RU2237805C1 - Method for treatment of face-adjacent well zone - Google Patents

Abstract

FIELD: oil and gas extractive industry.

SUBSTANCE: well is equipped with tubing column and inserted well pump having tail piece and filter on the end of no more than pump diameter. Inserted well pump with tail piece and filter is removed from the well. Pressure in the well is lowered by swabbing and extracting well fluid along tubing string until needed pressure is reached. Charges for thermo-gas-chemical treatment in tubing string are lowered. Thermo-gas-chemical treatment is performed at lowered pressure in the well. Influx is caused by swabbing and compressing. Well is taken into operation.

EFFECT: higher effectiveness of treatment, lower laboriousness of treatment process.

1 ex

Description

The invention relates to the oil and gas industry and may find application in the processing of the bottom-hole zone of a well.

A known method of processing the bottom-hole zone of a well, including injecting a treatment compound into the bottom-hole zone, pushing it into the formation, holding, positioning the implosion device in the interval of the treated formation, creating a depressed mode at the bottom of the well by lowering the pressure at the bottom, is lower than the reservoir, lowering the level of fluid in the annulus and cleaning the bottom-hole zone with repeated implosion exposure until the dynamic level in the annulus is stabilized (RF Patent No. 2168621, class E 21 V 43/25, publ. 06/10/2001).

The known method allows for exposure with reduced pressure on the bottom and to clean the bottomhole zone of the mechanical clogging elements, however, the absence of thermal exposure does not allow to clean the bottomhole zone, which is caked with asphalt-resin-paraffin deposits.

A known method of processing the bottom-hole zone of a well, including the descent of deep technological equipment with a source of thermogasochemical effects, burning the latter in the processed interval with the formation of gas of increased pressure and temperature, the depressive effect and the selection of part of the fluid from the bottom-hole zone (RF Patent No. 20011110018, class E 21 B 43/25, publ. 03/27/2003).

Due to the thermal element of the impact, the known method allows you to clean the bottomhole zone of asphalt-resin-paraffin deposits, however, the effectiveness of the method is small due to the lack of reduced pressure on the bottom, which is not compensated by the use of subsequent implosion exposure.

Closest to the invention, the technical essence is a method for treating the bottom-hole zone of an oil-bearing formation by cleaning it with the combustion products of a powder charge discharged into the well, with a pulse reducing pressure in the processing zone being carried out during combustion of the charge (USSR Author's Certificate No. 684948, class E 21 V 43/24, publ. 05/10/2000 - prototype).

The known method does not allow to effectively clean the bottom-hole zone of the clogging elements due to the lack of reduced pressure on the bottom, which is not compensated by the use of implosive effects. In addition, the application of the method requires considerable labor for lowering and lifting the string of tubing with downhole equipment.

The invention solves the problem of increasing the effectiveness of the impact and reducing labor costs for processing.

The problem is solved in that in the method for processing the bottom-hole zone of a well, which includes thermogasochemical treatment and putting the well into operation, according to the invention, the well is equipped with a tubing string and an inserted deep-well pump with a liner and a filter at the end of not more than the diameter of the pump; it is removed from the well before the gas-chemical treatment a plug-in deep well pump with a liner and a filter, reduce the pressure in the well by swabbing and withdrawing the borehole fluid along the tubing string d to achieve the necessary pressure, the descent of charges for thermogasochemical treatment is carried out in the tubing string, thermogasochemical treatment is carried out at reduced pressure in the well, and after the thermogasochemical treatment, inflow is caused by swabbing or compression.

The features of the invention are:

1. thermogasochemical effect;

2. putting the well into operation;

3. supplying the well with a tubing string and a plug-in deep pump with a liner and filter at the end of not more than the diameter of the pump;

4. before thermogasochemical exposure, removing from the well an inserted deep well pump with a liner and a filter;

5. the same decrease in pressure in the well by swabbing and withdrawing the borehole fluid along the tubing string until the required pressure is reached;

6. descent of charges for thermogasochemical effects in the tubing string;

7. thermogasochemical effect under reduced pressure in the well;

8. call inflow swabbing or compression.

Signs 1, 2 are common with the prototype, signs 3-8 are the essential distinguishing features of the invention.

SUMMARY OF THE INVENTION

During the operation of oil producing wells, the bottomhole zone of the well is bogged with products that reduce permeability and lead to a decrease in well production. Known methods can improve the efficiency of cleaning bottom-hole zone. However, the methods are laborious, multi-stage. When cleaning heavily clogged asphalt-resin-paraffin deposits of bottom-hole zones, the method is ineffective.

One of the effective methods used to increase the injectivity or recovery of formations is to increase the permeability of the bottomhole zone of the well by exposure to powder gases. The method is based on mechanical, thermal and chemical effects on rocks and formation fluids with a certain portion of powder gases generated directly in the well by burning a charge in a powder pressure generator.

Powder gases under high pressure and temperature, expanding, push the fluid in the well into the formation through perforations in the casing, penetrate the formation with the formation of cracks and thermochemical effects on the formation. At the same time, paraffin and asphalt-tar deposits are melted, water and oil-water barriers and hydrate plugs are destroyed, and the viscosity of oil is reduced. In addition, during the reverse movement from the reservoir, the powder gases clean the cracks from corrosion products and chemical reactions, as well as from sand and clay particles.

The disadvantages of thermogasochemical exposure to powder gases are the need for work on the complete extraction of underground equipment and the complete descent of underground equipment after exposure and a decrease in the cleaning effect due to cooling of the exposure zone during the descent of underground equipment.

The descent of underground equipment takes up to 12 hours, while the cooling of the impact zone occurs within 2 hours. This circumstance can minimize the effect obtained, since with cooling of the zone of influence resin-asphaltene compounds solidify and re-clog the bottom-hole zone.

The proposed method provides an influx of liquefied resinous-asphaltene compounds immediately after heating the bottom-hole formation zone by eliminating the lifting of the tubing string, lowering and lifting only the rod string, and reducing the time of lowering of underground equipment. The effectiveness of the impact increases and labor costs for processing are reduced.

The method is implemented for wells equipped with sucker rod pumps, which provide for the extraction of a plug-in deep pump with a shank and a filter on the rods. The tubing string is not removed. The pressure in the well is reduced by swabbing and withdrawing the wellbore fluid through the tubing string until the required pressure is reached. The descent of charges for thermogasochemical effects is carried out in a string of tubing. Thermogasochemical effect is carried out under reduced pressure in the well. After thermogasochemical treatment, inflow is caused by swabbing along the tubing string or by compression.

Thermogasochemical charge is lowered into the well on a geophysical cable. The size of the thermogasochemical charge in diameter is smaller than the inner diameter of the tubing string.

The tubing string from the inside is equipped with a lock support. The castle support is lowered together with the tubing string to the calculated depth. The well is equipped with a plug-in deep pump, lowered on the rod string and fixed in the castle support. Several pipes with a diameter not exceeding the diameter of the pump, called a shank, and a strainer also not exceeding the diameter of the pump, are fixed to the suction port of the pump. This circumstance makes it possible to extract a pump, a liner and a filter from the tubing string simultaneously while lifting the boom string.

The bottom of the tubing string is equipped with a funnel to ensure a smooth entry of the cable head when lifting it.

The proposed method is as follows.

Stop the well. A pump with a liner and a filter is removed from the well. Swabbing is performed on the tubing string. The swabbing process consists in repeatedly lowering and raising the swab cup on the cable in the cavity of the tubing string. In this case, the swab cup is immersed under the liquid level by 300-600 m, and then raised by cable.

When the swab cup moves upward due to the hydrodynamic pressure of the upstream fluid, the cup walls expand and overlap the internal cavity of the tubing string. When lifting the swab cup, the liquid located in the tubing string above the swab cup is simultaneously extracted. The swabbing process is performed to lower the liquid level in the well to a design depth that provides the required bottomhole pressure. This ensures the flow of formation fluid.

After swabbing the well, the thermogaschemical charge is lowered on the logging cable to the perforation interval and the thermogasochemical effect is produced.

By reducing the level of the liquid by swabbing, the thermogasochemical effect is produced under conditions of depression. Resin-asphaltene compounds begin to flow into the wellbore, which leads to the cleaning of the pore environment of the bottom-hole zone of the well.

With a free lift during the time when the bottom-hole zone is in a preheated state, the incoming formation products are selected.

After that, a pump with a liner and a filter is lowered into the well on the rod string and the pump is put into operation.

If swabbing is not possible due to the failure of the swab cup in the tubing string, the inflow can be called through the start-up couplings installed at depths of 600, 800 and 900 m. In this case, foam or inert gases are pumped into the annulus the space by the compressor and blowing the borehole fluid into the tubing string and then bleed off the injected gas. The depression created by this causes fluid flow from the formation.

To prevent leaks during pump operation, starting couplings are made in the form of a single-acting valve assembly. For this purpose, they are equipped with check valves, which ensure the injection of injected gas into the tubing string from the annulus and are hermetically closed during operation of the pump due to the pressure developed by the pump.

Concrete example

Bottom-hole treatment of an oil producing well is carried out with a depth of 1260 m and a perforation interval at 1230-1240 m. The well is equipped with a tubing string of 73 mm in diameter. The castle support is lowered together with the tubing string to a depth of 1100 mm. The well is equipped with a plug-in deep pump of the brand 175-RHMT-12-4-4, lowered on the rod string and fixed in the castle support. At the suction inlet of the pump, 1 pipe is fixed with a length of 10 m and a diameter of 25 mm, called a shank, and a strainer with a diameter of 25 mm. The bottom of the tubing string is equipped with a funnel. A rod string with a plug-in deep pump with a liner and a filter is removed from the well. Reduce the pressure in the well by swabbing and withdrawing the borehole fluid along the tubing string until the bottom-hole pressure decreases from 10 MPa to 3 MPa. The charge is lowered for thermogasochemical effects in the tubing string in the perforation interval. Thermogasochemical effect is carried out under reduced pressure at the bottom. After thermogasochemical exposure, inflow by swabbing is caused. On the column of rods, a pump with a shank and a filter is lowered and installed in the castle support. Launch the well into operation.

As a result, the flow rate of the well increased from 1 t / day to 4 t / day. The application of the proposed method will improve the effectiveness of the impact and reduce labor costs for processing.

Claims (1)

A method of treating a bottomhole zone of a well, including descent of charges for thermochemical treatment, thermogasochemical treatment and putting the well into operation, characterized in that the well is equipped with a tubing string and an inserted deep-well pump with a liner and a filter at the end of not more than the diameter of the pump, before thermogasochemical treatment remove the plug-in deep pump from the well with a liner and a filter, reduce the pressure in the well by swabbing and withdrawing the well fluid along the pump string -kompressornyh tube to the required pressure, for lowering the charges termogazohimicheskogo exposure is performed in the column tubing, termogazohimicheskoe exposure is carried out at reduced pressure in the well, and after exposure to cause the inflow termogazohimicheskogo swabbing or compression.