Earth boring – well treating – and oil field chemistry – Well treating – Contains organic component
Reexamination Certificate
1999-02-09
2001-02-20
Warden, Jill (Department: 1743)
Earth boring, well treating, and oil field chemistry
Well treating
Contains organic component
C507S116000, C507S260000
Reexamination Certificate
active
06191076
ABSTRACT:
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 (meaning an ester in which the carbon on the alkyl chain to which the carboxylate moiety is attached is a secondary carbon, i.e., one that is covalently bound to two other carbon atoms, rather than a primary or tertiary carbon, which are covalently bound 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.
Catalysts known to be effective in such esterification reactions can be in the form of metallosilicates, especially aluminum silicates (such as zeolites or zeolite mordenites) having exchangeable cations and hydrogen ion-exchanged, layered clays. For esterification reactions, these catalysts are often used with a strong acid added to them.
With hydrogen ion-exchanged, layered clays, it is also known that if the exchangeable cation in the layered clay is a metal cation, there is no need for strong acids to be added to the catalyst. The absence of strong acids renders the clays less corrosive and more readily separable from the reaction mixture.
Stabilized pillared interlayered clay in which the pillars are formed after exchanging the natural cations of the clay with more suitable cations are known to be effective for catalyzing the esterification reaction of olefins and carboxylic acids.
It is also known that monocarboxylic acid methyl esters can be used as the continuous phase or part of the continuous phase in invert drilling muds.
The present invention relates to an esterification reaction of olefins and carboxylic acids which results in a significant decrease in oligomerization and utilizes a catalyst which 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.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an invert 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, tridecylcarboxylates, tetradecylcarboxylates, pentadecylcarboxylates, hexadecylcarboxylates, heptadecylcarboxylates, octadecylcarboxylates, nonadecylcarboxylates, eicosylcarboxylates, uneicocarboxylates, doeicosylcarboxylates and isomers and mixtures thereof, wherein the secondary esters each have a carboxylate moiety with from one to five carbon atoms;
(b) a weight material; and
(c) water.
Still another object of the present invention is to provide a method of making 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.
Yet another object of the present invention is to provide a method of using a mixture of secondary esters as the continuous phase or part of the continuous phase of an invert drilling fluid, the mixture being 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.
Still another object of the present invention is to provide a method of using a mixture of secondary esters as an additive to water based drilling muds, the mixture being 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.
DETAILED DESCRIPTION OF THE INVENTION
This invention relates to the use of an acid catalyst, preferably a dry (extremely low moisture) acid washed natural clay, or a dry (extremely low moisture) macroreticular, sulfonated, cross-linked copolymer of styrene and divinyl benzene (for example an Amberlyst type catalyst) to catalyze the addition of a C
1
-C
5
carboxylic acid to an olefin. The process can utilize one acid or a mixture of acids, and it can utilize one 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. In a preferred embodiment, the flow rate is 0.7-4 WHSV; and in a more preferred embodiment, the flow rate is 1-1.5 WHSV. Some of the most surprising attributes of this invention are (1 ) that the catalyst must be nearly free of water in order for the esterification reaction to proceed; and (2) that olefin oligomerization is almost eliminated, as long as the concentration of carboxylic acid in the feedstock mixture is kept above about 3wt. %. In a preferred embodiment, the effluent resulting from the catalyzed addition of propionic acid and 1-tetradecene has a composition of about 35-45 weight % secondary ester, about 15-20 weight % propionic acid, about 36-45 weight % C
14
olefins, and less than 1 weight % C
14
oligomers.
As a hydrophobic synthetic fluid with a pour point below −10° C., a flash point above about 248° F., and a molecular weight near that of a C
14
-C
20
hydrocarbon, these synthetic mixtures would function well as the continuous phase or part of the continuous phase of an invert mud. Because these mixtures are mixtures of esters rather than hydrocarbons, they would biodegrade more rapidly than do synthetic hydrocarbons.
Another advantage that this invention gives over esters currently used in the drilling industry is that from it can be produced a suitable ester mixture having a lower viscosity than esters currently in use. Currently used esters derive from natural fatty acids, which are typically C
12
or heavier acids. When combined with a branched C
8
or heavier alcohol, which is the conventional practice used to get an ester with a sufficiently low pour point, the resulting ester is more viscous than the ones that can be achieved with the present invention.
The following non-limiting examples show various aspects of various embodiments of the present invention.
REFERENCES:
patent: 4009203 (1977-02-01), Schmerling
patent: 4927954 (1990-05-01), Knopf et al.
patent: 5318954 (1994-06-01), Mueller et al.
patent: 5318956 (1994-06-01), Mueller et al.
patent: 5441927 (1995-08-01), Mueller et al.
patent: 5593953 (1997-01-01), Malchow, Jr.
patent: 5977031 (1999-11-01), Patel
Organic Chemistry. Third Edition. Wad, Jr., 1995.
Ambrosius J. W.
Chevron Phillips Chemical Company LC
Cross LaToya
Haymond W. B.
Turner W. K.
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