Application of a chemical composition for viscosity modification of heavy and extra-heavy crude oils

Patent metadata

Field	Value
Publication number	US-9790446-B2
Application number	US-201414520734-A
Country	US
Kind code	B2
Filing date	Oct 22, 2014
Priority date	Oct 22, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

The present invention relates to the use of a chemical composition to modify the physical properties (viscosity and interfacial tension) of heavy and extra-heavy crude oils, to increase their mobility. The chemical composition comprises or consists of a combination of systems based on ionic and non-ionic liquids, which may be pure or modified, mixed in an aqueous or organic medium as a dispersing agent, depending on the nature of the crude to be treated, together with a surfactant. The composition is mixed with the crude oil at a temperature between 5 and 100° C., at pressures from 1 atm (14.7 psi) up to about 680.2 atm (10,000 psi). The composition can be mixed with heavy crude oils, at the point of extraction from the well in the field, during the transport of crude oil in pipelines, or in the well discharge pipelines.

First claim

What is claimed is:

1. A method for reducing the viscosity of heavy and extra-heavy crude oil, comprising the step of introducing a viscosity reducing composition into the heavy or extra heavy crude oil in an amount effective to reduce the viscosity of said crude oil, said composition comprising
an ionic liquid active compound of the general formula [CnH 2n-m ClN 2 O 2 ] x [H 2 O] y where 5≦n≦10; 1≦m≦6 with the coefficients x, y calculated according to the volume of crude oil (z) being treated, and where x and y range from x+y=0.25z to x+y=0.66z, and where the ratio x/y is in the range between 2×10 −4 and 1×10 −3 ;
an aqueous- or organic-based dispersing agent in an amount of up to 35% vol based on the volume of said composition and 60 to 97% based on the volume of said active compound; and
a surfactant in an amount to form a homogeneous emulsion, where said surfactant is an alkyl sulfonate-alkylamine, having an alkyl chain of 8 to about 14 carbons, and a cation formed by an isopropyl chain.

2. The method of claim 1 , wherein the dispersing agent comprises xylenes and methyl-benzene, the dispersing agent being integrated in variable proportions based on the type of crude oil to be treated in an amount of between 0.3 to 0.5 xylene, 0.1 to 0.5 methyl-benzene, and optionally 0.3 to 0.5 perchloroethylene, wherein the amounts are parts by volume with respect to the total volume of said dispersing agent; and where said surfactant is included in an amount between 0.01 to 0.025 parts by volume.

3. The method of claim 2 , wherein said ionic liquid is a modified ionic liquid, which is diluted in said organic dispersing agent, in an equivalent fraction up to 0.05 vol., with respect to the volume of the dispersing agent.

4. The method of claim 1 , wherein said ionic liquid is a modified ionic liquid obtained by a polymerization reaction of an ionic liquid with oxirane, and is dispersed in said aqueous-based or organic-based dispersing agent, according to the character of the crude oil and dynamic pumping conditions, under conditions of turbulence, with Reynolds number greater than 100, and with shear rates of between 0 and 20 Hz.

5. The method of claim 4 , wherein the aqueous dispersing agent containing said ionic liquid or modified ionic liquid, is mixed with said crude oil at a temperature between 10 and 90° C., at pressures between 1 and 350 atm, with pH between 4 and 12.5, whose exact values depend on the characteristics of the crude oil to be treated with a dosage between 3.75 l/h and 3,000 l/h, depending on the volume of crude to be treated.

6. The method of claim 4 , wherein the modified ionic liquid comprises 2 to 20 repeating groups of methylene or ethylene, and which are present in between 1 and 4 ppm of the 1H NMR spectra.

7. The method of claim 1 , wherein said composition is obtained by mixing and dispersing said active compound having thermal and structural stability with optional functional groups selected from the group consisting of methoxy-ethoxy-, -epoxy-, in said aqueous or organic dispersing agent, where said dispersing agent comprises a mixture of xylene, perchloroethylene and toluene in a volumetric ratio 0.425/0.425/0.142, or a mixture of Xy:0.37, Tol:0.16, PE:0.37, AS(surfactant): 0.02-0.05, which is added in proportion between 0.5 to 5%, with respect to the total mixture of such chemical composition.

8. The method of claim 1 , wherein the wherein said active compound is dispersed in said aqueous dispersing agent at temperatures between 15 and 35° C. at atmospheric pressure, and a pH in the range 7≦pH≦12.5, in the range 5×10 −4 ≦C≦1×10 −3 , with respect to the volume of crude oil to be treated.

9. The method of claim 1 , wherein said composition is prepared through a mixture using a container tank or reservoir, and where the composition is added to said crude oil at temperatures between 15 and 35° C., at atmospheric pressure and pH in the range 6≦pH≦8, at a concentration in the range 2×10-4 to 1.2×10 −3 , with respect to the volume of crude oil to be treated.

10. The method of claim 1 , wherein said ionic liquid is a modified ionic liquid prepared by a process of polymerization of an ionic liquid to obtain functionalized ionic liquids with alkoxy-, methoxy-, ethoxy-, -epoxy groups, with general formula C n H 2n-m ClN 2 O 2 (C 3 H 6 O) 2x , where 5≦n≦10, 1≦m≦6.

11. A method of reducing the viscosity of heavy and extra-heavy crude oil, comprising the step of adding an viscosity reducing composition to said heavy or extra-heavy crude oil in an amount effective to reduce the viscosity, wherein said viscosity reducing composition comprises an ion liquid active compound, an aqueous or organic dispersing agent and an alkyl sulfonate-alkylamine surfactant having a C 8 to C 14 alkyl and a cation formed from an isopropyl chain, wherein the active compound is dispersed in said aqueous or organic dispersing agent, in a proportion that can vary according to the general formula [C n H 2n-1 ClN 2 ] x [H 2 O] where H 2 O corresponds to water present in said crude oil, and where 8≦n≦12; with coefficients x, y calculated according to the volume of the crude oil (z) to be treated, within the following range: x+y=0.05 z to x+y=0.66 z, with respect to the volume of crude oil and the ratio x/y can vary in the range from 2×10 −4 to 1×10 −3 .

12. The method of claim 1 , wherein the presence of non-associated water in the crude oil is 20% or more, and where the relationship x+y varies from 0.2 to 0.45, while x/y remains the same or with a tolerance of ±0.5×10-4.

13. The method of claim 1 , wherein volumetric relationships between said components are injected through a pipe with a pumping system selected from the group consisting of: (1) downhole through capillary tubing, (2) capillary tubing or through the annular area or through the production tube, (3) surface discharge lines of heavy oil-producing wells, and (4) crude oil transportation pipelines.

14. The method of claim 1 , wherein said ionic liquid has functional groups selected from the group consisting of methoxy-, ethoxy and -epoxy, and is combined with said dispersing agent an amount of up to 5% vol with respect to the volume of said dispersing agent, and where said dispersing agent comprises xylene, toluene, perchloroethylene, and an alkyl-alkylamine sulphonate surfactant.

15. A method of reducing viscosity oft heavy and extra-heavy crude oil comprising introducing a viscosity reducing composition to the heavy or extra-heavy crude oil in an amount sufficient to reduce the viscosity, wherein said viscosity reducing compositions is selected from the group consisting of:
a. an active compound comprising an ionic liquid having the general formula [C n H 2n-m ClN 2 O 2 ] x [H 2 O] and 10≦n≦14, ≦2m≦6, where the value of n is based on the properties of said crude oil to be treated; or an ionic liquid polymerized with oxirane and having the general formula is CnH 2n-m ClN 2 O 2 Cl (C 3 H 6 O) 2x , dispersed in an aqueous or organic dispersing media, to reduce the viscosity of the heavy crude oils of C2 and C5 type;
b. an active compound comprising an ionic liquid having the general formula C n H m N p O 2 , where 8≦n≦10, m=n+4 and 2≦p≦8, m=n+4 and 4≦p≦6, or an ionic liquid obtained by polymerizing with an oxirane and having the formula C n H m N p O 2 (C 3 H 6 O) 2x , dispersed in aqueous or organic media for reducing the viscosity of heavy crude oils of type K, C or C1, C2, in a concentration determined by the relations [C n H m N p O 2 (C 3 H 6 O) 2x ] x [H 2 O] y with 9≦n≦12, 13≦m≦16;
c. an active compound comprising an ionic liquid having the general formula C n H m N 2 O p where 1

Assignees

• Mexicano Inst Petrol
• Univ Guanajuato
• Inst Mexicano Del Pertoleo

Inventors

• Miranda Olvera Alma Delia
• Dominguez Esquivel Jose Manuel
• Garcia Chavez Ricardo
• Vazquez Guevara Miguel Angel

Classifications

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C09K8/035

  Organic additives · CPC title

• C10M2203/1006

  used as base material · CPC title

• C10M2215/224

  Imidazoles · CPC title

• C10M101/02 Primary

  Petroleum fractions · CPC title