MXPA00006484A - Invert emulsion drilling fluid containing mixtures of secondary esters obtained by conversion of olefins, and preparation thereof - Google Patents

Abstract

Preparation of invert drilling muds containing a mixture of secondary esters, the process involving the addition of one or more C1-C5 carboxylic acids and one or more C3-C22 olefins in the presence of an acid catalyst.

Description

REVERSE EMULSION DRILL FLUID CONTAINS MIXTURES OF SECONDARY ESTERS OBTAINED BY CONVERSION OF OLEFINS, AND PREPARATION OF THE SAME FIELD OF THE INVENTION The invention relates to a process for combining an olefin and a carboxylic acid to produce a mixture containing secondary esters; the mixture of esters produced by the process, and the use of the mixture of esters.

BACKGROUND OF THE INVENTION It is known that carboxylic acids can be added to olefins to produce secondary esters (which means an ester in which the carbon of the alkyl chain to which the carboxylate moiety is attached is a secondary carbon, ie, one which is it covalently links to two other carbon atoms, rather than a primary or tertiary carbon, which are covalently bonded to one or three carbon atoms, respectively). These methods generally involve reaction of a low molecular weight olefin with a high molecular weight carboxylic acid to produce secondary esters. REF.121246 The known catalysts which are effective in such esterification reactions may be in the form of metallosilicates, especially aluminum silicates (such as zeolites or mordenite zeolite) having cation exchange clays and hydrogen ion exchange laminates. For esterification reactions, these catalysts are often used with a strong acid added thereto.

With stratified hydrogen ion exchange clays, it is also known that if the interchangeable cation in the stratified clay is a metal cation, it is not necessary that strong acids are added to the catalyst. The absence of strong acids makes the clay less corrosive and more easily separable for the reaction mixture.

Stabilized stacked interstratified clay, in which the pillars are formed after exchanging the natural cations of the clay with more suitable cations, is known to be effective in catalyzing the esterification reaction of olefins and carboxylic acids.

It is also known that the methyl esters of monocarboxylic acid can be used as the continuous phase or part of the continuous phase in reverse drilling muds.

The present invention relates to an esterification reaction of olefins and carboxylic acids that results in a significant decrease in oligomerization and utilizes a catalyst that is relatively easy to prepare and is relatively long lasting in its effectiveness. The present invention also relates to the product of this esterification reaction, which can be used as a component of a drilling fluid.

BRIEF DESCRIPTION OF THE INVENTION An object of the present invention is to provide a reverse emulsion drilling fluid comprising: (a) a continuous phase comprising a mixture of secondary esters selected from the group consisting of propylcarboxylates, butylcarboxylates, pentylcarboxylates, hexylcarboxylates, heptylcarboxylates, octylcarboxylates, nonylcarboxylates, decylcarboxylates, undecylcarboxylates, dodecylcarboxylates, tridecyl carboxylates, tet radecyl carboxylates, pentadecyl carboxylates, hexadecylcarboxylates, heptadecyl carboxylates, octadecylcarboxylates, nonadecylcarboxylates, eicosylcarboxylates, monocarboxylates, docosylcarboxylates and isomers and mixtures thereof, wherein the secondary esters each have a carboxylate radical of one to five carbon atoms; (b) a weight material; and (c) water.

Still another object of the present invention is to provide a method for producing secondary esters comprising combining carboxylic acids having from one to five carbon atoms or isomers or mixtures thereof with olefins selected from the group consisting of propene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, uneicosene, doeicosene and isomers and mixtures thereof in the presence of an acid catalyst.

Still another object of the present invention is to provide a method for using a mixture of secondary esters as the continuous phase or part of the continuous phase of an inverse drilling fluid, the mixture is produced by a method comprising the step of combining carboxylic acids have from one to five carbon atoms or isomers or mixtures thereof with olefins selected from the group consisting of propene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene , heptadecene, octadecene, nonadecene, eicosene, uneicosene, doeicosene and isomers and mixtures thereof in the presence of an acid catalyst to make secondary esters.

Still another object of the present invention is to provide a method for using a mixture of secondary esters as an additive to water-based drilling muds, the mixture is produced by a method comprising the step of combining carboxylic acids having from one to five carbon atoms or isomers or mixtures thereof with olefins selected from the group consisting of propene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, uneicosene, doeicosene and isomers and mixtures thereof in the presence of an acid catalyst to make secondary esters.

DESCRIPTION OF THE DRAWINGS Figure 1 is a diagram of a continuous unit used to produce mixtures of secondary esters.

Figure 2 is a GC / FID chromatogram of a product mixture obtained from the unit, when the unit was operating at approximately 0.65 WHSV and 140 ° C as described in Example 2.

Figure 3 is a GC / FID chromatogram of a product mixture obtained in a batch reactor, when the unit was operated for about 5 hours at 120 ° C as described in Example 3.

DETAILED DESCRIPTION OF THE INVENTION This invention relates to the use of an acid catalyst, preferably a dry natural clay (extremely low humidity) washed with acid, to catalyze the addition of a Ci-C3 carboxylic acid to an olefin. The process can use an acid or a mixture of acids, and can use an olefin or a mixture of olefins. The process can proceed in batch or continuous mode and operates at 60-300 ° C. In a continuous mode, the flow rate is generally 0.1-5 WHSV. Some of the most surprising attributes of this invention are (1) that the catalyst must be almost free of water for the esterification reaction to proceed; and (2) that the oligomerization of the olefin is almost eliminated, so much so that the concentration of carboxylic acid in the feed mixture is maintained above 3% p.

As a synthetic hydrophobic fluid with a pour point below -10 ° C, a flash point above about 120 ° C, and a molecular weight close to that of a C14-C20 hydrocarbon these synthetic blends would also function as the continuous phase or part of the continuous phase of a reverse mud. Because these mixtures of esters rather than hydrocarbons, they would biodegrade more rapidly than those of synthetic hydrocarbons.

Another advantage that this invention gives on esters commonly used in the drilling industry is that a suitable mixture of esters having a lower viscosity than the commonly used esters can be produced from these. The commonly used esters are derived from natural fatty acids, which are typically C12 or heavier acids. When combined with a C8 or heavier alcohol, which is the conventional practice used to obtain an ester with a sufficiently low pour point, the resulting ester is more viscous than those obtainable with the present invention.

The following non-limiting examples show various aspects of various embodiments of the present invention.

EXAMPLES Example 1 Synthesis of C ^ Propionates with F-25 F-25 (Engelhard) was dried in a vacuum oven overnight at about 200 ° C to remove water. The dried clay granules were packed in a fixed bed, and a mixture that was 50 mol% propionic acid and 50 mol% commercial 1-tetradecene was passed through the bed at a temperature of 140 ° C and a flow rate of 0.5 WHSV. By GC / FID analysis, the effluent contained approximately 20% secondary esters, approximately 10% propionic acid, approximately 70% C14 olefins, and less than 1% C14 oligomers. The most abundant simple ester in the mixture was 2-tetradecyl propionate, followed by 3-tetradecyl propionate, followed by 4-tetradecyl propionate, followed by 5-, 6- and 7-tetradecyl propionate. The C14 olefins in the effluent were approximately 70% internal linear olefins and approximately 30% alpha olefins. The unreacted acid and olefins were separated from the esters by distillation and suitable for recirculation.

Example 2 Synthesis of Propionates C with F-25 F-25 (Engelhard) was dried and packed in a fixed bed as in Example 1. A mixture that was 50 mol% propionic acid and 50 mol% 1-tetradecene commercial was passed through the bed at a temperature of 140 ° C and a flow rate of 0.65 WHSV. The chromatogram of Figure 2 shows the peaks of residual propionic acid and remaining tetradecenes as well as peaks for the secondary esters formed from tetradecenes and formed propionic acid. By GC / FID analysis, the effluent contained approximately 9% propionic acid, approximately 73% tetradecenes, and approximately 15% secondary esters. Of particular observation is the almost complete absence of peaks of olefin dimers, which, by GC / FID, resolved only about 1.8% of the product of the mixture.

Eiemolo 3 Treatment of 1-Dodecene with Filtrol 105 As a comparison to the results of Example 2, Filtrol 105 (Engelhard) was dried as in Examples 1 and 2, then added to a batch reactor. A sample of 1-dodecene was stirred and heated with the catalyst at 120 ° C for about 5 hours. By GC / FID analysis, the effluent contained approximately 34% C12 olefin monomer, 46% dimer and 20% trimer. By comparing these results with Examples 1 and 2, it can be seen that the presence of propionic acid, especially in an amount greater than about 63% propionic acid in the feed stream, clearly keeps the dimer level below 5%. The chromatogram of Figure 3 shows the peaks of the C12 oligomers.

Example 4 Stop reaction of Olisomerization with Propionic Acid Approximately 598 g of a mixture which was 67 mol% of 1-tetradecene and 33 mol% of propionic acid was heated and stirred at 140 ° C in a batch reactor with 50 g of F-25 (Engelhard) dry. After 6.5 hours, the level of secondary esters was recorded in peaks of approximately 20% by GC / FID, and the olefin oligomers were counted for 3% of the reaction mixture. Instead of remaining steady state, the ester level began to decline, and there was a rapid increase in the amount of olefin oligomer. For the first seven hours of reaction, the propionic acid was > 3% (by GC / FID) of the reaction mixture. Once the propionic acid dropped to < 3% (by GC / FID) of the reaction mixture, the level of olefin oligomer began to increase rapidly.

Example 5 Propionates C Evaluated as Base Fluid for Reverse Drilling Emulsion The suitability of C14 propionates for use in reverse drilling fluids was evaluated. The reverse emulsion was prepared by combining most of the components with the base fluid and mixing for 30 minutes at 49 ° C (120 ° F) using a Gifford Wood homogenizer. The ingredients were added in the order listed in the table below, but at least three were not added during the 30 minute cycle of the homogenizer. First, the suspension of the homogenizer was transferred to a disperser, and then the barite, the drilling solids, and CaCl2 were added, and the mixture was stirred for 30 minutes. The rheological properties of the resulting drilling fluid were determined at 49 ° C (120 ° F), before and after hot-rolling the emulsion for 16 hours at 65.5 ° C (150 ° F).

The drilling fluids showed the following rheological results at 49 ° C (120 ° F): The values of some physical properties of the C14 propionates were: Example 6 Toxicity Test for Mvsid Shrimp Additionally, the mysid shrimp toxicity of the drilling fluid of Example 4 was evaluated according to the US EPA protocol in Appendix 3 of "Effluent Limitation Guidelínes and New Source Performance Standards: Drilling Fluids Toxicity Test ", Federal Register Vol. 50, No. 165, 34631-34636. For unloading cuts, the drilling fluid must show an LC50 towards the mysid shrimp of at least ,000 ppm. The drilling fluid prepared using C14 propionates had an LC50 of = 1,000,000 ppm, indicating that C 14 propionates make a drilling fluid of extremely low toxicity.

Example 7 Synthesis of C12 Propionates with F-25 Dry A mixture that was 50 mol% propionic acid and 50 mol% commercial 1-dodecene was passed through the same dry F-25 catalyst (Engelhard) as described in the Examples 1 and 2. The flow velocity was 0.35 WHSV, and the temperature was 140 ° C. By GC / FID analysis, the effluent contained approximately 20% secondary esters, approximately 10% propionic acid, approximately 70% C12 olefins, and less than 1% C12 oligomers. The most abundant simple ester in the mixture was 2-dodecyl propionate, followed by 3-dodecyl propionate, followed by 4-dodecyl propionate, followed by 5 and 6-dodecyl propionate. The unreacted acid and olefins were separated from the esters by distillation and were suitable for recirculation.

Values of some physical properties of the C12 propionates were: Example 8 Synthesis of Propionatos Ct- > with Amberlyst 15 A mixture containing 15 g of propionic acid, 40 g of 1-tetradecene, and 15 g of Amberlyst 15 (Rohm and Haas) was stirred and heated to 140 ° C. In 30 minutes, the mixture contained 20% tetradecyl propionates and < 1% olefin oligomers by GC / FID. With additional reaction time, the oligomer content increased, and the ester level decreased.

Example 9 Synthesis of C12 Propionates with Amberlyst 15 A mixture containing 15 g of propionic acid, 40 g of 1-tetradecene, and 15 g of Amberlyst 15 (Rohm and Haas) was stirred and heated to 120 ° C. In one hour, the mixture contained 31% tetradecyl propionates and < 1% olefin oligomers by GC / FID. With additional reaction time, the oligomer content increased, and the ester level decreased.

Example 10 Synthesis of Propionates C-, -, with Amberlvst 15 A mixture containing 15 g of propionic acid, 40 g of 1-tetradecene, and 15 g of Amberlyst 15 (Rohm and Haas) was stirred and heated to 100 ° C. . In 1.5 hours, the mixture contained 39% tetradecyl propionates and < 1% olefin oligomers by GC / FID. With additional reaction time, the oligomer content increased, and the ester level decreased.

Example 11 Synthesis of Propionates U-, with Amberlyst 15 A mixture containing 15 g of propionic acid, 40 g of 1-tetradecene, and 15 g of Amberlyst 15 (Rohm and Haas) was stirred and heated to 80 ° C. At 8 hours, the mixture contained 45% tetradecyl propionates and < 1% olefin oligomers by GC / FID. With additional reaction time, the oligomer content increased, and the ester level decreased.

Example 12 Synthesis of Propionates C1? with F-25 Not Dry A mixture containing 8.1 g of 1-decene (1 eq), 17.5 g of propionic acid (4 eq), and 4.72 g of commercial F-25 clay (Engelhard) was stirred and heated to 120 ° C. (Clay had not dried on stove after purchase.) The mixture was refluxed and would not be heated above 120 ° C. After 5 days, the mixture contained 6.5% esters by GC / FID. Then the condenser was removed, and let out of the reaction vessel. In 2 hours, the temperature had reached 140 ° C, and the mixture had reached 11% of esters. Approximately 12 hours later, the ester level was 23%.

Example 13 Synthesis of Propionates C with F-25 Dry A mixture containing 30.0 g of 1-tetradecene (1 eq), 34.0 g of propionic acid (3 eq), and 10.1 g of clay F-25 (Engelhard) (dried 24 hours in a vacuum oven at 200CC) was stirred and heated to 140 ° C. The mixture showed no signs of reflux and easily reached 140 ° C.

At 20 hours, the mixture contained 35% esters per GC / FID. The ester level remained at this level, even after stirring another 24 hours at the reaction temperature.

Example 14 Synthesis of Propionates C with Non-Dry F-62 A mixture containing 20.0 g of 1-tetradecene (1 eq), 7.58 g of propionic acid (1 eq), and 5.0 g of extruded F-62 (Engelhard) was stirred and heated to 120 ° C. The mixture was refluxed and showed only traces of ester by GC / FID, even after 20 hours of heating.

Example 15 Synthesis of Propionates C with F-62 Dry A mixture containing 40.0 g of 1-tetradecene (1 eq), 15.1 g of propionic acid (1 eq), and 16.3 g of extruded F-62 (Engelhard) ( it had been heated in a vacuum oven at 200 ° C for 20 hours) stirred and heated to 140 ° C. After 19 hours, the mixture contained 31% esters by GC / FID. Additional reaction time did not increase the amount of ester in the mixture.

Example 16 Synthesis of C11 Propionates from Ct4 Isomerized v Filtrol 105 Dry A mixture containing 30.0 g (1 eq) of tetradecenes (obtained by complete isomerization of the double bond of 1-tetradecene), 34.0 g (3 eq) of propionic acid , and 10 g of dry Filtrol 105 (Engelhard) clay (which had been heated in a vacuum oven at 200 ° C for 20 hours) was stirred and heated to 140 ° C. After 31 hours, the mixture contained 23% esters by GC / FID. The product of esters of this process was the same obtained when 1-tetradecene was the initial olefin, but the distribution of isomers of. propionate was different for this mixture than for those obtained when 1-tetradecene was the initial olefin. There was approximately both 7-tetradecyl propionate and 2-tetradecyl propionate in this mixture, which showed a more uniformly distributed binding position for the propionate group in this mixture, than for the mixture obtained using 1-tetradecene as initial definition Example 17 Synthesis of Propionates C? N Using F-25 Dry A mixture containing 664 g (1 eq) of 1-octadecene, 195 g (1 eq) of propionic acid, and 51 g of F-25 (Engelhard) dry ( which had been heated in a vacuum oven at 200 ° C for 20 hours) was stirred and heated to 140 ° C. After 6 hours, the mixture contained 19% secondary esters by GC / FID.

Example 18 Propionates C? Evaluated as Base Fluid for Reverse Drilling Emulsion A slurry formulated using a mixture of dodecyl propionates as the base fluid had this composition: Drilling fluid showed the following rheological results at 49 ° C (120 ° F): Before hot rolling, the mud also showed these properties at 1.6 ° C (35 ° F): In the mysid shrimp test, this sludge showed an LC50 of = 1,000,000 ppm SPP.

The values of some physical properties of the C12 propionates were: Example 19 Propionates Cj 2 / £ L? 4 Evaluated as Base Fluid for Reverse Drilling Emulsion A slurry formulated using a mixture of dodecyl propionate (50% p.p.) and tetradecyl propionate (50% p.p.) as the base fluid had this composition: Drilling fluid showed the following rheological results at 49 ° C (120 ° F): Before hot rolling, the mud also showed these properties at 1.6 ° C (35 ° F): In the mysid shrimp test, this sludge showed an LC50 of = 1,000,000 ppm SPP.

Example 20 Synthesis of Ct Propionates, Using HS04 A mixture containing 20 g (1 eq) of 1-tetradecene, 7.6 g (1 eq) of propionic acid, and 0.62 g of concentrated sulfuric acid was stirred and heated to 115 ° C. . After 15 hours, the mixture contained 44% secondary esters by GC / FID.

Although few embodiments of the invention have been described in detail before, it will be apparent to those skilled in the art that various modifications and alterations can be made to the particular embodiments shown, without materially departing from the new indications and advantages of the invention. Therefore, it will be understood that all modifications and alterations are included within the spirit and scope of the invention as defined in the following claims. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (15)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. A process for producing a mixture of at least two secondary esters, characterized in that the process comprises the steps of: (a) preparing a mixture containing at least one carboxylic acid having from one to five carbon atoms or isomers or mixtures thereof same, with at least one olefin selected from propene, butene, pentene, hexene, heptene, octene, nonene, decene, undecene, dodecene, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, uneicosene, doeicosene and isomers and mixtures thereof, wherein the concentration of the carboxylic acid in the mixture is at least about 3 weight percent; and (b) contacting the mixture of step (a) in the absence of water with an acid catalyst under reaction conditions and for a sufficient time to react the carboxylic acid and the olefin while maintaining the concentration of the carboxylic acid in the mixture of reaction above about 3 weight percent, to form a mixture of at least two secondary esters.

2. A process according to claim 1, characterized in that step (a) is carried out at a temperature of 60 to 300 ° C.

3. A process according to claim 1, characterized in that step (a) is carried out in a batch mode.

4. A process according to claim 1, characterized in that step (a) is carried out in a continuous mode.

5. A process according to claim 4, characterized in that the flow rate is from 0.1 to 5 WHSV.

6. A process according to claim 1, characterized in that the acid catalyst is a natural clay washed with acid.

7. The method according to claim 1, characterized in that the weight of the carboxylic acid is greater than 5% by weight of the olefins and carboxylic acids combined in step (a).

8. A reverse emulsion drilling fluid, characterized in that it comprises: (a) a continuous phase comprising a mixture of at least two secondary esters produced by a process according to any of claims 1 to 7; (b) a weight material; and (c) water.

9. A reverse emulsion drilling fluid according to claim 8, characterized in that the kinematic viscosity of the secondary ester mixture is between 1 and 2 cSt when measured at 100 ° C, and because the pour point of the ester mixture secondary is below -10 ° C.

10. A reverse emulsion drilling fluid according to claim 8 or 9, characterized in that it also includes one or more additives selected from emulsifiers, wetting agents, thickeners, density boosters, and fluid loss preventatives.

11. A process for producing a drilling fluid, characterized in that it comprises the steps: (a) forming a mixture of at least two secondary esters according to the process of any of claims 1 to 7; and (b) combining the secondary esters produced in step (a) with water, a weight material and additives selected from emulsifiers, wetting agents, thickeners, density boosters, and fluid loss preventatives.

12. A process according to claim 11, characterized in that the mixture of secondary esters produced in step (a) is used as a continuous phase or part of a continuous phase of a reverse drilling fluid.

13. A process according to claim 11, characterized in that the mixture of secondary esters produced in step (a) is used as an additive to a water-based drilling mud.

14. A continuous phase of a drilling fluid, characterized in that the continuous phase comprises at least two secondary esters selected from propylcarboxylates, Butilcarboxilatos, pentilcarboxilatos, hexilcarboxilatos, heptilcarboxilatos, octilcarboxilatos, nonilcarboxilatos, decilcarboxilatos, undecilcarboxilatos, dodecilcarboxilatos, tridecyl latos carboxy, tetradecilcarboxi latos, pentadecyl carbo i latos, latos hexadecilcarboxi, heptadecyl latos carboxy, octadecyl latos carboxy, nonadecilcarboxilatos, eicosilcarboxilatos, uneicocarboxilatos, doeicosilcarboxilatos and isomers and mixtures thereof, wherein the secondary esters each have a carboxylate radical of one to five carbon atoms.

15. A drilling fluid, characterized in that it has a continuous phase according to claim 14.