Abstract This specification discloses a method of controlling lost circulation in drilling operations. In carrying out the method of the invention, an aqueous mixture of a dispersing agent and a water dispersible oleophilic colloid is introduced into the well. This aqueous mixture is circulated down the well and into the vicinity of a formation into which lost circulation is occurring. The aqueous mixture is there mixed with an oleaginous liquid and a gel is formed which tends to plug the formation into which lost circulation is occurring. The oleophilic colloid may be a normally water swellable clay such as bentonite which has been treated to render it oleophilic. The oleaginous liquid may comprise an oil-base drilling fluid utilized in drilling of the well.
Inventors
👤 J Kelly
Bibliographic Details
Application Number—
JurisdictionUS
Data Sourcegoogle_patents
Last Synchronized2026-11-07 22:09
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/003
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
22 words
The method of claim 1 wherein said dispersing agent is selected from the group consisting of lignites, lignosulfonates, tannins, and complex phosphates.
Claim 2
Dependent Claim
21 words
The method of claim 2 wherein said dispersing agent is selected from the group consisting of chrome lignosulfonates and ferrochrome lignosulfonates.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein said oleophilic colloid is a normally water swellable clay which has been treated to render it oleophilic.
Claim 4
Dependent Claim
24 words
The method of claim 1 wherein said oleaginous liquid comprises an oil-base drilling fluid present in said well when said aqueous mixture is introduced.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein said aqueous mixture is adjusted to an alkaline pH by the inclusion of a pH-adjusting chemical.
Claim 6
Dependent Claim
79 words
In the drilling of a well, the method of alleviating fluid loss into a subterranean formation penetrated by said well, comprising: forming a pumpable aqueous mixture of a dispersing agent and a water dispersible colloid which acts as an oleaginous gelling agent; circulating said aqueous mixture down said well and into the vicinity of said formation; and mixing said aqueous mixture with an oleaginous liquid whereby said oleophilic colloid is dispersed in said oleaginous liquid and forms a gel.
Claim 7
Dependent Claim
32 words
The method of claim 7 wherein said pumpable aqueous mixture is formed by adding said dispersing agent into water no later than the addition of said water dispersible colloid into said water.
Claim 8
Dependent Claim
34 words
The method of claim 8 further comprising adding a pH-adjusting chemical to said water to adjust the pH of said water to an alkaline pH and thereby improve the effectiveness of said dispersing agent.