Abstract Water injection wells are treated to increase their injectivity by first introducing a solvent such as carbon disulfide, carbon tetrachloride or a composition rich in monocyclic aromatics, into the formation surrounding the well. The waxes and/or bituminous materials normally found at or near the surface of such wells are highly soluble in solvents of this kind. In order to assure the stability of the subsequently injected micellar solution, a suitable buffer such as water or a predominantly aliphatic hydrocarbon, e.g., kerosene, gas oil or crude oil, etc., is injected to immediately follow the aromatic hydrocarbon solvent. Thereafter, the micellar solution, usually containing not more than about 50 percent water, is injected and is substantially miscible with the buffer slug. This system of solvent buffer and micellar solution is then forced out into the formation by means of water or other suitable drive agent.
Inventors
👤 H Froning
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-10-31 17:45
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/52; C09K8/524
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
28 words
The process of claim 1 wherein the buffer slug is injected in an amount corresponding to from about 0.1 to about 0.5 of the volume of solvent employed.
Claim 2
Dependent Claim
27 words
The process of claim 2 wherein a mixed xylene product from a catalytic reformer stream is employed as the solvent for said wax, tar or bituminous material.
Claim 3
Dependent Claim
25 words
The process of claim 2 wherein the solvent is selected from the group consisting of CS2, CCl4 and a hydrocarbon stream rich in monocyclic aromatics.
Claim 4
Dependent Claim
18 words
The process of claim 4 wherein a slug of a low asphalt-containing crude is employed as the buffer.
Claim 5
Dependent Claim
10 words
The process of claim 2 wherein said solvent is CS2.
Claim 6
Dependent Claim
23 words
The process of claim 2 wherein said solvent is displaced out into said formation with water prior to treatment with the micellar solution.
Claim 7
Dependent Claim
10 words
The process of claim 2 wherein the solvent is CCl4.
Claim 8
Dependent Claim
13 words
The process of claim 2 wherein the solvent is a monocyclic aromatic hydrocarbon.
Claim 9
Dependent Claim
10 words
The process of Claim 2 wherein the buffer is kerosene.
Claim 10
Dependent Claim
19 words
The process of claim 2 wherein the buffer is an aliphatic hydrocarbon containing no more than 10 percent CS2.
Claim 11
Dependent Claim
20 words
The process of claim 2 wherein the buffer is an aliphatic hydrocarbon containing no more than 10 percent of CCl4.