Enzymatic decomposition of drilling mud
AssigneePhillips Petroleum Company
InventorsFrancis J. Shell, Donald O. Hitzman
Life of this patent
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Abstract
Drilling mud is rapidly decomposed by admixing one or more enzymes with the mud to selectively degrade one or more polymeric organic viscosifiers therein. A method of cleaning up a well site drilling mud pit containing drilling mud is provided. Also provided are a composition and method of removing residual drilling mud from a wellbore and around the well face.
Claims18
A method of removing used drilling mud of the type comprising solid materials including at least one polymeric organic viscosifier from a wellbore and portions of formations adjacent thereto comprising:
- injecting a well treatment fluid comprising an enzyme capable of rapidly enzymatically degrading said polymeric organic viscosifier into said well;
- and
- allowing said enzyme to degrade said polymeric organic viscosifier and said well treatment fluid to disperse said used drilling mud.
In a method of drilling a well wherein a drill bit is advanced into the earth to form a bore therein, the drill bit is withdrawn from the bore, annular well casing having an outside diameter less than the diameter of the bore is placed in the bore and cement is placed between the wall of the bore and the casing, the improvement comprising:
- prior to placing the cement between the wall of the bore and the casing, injecting a well treatment fluid into said well to remove used drilling mud of the type comprising solid materials including at least one polymeric organic viscosifier therefrom, said well treatment fluid comprising an enzyme capable of rapidly enzymatically degrading said polymeric organic viscosifier;
- and
- allowing said enzyme to degrade said polymeric organic viscosifier and said well treatment fluid to disperse said used drilling mud.
Dependencies are inferred from the claim text.