RU2376336C1 - Hydrophobic polymer backfill composition (versions) - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in the oil and gas industry for repair works when sealing a production casing and a cement column, lost circulation control during well drilling, isolating stratal water during squeeze cementing in oil and gas wells. The hydrophobic polymer backfill composition, which contains carbamidoformaldehyde resin and aluminium hydroxochloride, additionally contains a hydrocarbon solvent-oil and is prepared by mixing carbamidoformaldehyde resin for 10 minutes with an inverted emulsion, formed by mixing oil and aluminium hydroxochloride, with the following ratio of components, pts. vol: carbamidoformaldehyde resin 100, aluminium hydroxochloride 10-50, oil 10-50. In another version of the hydrophobic polymer backfill composition, the inverted emulsion is formed with successive mixture of a surfactant - emunol with diesel fuel and with aluminium hydroxochloride with the following ratio of components, pts. vol: carbamidoformaldehyde resin 100, aluminium hydroxochloride 10-50, diesel fuel 10-50, said surfactant 0.5-1.0.

EFFECT: design of a water-insoluble polymer backfill composition with high strength and good adhesion properties.

2 cl, 3 ex, 1 tbl

Description

The invention relates to the oil and gas industry and is intended for the elimination of absorption during drilling, isolation of formation water during repair and insulation works (RIR) in oil and gas wells and for repair and restoration works (RRR) while eliminating leaks in the production string and cement ring.

Known polymer grouting compositions based on urea-formaldehyde resin and various acid hardeners, for example hydrochloric acid [Ivachev L.I. Flushing and plugging exploration wells. - M .: Nedra, 1989. P.156].

A disadvantage of the well-known grouting compositions is the short curing time of the resin and the shrinkage of the solid polymer.

The closest in technical essence to the invention is a polymer grouting composition for RIR and isolation of absorption zones containing a water-soluble urea-formaldehyde resin (KF-Zh brand) and an acid hardener - an aqueous solution of aluminum chloride (aluminum hydrochloride) [A.S. 1763638, IPC 7 Е21В 33/38, op. 09/23/91].

The disadvantages of the known composition are:

- dilution of water-soluble urea-formaldehyde resin with technical water while passing the composition along the wellbore, which leads to a deterioration in the strength properties of the cured resin;

- the reaction of the acid hardener with the carbonates that make up the rock and / or calcium hydroxide - the basis of cement stone, as a result, the grouting composition on the border with the rock and cement stone remains uncured.

These shortcomings reduce the success of ongoing RIR and RRR.

Based on the foregoing, the problem arises of creating a hydrophobic (insoluble in water) polymer cement composition with high strength and adhesive properties.

The specified technical result is achieved by the fact that the hydrophobic polymer grouting composition (options), including the water-soluble urea-formaldehyde resin and hydroxychloride aluminum, according to the invention additionally contains oil, and the grouting composition is prepared by pre-mixing oil and aluminum hydrochloride to obtain an invert emulsion with the subsequent addition to the resulting emulsion, followed by urea-formaldehyde resin emulsion, with the following components, vol.h:

urea-formaldehyde resin one hundred hydroxychloride aluminum 10-50 oil 10-50

A hydrophobic polymer grouting composition comprising a water-soluble urea-formaldehyde resin and hydroxychloride aluminum according to the invention additionally contains diesel fuel and surfactant-emunol, while a hydrophobic polymer composition is prepared by adding surfactant with continuous stirring into diesel fuel, followed by the introduction of aluminum hydroxyl chloride to obtain an invert adding urea-formaldehyde resin, with the following components, vol.h:

urea-formaldehyde resin one hundred hydroxychloride aluminum 10-50 diesel fuel 10-50 Surfactant emunol 0.5-1.0

The proposed composition uses:

- urea-formaldehyde resins of the KF-Zh brand according to GOST 14231-88 or the REZOIL K-1 brand according to TU 2221-637-55778270-2004;

- hydroxychloride aluminum according to TU 38.302163-94, rev. Nos. 1, 2 - a liquid with a density of 1.181-1.247 g / m ³ with a basic substance content in terms of AlCl ₃ in the range of 200-300 g / l, which has acidic properties (pH of at least 2)

- oil, GOST R 51858-2002 and diesel fuel GOST 2177-82

- emunol is used as a surfactant, a viscous liquid from brown to dark brown, corresponding to TU 2458-008-18947160-2001.

The use of oil or diesel fuel with hydroxychloride aluminum or hydroxychloride aluminum and surfactant emunol, respectively, contributes to the formation of stable invert emulsions, the external (dispersion) medium of which is a hydrocarbon fluid, which provides hydrophobic properties to the polymer cement composition when water-soluble urea-formaldehyde resin is introduced and prevents its technical or dilution formation water in the wellbore and formation, respectively.

The encapsulation of the urea-formaldehyde resin and the acid hardener (aluminum hydrochloride) in the hydrocarbon medium prevents direct contact and subsequent reaction of the hardener with the rock or cement stone, which increases the adhesion of the cured polymer composition to the rock and the "old" cement stone.

Oil or diesel fuel in the proposed composition, in addition to the above advantages, play the role of a plasticizer, located between the polymer chains, preventing the formation of a large number of polymer crosslinks, thereby helping to reduce the shrinkage of the cured polymer.

The following are examples confirming the possibility of carrying out the invention.

Example 1. The grouting composition is prepared as follows. 10 ml of oil is placed in a glass and, with constant stirring, using a propeller stirrer, 10 ml of aluminum hydrochloride are introduced until an invert emulsion is formed, then 100 ml of KF-G resin is added.

Stirring is continued for 10 minutes until the formation of oil-tar invert emulsion, which is left to harden at a temperature of 25 ° C. The grouting composition loses fluidity after 2 hours, the compressive strength is 16.20 Ma. Adhesion characteristics after 2 days of storage of the cured samples in formation water were, MPa: with the surface of the rock - 0.58; metal - 0.25 and the "old" cement stone - 0.31.

The adhesive properties of the resulting polymer composition with the surfaces of the metal, rock and the "old" cement stone were determined on the device with a cylindrical shape and punch according to the known scheme and technique (Danyushevsky BC, Aliev PM, Tolstykh MF Reference Guide for cementing materials. - 2- e ed., revised and revised-M .: Nedra, 1987. - S.352-353.)

Examples 2, 4, 5 are prepared similarly to the first, differ in the amount of oil, aluminum hydrochloride and the brand of resin.

Example 3. 10 ml of diesel fuel is placed in a glass beaker and 0.5 ml of emunol and 10 ml of aluminum hydrochloride are introduced with a propeller stirrer with constant stirring until an invert emulsion is formed, then 100 ml of KF-G resin is introduced. Stirring is continued for 10 minutes until an invert resin emulsion forms, which is left to harden at 25 ° C. The grouting composition loses fluidity after 1 h; the compressive strength reaches 14.70 MPa. Adhesion characteristics (MPa) after 2 days of storage of cured samples in formation water are: with a rock surface - 0.36; metal - 0.18 and the "old" cement stone - 0.27.

The use of oil or diesel fuel in an amount of 10-50 vol.h. due to the properties of cured polymer compositions that meet the requirements of RIR and RVR. Introduction less than 10 vol.h. oil or diesel fuel in the grouting composition does not eliminate the shrinkage of the solid polymer, more than 50 vol.h. - reduces the strength of the solid polymer. Surfactant-emunol in an amount of 0.5-1.0 vol.h. added with constant stirring in diesel fuel before the introduction of aluminum hydroxyl chloride, which further contributes to the formation of stable invert emulsions with the introduction of urea-formaldehyde resin. The latter, based on petroleum, hydroxychloride aluminum and urea-formaldehyde resin, are resistant to loss of fluidity without the use of surfactants.

The inventive hydrophobic polymer grouting composition, as the table shows, has an optimum curing time for RIR and RRP (2-2 h 30 min), high strength and adhesion to the surfaces of metal, rock and "old" cement stone, in contrast to the prototype composition.

In field conditions, a hydrophobic polymer composition is prepared using standard equipment used for conducting RIR and RVR. For example, to eliminate the annular flow in injection well No. 75 of the Kultyubinskoye field, an oil-tar emulsion was prepared as follows: 0.2 m ^{3 of} oil was poured into one compartment of the cementing unit and 0.4 m ^{3 of} aluminum hydrochloride was fed under continuous stirring until an invert emulsion was formed. To the resulting emulsion was added 1.0 m ^{3 of} Resoil K-1 resin, and the mixture was thoroughly mixed for 10 minutes. The finished oil-tar emulsion was pumped into the well. According to the results of a complex of geophysical studies, the annular flow was eliminated.

Thus, the proposed hydrophobic polymer cement composition is easy to prepare, is not diluted with technical and produced water, the cured polymer based on it has high strength and adhesion to the surfaces of the rock, metal, cement stone, which ensures the success of the conducted RIR and RVR.

Table - Curing of a hydrophobic polymer grouting composition Hydrophobic polymer grouting composition, ob.ch. The time loss of fluidity, h-min. Compressive strength, MPa Adhesion to the surface, MPa Note breeds cement stone metal urea-formaldehyde resin GHA oil diesel fuel Surfactant emunol KF-Zh 100 10 10 - - 2-00 16,20 0.58 0.31 0.25 no solid polymer shrinkage one hundred fifty fifty - - 1-30 10.40 0.28 0.22 0.15 one hundred fifty - 10 0.5 1-00 14.70 0.36 0.27 0.18 Resoil K-1 100 10 10 - - 2-30 17.10 0.62 0.41 0.23 one hundred fifty fifty - - 2-00 13.60 0.42 0.35 0.23 one hundred fifty - fifty 1,0 2-00 8.25 0.29 0.21 0.16 The composition of the prototype KF-Zh 100 fifty - - - 0-30 17,20 - - - significant shrinkage of the solid polymer one hundred

Claims (2)

1. A hydrophobic polymer grouting composition comprising urea-formaldehyde resin-CFS and aluminum hydroxyl chloride-GCA, characterized in that it additionally contains a hydrocarbon solvent-oil and is prepared by stirring for 10 minutes CFS with an invert emulsion, previously formed by mixing oil and GCA, with the following ratio of components, ob.ch .:
CFS one hundred GHA 10-50 Oil 10-50 2. A hydrophobic polymer grouting composition comprising urea-formaldehyde resin-CFS and aluminum hydroxyl chloride-GCA, characterized in that it further comprises a hydrocarbon solvent-diesel fuel and surfactant-surfactant-emunol and prepared by mixing for 10 minutes CFS with invert emulsion previously obtained by sequential mixing of a surfactant with diesel fuel and with GCA, in the following ratio of components, vol.h .:
CFS one hundred GHA 10-50 Diesel fuel 10-50 Surfactant 0.5-1.0