RU2236570C2 - Concentrate for preparing oil displacement composition and oil displacement composition - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: concentrate contains galactomanine as polysaccharide and surfactant at their ratio (0.05-2.0):(0.01-1.0), respectively. Concentrate further contains modified starch according to following ratio: (0.05-2.0):(0.01-1.0):(0.1-3.0), respectively, or sodium benzoate and/or potassium sorbate at following ratio: (0.05-2.0):(0.01-1.0):(0.01-0.5), respectively, or modified starch and/or sodium benzoate, and/or potassium sorbate at following ratio: (0.05-2.0):(0.01-1.0):(0.1-3.0):(0.01-0.5), respectively. Oil displacement composition contains 0.05 to 6.5% of indicated concentrate and solvent (the rest).

EFFECT: improved oil displacement properties from various-permeation formations with any mineralization.

5 cl, 2 tbl, 5 ex

Description

The invention relates to the oil industry, namely, compositions based on polymers for oil displacement.

A known method of developing an oil field, including the injection of a mixture of bio-surfactant KSHAS and polyacrylamide (see RF patent No. 2060373, MKI E 21 In 43/22, publ. 1996).

This method is not effective enough due to the exposure of polyacrylamide to degradation processes in mineralized water.

Known emulsion composition for the extraction of residual oil containing polyalkylhydridesiloxane, polysaccharides, surfactant and water (see patent No. 2154731, MKI E 21 43/22, publ. 2000). The known composition is not effective enough with strong mineralization of produced and injected water.

The closest in technical essence and the achieved effect is the composition for oil displacement, which is an aqueous dispersion of the bioreagent KSHAS-M, consisting of surface-active glycolipids and extracellular polysaccharide (see RF patent No. 2125152, MKI E 21 B 43/22, publ. 1999).

A disadvantage of the known composition is the lack of effectiveness of oil displacement, as well as the need to create special conditions for the preparation of a bioreagent.

The basis of the present invention is to create a concentrate to obtain a highly effective composition for displacing oil and a composition for displacing oil with high oil washing properties from formations of various permeability and with the presence of water of any salinity.

The problem is solved in that the concentrate for the preparation of a composition for oil displacement, containing a polysaccharide and a surfactant, contains galactomannan as a polysaccharide in the following ratio of components, respectively:

(0.05-2.0) :( 0.01-1.0),

or the concentrate further comprises modified starch in the following ratio of components, respectively:

(0.05-2.0) :( 0.01-1.0) :( 0.1-3.0),

or the concentrate additionally contains sodium benzoate and / or potassium sorbate in the following ratio, respectively:

(0.05-2.0) :( 0.01-1.0) :( 0.001-0.5),

or additionally contains modified starch, sodium benzoate and / or potassium sorbate in the following ratio of components, respectively:

(0.05-2.0) :( 0.01-1.0) :( 0.1-3.0) :( 0.001-0.5)

The problem is also solved by the fact that in the composition for the displacement of oil, including the active component and the solvent, as the active component it contains a concentrate according to claims 1 or 2, 3, or 4 in the following ratio of components, wt. %:

Concentrate 0.06-6.5

Solvent Else

In the preparation of compositions using galactomannans, which are heteroglycans contained in the seeds of leguminous plants. Commercial preparations of galactomannans are called gums, which are obtained by aqueous extraction of polysaccharides from crushed plant materials.

In the preparation of the concentrate and composition, guar gum, or karai gum, or xanthan gum, or locust bean gum, or gum, or oat gum, or gellan gum, or ghatti gum, or glucomannan cognac, or any mixture thereof, are used as galactomannan the ratio (see. "Great Soviet Encyclopedia." Moscow: Publishing House "Soviet Encyclopedia", 1973, p. 737).

As modified starch, starch is used that has undergone physical, chemical and biological treatment, which significantly changes the structure and properties of starch, including the ability to dissolve in cold water.

As a surfactant use anionic, or cationic, or nonionic surfactants, or mixtures thereof in any ratio, for example:

- petroleum sulfonates according to TU 38.50729-88;

- alkyl sulfonates, mono- and dialkylbenzoalsulfonates according to TU 6-01-1043-86, TU 6-01-18-28-87;

- sulfonol NP-3 according to TU 84.509.81;

- ethoxylated alkylene phenols according to GOST 8433-81, TU 38.507-63-171-91;

- catapine A according to TU 6-01-816-75;

- DON-52 according to TU 2484-006-047-6205-93;

- IVV-1 according to TU 6-01-407-89;

- Laprol 4202-2B-30 according to TU 2226-039-05766801-95, laprol 5003-2B-10 according to TU 2226-023-104V8057-95, laprol 5003-2-15 according to TU 2226-006-10488057-94, laprol 6003-2B-18 according to TU 2226-020-10488057-94, ML-81B according to TU 2481-007-48482528-99.

As a solvent, water or a mixture thereof with an aliphatic alcohol, for example ethyl alcohol (ES) according to GOST 18300-87, or methyl alcohol (MS) according to GOST 2222-78, or isopropyl alcohol (IPA) according to GOST 9805-84, or its a mixture with glycol, for example ethylene glycol (EG), or diethylene glycol (DEG), or tetraethylene glycol (TEG) (see B.N. Stepanenko. Organic chemistry. Moscow: "Medicine", 1975, p.119-124) at the ratio of water: alcohol (1-100): 0.001, respectively.

The concentrate and composition are prepared by adding other components of the concentrate and composition to the surfactant. When sodium benzoate and / or potassium sorbate are introduced into the concentrate and composition, they are also first added to the surfactant and then introduced into the concentrate and composition. The resulting concentrate and composition are stable at temperatures from -25 ° C to 100 ° C, have good surface-active properties, exhibit demulsifying properties in water of any mineralization, and have high dispersibility with respect to oil.

The concentrate and composition can be prepared at the wellhead or under industrial production conditions with subsequent transportation to the place of use. Depending on the conditions of the field, its geological structure, the composition is selected by varying the content of components and solvent.

The composition, if necessary, can be further dissolved.

The mixing is carried out in mill type mixers, for example, in a rotor-colloid mill with a rotor speed of 3000 rpm and above, in which the components of the composition are simultaneously dissolved and ground.

A new set of claimed essential features allows you to get a new technical result, namely to create a concentrate and composition for effective oil displacement.

An analysis of the known solutions selected in the search process showed that in science and technology there is no object similar to the claimed combination of features and having high rates when used for oil displacement.

To prove the compliance of the claimed invention with the criterion of "industrial applicability" we give specific examples of the preparation of the concentrate and composition with the determination of their physico-chemical characteristics, as well as determining the effectiveness of oil displacement using the proposed composition.

The following physicochemical characteristics are determined: surface and interfacial tension using the stalagmometric method and viscosity using a VPZh-2 viscometer. During the measurement of interfacial tension at the border with oil, it was noticed that oil droplets do not spread on the surface of the injected composition, but are collected on the surface in the form of individual drops, which indicates good dispersing properties of the compositions with respect to oil. The measurement results are given in table 1.

Example 1

Take 1.0 g of non-ionic surfactant OP-10, add to it 1.0 g of guar gum at a ratio of 1: 1, then the resulting concentrate is mixed with fresh water (see table 1, example 1).

Similarly, using various components and varying the content of components, other concentrates and compositions are also prepared (see table 1, examples 2-10).

Studies of the effectiveness of oil displacement are carried out on single reservoir models consisting of a glass tube 100 cm long and 2 cm in diameter, and on models of a heterogeneous oil reservoir composed of two hydrodynamically unconnected differently permeable tubes with the same parameters. The tubes are filled with ground rock. A predetermined permeability value is obtained by a specific set of rock fractions. The prepared tubes are saturated with formation water under vacuum. To create oil saturation, water is displaced from models by oil; to obtain residual oil saturation, oil is displaced to complete water cut of products at the outlet of the porous medium. Then, the studied compositions are introduced into the model and the oil is replaced by water. Measure hydrodynamic parameters of the model.

The effectiveness of the composition during oil displacement is evaluated by the increase in the oil displacement coefficient. The results of the studies are given in table.2.

Example 1. In the model of a heterogeneous reservoir pump the composition No. 1 from table 1. The increase in oil displacement coefficient averages 25.1% in the reservoir (see table 2, example 1).

Example 2-3. Carried out analogously to example 1.

Example 4. In the model, which is a homogeneous reservoir, inject the composition No. 10 from table 1. The increase in oil displacement coefficient is 23.0% (see table 2, example 4).

Example 5 (prototype). An aqueous solution of bio-surfactant KSHAS-M, diluted with water 250 times, is pumped into the model, which is a homogeneous reservoir. The oil displacement coefficient is 15.0% (see table 2, example 5).

As can be seen from the data in table 2, the proposed composition has high oil displacing properties when used in formations of various heterogeneities.

Using the proposed concentrate and composition using the concentrate allows you to:

- increase the growth rate of oil displacement in oil reservoirs with water cut to 98%;

- prepare and apply in formations with the presence of water of any salinity, as well as in high-temperature formations,

- prepare the composition in an industrial environment, store for a long time and transport to the place of use.

Claims (5)

1. A concentrate for the preparation of a composition for oil displacement, containing a polysaccharide and a surfactant, characterized in that it contains galactomannan as a polysaccharide with a ratio of components, respectively (0.05-2.0) :( 0.01-1.0 ) 2. The concentrate according to claim 1, characterized in that it further comprises a modified starch with a ratio of components, respectively (0.05-2.0) :( 0.01-1.0) :( 0.1-3.0). 3. The concentrate according to claim 1, characterized in that it further comprises sodium benzoate and / or potassium sorbate with a ratio of components, respectively (0.05-2.0) :( 0.01-1.0) :( 0.001-0 ,5). 4. The concentrate according to claim 1, characterized in that it further comprises a modified starch, sodium benzoate and / or potassium sorbate with a ratio of components, respectively (0.05-2.0) :( 0.01-1.0) :( 0.1-3.0) :( 0.001-0.5). 5. The composition for the displacement of oil, including the active component and the solvent, characterized in that as the active component it contains the concentrate according to claim 1, or 2, 3, or 4 in the following ratio, wt.%: Concentrate 0.06 - 6.5 Solvent Else

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