SU1559114A1 - Gel-like composition for confining water inflow into well - Google Patents

Abstract

The invention relates to the oil industry. The goal is to increase the strength of the gel while simultaneously increasing its resistance to the effects of saline water and increasing the gelation time in reservoir conditions. The composition contains the following components with their ratio, wt.%: Polyacrylamide - 0.4-0.6, condensed chromic alcoholic bardite sulfite 2-3, surfactant 2-3, water - the rest. This composition provides a durable gel under reservoir conditions, which allows it to withstand large pressure drops and increases the duration of the insulation effect. Long gelling times on the surface allow pre-preparation of the gelling composition for carrying out insulation works on a whole group of wells during system processing of the bottom-hole zone. 1 tab.

Description

one

(21) 4349779 / 24-03

(22) 12/24/87

(46) 04.23.90. Bul, № 15

(71) All-Union Oil and Gas Research Institute

(72) I.A.Sidorov, Yu.A.Poddubny, V.A.Kan, A.Ya.Sorkin, G.I. Parfenova, V.M.Gorbachev, R.S. Khairetdinov, V.I. Berchenko and A.G.Ivanenko

(53) 622.245.42 (088.8)

(56) US Patent No. 4018286, CL 166-295, published, I977,

USSR author's certificate 985256, cl. E 21 V 33/138, 1980.

USSR Copyright Certificate № 1303699, cl. E 21 V 33/138, 1985.

(54) GLOBAL COMPOSITION FOR LIMITING WATERPROOFERS IN t WELL (57) The invention relates to oil production. The goal is to increase the strength of the gel while simultaneously increasing its resistance to the effects of saline water and increasing the gelation time in reservoir conditions. The composition contains the following components in their ratio, wt.%: Polyacrylamide 0.4-0.6, condensed chromium sulfite-alcohol bard, surfactant 2-3, water the rest. This composition provides a durable gel under reservoir conditions, which allows it to withstand large pressure drops and increases the duration of the insulation effect. Long gelation times on the surface allow pre-fabrication of a gelling composition for carrying out insulation works on a whole group of wells during system processing of the downhole zone. 1 tab.

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The invention relates to the oil industry, in particular, compositions for restricting water production in oil and gas wells.

The aim of the invention is to increase the strength of the gel while increasing its resistance to the effects of low-mineralized water and increasing the time of gelation on the surface while maintaining the gelation time in reservoir conditions.

The gel composition contains polyacrylamide, a condensed chromium-containing sulfite-alcohol bard, a surfactant and water.

in the following ratio of ingredients, wt.%:

Polyacrylamide 0.4-0.6

Condensed chromium sulfite-alcohol bard2-3

Surfactant 2-3 Water Else

This composition provides a strong gel and formation conditions, which, in turn, allows it to withstand large pressure drops and gives the duration of the isolation effect to be increased. Increased resistance

with

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The effectiveness of the system to the effects of low-mineralized formation water increases the duration of the isolation effect when working on wells flooded with this type of water.

Long gelation times on the surface allow pre-preparation of the gelling composition for carrying out insulation works on a whole group of wells during system processing of the bottomhole formation zone.

The low (short) time of gelation of the composition under reservoir conditions prevents the system from washing out in the reservoir due to interlayer flows or flows within the isolated object itself during the process of shutting down the well to a response, as a result of which gel is obtained in the whole experimentally determined time. .

Technical characteristics of reagents used

Polyacrylamide (PAA). The technical PAA of the lime or ammonia neutralization method is a water-soluble polymer with a linear molecular weight of 1-6 minutes. It is produced in the form of a gel containing 6-9% of the main product or in the form of granulated particles (0.3 - 7 mm) 50-56% concentration of the main product,

Barda sulfite-alcohol chromium-containing condensed powder (KSSB-4) is prepared from lignosulfonates by oxidation with chromium and condensation with formaldehyde in a sulfate medium, followed by neutralization with caustic soda and drying by spraying.

Surfactant. A sulfonic acid, for example, a 45% solution of a synthetic surfactant, is a mixture of sodium salts of alkyl benzene sulfonic acids.

OP-10 - Auxiliary substance - mono. Alkylphenol ether polyethylene glycol,

Disolvan 4411–00% non-ionic surfactant, a high molecular weight poly (alkylene glycol), is a viscous dark brown liquid.

Experiments were carried out to reveal the optimal ratio of components, the results of which are given in the table

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5 o

P -

five

50

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Gelling compositions 1-11 are prepared in such a way that polyacrylamide is dissolved in 70% of the calculated amount of water. KSSB-4 is dissolved in 30% water. Then, a KSSB-4 solution is injected into the polyacrylamide solution, mixed thoroughly until a homogeneous composition is obtained, and then surfactants are added. In practice, the gel-forming compositions can be prepared both on the surface and sequentially injected into the well with reagent solutions. gelling composition directly in the reservoir.

The gel time is determined visually. Gel strength is determined on a Weiler-Rebinder instrument by removing corrugated metal plates from hardened compositions and on a Rheotest-2 rheological test. Gel stability in low-mineralized produced water is measured at a temperature of t 20 ° C for 30 days. The percentage is determined change in the mass of the gel over time.

As can be seen from the table, composition 1 at t «60 C forms a gel only after 9 h. In addition, it has rather weak strength characteristics,

An increase in the concentration of reagents in composition 5 leads to a sharp decrease in the time of gelation and the composition becomes technologically inoperative.

It follows from the table that the gel-forming compounds 2-4, 6-11 have significantly higher strength properties, increased resistance to the effect of low-mineralized produced water with a simultaneous increase in the time of gelation on the surface. Compounds of 3.7 and 10 are optimal (gels obtained from these compositions have tangential shear stress 5,, 5 times, and tensile strength - 1.5-1.7 times greater). for 30 days, they only swell in the slightly mineralized Cenomanian water, which indicates an increase in the duration of the isolation effect, while the known gels in control examples 13 and 5 partially dissolve, which indicates a decrease in the effectiveness of water insulation

ny works. In normal conditions, the gelation time of compositions 3.7 and 10 is 8-1.5 days, and at 30-150 minutes. Using the proposed composition improves the efficiency of water insulation works and the duration of the insulation effect.

Claims (1)

Invention Formula The gel-like composition for restricting water inflow into the well, including polyacrylamide, condensed chromium sulfite alcohol bard, water and an additive, and 0 five 146 due to the fact that, in order to increase the gel strength while increasing its resistance to the effects of low-mineralized water and increasing the gelation time in reservoir conditions, it contains a surfactant as an additive in the following ratio of components, wt.%: Polyacrylamide 0.4- 0.6 Condensed chromium sulfite-alcohol bard 2-3 Surfactant2-3 WaterEverything,