RU2247138C2 - Solid foaming agent for carrying over formation fluid from well - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention relates to solid foaming agent for carrying over formation fluid from gas well and water/condensate mixture from gas condensate well. Solid foaming agent containing, wt %: carboxymethylcellulose 40.0-50.0, sodium sec-alkyl sulfate 35.0-45.0, and sodium sulfonate as anionic surfactant 25-35 additionally contains: disodium ethylenediaminetetraacetate as complexone 3.0-7,0, sodium carbonate as pH stabilizer 3.0-7.0, and foaming-enhancing detergent - the rest.

EFFECT: improved fluid-carrying ability.

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Description

The present invention relates to the field of gas and gas condensate production, namely to solid blowing agents for removing formation fluid from a gas well or a water-condensate mixture from a gas-condensate well.

Known solid foaming agent for the removal of formation fluid from gas and gas condensate wells, containing the following components, wt.%: Powder base (KSSB or sulfonol) 20-80, a surfactant based on monoalkylphenol ether of polyethylene glycol based on polymeric distillate (OP-10, OP -7) 10-70, plasticizing additive (CMC) 1-18, facilitating the addition of 0.3-0.7 [1].

However, the disadvantage of this composition is the low removal efficiency of the mineralized water-condensate mixture.

The closest in technical essence and the achieved result is a solid foaming agent for removing liquid from a gas well [2]. The solid foaming agent has the following composition, wt.%: Anionic surfactant 10-60, water-soluble salt of hydrofluoric acid 7-56, carboxymethyl cellulose 6-12 and water 27-29.

A disadvantage of the known solid foaming agent is the presence in its composition of a water-soluble salt of hydrofluoric acid. Soluble salts of hydrofluoric acid when interacting with soluble salts of calcium and magnesium form poorly soluble in water precipitates of calcium and magnesium fluorides. In addition, the known foaming agent removes formation water with a soluble calcium and magnesium salt content of 0.1-5.0 wt.% From gas wells, which is not applicable for wells with a higher content of hardness salts.

The aim of the present invention is to increase the efficiency of the removal of formation fluid from the well, producing produced water with a higher content of water-soluble salts of calcium and magnesium.

This goal is achieved by the fact that the known solid foaming agent for the removal of formation fluid from the well containing carboxymethyl cellulose and an anionic surfactant, according to the invention it further comprises a complexing agent - disodium salt of ethylene diamine tetraacetic acid, a pH stabilizer - sodium carbonate and a foaming enhancer - detergent, and in as an anionic surfactant contains sodium thoracyl sulfate in the following ratio of components, m .% With:

Carboxymethyl cellulose - 40-50 Sodium sulphate - 35-45 Disodium salt of ethylenediamine - tetraacetic acid - 3-7 Sodium carbonate - 3-7 Detergent - the rest 100.0

Carboxymethyl cellulose (CMC) is a binder and an anti-resorber.

Anionic surfactant (surfactant) - sodium vtorakylsulfate - is the main substance - foaming agent.

Ethylenediaminetetraacetic acid disodium salt is a complexing agent that converts polyvalent metal cations into solution, improves foaming conditions and, therefore, facilitates the conditions for formation fluid to be removed from the well to the surface.

Sodium carbonate is a water softener and pH regulator.

Detergent - foaming enhancer, for example, a synthetic detergent "Crystal", etc.

Example. A mixture of dry components is prepared: carboxymethyl cellulose (CMC), sodium carbonate, Trilon-B disodium salt of ethylenediaminetetraacetic acid, CMC Crystal detergent-synthetic detergent, and sodium vodoalkyl sulfate solution is added. The mixture is pre-mixed, then extruded to obtain uniform rods emerging from the extruder dies. The solid foaming agent rods (surfactants) are delivered to the bottom of the well using known equipment.

The number of foaming agent rods introduced into the well is determined for each specific well separately, depending on the characteristics of the well (reservoir pressure, volume of outflowing fluid, gas condensate content, etc.).

The multiplicity of the foam is determined as follows.

The compositions of the inventive solid foaming agent of the required concentration are prepared. The prepared compositions are placed in a glass and mixed on a mixer of the type "Voronezh" at 10000-12000 rpm ^-1 . At the end of mixing, the foam is determined in a known manner.

Composition 1, wt.%: Carboxymethyl cellulose (CMC) - 38.0 Sodium sulphate - 40.0 Disodium salt ethylene diaminetetraacetic acid - 9.0 Sodium carbonate - 9.0 Detergent - 4.0 100.0 Composition 2, wt.%: Carboxymethyl cellulose - 40.0 Sodium sulphate - 45.0 Ethylene disodium salt diaminetetraacetic acid - 5.0 Sodium carbonate - 5.0 Detergent - 5.0 100.0 Composition 3, wt.%: Carboxymethyl cellulose - 40.0 Sodium sulfate - 45.0 Ethylene disodium salt diaminetetraacetic acid - 3.0 Sodium carbonate - 3.0 Detergent - 9.0 100.0 Composition 4, wt.%: Carboxymethyl cellulose - 50.0 Sodium sulphate - 35.0 Ethylene diamine tetraacetic acid disodium salt - 7.0 Sodium carbonate - 7.0 Detergent - 1.0 100.0 Composition 5, wt.%: Carboxymethyl cellulose - 53.0 Sodium sulphate - 36.0 Ethylene diamine tetraacetic acid disodium salt - 2.0 Sodium carbonate - 2.0 Detergent - 7.0 100.0 Composition 6 (prototype), wt.%: Anionic Surfactant - 43.0 Water Soluble Hydrofluoric Acid Salt - 20.0 Carboxymethyl cellulose - 10.0 Water - 27.0 100.0

Data on the foaming of the proposed composition in comparison with the prototype are shown in the table.

p / p Concentration foam solution,% The multiplicity of the foam, K Composition number prototype 1 2 3 4 5 6 1 0.1 2,5 2,8 3.0 2.7 2.7 2.2 2 0.3 3.0 3.4 3,5 3.4 3.3 2.9 3 0.5 4.1 4.6 4.7 4.6 4,5 3.8

The effectiveness of the proposed foaming agent is determined by the values of K (the multiplicity of foaming).

From the data obtained it can be seen that the greatest multiplicity of the foam are the compositions 2, 3, 4, which are optimal.

Using the present invention will improve the efficiency of removal of formation fluid from wells producing produced water with a higher content of water-soluble salts of calcium and magnesium.

Sources of information:

1. AS of the USSR No. 1710705, IPC E 21 B 43/00, 1992, BI No. 5.

2. AS of the USSR No. 1354812, IPC 4 Е 21 В 21/14, 02/26/86.

Claims (1)

A solid foaming agent for removing the formation fluid from the well, containing carboxymethyl cellulose and an anionic surfactant, characterized in that it additionally contains a complexing agent - disodium salt of ethylenediaminetetraacetic acid, a pH stabilizer - sodium carbonate and a foaming enhancer - detergent, and as an anionic active surface the substance contains sodium thoracyl sulfate in the following ratio of components, wt.%: Carboxymethyl cellulose 40.0-50.0 Sodium Valkyl Sulfate 35.0-45.0 Ethylenediaminetetraacetic disodium salt acids 3.0-7.0 Sodium Carbonate 3.0-7.0 Detergent Else