SU712491A1 - Solution for treating carbonate formations - Google Patents

Description

one

The invention relates to the field of oil and gas industry, namely to the production of solutions for the treatment of carbonate formations in order to intensify the flow of oil and gas from the reservoir.

Known solution based on hydrochloric acid {.

The disadvantage of this solution is the high rate of reaction with lime and its quick neutralization, as a result of which a sufficiently deep impact on the formation is not achieved, especially in wells with high bottomhole temperatures.

A known solution for treating carbonate formations containing esters of an organic carboxylic acid, for example acetic acid, and water 2.

This solution has the following characteristics:

The rate of dissolution of limestone at a temperature of 150 ° C and a pressure of 300 kgf / cm 140-250g / m2-h

dissolving ability

in relation to limestone 24-35 kg / m

The disadvantage of this solution is its low dissolving ability, as a result of which insignificant

increase of permeability of the bottomhole formation zone.

The purpose of the invention is to increase the dissolving ability.

The goal is achieved by the fact that acetic anhydride and ethylidene diacetate are additionally added to a known solution containing esters of acetic acid and water at the following ratio of components, wt.%:

Acetic esters

acid1.0-4.5

Acetic anhydride 3.0-13.5

Ethylidene diacetate 16-72

WaterEverything

To obtain the proposed solution used waste production of acetic acid, containing, weight. %:

Acetic acid esters 5 Acid anhydride15

Ethylidene diacetate80

These production wastes were mechanically agitated with water until homogeneous solutions were obtained. The compositions of the obtained solutions are given in table. one.

The resulting solutions had the following characteristics.

As can be seen from the table. 2, the proposed liquid dissolves 1.49-28.6 times

Table)

Components, weight.

table 2

Dissolving methodLimestone dissolution rate, kg / m3

more limestone than known liquids, and also has a delayed effect on carbonate rocks. Changing the content of the components of the solution allows you to adjust the depth of the treatment layer.

The proposed solution has a low surface tension at the interface with hydrocarbon fluids and has low viscosity. Due to these properties, the penetrating ability of the solution is improved and the well treatment efficiency is improved. In addition, the proposed solution has a reduced corrosivity.

The processing technology of the proposed solution does not vary compared with the known.

The use of such a solution will make it possible to carry out treatments effectively in deep high-temperature wells and to obtain an economic effect on the order of 2 thousand rubles. per 1 processing.

Claims (2)

Invention Formula A solution for treating carbonate reservoirs containing acetic acid esters and water is distinguished by the fact that, in order to increase its dissolving power, acetic anhydride and ethylidene diacetate are added with the following ratio of components, wt%: Acetic esters acid1.0-4.5 Acetic anhydride 3.0-13.5 Ethylidene diacetate 16-72 WaterEverything Sources of information taken into account during the examination 1. USSR Author's Certificate No. 377505, cl. E 21B 43/12, 1970. 2. US patent No. 3630285, cl. 166-200, publ. 1970.