WO2014068390A1

WO2014068390A1 - Formulation of nanoparticulated surfactants for the transport of hydrocarbons

Info

Publication number: WO2014068390A1
Application number: PCT/IB2013/002437
Authority: WO
Inventors: Lilia Rodriguez Rodriguez; Edgar Javier PATIÑO REYES; Rigoberto BARRERO ACOSTA
Original assignee: Ecopetrol S.A.
Priority date: 2012-11-01
Filing date: 2013-11-01
Publication date: 2014-05-08
Also published as: CO6940084A1

Abstract

The invention relates to nanoparticulated surfactant formulations allowing heavy hydrocarbons to be transported with more ease. The formulation comprises a nanoparticulated surfactant agent selected from the group consisting of hydrophilic silica or metal nanoparticles or mixtures of same, and a liquid ionic or non-ionic surfactant agent or a mixture of same.

Description

FORMULATION OF NANOPARTICULATED SURFACTANT FOR THE TRANSPORTATION OF HYDROCARBONS

TECHNOLOGICAL SECTOR

The present invention relates to nanoparticulate surfactant formulations that make it easier to transport heavy hydrocarbons.

STATE OF THE TECHNIQUE

Hydrocarbons generate more than 50% of the energy consumed worldwide and its reliable supply is vital for the functioning of all countries. Heavy hydrocarbon reserves are constituted as the new source of production due to the reduction of medium and light hydrocarbons. Heavy, extra heavy, fuel oil and barrel bottom products are characterized by having high viscosity, since being chemically constituted by long carbon chains generates high resistance to flow with low or zero mobility. These high viscosity hydrocarbons at a temperature of 25 ° C and atmospheric pressure can be found in a liquid, semi-solid and solid state, requiring high energy consumption for their movement with significant operating costs and a complex infrastructure that limits their transportation through pipelines and subsequent commercialization. . Similarly, there are hydrocarbons that due to the presence of paraffinic compounds present flow problems generated by deposits when the temperature is below 25 ° C.

In order to overcome the operational difficulties of transporting heavy hydrocarbons, several alternatives have been developed whose main objective is to reduce the viscosity of these hydrocarbons to bring them to pipeline transport specifications. The best known method is dilution with light hydrocarbons and refinery products. These types of diluents need to be transported to the production fields either by pipe or in tank vehicles. Additionally the requirement for using these diluents is conditioned by the availability in the refineries and their cost. Another alternative is the heating in several sections of the pipeline to maintain the temperature of the oil in the appropriate viscosity range, but this option has the disadvantage of compromising expensive equipment and requiring a high cost of electric or fuel energy to reach temperatures specification equivalents that guarantee the required viscosity.

Another method for transporting these hydrocarbons with mobility problems consists in using dispersions and emulsions of hydrocarbon in water, where the hydrocarbon is distributed in small particles within an aqueous continuous phase and is stabilized by the action of a surfactant product (also called surfactant). An emulsion is a dispersion of a liquid in another, not miscible, stabilized by a surfactant (also called emulsifier or emulsifier), whereby the emulsion constitutes a particular case of the dispersions.

In the state of the art, the use of different types of surfactants, whether ionic, non-ionic or mixture thereof in different proportions to improve dispersion formation and stabilization properties, is revealed. Ionic surfactants in turn can be anionic, cationic or amphoteric.

Within the documents of the state of the art is the Brazilian patent application BRPI1002Ó01 A2 which teaches a flow additive useful for improving the extraction and displacement of light or heavy crude oils, which comprises an aqueous emulsion containing hollow synthetic microspheres or solids, a component capable of altering surface tension, high molecular weight polyelectrolytes, a glycol of antifreeze type, a fluidity improving agent and a thickening agent. The additive according to this document improves the flow of crude oil that is pumped from the wells to the storage tanks and also cleans and prevents against encrustation of paraffin and heavy hydrocarbons derived from the drilling of oil well drilling, even at low temperatures (below 0 degrees Celsius). This document indicates that the spheres have the advantage of form a film between the crude oil and the surface of the pipe, improving oil slippage.

On the other hand, US patent application US2009127505 A1 refers to the preparation of rare earth metal oxide nanoparticles from inverse aqueous micelles, where the particles have a large surface area with respect to volume and where it is incorporated a surfactant uniformly in each of them, so that when applied to the inner surface of a pipe or sprayed on a stream of fluid in a pipe, the particles reduce the roughness of the inner surface of that pipe. The application mixing this application causes a significant reduction in pressure drops, friction and a better recovery and performance of fluid flowing through the pipe.

For its part, the international publication WO 2008101947 describes a procedure to reduce the viscosity of a hydrocarbon mixture having a viscosity greater than 10 Pa s (10000 cP) at 20 ⁰ C. The process comprises the steps of: a) putting contact the hydrocarbon mixture with inorganic catalyst particles in the presence of water and a surfactant; b) catalytically reduce the average molecular weight of the hydrocarbon mixture. The process is particularly suitable in order to improve the behavior of heavy fossil fuel sources for processing in conventional refinery equipment. .

US patent application 5910467 describes a stabilized solid emulsion and a method of manufacturing it, which is useful in the recovery of hydrocarbons from underground formation. More specifically, the emulsion comprises oil and water and is stabilized using undissolved solid particles, which are preferably at least partially oleophilic. Additionally, carbon dioxide or other gas is added to the emulsion to adjust the viscosity of the emulsion to the desired level. The stabilized solids emulsion can be used as a drive fluid to displace hydrocarbons from the formation or to produce a barrier in order to divert the flow of fluids in the formation. Such solid particles well they may be particles of the formation (ie, native of the formation) or particles not characteristic of the formation (ie, obtained outside the formation). Solid particles not characteristic of the formation may be of natural or synthetic origin. Some preferred solids include clays, quartz, feldspar, plaster, coal dust, asphaltenes and polymers. This document indicates that the fine particles allow to stabilize the emulsion, since the films surrounding the drops of the internal phase of the emulsion are kept in a stable state under formation conditions for a sufficient time to use the emulsion as intended. (for example, increase the rate and / or amount of hydrocarbon production from a formation). Additionally, solid particles are resistant to chemical reactions that tend to deactivate surfactants, thereby causing destabilization or breakage of the emulsion. Consequently, the revealed emulsions are stable over a wide range of salinity of the formation water. This document also indicates that solid particles that interact with water and oil stabilize the foam film.

US patent application 7121339 discloses an oil-in-water emulsion stabilized with solids and a method for preparing the dry oil-in-water stabilized extract. The oil-in-water emulsion is formed by combining oil, water, solid particles and a pH enhancing agent, mixing until the emulsion is formed. The low viscosity of the oil-in-water emulsion can be used to increase oil production from underground deposits. The low viscosity of the oil-in-water emulsion can also be used to improve the transport of oil through a pipe. This document indicates that the emulsion disclosed there does not require surfactants, making it less expensive than the solutions that do contain them. Additionally, he points out that it is an emulsion that is easy to demulsify.

In general, hydrocarbon dispersions in water manage to significantly reduce the viscosity of the heavy hydrocarbon depending on the oil concentration present. For example, for a heavy hydrocarbon with a viscosity value of 5 passes per second (Pa-s) (5000 centi Poise (cP)) measured at 30 ° C and 30 s ^' dispersions with a hydrocarbon content heavy in water of 70% by volume have a viscosity of less than 0.5 Pa s (500 cP) (30 ° C, 30 s ^"1 ). Also, for a dispersion with 75% hydrocarbon, a viscosity between 0.5 Pa s and 1 Pa s (500 cP and 1000 cP) However, when heavy hydrocarbon dispersions are transported by pipe, they are required to have a viscosity of less than 0.5 Pa s (500 cP), whereby the use of dispersions is limited to hydrocarbon concentrations greater than 70% by volume, although it is revealed in the art that bimodal emulsions (combining emulsions of two different sizes) can be used to increase the hydrocarbon content, these have the disadvantage of present a lower stability during storage and transport than a conventional emulsion On the other hand, the decrease in the concentration of the surfactant favors a larger particle size of the hydrocarbon in the dispersion and lower viscosity thereof, but with that of Advantage of decreasing the stability of the prepared dispersion.

Taking into account the above, a surfactant is required that improves contact between the phases of the dispersion to achieve a hydrocarbon dispersion in water of lower viscosity or increase the hydrocarbon content to a viscosity suitable for pipeline transport minimizing the consumption of additive at values below 5000 ppm to reduce the production and separation costs of hydrocarbon dispersions in water.

BRIEF DESCRIPTION OF THE INVENTION

In view of the above, it is an object of the present invention to provide a nanoparticulate surfactant formulation using hydrophilic nanoparticles, ionic, non-ionic surfactants or mixtures thereof and water. This nanoparticulate surfactant formulation improves the flow properties of hydrocarbon dispersions in water as well as their stability. Likewise, it is another object of the present invention to provide a surfactant formulation comprising a nanoparticle surfactant of metallic and / or non-metallic origin with a concentration between 15% and 100% of the mass content of the formulation. The concentration of the liquid surfactant of ionic, non-ionic origin or mixture thereof is in the range of 0 to 85% of the mass content of the surfactant formulation. According to the viscosity of the surfactant obtained, water between 0% and 70% by mass is added to improve the fluidity of the obtained surfactant.

Still another objective of the present invention is to provide a surfactant formulation comprising a surfactant in nanoparticles with a concentration between 250 and 2000 ppm in the hydrocarbon dispersion in water and wherein the concentration of the liquid surfactant of ionic, non-ionic origin or mixture thereof is in the range of 0 to 2500 ppm in the hydrocarbon dispersion in water.

The hydrocarbon dispersion in water obtained by using the surfactant formulation of the present invention has a lower viscosity than that obtained with a dispersion prepared with a liquid surfactant of ionic, non-ionic origin or mixture thereof under equal conditions of preparation, hydrocarbon content and total surfactant content.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a block diagram of obtaining the nanoparticulate surfactant formulation in accordance with the present invention.

Figure 2 illustrates a block diagram of obtaining hydrocarbon dispersions in water with the nanoparticulate surfactant formulation in accordance with the present invention.

Figure 3 corresponds to a rheological curve of hydrocarbon dispersions in water with a conventional ionic surfactant formulation derived from petroleum sulphonates. Figure 4 corresponds to a rheological curve of hydrocarbon dispersions in water with a nanoparticulate surfactant formulation in accordance with the present invention and with a conventional ionic surfactant formulation derived from petroleum sulphonates.

DETAILED DESCRIPTION OF THE INVENTION

The nanoparticulate surfactant formulation object of the present invention comprises a nanoparticulate surfactant (1) and a liquid surfactant of ionic, non-ionic origin or mixture thereof (2) which are added to a stream of water (3) in a homogenization unit (100) to obtain the nanoparticulate surfactant mixture (4). The pH of the nanoparticulate surfactant mixture (4) is adjusted in the homogenization unit (200) by the addition of an aqueous acidic or basic solution (5) to obtain a nanoparticulate surfactant formulation (6) with the pH of specification.

The nanoparticulate surfactant (1) has a hydrophilic nature and has a metallic and / or non-metallic origin with an average particle size between 20 and 90 nm, a surface area between 150 and 250 m ² / g and a concentration of acid sites between 0, 5 and 3.5 equivalent / kg. The mass content of the nanoparticulate surfactant (1) in the surfactant formulation is between 15% and 100%. The nanoparticulate surfactant (1) is obtained from various natural sources and comprises silica, metallic nanoparticles or mixtures thereof, which have been modified to provide the desired properties. Modified silica-derived nanoparticles and nanoparticulate surfactant component (1) characterized in that the percentage of unreacted silanol (Si-OH) groups is in a range between 50 and 100%. The nanoparticles of metallic origin component of the nanoparticulate surfactant (1) that include metal compounds such as calcium oxide, magnesium oxide, copper oxides, aluminum oxide, iron oxides among others. The liquid surfactant (2) can be an ionic, cationic, anionic, amphoteric, non-ionic surfactant or a mixture thereof. The liquid surfactant (2) is selected according to the pH and hardness conditions of the water used to form the hydrocarbon dispersion in water thus:

I. Anionic liquid ionic surfactant for waters with hardness greater than 180 mg / L (expressed as mg CaC0 ₃ / L), pH between 6 and 14, selected from the group of: petroleum alkyl sulphonates, sodium and potassium alkyl benzene sulphonates , sodium and potassium alkyl aryl benzene sulfonate, alpha olefin sulphonates, hydroxy alkane sulphonates, hydroxy alkane sulfate sulfate, alpha olefin sulfonate and alkyl aryl sulfonates of petroleum.

II. Ionic liquid cationic liquid surfactant for water with hardness greater than 120 mg / l and less than or equal to 180 mg / L (expressed as mg CaC0 ₃ / L), pH between 2 and 4, selected from the group of: quaternary ammonium salts, alkyl linear amine and alkyl ammonium, dodecyl amine or lauryl amine, alkyl dimethyl benzyl ammonium, quaternary salts.

III. Liquid non-ionic surfactant for water with hardness less than or equal to 120 mg / L (expressed as mg CaC0 ₃ / L), pH between 2 and 4, selected from the group of: alkyl ethoxylated phenols, ethoxylated fatty acids (poly ethoxy esters) , ethoxylated nonyl phenol, ethoxylated poly alcohol (Between C11 and C17), ethoxylated poly ester.

The liquid surfactant (2) is present in the formulation of the invention in a mass proportion is between 0 and 85% of the formulation.

Additionally, water can be added to the nanoparticulate surfactant formulation in an amount between 0 and 70% to obtain a formulation viscosity of less than 0.5 Pa s (500 cP) at 30 ° C. For its part, the surfactant formulation (6) has a pH between 4.0 and 8.5 and is adjusted by an acidic or basic aqueous current (5) as required.

The homogenization units (100, 200) correspond to a tank arrangement with mechanical agitation and / or a static mixer or a series of them to achieve adequate homogenization of the materials that make up the formulation of the nanoparticulate surfactant (6) according to the present invention.

The nanoparticulate surfactant (6) is used to obtain hydrocarbon dispersions in water for which it is added to a stream of water (7) in order to homogenize it in a static mixer or a series of them (300) and obtain a diluted stream of water and nanoparticulate surfactant (8). The hydrocarbon (9) is in fluid form by heating, dilution or mixing and is pumped to a dispersion unit (400) where it is pre-mixed with the diluted stream of water and nano-particulate surfactant (8). This premix stream (10) passes to the homogenization unit (500) where the hydrocarbon dispersion in water (1) is formed. The hydrocarbon dispersion in water (11) can be stored in tanks or pumped directly to a transport pipeline as required.

The homogenization unit (500) corresponds to a mixer or a series of them, which can be sonic, magnetic, mechanical or static as required.

Once the hydrocarbon dispersion in water (11) is prepared, it has a concentration of the nanoparticle surfactant (1) between 250 and 2000 ppm and in turn the concentration of the liquid surfactant (2) of ionic, non-ionic origin or mixture of they are in the range of 0 to 2500 ppm.

EXAMPLES

In order to demonstrate a better efficiency of the nanoparticulate surfactant formulation according to the present invention with respect to the formulations conventionally employed and containing only Ionic, non-ionic surfactants or mixtures thereof to obtain dispersions of hydrocarbons in water, the two formulations are evaluated under the same conditions of preparation, hydrocarbon content and surfactant dosage. In the following examples all the dynamic viscosities presented are measured at 30 ° C and 30 S ^"1

Example 1

A typical liquid surfactant formulation with a 25% mass content of petroleum sulphonate ionic surfactant was prepared. On the other hand, a surfactant formulation with a content of 6% nanoparticles and 19% ionic liquid surfactant was prepared. A hydrophilic silica nanoparticulate surfactant with a particle size of 55 nm was used.

Example 2

The conventional ionic surfactant formulation prepared in Example 1, water and a heavy hydrocarbon with a viscosity of 4.53 Pa s (4530 cP) was used to prepare hydrocarbon dispersions in water (Figure 3) with a concentration of 1300 ppm of surfactant additive. Table 1 presents the viscosity results of the different dispersions of hydrocarbons in water using the ionic surfactant derived from petroleum sulphonates.

Table 1. Hydrocarbon dispersions in water obtained with typical ionic surfactant formulation.

The above clearly shows that hydrocarbon dispersions in water make it possible to reduce the viscosity of the heavy hydrocarbon. However, with the use of the conventional ionic surfactant, the 75/25 dispersion has a viscosity greater than 0.5 Pa s (500 cP) which limits its transport by pipe.

Similarly, three hydrocarbon dispersions with the same hydrocarbon concentration were prepared, using the nanoparticulate surfactant formulation object of the present invention with the same surfactant concentration, i.e. 1300 ppm. The results are presented in Table 2 and show that with the new formulation the viscosity of the heavy hydrocarbon is reduced to 96% and the viscosity of the 75/25 dispersion is less than 0.5 Pa s (500 cP).

Table 2. Hydrocarbon dispersions in water obtained with nanoparticulate surfactant formulation.

The comparison of the viscosity results of the dispersions with the two formulations demonstrates the superior performance of the nanoparticulate surfactant formulation (Figure 4), which has a performance up to 46% in viscosity reduction compared to the conventional surfactant as observed in the table 3. Table 3. Comparison of the performance of surfactant formulations to prepare hydrocarbon dispersions in water

However, a fundamental aspect in the use of hydrocarbon dispersions in water is their stability. The stability of the dispersions prepared with the nanoparticulate surfactant formulation according to the present invention was analyzed and they exhibit a high stability behavior, greater than 20 days, similar to the dispersions prepared with the liquid surfactant.

By using the nanoparticulate surfactant formulation it is possible to obtain hydrocarbon dispersions in water with lower viscosity and stability suitable for transport and storage.

Claims

68390 13 CLAIMS

1. A nanoparticulate surfactant formulation comprising:

• a nanoparticulate surfactant selected from the group consisting of hydrophilic silica, metallic nanoparticles or mixtures thereof.

• an ionic, non-ionic liquid surfactant or mixture thereof.

2. The formulation according to claim 1 further comprising water.

3. The formulation according to claim 2, wherein the amount of water is between 0% and 70%.

4. The formulation according to any of the preceding claims wherein the nanoparticulate silica surfactant has between 50 and 100% unreacted silanol (Si-OH) groups.

5. The formulation according to any of the preceding claims wherein the metal nanoparticulate surfactant is selected from the group of calcium oxide, magnesium oxide, copper oxides, aluminum oxide, iron oxides or mixture thereof.

6. The formulation according to any of the preceding claims wherein the nanoparticulate surfactant has an average particle size between 20 and 90 nm.

7. The formulation according to any of the preceding claims wherein the nanoparticulate surfactant has a surface area between 150 and 250 m ² / g.

8. The formulation according to any one of claims 1 to 7 wherein the nanoparticulate surfactant has an acid site concentration between 0.5 and 3.5 equivalent / kg.

9. The formulation according to any of the preceding claims wherein the mass content of the nanoparticulate surfactant is between 15% and 100%.

10. The formulation according to any of the preceding claims wherein the concentration of the nanoparticulate surfactant is between 250 and 2000 ppm in the hydrocarbon dispersion in water.

11. The formulation according to any of the preceding claims wherein the mass content of the ionic, non-ionic liquid surfactants or mixture thereof is between 0% and 85%.

12. The formulation according to any of the preceding claims wherein the liquid surfactant is selected according to the pH and hardness conditions of the water used to form the hydrocarbon dispersion in water thus:

I. Anionic liquid ionic surfactant for water with hardness greater than 180 mg / l (expressed as mg CaC0 ₃ / l), pH between 6 and 14, selected from the group of: petroleum alkyl sulphonates, sodium and potassium alkyl benzene sulphonates , sodium and potassium alkyl aryl benzene sulfonate, alpha olefin sulphonates, hydroxy alkane sulphonates, hydroxy alkane sulfate sulfate, alpha olefin sulfonate, alkyl aryl petroleum sulphonates.

II. Ionic liquid cationic liquid surfactant for water with hardness greater than 120 mg / l and less than or equal to 180 mg / l (expressed as mg CaC0 ₃ / l), pH between 2 and 4, selected from the group of: linear quaternary ammonium salts, alkyl amine and alkyl ammonium, dodecyl amine or lauryl amine, alkyl dimethyl benzyl ammonium, quaternary salts.

III. Non-ionic liquid surfactant for waters with hardness less than or equal to 120 mg / l (expressed as mg CaC0 ₃ / l), pH between 2 and 4, selected from the group of: alkyl ethoxylated phenols, ethoxylated fatty acids (poly ethoxy esters), ethoxylated nonyl phenol, ethoxylated poly alcohol (Between C11 and C17), ethoxylated poly ester.