Method of inhibiting water penetration into oil- and gas-producing formations
Water penetration into a siliceous subterranean hydrocarbon fluid-bearing formation is inhibited by introducing into the formation organosiloxane possessing at least one alkoxy group directly bonded to a silicon atom.
1. A method for inhibiting penetration of water from a water-producing layer, section or zone located within, near or adjacent to a siliceous subterranean hydrocarbon fluid-bearing formation, wherein the siliceous subterranean hydrocarbon fluid-containing formation contains halide is in need of halite inhibition, into such formation, and which consists of introducing into the formation a water penetration-inhibiting amount of a water penetration-inhibiting composition comprising an organosiloxane possessing at least one alkoxy group directly bonded to a silicon atom, the organosiloxane reacting with the siliceous formation to decrease its hydrophilic character and increase its hydrophobic character thereby inhibiting the penetration of water into the hydrocarbon fluid-containing formation and also preventing or impeding crystallization or deposition of halite onto the surface of the formation.
2. The method of claim 1 wherein the organosiloxane is of the general formula:
M x D y T z Q k
wherein
M=R 1 R 2 R 3 SiO 1/2 ;
D=R 4 R 5 SiO 2/2 ;
T=R 6 SiO 3/2 ; and,
Q=SiO 4/2
wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 each independently is a monovalent hydrocarbon group having from 1 to 20 carbon atoms optionally containing at least one heteroatom, or an OR 7 group in which R 7 is hydrogen or a monovalent hydrocarbon group having from 1 to 20 carbon atoms optionally containing at least one heteroatom and/or hydroxyl group, with the proviso that at least one OR 7 group is present; x is 1 to 50; y is 1 to 400; z is 0 to 20; and, k is 0 to 10, subject to the limitation that z+k>0.
3. The method of claim 1 wherein the organosiloxane is of the general formula:
R 8 Me 2 SiO(SiMe 2 O) a (SiR 9 R 10 O) b SiMe 2 R 8
wherein R 8 and R 9 each independently is hydrogen, a hydroxyl group, an alkoxy group, a vinyl group or a monovalent hydrocarbon group having from 1 to 20 carbon atoms and radical, optionally containing at least one heteroatom; R 10 is (CH 2 ) 3 NH(CH 2 ) 2 NH 2 , (CH 2 ) 3 NH 2 , (CH 2 ) 2 CF 3 or a monovalent hydrocarbon group having from 1 to 20 carbon atoms; a is 3 to 2500; and, b is 1 to 460; with the proviso that at least one alkoxy group is present.
4. The method of claim 1 wherein the organosiloxane is selected from the group consisting of
(CH 3 ) 2 (OCH 3 )Si[OSi(CH 3 ) 2 ] x [OSi(CH 3 )R 10 ] y OSi(CH 3 ) 2 (OCH 3 ) wherein R 10 is H 2 NCH 2 CH 2 NH(CH 2 ) 3 -, (CH 3 ) 2 (OCH 3 )Si[OSi(CH 3 ) 2 ] x [OSi(CH 3 )R 10 ] y OSi(CH 3 ) 2 (OCH 3 ), wherein R 10 is H 2 N(CH 2 ) 3 -, and (CH 3 ) 2 (OCH 3 )Si[OSi(CH 3 ) 2 ] x [OSi(CH 3 )R 10 ] y OSi(CH 3 ) 2 (OCH 3 ) wherein R 10 is F 3 C(CH 2 ) 3 -.
5. The method of claim 1 wherein the water penetration-inhibiting composition is an oil-in-water emulsion or microemulsion in which the organosiloxane is present in the oil phase.
6. The method of claim 1 wherein the water penetration-inhibiting composition comprises an organic solvent solution of the organosiloxane.
7. The method of claim 1 wherein the water penetration-inhibiting composition is an oil-in-water emulsion or microemulsion in which an organic solvent solution of the organosiloxane is present in the oil phase.
8. The method of claim 1 wherein the water penetration-inhibiting composition further comprises an organosilane.
9. The method of claim 8 wherein the organosilane is selected from the group consisting of methyltriethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, divinyldimethoxysilane, divinylmethoxyethoxysilane, di(3-glycidoxypropyl)dimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethyoxysilane, 3-glycidoxypropyl-tri-methoxysilane, 3-methacryloxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl-trimethoxysilane, N-2-aminoethyl-3-propylmethyldimethoxysilane, N-2-aminoethyl-3-propyltrimethoxysilane, N-2-aminoethyl-3-aminopropyltriethoxysilane, 3-aminopropyltriethoxysilane, octyltriethoxysilane, tetraethoxysilane, triethoxysilylpropoxy(hexaethyleneoxy)dodecanoate, triethoxysilylpropoxy(triethyleneoxy)octadecanoate, tridecafluorooctyltriethoxysilane, heptadecafluorodecyltrimethoxysilane, and mixtures thereof.
10. The method of claim 1 wherein the water penetration-inhibiting composition comprises from 0.1 to 33 weight percent of the organosiloxane.
11. The method of claim 1 wherein the water penetration-inhibiting composition comprises from 0.1 to 33 weight percent of the organosiloxane and from 0.1 to 20 weight percent organosilane.
12. The method of claim 1 wherein the total amount of water penetration-inhibiting composition introduced into the formation is sufficient to reduce the wettability index of a pre-treatment core sample of the formation from an initial reference value of approximately 1 to a post-treatment value of not greater than 0.60.
13. A composition comprising an oil-in-water emulsion or microemulsion in which the oil phase contains an organosiloxane possessing at least one alkoxy group and at least one organosilane.
14. The method of claim 1 , wherein the formation is located from a few hundred feet to ten thousand feet beneath the earth' surface, or the surface of an offshore sea bed.
15. The method of claim 1 , wherein the formation contains trapped oil and/or gas.