RU2270229C1 - Oil recovery enhancing composition - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention relates to compositions for treating well bottom zone and performing water shutoff operations. Composition of invention contains 5-30% of naphthenic acid of its salt, 5-30% of an additional reagent (Galka-Termogel), and water. Composition can further contain water-dissolved calcium chloride in amounts 5 to 15%.

EFFECT: enhanced composition efficiency due to enabled gelation time and viscosity growth control, extended application area, and utilized petrochemical production waste.

2 cl, 1 tbl, 3 ex

Description

The invention relates to the oil industry, in particular to compositions for treating the bottom-hole zone and conducting waterproofing works.

A known composition for increasing oil recovery, containing the following components in the ratio, wt.%: Aluminum chloride 2.8-17.0, urea 5.0-30.0, the rest is water [1].

However, this composition can only be used for formations with a temperature above 70 ° C, its penetrating ability is small, which allows it to be used only in certain geological and technical conditions.

A known composition for increasing oil recovery, containing the following components in the ratio, wt.%: A solution of calcium chloride 10-15%, a solution of sodium or potassium naphthenate, or a mixture of 0.5-10% [2].

The disadvantage of this composition is the high rate of formation of viscoelastic systems, which limits its scope.

The objective of the invention is to increase the efficiency of the composition by adjusting the time of its gelation and viscosity, expanding the scope, solving the problem of recycling petrochemical waste.

This goal is achieved in that the composition for enhanced oil recovery contains naphthenic acids or their salts. New in the composition is that it additionally contains a Galka-Thermogel reagent based on aluminum polyoxychloride in the following ratio of components, wt.%:

naphthenic acids or their salts 5-30 Galka Thermogel 5-30 water rest

The composition may additionally contain 5-15 wt.% Calcium chloride in water.

The composition is a yellowish-brown solution with an initial viscosity of 1.70 MPa, having a large penetrating ability, a wide range of gelation time at temperatures from 25 to 100 ° C.

The Galka-Thermogel reagent is manufactured according to TU 2163-015-00205067-01 and is a composition based on aluminum polyoxychloride Al (OH) _1.3 Cl _1.7 * 2H ₂ O.

The synergistic effect of the interaction of naphthenic acids or their salts with the Galka-Thermogel reagent is that the product of their chemical interaction, representing a uniform and stable system (this is confirmed by a change in the viscosity of the composition), ensures the formation of a hydrocarbon-containing gel inside the formation that can block permeable areas and simultaneously penetrate into the oil and gas horizons without blocking them and thus contributing to enhanced oil recovery.

If you need short gelation periods, calcium chloride in the form of a 5-15% solution can serve as a hardener.

The effectiveness of the composition is confirmed by laboratory studies of the dependence of the gelation time on the concentration and the ratio of its components.

Example 1. To prepare 1 l of the composition, naphthenic acid in an amount of 50 g (5 wt.%) Was loaded into a container with 500 ml of water and mixed, then 450 ml of Galka-Thermogel reagent previously dissolved in water (in an amount of 300 g ( 30 wt.%), The components were mixed and the resulting composition was tested under well conditions. The gelation time was measured at various temperatures and the viscosity of the composition changed during gelation. The results are shown in the table, experiment 4.

Example 2. The composition was prepared analogously to example 1 from 300 g of sodium naphthenate (30 wt.%), 300 g of reagent "Galka-Thermogel" (30 wt.%) And 400 ml of water. The test results of the composition are shown in the table, experiment 2.

Example 3. The composition was prepared analogously to example 1 from 150 g of potassium naphthenate (15 wt.%), 150 g of Galka-Thermogel reagent (15 wt.%), 700 ml of a 10% solution of calcium chloride. The test results of the obtained composition are shown in the table, experiment 3.

Experience number The concentration of the components of the composition, wt.% Gelling time at various temperatures, h Naphthenic compounds, their derivatives Galka Thermogel Water 25 ° C 75 ° C 100 ° C 0
prototype 15.0 30,0 55.0 Not an image. 144 twenty one 5,0 5,0 90.0 Not an image. Not an image. 144 2 30,0 30,0 40,0 140 46 12 3 15.0 15.0 10% solution of CaCl ₂ -70,0 46 12 5 four 5,0 30,0 65.0 310 295 fifty 5 30,0 5.0. 10% solution of CaCl ₂ -65,0 120 40 10

The table also shows the test results of the composition with other claimed component ratios, from which it is clear that the gelation time of the inventive composition can be adjusted at temperatures from +25 to + 100 ° C, which significantly exceeds the capabilities of the known compositions for enhanced oil recovery, where gelation temperatures are limited range from 50 to 90 ° C.

The introduction of additional 5-15 wt.% Calcium chloride into the water may be due to the geological and technical conditions of the well and aimed at maintaining the achieved technical result.

The result of processing the formation of the claimed composition is to reduce the permeability of only aquifers. The components of the composition are non-toxic and non-deficient.

Information sources

1.SU 1654554 A1 06/07/1991,

2. RU 2172825 C1 11.23.2000.

Claims (2)

1. Composition for enhancing oil recovery, containing naphthenic acid or its salt and water, characterized in that it additionally contains a reagent "Galka-Thermogel" in the following ratio of components, wt. %: Naphthenic acid or its salt 5-30 Reagent "Galka-Thermogel" 5-30 Water Rest 2. The composition according to claim 1, characterized in that it further comprises calcium chloride in water in an amount of 5-15 wt. %