Sealing compound and method of its use

Abstract

FIELD: seals.SUBSTANCE: sealing system is proposed, comprising component A, which comprises in wt.% 38.05-40.0 low molecular weight polyester, 58.1-58.35 polyether, 0.05-0.16 alkaline earth metal salt of an organic acid, 0.07-0.20 non-ferrous metal carboxylate, 0.25-0.40 foaming solvent, 0.07-0.25 liquid glass, 0.35-0.64 corrosion inhibitor, and component B, which is 4,4'-diphenylmethane diisocyanate, wherein the ratio of components A and B is such that component B is taken in excess ~10-20% by weight, wherein components A and B are placed in sections of a sealed two-section package made of foil-coated polymer material with a plastic divider, isolated from each other; and a method for sealing an object using the proposed sealing system.EFFECT: creating an alternative version of a sealing system and a simple and quick method for its use for sealing various objects, as well as an expansion of the range of sealing compositions and devices for sealing various objects that ensure effective sealing.2 cl, 2 dwg, 1 tbl, 1 ex

Description

[0001] Technical field

[0002] The present invention relates to the field of chemistry, specifically to the composition of a sealing system used to seal gas wells (for degassing, for gas pressure testing), cable ducts, road structures, and other technical facilities requiring isolation and prevention of uncontrolled fluid flows (gas, liquid) by filling cavities, voids, and cracks. The invention also relates to a method for using such a sealing system.

[0003] Technology Level

[0004] Well sealing is the process of creating a barrier between the well's interior and the surrounding environment. It prevents hazardous leaks, reduces the risk of accidents, helps maintain well stability, and extends its service life. Sealing can also be used to protect the well from contaminants, such as surface water or groundwater.

[0005] The present invention is primarily directed to sealing gas wells, but can also be successfully applied to any field where sealing is required.

[0006] Thus, the invention can be used for the following applications:

[0007] - sealing wells for degassing;

[0008] - sealing of wells for gas pressure testing;

[0009] - fastenings of various diaphragms;

[0010] - well fastenings for well water drainage;

[0011] - filling pits for road foundations;

[0012] - sealing of cable wells;

[0013] - protection of equipment from corrosion.

[0014] This list is not exhaustive, and the proposed development is suitable for other technical objects where isolation and prevention of uncontrolled flows of fluids (gas, liquid) by filling cavities, voids, and cracks are required.

[0015] Currently, various means, both chemical and non-chemical, are used to seal wellheads. Wellhead seals are made using O-rings and gaskets. For oil and gas wells, wellhead seals are made using blowout preventers, such as ram preventers (pipe, blind, and shear rams). Bentonite cords are used to seal the annulus of the casing. When they swell, they create a watertight plug, preventing surface water from penetrating through the annulus. To isolate the wellhead from precipitation or groundwater flooding, a protective inspection well (caisson) is installed, ensuring a watertight seal around the casing. A sealant made of a single plastic pipe is used to seal the wellhead of short wells, while for long wells, a composite pipe is used, the sections of which are connected with metal couplings and secured with a rubber cuff.

[0016] Thus, at the present time, the urgent problem is the creation of new alternative systems suitable for sealing wells and other objects.

[0017] The use of chemical sealing systems is widely known, for example, from Japanese application JPH 10120899 (A), published on 12.05.1998, it is known to produce a water-swellable, storage-resistant and moisture-reactive polyurethane composition, which makes it possible to create a sealed system that is resistant to deformation and the formation of bubbles, and also maintains mechanical stability for a long time even in a swollen state due to the use of a polyurethane composition containing a binder with a certain group and a latent hardener.

[0018] From Japanese Patent Application JPS 6327583 (A), published on 05.02.1988, it is known to provide a sealant with adequate waterproofing properties and good weather resistance using polyurethane foam, which is formed by the reaction of a polyolefin polyol, water and an organic isocyanate and has a polyolefin resin base. The sealant comprises a polyolefin resin-based polyurethane foam obtained by the reaction of (A) a polyolefin polyol (for example, a hydroxyl-terminated polymer with a molecular weight of preferably 1,000 to 5,000, such as polyethylene glycol) as a polyhydroxyl compound, (B) water as a foaming agent and (C) an organic isocyanate (for example, toluene diisocyanate). Component B is preferably added in an amount of 0.5 to 0.3% (by weight) per 100% of component A.

[0019] Japanese Patent Application JP 2024103290 (A), published on August 1, 2024, discloses a two-component polyurethane sealant composition that will enable the production of a sealant with improved stretchability, paint adhesion, and stain resistance. The two-component polyurethane sealant composition comprises a base comprising a urethane prepolymer with an isocyanate group and a curing agent comprising a polyol and a polyepoxy compound containing multiple epoxy groups in a single molecule, with an epoxy group equivalent of 100 to 200 g / eq.

[0020] The closest analogue in technical essence for the composition of the sealing system, we have adopted, is the solution disclosed in patent application RU 2005140940, published on 05 / 27 / 2006. This document discloses a method for producing polyurethane or polyisocyanurate foam, including (a) obtaining a premix composition including a catalytic system, at least one reagent and at least one foaming agent, wherein the catalytic system contains a carrier and an alkali metal salt in an amount not exceeding approximately 60% of the total weight of the salt and the carrier, (b) introducing the premix composition into a foamable reactive mixture and (c) foaming the reactive mixture to obtain polyurethane or polyisocyanurate foam.

[0021] The closest analogue in technical essence for the method of using a sealing system, we have adopted the solution disclosed in patent application RU 2005103121, published on 20.07.2006. From it, a method is known for restoring the tightness of gas-water-oil producing wells without stopping for repair of production wells, which consists in the fact that first, excess pressure is released from the annular spaces to the atmospheric value, then the annular and casing spaces are filled to the upper zone of the wellhead with a sealing liquid or composition by free topping up or, at least, by pumping it once into the annular spaces, if necessary, under a pressure of 5-50 atm, while using a low-viscosity sealing liquid or composition that is capable of further penetrating into the formed macrochannels and microchannels of fluid migration (gas, foam, liquid) in the cemented annular and casing spaces of the well,ensuring, under the influence of mass transfer forces, their blockage until these channels are completely sealed, achieved over a period of time that is determined by the drop to zero of the excess well pressure according to the pressure gauge or the gas flow rate according to the flow meter from the mouth of the well's micropressure control unit.

[0022] The disadvantage of the known solution is the limited use of the sealing system and the inconvenience of its use.

[0023] The technical objective of the proposed technical solutions is to create an alternative sealing system and use it for sealing various objects. Moreover, the method for using such a system is simple. Another objective is to expand the range of sealing compositions and products for sealing various objects that provide effective sealing and are easy to use.

[0024] List of drawings

[0025] Fig. 1 and 2 show the structure of the sealing system before and after use.

[0026] Disclosure of invention

[0027] To solve the technical problem, a sealing composition and a method for its use are proposed.

[0028] The technical result of the invention is the creation of an alternative sealing system and a simple and quick method for its use for sealing various objects, as well as an expanded range of sealing compositions and sealants for various objects that ensure effective sealing. The technical result also eliminates the need for specialized equipment for pumping the sealing mixture, making the sealing system easier to use.

[0029] To solve the stated technical problem and achieve the stated technical results, a sealing system is proposed, containing a composition that is a two-component liquid containing component A and component B, where component A is a liquid based on polyester compounds of the following composition, in wt.%:

[0030] - low molecular weight polyester - 38.05-40.0

[0031] - polyester – 58.1-58.35

[0032] - alkaline earth metal salt of organic acid – 0.05-0.16

[0033] - non-ferrous metal carboxylate – 0.07-0.20

[0034] - solvent-foaming agent – ​​0.25-0.40

[0035] - liquid glass– 0.07-0.25

[0036] - corrosion inhibitor 0.35-0.64,

[0037] a component B is a crosslinking agent and is 4,4'-diphenylmethane diisocyanate,

[0038] in this case, the ratio of components A and B is such that component B is taken with a slight excess (~10-20% by weight).

[0039] in this case, components A and B are placed in sections of a sealed two-section package made of foil-coated polymer material, isolated from each other.

[0040] The present invention also relates to a method for sealing an object using the above-mentioned sealing system, in which components A and B of the composition are placed in separate, isolated from each other, sections of a sealed two-section bag made of foil-coated polymeric material, equipped with a plastic divider with a safety tape-lock, wherein immediately before using the composition, the bag is released from the plastic divider and then components A and B are mixed in the bag, without breaking its hermetic seal, for polymerization of the composition and formation of a foamed sealing material, wherein the mixing of the components is carried out by kneading the contents of the bag for 10-20 seconds, wherein the formation of the foamed sealing material is accompanied by spontaneous opening of the bag, and the bag is placed on the object to be sealed until the composition is completely foamed and the bag is opened to fill the cavity of the object to be sealed.

[0041] The sealing system is a two-component liquid (component A, component B), packed in a sealed two-section bag made of foil-coated polymer material, equipped with a plastic divider with a safety tape (retainer), as shown in Fig. 1.

[0042] Below we provide more detailed information about the substances used and their functions.

[0043] Low molecular weight polyester and polyether are common components for the production of polyurethane systems. Examples of low molecular weight polyethers that can be used include PEG300, 2,2-bis-(4-(2-oxyethoxy)-phenyl)-propane, PEG400, polypropylene glycol, etc. Laprol 503B, Laprol 3003, Laprol 3600-2-12, Laprol 5003-2B10, Polyether 6003-DE, PP-5004, etc. can be used as polyethers. These substances are well known to those skilled in the art, and there is no need to further disclose them.

[0044] Alkaline earth metal salt of an organic acid is used as a catalyst to accelerate the reaction. Suitable substances include: potassium octoate, potassium 2-ethylhexanoate, potassium acetate, potassium oleate, sodium stearate, potassium stearate, potassium isooctate-tertiary amine complex, zinc salts, etc.

[0045] Non-ferrous metal carboxylate is used as a catalyst to accelerate curing (hardener). Suitable substances include: tin dibutyl laurate (DBTL), bismuth carboxylates, zirconium complexes, zinc neodecanoate, BDMAEE, etc.

[0046] Running water, ethyl acetate, cyclopentane, hydrofluoroolefins, carboxylates in combination with petroleum ethyl acetone are used as a foaming solvent.

[0047] The following can be used as the alkaline earth metal inorganic acid solution: liquid glass, perlite, aluminum silicate, epoxy resin, silicone, TCPP, chlorinated phosphates, melamine dispersions, TEP, DMMP, magnesium hydroxide.

[0048] Thiourea, urea, alkylaminomethyl derivatives of thiourea, urotropine, benzotolittriazole, 2-mercaptobenzothiazole and neonol AF 9-12 complex, thiourea and urotropine complex and copper salts can be used as corrosion inhibitors.

[0049] Component B is a crosslinking agent and is 4,4'-diphenylmethane diisocyanate.

[0050] The ratio of component A and B is such that component B is taken with a slight excess (~10-20% by weight), for example, the amount of component A is 190 g (170 ml), and component B is 220 g (180 ml).

[0051] Components A and B are mixed in the bag without breaking its seal immediately before use, which initiates a polymerization reaction and the formation of a dense foam sealant material.

[0052] The foamed sealing material has a number of necessary technological properties:

[0053] - high adhesion to various surfaces

[0054] - ability to expand

[0055] - effective in preventing penetration of unwanted fluids.

[0056] The sealing system ensures fast and reliable sealing of gas wells, cable channels, road structures and other technical objects where isolation and prevention of uncontrolled flows of fluids (gas, liquid) are required by filling cavities, voids and cracks.

[0057] The distinctive feature of this sealing material is that it creates significant expansion pressure during the chemical reaction. This not only ensures maximum sealing and enhances the insulating effect, but also increases the negative pressure during operation, significantly improving the reliability of protection.

[0058] Method of using the sealing system (using well sealing as an example):

[0059] 1. Before performing sealing work, the wellbore must be prepared. Due to the potential presence of large amounts of rock particles or evidence of collapse in the borehole, it is necessary to first assess the wellbore's condition:

[0060] - carry out inspection of the wellbore;

[0061] - clean the well from loose rock particles using the air blowing method.

[0062] Carrying out preparatory work ensures smooth placement of the sealing system and ensures more effective subsequent sealing.

[0063] 2. Secure the bags to the sealing tube using transparent tape. During installation, place a plastic spacer on the outside of the structure.

[0064] The spacing between bags is calculated based on the available space in the work area. It is important to ensure that the bags are evenly distributed along the entire length of the tube.

[0065] The optimal strapping technique involves sequentially placing the bags symmetrically, from the top layer to the bottom. This approach ensures high-quality work and maximum results.

[0066] 3. Upon completion of installation, the tape (retainer) must be removed from all dividers in a specific sequence, starting from the outermost point of the tube. The removal procedure involves carefully peeling the transparent retaining tape off the face of each divider, then firmly holding the edge of the tape with two fingers and gently pulling it back until it is completely removed.

[0067] It is extremely important to adhere to the established sequence when working with all dividers, as this ensures the safety of the structure and guarantees the achievement of the required quality of work.

[0068] 4. To activate the components, mix all the packets sequentially, starting from the end of the tube. Remove the transparent tape from the center of each packet, remove the divider, and evenly mix the contents for 10-20 seconds. Repeat this procedure with the remaining packets. It is important to maintain the total mixing time—it should not exceed 60 seconds—to ensure effective mixing.

[0069] 5. Once mixing is complete, the sealing tube must be installed immediately into the well. Two minutes after installation, the sealed bag will open, ensuring uniform distribution of the working material in the space between the well walls and the installed tube.

[0070] To achieve maximum sealing efficiency, connection to the gas exhaust system should be made no earlier than 4 hours after the installation of the bags is completed.

[0071] 6. To ensure maximum well sealing efficiency and prevent sealant leakage, it is necessary to use special locking elements. The following methods provide the best results: installing a locking material, installing a plug, or forming a locking ring. Using these locking methods allows for: securely holding the sealant in place, preventing material displacement during operation, and achieving high-quality, long-lasting well sealing.

[0072] Foil-lined bags provide insulation from air and UV rays. Bag durability is also important, as it ensures transportation, storage, and use in harsh conditions (friction, compression, and securing to the designated location).

[0073] The bag's polymer interlayer ensures strong seam seals and prevents corrosion from the environment and the components themselves. The interlayer material is selected experimentally depending on the bag's intended use and can be made of PE, PP, PVC, PET, etc.

[0074] The amount of reaction mixture in the bag is also selected experimentally. It should not be too small and should be sufficient to allow the bag to open when it swells. Bag size: width 15 cm, total length 35 cm including seams. For the total area of ​​the bag (525 cm 2 ) the total volume of contents required to open the package is 350-400 ml.

[0075] The quantitative content of the components was selected empirically to obtain the optimal foaming and reaction speed, as well as to obtain the optimal properties of the resulting foam.

[0076] Implementation of the invention

[0077] Experimental studies of the proposed technical solutions were carried out, the results of which are given below.

[0078] The composition of the sealing system has been prepared:

[0079] Component A, in wt. %:

[0080] - low molecular weight polyester PEG 300 (Sibur) - 39.35

[0081] - simple polyester Laprol 503B (Khimprom) - 59.4

[0082] - alkaline earth metal salt of organic acid Potasium octoate NT Cat K15 - 0.11

[0083] - non-ferrous metal carboxylate DBTL (Nortex) - 0.14

[0084] - solvent-foaming agent running water - 0.34

[0085] - sodium silicate solution Silex - 0.16

[0086] - corrosion inhibitor thiourea - 0.50.

[0087] Component B is 4,4'-diphenylmethane diisocyanate.

[0088] The total amount of component A is 190g (170ml), and component B is 220g (180ml).

[0089] Components A and B were placed in isolated sections of a two-piece foil-clad polypropylene bag equipped with a plastic divider and a safety tape (lock), as shown in Fig. 1. The bag seams were sealed to ensure a tight seal. Bag dimensions: width 15 cm, total length 35 cm including seams.

[0090] Before use, the divider was removed and the contents of the sections were manually mixed for 10-20 seconds by kneading without breaking the bag's seal. The reaction and foaming times were measured. The results are shown in Table 1.

[0091] The intermediate state of the package before it ruptures is shown in Fig. 2. Also, Fig. 2 shows an example of sealing using a transparent plastic pipe as an example.

[0092] Studies were also conducted with other components of composition A listed in the description, which showed similar results.

[0093] The information and experimental studies provided in this description demonstrate the possibility of realizing the purpose of the group of inventions and achieving the stated technical results.

[0094] Using the proposed solutions eliminates the need for specialized equipment for pumping the sealant mixture and guarantees ease of use of the sealing system. The ready-to-use bags can be transported and stored, and used anywhere without additional equipment. The bags foam quickly and without additional heating. The foamed mixture expands several times, ensuring a reliable seal. This sealing method is simpler than other similar solutions we know.

[0095] An information patent search showed that similar developments are not known, and accordingly, the proposed solutions correspond to novelty and inventive step.

[0096] Also, tests conducted on real objects demonstrated the high efficiency of the proposed developments and their practical significance, from which one can conclude about its industrial applicability.

Claims

1. A sealing system containing a composition that is a two-component liquid containing component A and component B, where component A is a liquid based on polyester compounds of the following composition, wt.%: low molecular weight polyester 38,05-40,0 polyether 58,1-58,35 alkaline earth metal salt organic acid 0,05-0,16 non-ferrous metal carboxylate 0,07-0,20 foaming solvent 0,25-0,40 liquid glass 0,07-0,25 corrosion inhibitor 0,35-0,64, and component B is a crosslinking agent and is 4,4'-diphenylmethane diisocyanate, in this case, the ratio of components A and B is such that component B is taken with an excess of ~10-20% by weight, In this case, components A and B are placed in sections of a sealed two-section package made of foil-coated polymer material with a plastic divider, isolated from each other.

2. A method for sealing an object using a sealing system according to claim 1, in which components A and B of the composition are placed in separate sections isolated from each other of a sealed two-section bag made of foil-coated polymeric material, equipped with a plastic divider with a safety tape-lock, wherein immediately before using the composition, the bag is released from the plastic divider and then components A and B are mixed in the bag, without breaking its hermetic seal, for polymerization of the composition and formation of a foamed sealing material, wherein the mixing of the components is carried out by kneading the contents of the bag for 10-20 seconds, wherein the formation of the foamed sealing material is accompanied by spontaneous opening of the bag, and the bag is placed on the object to be sealed until the composition is completely foamed and the bag opens to fill the cavity of the object to be sealed.

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