Wellbore fluid comprising a base fluid and a particulate bridging agent
AssigneeBP Exploration Operating Company Limited
InventorsSimon Neil Duncum, Christopher Alan Sawdon
Life of this patent
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Abstract
Wellbore fluid containing a base fluid and a particulate bridging agent comprised of melamine. A method is also described of forming a removable filter cake on the walls of a wellbore that penetrates a porous and permeable rock formation by placing in the wellbore a wellbore fluid containing a base fluid and melamine, and permitting the melamine to deposit from the wellbore fluid onto or into the walls of the wellbore to form the filter cake, whereby fluid loss to the formation through the removable filter cake is reduced.
Claims17
A wellbore fluid comprising a base fluid and a particulate bridging agent comprised of a sparingly water-soluble material which is melamine.
A method of forming a removable filter cake on the walls of a wellbore that penetrates a porous and permeable rock formation comprising the steps of:
- (a) placing a wellbore fluid in the wellbore wherein the wellbore fluid comprises a base fluid and a particulate bridging agent comprised of melamine;
- and
- (b) permitting the particulate bridging agent to deposit from the wellbore fluid onto and/or into the walls of the wellbore thereby forming the filter cake, whereby fluid loss to the formation through the removable filter cake is reduced.
A method of drilling a wellbore through a porous and permeable rock formation using a drilling fluid comprising a base fluid, a fluid loss control additive, and a particulate bridging agent comprised of melamine, wherein the pressure of the drilling fluid in the wellbore is maintained at above the pressure in the porous and permeable rock formation such that a filter cake deposits on and/or in the walls of the wellbore and reduces fluid loss from the drilling fluid to the rock formation.
Dependencies are inferred from the claim text.