inhibitor penetrates through the perforation intervals 5 into the bottomhole zone of formation 6.

After 2 hours, the process valves 16 and 20 are closed and the process valves 21 and 22 are opened. The SRP drive 3 is switched on. Then, for 12 hours, the well fluid mixed with the scale inhibitor is circulated (see Fig. 3) along the pipe string 2 up through the flow switch 10 and downward in the annulus 24, i. e. between the wellhead and the bottom of the well 1. In the process of circulation, the scale inhibitor gradually dissolves salts from the surfaces of production equipment and the walls of the well, including in the perforation interval 5.

After 12 hours, the sucker rod pump 3 drive is stopped and the liquid level in the annulus 24 of well 1 is expected to drop.

A decrease in the liquid level in the annular space of well 1 24 is expected, for example, within 1.5 hours in order to reduce the liquid level in the annular space of well 1 24 to the previously hit-off value of 900 m or less, but not more than the volume of the scale inhibitor equal to 0.2 m ³ , the level of which in well 1 is, for example, 15 m, i.e. 900 m-15 m = 885 m.

After that, borehole 1 is examined by re-chipping the liquid level in the annulus of well 1. The chipping of the 25 "level is performed using an echo sounder, for example,

L ₂ = 890 m. Having made sure, according to the results of the studies, that the level - L _{2 of the} liquid in the annulus 24 (see Fig. 2-3) of well 1 is greater than the level of 885 m, the annular 8 and process valves 21 and 22 are closed.

The sucker rod pump 3 is removed from the lock support 4 of the pipe string 2, for example, using a crane 25 installed at the wellhead 1.

Set the fluid flow switch 10 to position "a" (see Fig. 3).

The casing 8 and technological valves 17, 20, 21 are opened.

First, the volume of acid for injection into the annulus 24 (see Fig. 3) of well 1 is determined from the condition of performing the installation of an acid "bath" in the intervals of perforation 5 of formation 6 according to the formula:

_To V = π · D ^2/4 · (h ₁ + h ₂ + h _3),

where, D is the inner diameter of the wellbore, for example 15 cm = 0.15 m

h ₁ - the height from the bottom of the well to the bottom of formation 6 of well 1. For example, h ₁ = 50 m.

h ₂ - height of perforation intervals 5 of layer 6. For example, the height of perforation intervals 5 of layer 6 is 5 m.

h ₃ - height, providing overlapping intervals in the acid bath mode 5-10 m. Let's take h ₃ = 7 m.

Substituting numerical values into the formula, we get:

_To V = π · D ^2/4 · (h ₁ + h ₂ + h ₃₎ = 3.14 + (0.15 m) ^2/4 + (50 + m + 5 m 7 m) = 1.1 m ³

Then, using pump 9 from the tank truck with acid 12 through the flow switch 10, hydrochloric acid is pumped into the annulus 24 of well 1 in a volume of 1.1 m ³ .

Then the required volume of injection of anti-corrosive fluid (ACL) is determined to bring hydrochloric acid to the perforation intervals 5 of reservoir 6 of well 1. For example, the volume (V ₃ ) of the annulus 24 is 10 m ³ . Then the volume of AKL (V _aq ) used to bring the acid to the perforation intervals 5 of reservoir 6 is:

V _akzh = V ₃ - 2 m ³ = 10 m ³ -2 m ³ = 8 m ³ .

Then, the process valve 17 is closed (see Fig. 3) and the process valve 18 is opened and with the help of the pump 9 from the tank truck with the anticorrosive liquid 13 through the flow switch 10, hydrochloric acid is pumped into the annulus 24 and the hydrochloric acid is brought to the perforation intervals 5 of the formation 6 (without squeezing into layer 6).

AKL, injected into the annulus 24 of well 1, when pumping acid into the perforation interval of the formation, reduces the negative effect of acid on the production string and downhole equipment (pipe string 2 and sucker rod pump 3) of well 1 and multiply slows down the corrosion process that occurs during work to prevent sedimentation salts in the well 1.

Well 1 is left for technological exposure for 1 hour in the acid "bath" mode, while the acid solution slowly penetrates through the perforation intervals 5 into the bottomhole zone of formation 6 and dissolves the bridging compounds and rock particles.

Then, in 3 cycles, every 0.5 hours, alternately, then into the pipe string 2, then into the annulus 24 of the well 1, 0.5 m ^{3 of the} process fluid are injected.

To pump the process fluid into the pipe string 2 (see Fig. 4), the flow switch 10 is moved to position "b" and the annular 8 and process valves 20, 21, 23 are opened, while all other valves are closed. The pumping unit 9 from the tank truck with the process fluid 14 pumps the process fluid through the flow switch 10 into the pipe string 2, which causes the acid to move from the bottomhole zone in the annulus 24, while the excess liquid from the annular space 24 through the flow switch 10 enters the gutter tank 15 ...

Leave the well for 0.5 hour to react with hydrochloric acid. Then, the process fluid is pumped into the annular space 24 (see Fig. 3). Pumping unit 9 from a tanker truck with process fluid 14 pumps process fluid through the flow switch 10 into the annulus 24, which causes the acid to move from the bottomhole zone into the tubing string 2, while excess fluid from the tubing string 2 through the flow switch 10 enters the trough tank 15 Leave the well for 0.5 hour to react with hydrochloric acid.

The first acid rinse cycle is complete. Two more acid rinse cycles are carried out in the same way. Then all the valves are closed.

As a result of the technological manipulations carried out in the bottomhole zone 6 of well 1, acidic "rinsing" occurs, i.e. the movement of acid in a dynamic mode in opposite directions, leading to the dissolution of 6 clogging compounds in the bottomhole zone of the formation, the products of the reaction of salts with a scale inhibitor, as well as rock particles and their removal from the bottomhole zone of formation 6 into the wellbore 1, which ensures the restoration of the filtration capacity of the bottomhole formation zones 6.

In the process of "acid rinsing", acid does not get inside the pipe string 2, which reduces the negative effect of the acid both on the pipe string 2 itself and on the sucker rod pumping pump 3.

With the help of a crane, the sucker rod pump 3 is installed in the lock support 4 of the pipe string 2. The fluid flow switch 10 (see Fig. 5) is set to position "a", the process valves 21 and 23 are opened, while all other valves are closed.

The drive of the sucker rod pump 3 is started and the sucker rod pump 3 is pumped out of the waste fluid from the bottomhole zone (perforation intervals 5 of layer 6) of well 1 into the trough tank 15 to neutral pH. Neutral pH = 7. The pH value is measured at the entrance to the trough tank 13.

For example, at the beginning of pumping, pH = 5.0 and as the pumping sucker rod pump 3 is pumped out of the production well 1 in a volume of 6 m ^{3, the} pH reached a neutral value equal to 7. After that, the sucker rod pump 3 drive is stopped.

The pH is measured, for example, using a digital portable pH meter manufactured by OOO Trias, Russian Federation, Moscow.

At the wellhead, dismantle: pumping unit 9 (see Fig. 1), fluid flow switch 10, tank truck with scale inhibitor 11, tank truck with acid 12, tank truck with anticorrosive liquid (ACL) 13, tank truck with process fluid 14, gutter tank 15 , technological valves 16, 17, 18, 19, 20, 21, 22, 23. Close the annular valve 8 (see Fig. 1) and open the linear valve 7.

The sucker rod pump 3 drive is re-started and oil is withdrawn from the producing well 1.

In order to prevent salt deposition in the well and the bottomhole zone of the well, as well as to restore the production rate of the well after such treatment, the above process is repeated 3-4 times a year.

The efficiency of removal and prevention of salt deposition in the well and the bottomhole formation zone of the well increases, the turnaround time of the well is increased by 20% due to the complex effect:

- firstly, an inhibitor of salt formation, which circulates in well 1 for 12 hours, gradually destroying the crystals of salts of solid calcium sulfate - gypsum CaSO4 · 2H2O and anhydrite - CaSO4 · 0.5H2O;

- secondly, hydrochloric acid, which in a gentle mode (without deep penetration into the formation) in the "acid bath" and "rinsing" mode (dynamic BHT)

dissolves various bridging agents in the bottomhole zone (products of salt dissolution with a scale inhibitor, a clay crust, as well as 6 calcium, magnesium carbonates and other minerals and contaminants present in the formation rock that can react actively with acid).

Colmatants are extracted from the bottomhole zone into the wellbore and beyond the wellbore and therefore do not remain in the pores of the bottomhole formation zone, which leads to the restoration of the filtration capacity of the bottomhole zone, and as a consequence, to an increase in the productivity of the producing well.

The quality of treatment of downhole equipment is improved, since the products of salt dissolution and chemical reagents injected into the well, which are in the well after the end of treatment, are pumped out using the sucker rod pump into a trough tank and disposed of, and do not remain in the well, as described in the prototype, and do not settle on surface of downhole equipment.

When implementing the method, the installation and dismantling of equipment at the wellhead (closed system) is excluded, which is guaranteed to exclude environmental pollution due to the outflow of acid at the wellhead.

The duration of the treatment of the bottomhole zone of the production well is reduced, since all equipment is mounted before the implementation of the method and dismantled after the implementation of the method, and all work during the implementation of the method is carried out by manipulating the linear, annular and technological valves and changing the position "a" or "b" of the switch liquid flow, and also excludes the use of a packer.

The cost of implementing the method is reduced, since all work is performed with the production equipment lowered into the well: pipe string 2 and pump 3 (SRP). Therefore, it is not required to involve a well workover team to extract production equipment (pipe string and pump) from the production well, run the production string into the well, and after processing the bottomhole zone of the production well to remove the production string from the well, install production equipment in the production well. ...

The method for treating the bottomhole zone of a production well operated by a borehole pump allows:

- to increase the efficiency of removal and prevention of salt deposition in the well and the bottomhole formation zone;

- improve the quality of treatment of downhole equipment, increase the turnaround time of the well by 20%;

- to exclude environmental pollution due to acid spillage at the wellhead during installation and dismantling of equipment at the wellhead;

- to reduce the cost of implementing the method;

- to reduce the duration of the treatment process of the bottomhole zone of the producing well.

Claims (1)

A method for removing and preventing salt deposition in a well operated by a sucker rod pump, including lowering a string of pipes with a sucker rod pump inserted into the key support of the pipe string into a production well, pumping a scale inhibitor into the bottomhole zone of a production well, holding the well and then withdrawing oil from the producing well wells, characterized in that before pumping the inhibitor, the drive of the sucker rod pump is stopped, the pump unit, the flow switch, tank trucks with acid, anticorrosive liquid and scale inhibitor are installed and hydraulically connected to each other, as well as a trough tank, after which the well is examined by beating the liquid level in the annulus of the well, the injection of the scale inhibitor is carried out in a volume of 0.2 m ³ into the annular space of the well, without exceeding the injection pressure of 3.0 MPa, holding is carried out for 2 hours and a decrease in the level of liquid in the annular space is expected important, after which they examine the well by re-beating the liquid level in the annulus of the well, then close the linear valve and turn on the sucker rod pump drive, then circulate the well fluid mixed with the scale inhibitor between the wellhead and the bottom of the well for 12 hours, then stop the drive sucker rod pump, remove the sucker rod pump from the key support of the pipe string, then pump hydrochloric acid into the annulus of the well, then pump hydrochloric acid into the annular space of the well with anti-corrosion fluid to bring the hydrochloric acid to the perforation intervals and leave the well for technological exposure for 1 hour, then in 3 cycles every 0.5 hours alternately, then into the pipe string, then into the annulus of the well, 0.5 m ^{3 of} process fluid are injected, after the end of the holding time, a sucker rod pump is installed in the key support of the pipe string, and it is started sucker rod pump drive and pumping out of the waste fluid from the reservoir into the trough tank to neutral pH is performed by the deep rod pump, after which oil is withdrawn from the production well.

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