RU2468186C1 - Isolation method of brine water influx in well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: isolation method of brine water influx in the wall watered with brine waters with rise of gas-water contact above the middle of perforation interval, at which an adhesive patch is installed after the well is killed and production tubing is removed from it at the perforation interval of non-flooded part of productive formation. Water-isolating composition, for example gel, is pumped under pressure to the interval of watered part of productive layer through lower perforation holes so that water-isolating screen is created in the depth of watered part of productive formation. Water-isolating screen is fixed by pumping plasticised cement grouting through lower perforation holes, which has increased spreadability and penetrability. Cement bridge of cement grouting of normal density, which covers lower perforation holes, is installed in the well shaft at the interval of watered part of productive formation. After wait-on-cement time (WOC) is over and strength and leakage test of cement bridge is completed, repeated perforation of the perforation interval of non-watered part of productive formation covered with adhesive patch is performed at the most effective gas-saturated part of the section. Production tubing is lowered into the well to the depth of upper holes of new perforation interval and the well is developed.

EFFECT: increasing brine water influx isolation efficiency.

3 ex, 5 dwg

Description

The invention relates to the oil and gas industry, namely, to isolate the influx of formation water in gas and gas condensate wells flooded with produced water with a rise in gas-water contact (GWC) above the middle of the perforation interval.

In Western Siberian fields, isolation of formation water inflow is carried out mainly by pumping a water-insulating composition into the flooded area and fixing it in the reservoir, which is installed in the wellbore with a cement bridge. In this case, if there is a highly permeable gas-saturated interval over the waterlogged part of the reservoir, the water-insulating composition and cement mortar are likely to penetrate into the highly permeable, non-flooded gas-saturated interval, and not into the flooded part of the reservoir. Often, to eliminate this undesirable circumstance, a highly permeable, non-water-saturated gas-saturated interval is cut off from the encircled part of the reservoir by insulating packers. However, in the case of overlapping the lower holes of the perforation interval with formation water, it is not advisable to install an insulating packer in the perforation interval, since it will not ensure the tightness of the overlap of the production string and cannot be fixed in the column in this interval.

A known method of isolating the influx of formation water, including pumping grouting mortar under pressure into the water producing part of the reservoir (Reference book on the current and overhaul of wells. A.D. Amirov et al. - M: Nedra, 1979. - P.238-241) .

The disadvantage of this method is the contamination of a highly permeable non-watered gas-saturated interval of the reservoir with cement slurry during waterproofing operations.

The challenge faced by the invention is to increase the reliability and efficiency of isolation of formation water inflow.

Achievable technical result, which is obtained as a result of the invention, is to increase the efficiency of isolation of formation water inflow.

The problem and the technical result are achieved by the fact that in the method of isolating the influx of produced water in the well, flooded with produced water with the rise of the gas-water contact (GWC) above the middle of the perforation interval, after killing the well and removing the lift column from it in the perforation interval of the non-watered part of the reservoir, repair patch, in the interval of the flooded part of the reservoir through the lower perforations, a waterproofing composition is pumped under pressure, for example gel, with the creation of a water-proof screen in the depth of the flooded part of the productive formation, fix the water-proof screen by pumping cement mortar plasticized with increased spreadability and penetration through the lower perforation holes, a cement bridge of normal density cement mortar is installed in the borehole in the interval of the water-cut part of the productive formation, covering the lower perforations, after waiting for the hardening of cement (OZZ) and testing cement bridge on strength and tightness carried retransmission perforation neobvodnivsheysya portion of the producing formation, the overlapped adhesive, in the most efficient gas-saturated part of the section in the wellbore to the depth of a new row of holes perforated interval lowered tubing and master hole.

Figure 1 presents the design of the well, watered with produced water with the rise of GWC above the middle of the perforation interval.

Figure 2-5 presents a diagram of the implementation of the proposed method for isolating the influx of formation water.

The method is implemented in a plugged well (Fig. 1), having production 1 and lift 2 columns, flooded with produced water with the rise of GWC 3 above the middle of the perforation interval 4.

The implementation of the method is as follows.

Before carrying out repair work (Fig. 2), an elevator column 2 is removed from the well. After removing the elevator column 2, a repair plaster 6 is installed in the perforation interval 4 of the non-irrigated part 5 of the reservoir.

In the interval (Fig. 3) of the flooded part 7 of the reservoir through the existing lower holes of the perforation interval 4, a water-proofing composition 8, for example, gel, is injected under pressure to create a water-proofing screen 9 in the depth of the flooded part 7 of the productive reservoir 9. In the practice of the oil and gas industry, as water-proofing compositions can be used, for example, the compositions described in the book (The reference book on the current and capital repair of wells. A.D. Amirov et al. - M .: Nedra, 1979. - S.238-241) and other compositions, priv eaten in books (Insulation work during the completion and operation of oil wells. II Kleshenko and others. - M .: Nedra, 1998. - 267 p .; Overhaul of wells. Insulation work. V.G. Umetbaev and others. - Ufa: RITS ANK "Bashneft", 2000, 424 pp .; Technology for overhaul and underground repair of oil and gas wells: A textbook for universities.U.M. Basarygin and others - Kransodar: Sov. Kuban, 2002, 584 pp .; Gasumov R .A., Nersesov SV, Mosienko VG Technology of isolation of formation water inflow in gas and gas condensate wells. Review Inform. Ser .: development and operation of gas and gas condensate fields. - M.: IRC Gazprom, 2005, 107 pp.).

In addition, the following waterproofing compositions are known:

- modifier (113-63 or 113-65) + ethyl silicate (ETS-40 or ETS-16) + hydrophobic organosilicon liquid (GFA);

- ethyl silicate (ETS-40 or ETS-16) + synthetic grape acid (ICS) + calcium chloride (CaCl ₂ );

- polyvinyl alcohol (PVA) + hydrophobic organosilicon liquid (GKZh).

Gel-forming water-insulating compositions are also known, for example, silicate gel-gel-forming base + calcium chloride (CaCl ₂ ) + hydrochloric acid (HCl) + ammonium sulfate (NH ₄ ) ₂ SO ₄ or polymer gel-gel-forming base + polyacrylamite (PAA).

Then, the waterproofing screen 9 is fastened with a plasticized cement mortar 10 with increased flowability and penetration by pumping it through the lower perforations of the perforation interval 4. Plasticized cement grout means cement mortar containing a plasticizing agent, for example, 1.0-3.0 % by weight of cement (see, for example, http://www.emaco-spb.ru/glenium_sky_591). Such plasticized grouting cement mortars have increased spreadability and penetration. From the prior art (see, for example, www.dobi.oglib.ru/bgl/2684/303.html) it is known that the increased flowability and penetration of cement slurry is characterized by plastic viscosity. Increased spreadability and penetration are characteristic of cement grouts, the viscosity of which is close to the viscosity of water. The plastic viscosity of plasticized cement slurry is 30-50 Sp. The absence of a solid phase also leads to a high increased flowability and penetration of the solution and good filterability in a porous medium.

In the wellbore (Fig. 4), in the interval of the flooded part 7 of the reservoir, a cement bridge 11 is installed from a normal density cement mortar that overlaps the lower perforation holes of the perforation interval 4. Normal cement grouting cement refers to cement grout with a density of 1750-1950 kg / m ³ (see, for example, http://www.ng-burenie.ru/reastab.php), for example, PTC-1-50 - 60%, water - 40%.

After the OZZ (figure 5) and testing the cement bridge 11 for strength and tightness, re-perforation of the upper part of the existing perforation interval 4 of the non-watering part 5 of the productive formation, covered by repair patch 6, is carried out in the most effective gas-saturated non-watering 5 part of the section of the productive formation, determined by the results geophysical exploration, with the formation of a new interval of perforation 12.

An elevator column 2 is lowered into the well to the depth of the upper holes of the new perforation interval 12 and the well is mastered, the well is drilled to the torch before reaching the operating mode and put it into operation.

The proposed method of isolating the influx of formation water in the wells allows repair and insulating work to irrigate part of the formation without contaminating a highly permeable, non-watered, gas-saturated part of the productive formation by covering it with a repair patch.

In well-known technical solutions for isolating wells from the influx of formation water during the rise of GWC when injecting a water-proofing composition into a well, the water-proofing composition penetrates into an un-flooded gas-saturated section of the reservoir, because in a gas-saturated area, the hydraulic resistance to movement of the composition through the pores of the formation is less than when it moves through the pores of the formation in the flooded area, since these pores are occupied by water during the flooding of the reservoir and create obstacles for the injected composition.

As a result, a water barrier will be created in the non-flooded part of the reservoir, above the flooded part of the well, and the reservoir water will continue to move along the reservoir into the well, bypassing the water barrier, and further watering of the well in the drained zone will occur.

In the claimed invention, when injecting a water-proofing composition, the drained part of the formation is reliably blocked by a repair patch placed in the non-flooded part of the well, and the water-insulating composition will enter the flooded part of the well, creating a waterproofing screen. This is due to the high efficiency of waterproofing the influx of formation water into the well.

Examples of the claimed method

Example 1

The method is implemented in a plugged well having production 1 (diameter 219) and lift 2 columns (diameter 168), flooded with produced water with a rise of GWC 3 above the middle of perforation interval 4.

An elevator column 2 is removed from the well. After removing the elevator column 2, a repair plaster 6 of Dorn-219 brand is installed in the perforation interval 4 of the non-watered part 5 of the reservoir.

In the interval of the flooded part 7 of the reservoir through the existing lower holes of the perforation interval 4, a water-proofing composition 8 (modifier 113-63 or 113-65) + ethyl silicate (ETS-40 or ETS-16 + hydrophobic) are pumped under pressure 5.8 MPa with a TsNB-20 pump organosilicon liquid (GLC), with the creation in the depths of the flooded part 7 of the productive layer of the waterproofing screen 9.

Then, the waterproofing screen 9 is fastened with plasticized cement grout 10 with increased spreadability and penetration (PTC-1-50 - 60 wt.% + Mk-85 - 40 wt.% (Condensed silica fume) + aqueous solution of calcium chloride CaCl ₂ - 150 wt. .% (density 1065 kg / m ³ ) + SP-1 - 2 wt.% (superplasticizer) + 250 EXR - 0.8 wt.% (natrosol to reduce water loss) by pumping it through the lower perforations of the perforation interval 4.

In the wellbore, in the interval of the flooded part 7 of the reservoir, a cement bridge 11 is installed from a normal density cement slurry that overlaps the lower perforations of the perforation interval 4. Normal density grouting cement means PTZ-1-50 grouting cement mortar - 60%, water - 40% , with a density of 1750-1950 kg / m ³ .

After OZC and testing of cement bridge 11 for strength and tightness, re-perforation of the upper part of the existing perforation interval 4 of the non-watering part 5 of the productive formation, covered by repair patch 6, is carried out in the most effective gas-saturated non-watering 5 part of the section of the productive formation, determined according to the results of geophysical studies, with the formation a new interval of perforation 12. Perforation is carried out with a PKS-80 puncher.

An elevator column 2 is lowered into the well to the depth of the upper holes of the new perforation interval 12 and the well is mastered, the well is drilled to the torch before reaching the operating mode and put it into operation.

Example 2

The method is implemented in a plugged well having production 1 (diameter 168) and lift 2 columns (diameter 114), flooded with produced water with a rise of GWC 3 above the middle of the perforation interval 4.

An elevator column 2 is removed from the well. After removing the elevator column 2, a repair plaster 6 of Dorn-168 grade is installed in the perforation interval 4 of the non-watered part 5 of the reservoir.

In the interval of the flooded part 7 of the reservoir, through the existing lower holes of the perforation interval 4, a waterproofing composition 8 (ethyl silicate (ETS-40 or ETS-16) + synthetic acid (ICS) + calcium chloride (CaCl ₂ ) is pumped under a pressure of 5.6 MPa with a CFS 160 pump ) with the creation in the depths of the flooded part 7 of the productive layer of the waterproofing screen 9.

Then, the waterproofing screen 9 is fixed with plasticized cement grout 10 with increased spreadability and penetration ((PTC-1-50 - 60 wt.% + Mk-85 - 40 wt.% (Condensed silica fume) + aqueous solution of calcium chloride CaCl ₂ - 150 wt.% (density 1065 kg / m ³ ) + SP-1 - 2 wt.% (superplasticizer) + polypropylene fibers + F-1 - 0.04 wt.% + 250 EXR - 0.8 wt.% (natrosol for reduction of water loss) by pumping it through the lower perforations of the perforation interval 4.

In the wellbore, in the interval of the flooded part 7 of the reservoir, a cement bridge 11 is installed from a normal density cement slurry that overlaps the lower perforations of the perforation interval 4. Normal density grouting cement means PTZ-1-50 grouting cement mortar - 60%, water - 40% , with a density of 1750-1950 kg / m ³ .

After OZC and testing of cement bridge 11 for strength and tightness, re-perforation of the upper part of the existing perforation interval 4 of the non-watering part 5 of the productive formation, covered by repair patch 6, is carried out in the most effective gas-saturated non-watering 5 part of the section of the productive formation, determined according to the results of geophysical studies, with the formation a new interval of perforation 12. Perforation is carried out with a PI-2906 Omega punch or ZPKT-73 GP.

An elevator column 2 is lowered into the well to the depth of the upper holes of the new perforation interval 12 and the well is mastered, the well is drilled to the torch before reaching the operating mode and put it into operation.

Example 3

The method is implemented in a plugged well with production 1 (diameter 146) and lift 2 columns (diameter 73), flooded with produced water with a rise of GWC 3 above the middle of the perforation interval 4.

The elevator column 2 is removed from the well. After the elevator column 2 is removed, a repair patch 6 of the Dorn-146 brand is installed in the perforation interval 4 of the non-watered part 5 of the reservoir.

In the interval of the flooded part 7 of the reservoir through the existing lower holes of the perforation interval 4, a water-proofing composition 8 (modifier 113-63 or 113-65) + ethyl silicate (ETS-40 or ETS-16 + hydrophobic) are pumped under a pressure of 5.5 MPa with a TsNB-250 pump organosilicon liquid (GLC)), with the creation in the depths of the flooded part 7 of the productive layer of the waterproofing screen 9.

Then, the waterproofing screen 9 is fixed with plasticized cement grout 10 with increased spreadability and penetration (PTC-1-50 - 98 wt.% + Mk-85 - 2 wt.% (Condensed silica fume) + water 55 wt.% + Oksil - 04 wt.% (plasticizer) + 250 EXR - 0.8 wt.% (natrosol to reduce water loss) by pumping it through the lower perforations of the perforation interval 4.

In the wellbore, in the interval of the flooded part 7 of the reservoir, a cement bridge 11 is installed from a normal density cement slurry that overlaps the lower perforations of the perforation interval 4. Normal density grouting cement means PTZ-1-50 grouting cement mortar - 60%, water - 40% , with a density of 1750-1950 kg / m ³ .

After OZC and testing of cement bridge 11 for strength and tightness, re-perforation of the upper part of the existing perforation interval 4 of the non-watering part 5 of the productive formation, covered by repair patch 6, is carried out in the most effective gas-saturated non-watering 5 part of the section of the productive formation, determined according to the results of geophysical studies, with the formation a new interval of perforation 12. Perforation is carried out with a PRK 42C puncher.

An elevator column 2 is lowered into the well to the depth of the upper holes of the new perforation interval 12 and the well is mastered, the well is drilled to the torch before reaching the operating mode and put it into operation.

Claims (1)

A method of isolating the influx of formation water in a well flooded with formation water with a rise in gas-water contact above the middle of the perforation interval, in which, after killing the well and removing the lift string from it, a repair patch is installed in the perforation interval of the non-watered part of the reservoir, in the interval of the flooded part of the reservoir through the lower perforations inject a water-proofing composition, for example gel, under pressure, with the creation of a productive depth in the depth of the flooded part of the first layer of the waterproofing screen, fix the waterproofing screen by pumping cement mortar plasticized with increased spreadability and penetration through the lower perforations, in the well bore, in the interval of the flooded part of the reservoir, install a cement bridge of normal density cement that overlaps the lower perforations after waiting for the cement to solidify and tests of the cement bridge for strength and tightness conduct reperforation ation perforation interval neobvodnivsheysya portion of the producing formation, the overlapped adhesive, in the most efficient gas-saturated part of the section in the wellbore to the depth of a new row of holes perforated interval lowered tubing and master hole.

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