RU2340761C1 - Method of elimination of leakage of producing well column - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to oil industry and can be employed at elimination of leakage of producing well column. The essence of the invention is as follows: according to the method insulation for preventing inflow of liquid of lower part of a well is installed 3-5 m lower of leakage interval. Then capacity of leakage interval is determined. When capacity of leakage interval exceeds 300 m³/day and pressure at the wellhead exceeds 10 MPa, stabilising water-oil emulsion is pumped as insulation material; when capacity of leakage interval exceeds from 150 to 300 m³/day and pressure at the wellhead exceeds 10 MPa, a polymer-cement solution "Monolit-P" is pumped as an insulating material; and if capacity is less, than 150 m³/day and pressure at the wellhead less, than 10 MPa, material "Granite" is pumped as an insulating material. At that pumped insulating material is brought in the flow column to the leakage interval , then partially it is pressed into the well till levels of insulating material in the flow column and annulus space equalise, then the flow column is lifted and insulating material is pressed into the leakage interval.

EFFECT: facilitating elimination of lower annulus circulation of well.

2 cl, 1 ex

Description

The invention relates to the oil industry and may find application in eliminating leaks in the production casing of a well.

A known method of restoring the integrity of the production casing of the well, according to which a gelling composition is pumped into the zone of the interval of violation of the integrity of the production casing. A pipe string is lowered into the well with a layout installed at its lower end. Place the specified layout below the violation interval. Use the layout represented by a conical shoe made in the form of a frame of soft metal filled with a mixture of cement and crumbs of soft metal. Disconnect the cone shoe and push it to the bottom. Fill the perforation interval with sand. The deflated pipe string is sealed relative to the production string by pouring cement. A deflated pipe string is suspended. After drilling a cement cup, sand is removed from the well and put into operation (RF Patent No. 2142112, published. 1998.12.27).

The known method does not exclude the inclusion of a gelling composition in the perforation interval.

Closest to the invention in technical essence is a method of installing a bridge that cuts off the oil reservoir, according to which a column of sand is washed over the perforation interval, and a cement composition is pumped above it. As components of the grouting composition, an aqueous dispersion of fresh water and water-swellable polymer powder — GNP based on AK-639 is used in a ratio of 1.5 weight parts per 100 parts of fresh water with up to 5% by weight of fresh water being introduced into the dispersion of gel aggregates of GNP dispersion (RF Patent No. 2276250, published. 2006.05.10 - prototype).

The known method allows you to isolate the leakage of the production string above the sand layer, however, the reliability of the insulation is low due to the low penetration of insulating materials into the near-wellbore space.

The proposed invention solves the problem of improving the reliability of isolation of leaks in the production casing of the well.

The problem is solved in that in the method for eliminating leaks in the production casing of a well, including isolation from the inflow of liquids from the lower part of the well and injecting insulating material, according to the invention, the isolation from the inflow of liquids from the lower part of the well is set 3-5 m below the leakage interval, the injectivity of the leakage interval is determined, when leakage pickup interval of more than 300 m ³ / day and the wellhead pressure of 10 MPa as an insulating material is injected stable w water emulsion, with pick-up of 150 to 300 m ³ / day and the pressure at the wellhead 10 MPa as an insulating material is injected, polymer solution "Monolith-R", when pick-up of less than 150 m ³ / day and the pressure at the wellhead 10 MPa Granite material is pumped as an insulating material, while when injecting insulating material, the injected volume of insulating material is brought through the tubing string to the leakage interval, partially squeezed out into the well to balance the insulation levels Nogo material in the column tubing and the annulus, the column is raised tubing and forced into the insulating material leaking interval.

If it is not possible to eliminate the leak after a stabilized oil-water emulsion, polymer-cement solution "Monolith-R" and / or material "Granite" is pumped.

The features of the invention are:

1) isolation from the flow of fluids of the lower part of the well;

2) injection of insulating material;

3) installation of isolation from the flow of fluids of the lower part of the well 3-5 m below the leakage interval;

4) determination of the injectivity of the leakage interval;

5) when the injectivity of the leakage interval is more than 300 m ³ / day and the pressure at the wellhead 10 MPa injection as an insulating material of a stabilized oil-water emulsion, when the injectivity is from 150 to 300 m ³ / day and the pressure at the wellhead 10 MPa injection as an insulating material Monolith-R polymer-cement mortar, with an injectivity of less than 150 m ³ / day and a pressure at the wellhead of 10 MPa; injection of Granit material as an insulating material;

6) when injecting insulating material, bringing the injected volume of insulating material along the tubing string to the leakage interval, partially squeezing into the well to balance the levels of insulating material in the tubing string and annular space, lifting the tubing string and selling insulating material in the leakage interval;

7) if it is not possible to eliminate leakage after a stabilized oil-water emulsion, polymer-cement solution "Monolith-R" and / or material "Granite" is pumped.

Signs 1, 2 are common with the prototype, signs 3-6 are the salient features of the invention, sign 7 is a particular feature of the invention.

SUMMARY OF THE INVENTION

Due to the aging of the well stock, leakages in production casing are widespread. Known methods can isolate leaks in the production string, however, the reliability of the insulation is low due to the low penetration of insulating materials into the near-wellbore space. The proposed invention solves the problem of improving the reliability of isolation of leaks in the production casing of the well. The problem is solved as follows.

Set isolation from the inflow of fluids of the lower part of the well 3-5 m below the leakage interval. An explosion packer, cement bridge, etc. can be used as such insulation. The injectivity of the leakage interval is determined. When the injectivity of the leakage interval is more than 300 m ³ / day and the pressure at the wellhead is 10 MPa, a stabilized oil-water emulsion is pumped as an insulating material. At an injection rate of 150 to 300 m ³ / day and a pressure at the wellhead of 10 MPa, the Monolith-R polymer-cement solution is pumped as an insulating material. At an injection rate of less than 150 m ³ / day and a pressure at the wellhead of 10 MPa, Granite material is pumped as an insulating material. At the same time, when injecting insulating material, the injected volume of insulating material is brought through the tubing string to the leakage interval, partially squeezed out into the well until the levels of insulating material in the tubing string and the annulus are balanced, the tubing string is lifted and the insulating material is forced through in the leakage interval.

If it is not possible to eliminate the leakage, especially at high injection rates of the order of 700-1000 m ³ / day after the stabilized oil-water emulsion, the Monolit-R polymer-cement solution is pumped. If the tightness is not achieved, in this case, the Granite material is pumped. In this case, it is possible to pump Granite material after a stabilized oil-water emulsion instead of the polymer-cement solution "Monolith-R".

The stabilized water-oil emulsion is mainly pumped at a rate of 2-4 m ³ / linear m, the polymer-cement solution "Monolith-R" is mainly pumped at a rate of 0.2-1.0 m ³ / linear m, the material "Granite" is mainly pumped in a volume of 0, 1-0.3 m ³ / linear m of leakage interval.

After the injection of each material, technological exposure is carried out to structure the material, gain strength and create a tampon in the formation.

As a stabilized oil emulsion, an emulsion based on a hydrocarbon phase, an aqueous phase and an Emulsifier type emulsifier or an emulsion based on a distillate, an Yalan-E1 emulsifier and an aqueous solution of hydrochloric acid inhibitor (US Pat. RF No. 2304710, 08.20.2007) can be used. ), or emulsion of the following composition, wt.%:

hydrocarbon phase (oil) 25-50% product "Isoplast" 1.5-3.0% emulsifier 1-2% water phase (water) rest.

The formulation of the oil-water emulsion is selected in each case depending on the permeability of the formation, the type of reservoir and the effective thickness of the formation. Recommended ratios of the aqueous phase and hydrocarbon are from 2: 1 to 3: 1. With these ratios, a water-oil emulsion with a nominal viscosity in the range of 250-1000 s is obtained, which can significantly reduce the permeability of the bottomhole zone of the well. The required volume of emulsion injection into the bottom-hole zone depends on injectivity and porosity and ranges from 1 to 3 m ^{3 of} prepared emulsion per 1 m of effective reservoir power.

The Isoplast product is manufactured according to TU 2458-002-93481995-2006 and is a highly dispersed silicon dioxide with a bulk density of 40-220 g / dm ³ . In appearance, the Isoplast product is a loose powder from white to light yellow in color, the suspension with the Isoplast product has a pH of 2 to 8.

As an emulsifier in the composition of a stabilized oil-water emulsion, olenol, neonol, sinol, etc. can be used.

Polymer-cement mortar "Monolith-R" is a cement mortar with the additive "Monolit-R", manufactured according to TU 2458-003-93481995-2006. The additive "Monolith-R" includes a water-retaining additive - 3-10%, a plasticizer based on polyvinyl alcohol - 3-10%, a preservative - 0.1-0.5%, antifoam - 0.1 0.5%, amine plasticizer - 0.5-1.0%, dye - up to 2% and water - the rest up to 100%.

Polymer-cement mortar "Monolith-R" in its rheological properties meets all the requirements for cement mortars. It possesses low fluid loss not exceeding 5 cm ^3/30 min at 0.1 MPa. Bending strength after 7 days increases by 1.67 times, and compressive strength by 1.6-2.3 times. The introduction of cement "Monolith-R" into the grouting cement leads to an increase in adhesion to the metal of the casing pipe compared to the control sample by 2-2.5 times. Cured within 7 days, the polymer cement stone is virtually non-shrinking - linear expansion is 0.1-0.2%. The results of measurements of polymer cement mortar "Monolith-R":

fluid loss, cm ^3/30 min 3.6 water separation,% 1,6 hardening start time, hour 4,5 solidification end time, hour eighteen

Monolith-R has a positive effect on the sedimentation stability of cement slurry, increases the strength of cement stone, and also increases the adhesive strength at the rock-stone-metal boundary. So the adhesion of cement stone with metal after 72 hours when using "Monolith-R" is 13.5 times higher compared to cement without cement.

To prepare the Monolit-R polymer-cement mortar, the Monolit-R additive is introduced into a container with fresh water at the rate of 200 l per 1 ton of cement and forced to circulate for 10-15 minutes until a homogeneous consistency of the process fluid, then grouting cement is introduced and adjusted to the planned specific gravity.

Grouting material "Granite" is produced according to TU 2458-004-93481995-2006 and is a product based on phenol-formaldehyde resin and additives. In appearance, it is a homogeneous liquid from reddish brown to dark cherry in color with a viscosity of not more than 55 MPa · s and a mass fraction of solids of not less than 40%.

When determining the component and percentage composition of the Granit grouting material, the determining factor is the temperature and throttle response in the repair area. The temperature range is set in the following limits:

- in the range from 15 ° C to 80 ° C "Granite" is used in the composition with a process catalyst in an amount of 5-25%;

- in the range from 80 ° C to 110 ° C "Granite" is used in the composition with a process catalyst of 50% 0-10%.

As a catalyst, a solution of sulfuric, hydrochloric and other acids can be used.

Concrete example

Repair a well with a leak in the interval 1656-1660 m. Install an explosion packer 4 m below the leak interval. The injectivity of the leakage interval is determined, which is 800 m ³ / day at a wellhead pressure of 10 MPa. As an insulating material, a stabilized oil-water emulsion is pumped at a rate of 3 m ^{3 /} pog.m. Carry out technological exposure for 24 hours. The injectivity of the leakage interval is determined, which is 280 m ³ / day. Injected as an insulating material polymer-cement solution "Monolith-R" at the rate of 0.5 m ^{3 /} pog.m. Spend technological exposure for 24 hours and determine the throttle response interval, which is equal to 50 m ³ / day. Granite material is pumped as an insulating material at the rate of 0.2 m ^{3 /} pog.m to a technological stop, i.e. before the termination of the throttle response and the absence of a drop in pressure for 30 min exposure. Spend technological exposure for 24 hours, drill the blast packer and put the well into operation. In this case, when injecting any insulating material, the injected volume of insulating material is brought through the tubing string to the leakage interval, partially squeezed out into the well until the levels of insulating material in the tubing string and the annulus are balanced, the tubing string is lifted and the insulating string is forced through material in the leakage interval.

As a result, it is possible to completely eliminate the leakage of the production string even with ultra-high injectivity of the leakage interval. For comparison, the known methods do not provide for the elimination of leaks with a similar injectivity interval leaks.

Application of the proposed method will allow to solve the problem of improving the reliability of isolation of leakage of the production casing of the well.

Claims (2)

1. A method of eliminating leaks in the production casing of a well, including isolation from the inflow of liquids from the bottom of the well and pumping insulating material, characterized in that the isolation from the inflow of liquids from the bottom of the well is set 3-5 m below the interval of the leak, the injectivity of the leak interval is determined at injectivity a leakage interval of more than 300 m ³ / day and a pressure at the wellhead of 10 MPa, a stabilized oil-water emulsion is pumped as an insulating material, at an injection rate of 150 to 300 m ³ / day and a pressure at the wellhead of 10 MPa, the Monolit-R polymer-cement solution is pumped as an insulating material; at an injection rate of less than 150 m ³ / day and a pressure at the wellhead of 10 MPa, they are pumped as an insulating material Granite material, while injecting insulating material, the injected volume of insulating material is brought through the tubing string to the leakage interval, partially squeezed into the well to balance the levels of insulating material in the string tubing and annular space, raise the tubing string and push the insulating material into the leakage interval. 2. The method according to claim 1, characterized in that if it is not possible to eliminate leakage after a stabilized oil-water emulsion, a polymer-cement solution "Monolith-R" and / or material "Granite" is pumped.