Mutual Solvent for Downhole Use
A mutual solvent for use in oil and gas well operations comprising an ethoxylated alcohol surfactant, having a six carbon backbone chained to three ethylene oxide groups with a hydrophilic lipophilic balance between 11 and 12 but more preferably of about 11.3. Such a mutual solvent may be used in an oil and gas well as a spacer system, in acid treatments to remove the spent acid, and in solvent systems to remove asphaltenic or paraffinic compounds.
1 . A chemical for use in oil and gas well operations comprising:
an ethoxylated alcohol surfactant, having a hydrophilic lipophilic balance between 11 and 12;
wherein the ethoxylated alcohol surfactant is used as a mutual solvent.
2 . The chemical for use in an oil and gas well operations of claim one 1 wherein the ethoxylated alcohol surfactant has a hydrophilic lipophilic balance of about 11.3.
3 . The chemical for use in an oil and gas well operations of claim one 1 wherein the ethoxylated alcohol surfactant has a six carbon backbone chained to three ethylene oxide groups.
4 . An acid system comprising:
an acid, and
a mutual solvent,
wherein the mutual solvent is an ethoxylated alcohol surfactant having a hydrophilic lipophilic balance between 11 and 12.
5 . The acid system of claim 4 wherein the ethoxylated alcohol surfactant has a hydrophilic lipophilic balance of about 11.3.
6 . The acid system of claim 4 where the ethoxylated alcohol surfactant has a six carbon backbone chained to three ethylene oxide groups.
7 . The acid system of claim 4 wherein the acid is hydrochloric acid.
8 . The acid system claim 4 wherein the mutual solvent is present in an amount from about 0.1 pounds per barrel to about 70 pounds per barrel.
9 . The acid system claim 4 wherein the mutual solvent is present in an amount from about 1.0 pounds per barrel to about 25 pounds per barrel.
10 . The acid system claim 4 wherein the mutual solvent is present in an amount from about 2.0 pounds per barrel to about 7 pounds per barrel.
11 . A spacer system for use in a wellbore comprising:
a water;
a water-soluble viscosifier:
a weighting agent;
a water wetting agent;
a sulfonic acid surfactant;
and a mutual solvent;
wherein the mutual solvent is an ethoxylated alcohol having a hydrophilic lipophilic balance between 11 and 12.
12 . The spacer system of claim 11 wherein the ethoxylated alcohol has a hydrophilic lipophilic balance of about 11.3.
13 . The spacer system of claim 11 wherein the ethoxylated alcohol has a six carbon backbone chained to three ethylene oxide groups,
14 . The spacer system of claim 11 wherein the water-soluble viscosifier is a polysaccharide.
15 . The spacer system of claim 11 wherein the water-soluble viscosifier is a polysaccharide derivative.
16 . The spacer system of claim 11 wherein the water-soluble viscosifier is a synthetic polymer.
17 . The spacer system of claim 11 wherein the water-soluble viscosifier is hydroxyethyl cellulose.
18 . The spacer system of claim 11 wherein the weighting agent is barite.
19 . The spacer system of claim 11 wherein the water wetting agent is tridecyl alcohol with six ethylene oxide groups.
20 . The spacer system of claim 11 wherein the sulfonic acid surfactant is neutralized dodecyl benzene sulfonic acid.
21 . The spacer system of claim 11 wherein the mutual solvent is present in an amount from about 0.1 pounds per barrel to about 70 pounds per barrel.
22 . The spacer system of claim 11 wherein the mutual solvent is present in an amount from about 1 pound per barrel to about 25 pounds per barrel.
23 . The spacer system of claim 11 wherein the mutual solvent is present in an amount from about 2 pounds per barrel to about 7 pounds per barrel.
24 . The spacer system of claim 11 wherein the viscosifying agent is present in an amount from about 0.01 pounds per barrel to about 10 pounds per barrel.
25 . The spacer system of claim 11 where the viscosifying agent is present in an amount from about 0.5 pounds per barrel to about 7 pounds per barrel.
26 . The spacer system of claim 11 wherein the viscosifying agent is present in an amount from about 1 pound per barrel to about 3 pounds per barrel.
27 . The spacer system of claim 11 wherein the water wetting agent is present in an amount from about 0.1 pounds per barrel to about 25 pounds per barrel.
28 . The spacer system of claim 11 wherein the water welting agent is present in an amount from about 0.5 pounds per barrel to about 5 pounds per barrel.
29 . The spacer system of claim 11 wherein the water wetting agent is present in an amount from about 1 pound per barrel to about 3.5 pounds per barrel.
30 . The spacer system of claim 11 wherein the sulfonic acid surfactant is present in an amount from about 0.1 pounds per barrel to about 25 pounds per barrel.
31 . The spacer system of claim 11 wherein the sulfonic acid surfactant is present in an amount from about 0.5 pounds per barrel to about 5 pounds per barrel.
32 . The spacer system of claim 11 wherein the sulfonic acid surfactant is present in an amount from about 1 pound per barrel to about 3.5 pounds per barrel.