CRUDE OIL PRODUCTION USING A COMBINATION OF EMULSION VISCOSITY REDUCER AND SCALE INHIBITOR
The present invention pertains to a composition for crude oil production, comprising an emulsion viscosity reducer (EVR); a scale inhibitor, and a solvent system comprising water, an oil soluble solvent and a co-solvent; to a process for production of crude oil using the compositions; and the use of the compositions as flow improver or viscosity reducer.
1 . A composition for crude oil production, comprising
a) an emulsion viscosity reducer;
b) a scale inhibitor; and
c) a solvent system; which comprises
i) water,
ii) an oil soluble solvent, and
iii) a co-solvent.
2 . Composition according to claim 1 , wherein the oil soluble solvent is selected from aromatic solvents, alkyl alcohols having 6 or more carbon atoms; glycols, glycol esters, glycol ethers comprising more than 6 carbon atoms; and any mixture thereof.
3 . Composition according to claim 2 , wherein the aromatic solvent has a boiling point in the range from 135° C. to 290° C.
4 . Composition according to any one of claims 1 to 3 , wherein the oil soluble solvent is selected from ethylene glycol monobutyl ether, diethylene glycol monoethylether, dipropyleneglycol methyl ether, ethylene glycol diethyl ether, ethylene glycol monoethyl ether acetate, propylene glycol methyl ether acetate, and any mixtures thereof.
5 . Composition according to any one of claims 1 to 4 , wherein the co-solvent is selected from alkyl alcohols comprising 1 to 3 hydroxyl groups and less than 6 carbon atoms and any mixture thereof.
6 . Composition according to claim 5 , wherein the co-solvent is selected from methanol, ethanol, propanol, isopropanol, butanol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, monoethylene glycol, diethylene glycol, glycerol and any mixture thereof.
7 . Composition according to any one of claims 1 to 6 , wherein the composition comprises 60 to 94.6 wt. % of the solvent system.
8 . Composition according to any one of claims 1 to 7 , wherein the composition comprises 0.1 to 10 wt. % of scale inhibitor.
9 . Composition according to any one of claims 1 to 8 , wherein the composition comprises 1 to 20 wt. % of emulsion viscosity reducer.
10 . Composition according to any one of claims 1 to 9 , wherein the composition further comprises a surfactant.
11 . Composition according to claim 10 , wherein the composition comprises the surfactant in an amount of 0.1 to 10 wt. %.
12 . Composition according to any one of claims 10 and 11 , wherein the surfactant is an anionic surfactant.
13 . Composition according to any one of claims 10 to 12 , wherein the surfactant is selected from dodecyl benzene sulfonic acid (DDBSA), 2-ethylhexanol phosphate ester, pivalic acid, neodecanoic acid, oxalic acid or mixtures thereof.
14 . A process for production of crude oil comprising
injecting a composition according to any one of claims 1 to 13 into the well, and
lifting the resulting fluid to the surface for processing.
15 . Process according to claim 14 , wherein the fluid comprises crude oil, gas and brine.
16 . Process according to any one of claims 14 and 15 , wherein the composition is injected into the well via a chemical injection line.
17 . Process according to anyone of claims 14 to 16 , wherein the composition is injected into the gas lift.
18 . Use of a composition according to any one of claims 1 to 13 as a flow improver.
19 . Use of a composition according to any one of claims 1 to 13 as a viscosity reducer.