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US 4,381,241 AGranted
Invert emulsions for well-drilling comprising a polydiorganosiloxane and method therefor
AssigneeDow Corning Corporation
InventorsDavid J. Romenesko, Harry M. Schiefer
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Abstract
The preparation of emulsions of light and heavy brines in a liquid hydrocarbon is described, using a polydiorganosiloxane bearing at least one polyoxyalkylene radical and at least one monovalent hydrocarbon radical having from 6 to 18 carbon atoms. The emulsions are useful in the well-drilling art as drilling fluids, completion fluids, packer fluids, spacer fluids and workover fluids because of their thermal stability and because they can be formulated to have a relatively high density, with or without added weighting agents.
Claims20
An emulsion composition to be used in well-drilling and comprising
- (A) 1 to 75 parts by volume of a brine as a discontinuous phase,
- (B) 25 to 99 parts by volume of a liquid hydrocarbon selected from the group consisting of kerosene, diesel oil, crude oil, turbine fuel, mineral oil, gas oil and paraffins having a flash point of at least 100.degree. F. as a continuous phase, and
- (C) 0.05 to 15 parts by weight, for every 100 parts by weight of brine plus liquid hydrocarbon, of a polydiorganosiloxane having the formula
- Z.sub.3 SiO{(CH.sub.3).sub.2 SiO}.sub.x {(CH.sub.3)(R)SiO}.sub.y {(CH.sub.3)(Q)SiO}.sub.z SiZ.sub.3
- wherein
- Q denotes a polyoxyalkylene radical having the formula
- --R'(OCH.sub.2 CH.sub.2).sub.p (OCH.sub.2 CHCH.sub.3).sub.q OR",
- R denotes a monovalent hydrocarbon radical having from 6 to 18 carbon atoms, inclusive,
- R' denotes a divalent radical bonded to a silicon atom by a silicon-carbon bond,
- R" denotes a monovalent radical selected from the group consisting of hydrogen, alkyl, cycloaliphatic, aryl, arylalkyl and acyl radicals,
- Z denotes a monovalent hydrocarbon radical having from 1 to 5 carbon atoms, inclusive, or a Q radical, or an R radical,
- x has an average value of from 0 to 400,
- y has an average value of from 0 to 400,
- z has an average value of from 0 to 5,
- x+y+z has an average value of from 30 to 400,
- p has an average value equal to or greater than the average value of q and
- p+q has an average value sufficient to provide a formula weight of from 600 to 3500 for the --(OCH.sub.2 CH.sub.2).sub.p (OCH.sub.2 CHCH.sub.3).sub.q -- portion of the Q radical, there being an average of at least one Q radical and an average of at least one R radical per molecule of the polydiorganosiloxane.
14 more elements
A method comprising
- (I) mixing to form a solution,
- (i) 0.5 to 15 parts by weight of a polydiorganosiloxane having the formula
- Z.sub.3 SiO{(CH.sub.3).sub.2 SiO}.sub.x {(CH.sub.3 (R)SiO}.sub.y {(CH.sub.3)(Q)SiO}.sub.z SiZ.sub.3
- wherein
- Q denotes a polyoxyalkylene radical having the formula --R'(OCH.sub.2 CH.sub.2).sub.p (OCH.sub.2 CHCH.sub.3).sub.q OR",
- R denotes a monovalent hydrocarbon radical having an average of from 6 to 18 carbon atoms, inclusive,
- R' denotes a divalent radical bonded to a silicon atom by a silicon-carbon bond,
- R" denotes a monovalent radical selected from the group consisting of hydrogen, alkyl, cycloaliphatic, aryl, arylalkyl and acyl radicals,
- Z denotes a monovalent hydrocarbon radical having from 1 to 5 carbon atoms, inclusive, or a Q radical, or an R radical,
- x has an average value of from 0 to 400,
- y has an average value of from 0 to 400,
- z has an average value of from 0 to 5,
- x+y+z has an average value of from 30 to 400,
- p has an average value equal to or greater than the average value of q and
- p+q has an average value sufficient to provide a formula weight of from 600 to 3500 for the --(OCH.sub.2 CH.sub.2).sub.p (OCH.sub.2 CHCH.sub.3).sub.q -- portion of the Q radical, there being an average of at least one Q radical and an average of at least one R radical per molecule of the polydiorganosiloxane, and
- (ii) aV parts by volume of a liquid hydrocarbon selected from the group consisting of kerosene, diesel oil, crude oil, turbine fuel, mineral oil, gas oil and paraffins having a flash point of at least 100.degree. F.,
- (II) mixing the solution of step (I) with bV parts by volume of the liquid hydrocarbon,
- (III) mixing V' parts by volume of a brine with the solution of step (II) with sufficient shear energy to provide an emulsion having a brine particle size of less than 10 micrometers in diameter, and
- (IV) mixing the emulsion of step (III) with cV parts by volume of the liquid hydrocarbon, wherein,
- V has a value of from 25 to 99 parts by volume,
- V' has a value of from 1 to 75 parts by volume,
- V+V' has a weight of 100 parts by weight,
- a has a value of from greater than zero to 1,
- b has a value of from zero to less than 1,
- c has a value of from zero to less than 1, and
- a+b+c has a value of 1.
23 more elements
Dependencies are inferred from the claim text.