Thermochemical composition for removing deposits asphaltoresinparaffin
The invention relates to the oil industry and can be used to remove asphaltoresinparaffin sediments from the bottom-hole formation zone, oilfield equipment, piping and tanks. The technical result is a simplification of thermochemical composition. Thermochemical composition for removing asphaltoresinparaffin deposits, comprising an aqueous solution of sodium nitrite, an organic solvent and an aqueous solution of the initiator of the reaction, contains an aqueous solution of sodium nitrite composition, wt.%: sodium nitrite - 8-100, water - the rest, and as an initiator of the reaction of sulfamic acid in the composition, wt.%: sulfamic acid - 13-36, water - the rest. Moreover, an aqueous solution of sulfamic acid additionally contains a reagent that neutralizes sulfamic acid to the extent of not more than 97%, as such a reagent use technical aqueous ammonia, carbonate or bicarbonate of ammonium, hydroxide, carbonate or bicarbonate of an alkali metal or a mixture, the volume ratio of organic solvent and other components of thermochemical composition is (0.5 to 3): 1, as the organic solvent used aliphatic or aromatic the yle=" page-break-before:always;">The invention relates to the oil industry and can be used to remove asphaltoresinparaffin deposits (ARPD) of the bottom-hole formation zone, oilfield equipment, piping and tanks. ASPO, having a density of 900-1000 kg/m3and consisting of asphaltenes, resins, waxes, water and mechanical impurities, little soluble in petroleum solvents nature. The removal of sediment intensified at temperatures close to the temperature of melting (50-80oC).To remove the deposits are chemical compounds consisting of two or more reagents that interact with each other, emitting a large amount of heat. The heat leads to the heating of the reaction system, the melting and dissolution of deposits.Widespread removal of deposits received thermochemical Nitrogen Generating Composition (AGS) based on the redox reaction of aqueous solutions of ammonium salts and sodium nitrite in an acidic environment. The reaction AGS leads to the formation of salts of sodium, water and nitrogen and is accompanied by heat, for example: NH4Cl+NaNO2-->NaCl+2H2O+N2+Heat (1) the Advantage of thermochemical AGS is using the AI, high thermal interaction effect and providing mechanical mixing system for allocating nitrogen gas.Thermochemical reaction AGS is initiated in an acidic environment. As the initiators of the reaction AGS were used acetic acid [1-3], copper sulfate and aluminum chloride [4-5]. For speed control of thermochemical reactions were used buffer systems [6-8], as well as polyanhydride organic acids [9-10].The removal efficiency of sediment can be increased by using thermochemical AGS in combination with an organic solvent. While thermochemical reaction provides heating system, and an organic solvent helps dissolve the deposits and prevents re-deposition of sediment during cooling of the system [2, 11]. Aqueous solutions of reagents AGS can be emulsified in an organic solvent . Emulsion thermochemical AGS used when cleaning of paraffin long pipelines [8-10, 12].Closest to the proposed technical solution to the technical essence and the achieved effect is a composition for removing deposits on the basis of an aqueous solution containing ammonium chloride and acetic acid, and water RA is the face of a mixture of aliphatic and aromatic solvent, at this volume fraction of organic solvent is 30-50%. Acetic acid is used as the initiator of the oxidation reaction, its volume fraction is 0.2-0.4% of the total volume of the emulsion. The composition further comprises an emulsifier in an amount of 0.2-1.0% of the total volume of the emulsion.The disadvantage of the prototype, as well as all known thermochemical AGS, is the need for a special initiator reaction - acid or salt.Solved by the invention the task is simplified thermo-chemical composition by using as an initiator of the reaction of one of the reactants participating thermochemical reactions.The technical result is achieved by the fact that you are using thermochemical composition for removing asphaltoresinparaffin deposits, comprising an aqueous solution of sodium nitrite, an organic solvent and an aqueous solution of a reaction initiator, which contains an aqueous solution of sodium nitrite composition, wt.%: Sodium nitrite - 8 - 100 Water - the Rest and as the initiator of the reaction of sulfamic acid with the following composition of an aqueous solution of the specified initiator, wt.%: Sulfamic acid - 13 - 36 Water - the Rest Aqueous solution of sulfamic acid is shown reagent use technical aqueous ammonia, the carbonate or bicarbonate of ammonium, hydroxide, carbonate or bicarbonate of an alkali metal or a mixture thereof.The volume ratio of organic solvent to the other components of thermochemical composition is (0.5 to 3): 1.As the organic solvent used aliphatic or aromatic hydrocarbon or oil or their mixture. The composition additionally contains an emulsifier.The main components of thermochemical composition are: - sulfamic acid - NH2SO3N (TU 6-03-381-75);
- sodium nitrite - NaNO2(GOST 19906-74).Sulfamic acid contains oxidizable amide nitrogen and the acid function. Amide group of sulfamic acid is oxidized by sodium nitrite, with the formation of sodium hydrosulphate, water and gaseous nitrogen. The oxidation reaction takes place only in an acidic environment, and sulfamic acid at the same time acts as a reagent party thermochemical reaction and the reaction initiator:
NH2SO3H + NaNO2--> NaHSO4+ H2O + N2+ Heat (2)
To increase the solubility of sulfamic acid in water, to regulate the speed of thermochemical reactions, as well as to improve thermal effect thermochemicalmicrobes reagent (base), in particular, make use of the following substances:
technical aqueous ammonia (GOST 19906-74);
the ammonium bicarbonate;
ammonium salt (GOST 9325-79);
sodium hydroxide (GOST 2263-79, THE 6-01-1306-85);
sodium carbonate (GOST 5100-85);
sodium bicarbonate (GOST 2156-76).The neutralization reaction is accompanied by formation of ammonium or sodium salt of sulfamic acid (reaction 3-8):
In the acidic environment of sodium nitrite oxidizes ammonium or sodium salt of sulfamic acid with evolution of heat (reactions 9 and 10):
is the expense per unit volume of the reaction mixture, since the ammonium group in the acidic environment also oxidized by sodium nitrite to produce heat (reaction 9). In this case, sulfamic acid is initiated oxidation reactions as ammonium and amide groups.When used as a neutralizing reagent alkali metal salts of the latter increase the solubility of sulfamic acid in water and adjust the speed of its interaction with sodium nitrite (reaction 10).Sodium nitrite should be taken in an amount sufficient to oxidize the sulfamic acid and its salts according to equations 2, 9, and 10.To increase the efficiency of removal of deposits sodium nitrite and/or an aqueous solution of sulfamic acid should be emulsified in an organic solvent, a good solvent) and having a boiling point of greater than 100oC. the Organic solvent may include aliphatic or aromatic solvents or oil and their mixture. To create emulsions thermochemical composition may further comprise an emulsifier.Experiments were conducted to determine the required degree of neutralization of sulfamic acid base, the results of which are shown in table 1. Determined the maximum is roxid sodium. The oxidation reaction with evolution of heat is observed when the degree of neutralization of sulfamic acid, not exceeding 97%. Free sulfamic acid is essential as the initiator of the interaction. For practical application it is recommended that the degree of acid neutralization in the range of 55-85%, while achieving high solubility of sulfamic acid in water and the maximum temperature of heating of the reaction mixture (experiments 3-5, table 1). As the organic solvent, in the examples shown in table 1, used middle distillate, which is a mixture of high-boiling aromatic solvents (TU 38.401-58-196-97). The emulsion was created by adding the emulsifier Sinol EM in a concentration of 1% by volume of an organic solvent.To determine the efficiency of thermochemical composition on the basis of sulfamic acid were experiments on the removal of sediment from a steel plate. On the steel plate weighing 1.5 g evenly applied ASPO, determined the weight applied ARPD and put the plate in a cylindrical vessel containing a solution or a dry salt of sodium nitrate (solution B). Then sodium nitrite for 20-30 seconds was added to the emulsion an aqueous solution of the sylphs is about time there was a clean steel plate from ASPO. The maximum temperature of heating of the reaction mixture was 58-97oWith depending on the concentration of the reactants. After the reaction was weighed dry plate to determine weight not washed ARPD and expected removal efficiency. The experiments were carried out at a temperature of 20oC.Examples of removal of deposits claimed thermochemical composition on the basis of sulfamic acid, neutralized technical aqueous ammonia, are shown in table 2; on the basis of sulfamic acid, neutralized with ammonium carbonate, the carbonate and sodium bicarbonate, in table 3; based on sulfamic acid, neutralized with sodium hydroxide, table 4; on the basis of sulfamic acid in the absence of neutralizing agents in table 4 (example 1).The melting temperature of the paraffin used in the experiments of table 2, was pp.63-72oWith and is listed in the appropriate column. In the experiments, are shown in tables 3 and 4, used paraffin with a melting point 67-70oC.As the organic solvent, in the experiments are shown in tables 2-4, used middle distillate (TU 38.401-58-196-97) or its mixture with oil. The emulsion was created by adding the emulsifier Sinol EM in a concentration of 1% Olya used oil. The oil led to the formation of a stable emulsion of an aqueous solution of sulfamic acid in the absence of emulsifier.Thermochemical composition effectively removes refractory ASPO when using solutions with concentrations of sodium nitrite in the range 8-100% (experiments 1-3, table 3) and the concentration of sulfamic acid within 13-36% (experiments 1, 7 and 9, table 4). The ratio of volume of organic solvent to the total volume of aqueous solutions of the reagents included in thermochemical composition may be in the range of from 0.5 to 3 (experiments 3 and 7, table 4).In the proposed thermochemical composition used cheap inorganic reagents and the reaction products do not form insoluble compounds do not affect the further preparation of the oil, as well as technologically and environmentally safe. The advantages of the new thermochemical composition can include the fact that it does not require the introduction of the initiator of the interaction, as sulfamic acid is both the initiator and participant of thermochemical reactions.Literature
1. Patent US 5183581; 1993.02.02; E 21 In 043/25; E 21 In 043/28. The prototype.2. Patent US 5580391; 1996.12.03; 08 In 007/00; 08 In 009/00; C 23 G 001/00; F 23 J 001/00; 35; 36.3. Patent US 5891262; 1999.04.06; 08 In 007/04; 08 In 009/02.E 21 IN 043/24; E 21 IN 047/00.7. Patent US 4399868; 1983.08.23; E 21 In 037/00; E 21 In 043/25.8. Patent US 4755230; 1988.07.05; C 23 G 005/036; C 23 G 005/024.9. Patent US 5824160; 1998.10.20; 08 In 007/00; 08 In 009/00.10. Patent US 6003528; 1999.12.21; 08 In 009/00.11. Patent US 4399868; 1983.08.23; E 21 In 037/00; E 21 In 043/25.12. Patent US 5639313; 1997.06.17; 08 In 007/04; 08 In 009/02.
1. Thermochemical composition for removing asphaltoresinparaffin deposits, comprising an aqueous solution of sodium nitrite, an organic solvent and an aqueous solution of a reaction initiator, characterized in that it contains an aqueous solution of sodium nitrite composition, wt.%:
Sodium nitrite - 8-100
Water - the Rest
and as the initiator of the reaction of sulfamic acid with the following composition of an aqueous solution of the specified initiator, wt.%:
Sulfamic acid - 13-36
Water - the Rest
2. Thermochemical composition under item 1, characterized in that an aqueous solution of sulfamic acid additionally contains a reagent that neutralizes sulfamic acid to the extent of not more than 97%.3. Thermochemical composition under item 2, characterized in that, as specified reagent use technical aqueous ammonia, carbonate or bicarbonate of ammonium, hydroxide, carbonate or Hydra is the volumetric ratio of the organic solvent and other components of thermochemical composition is (0.5 to 3):1.5. Thermochemical composition according to any one of paragraphs.1-4, characterized in that the organic solvent used aliphatic or aromatic hydrocarbon, or oil, or a mixture.6. Thermochemical composition according to any one of paragraphs.1-5, characterized in that the composition additionally contains an emulsifier.
FIELD: oil and gas production.
SUBSTANCE: invention is intended to protect inner surface of transmission pipelines against asphalt-tar-paraffin deposits and provides appropriate composition containing 0.5-10% polyvinyl alcohol, 0.01-1% nonionic surfactant (FK 2000 PLUS), and water.
EFFECT: prolonged pipeline protection effect of composition and manifested demulsification activity.
1 dwg, 5 tbl, 5 ex