Equivalent circulating density control in deep water drilling
AssigneeElementis Specialties, Inc.
InventorDavid DINO
Life of this patent
Estimating the term…
Abstract
A method of providing a substantially constant rheological profile of a drilling fluid over a temperature range of about 120° F. to about 40° F. includes adding a drilling fluid additive to the drilling fluid, wherein the drilling fluid additive includes the reaction product of a carboxylic acid with at least two carboxylic moieties; and a polyamine having an amine functionality of two or more. A composition, such as an oil based drilling fluid, includes the reaction product of a carboxylic acid with at least two carboxylic moieties and a polyamine having an amine functionality of two or more.
Claims14
-49. (canceled)
A method of improving the suspension characteristics of an oil-based drilling fluid comprising adding a drilling fluid additive to the drilling fluid, wherein the drilling fluid additive consists essentially of a polyamide having repeat units of (a) a carboxylic unit with at least two carboxylic moieties;
- and (b) a polyamine unit having an amine functionality of two or more, wherein the oil-based drilling fluid exhibits a rheological profile corresponding to a change in Fann reading no more than 50-70 units as shear rate is varied from 600 rpm to 6 rpm at a temperature of 120° F.
The method of claim 1, wherein the carboxylic unit is derived from a dimer fatty acid.
The method of claim 2, wherein the dimer fatty acid is selected from the group consisting of hydrogenated, partially hydrogenated and non-hydrogenated fatty dimer acids with from about 20 to about 48 carbon atoms.
The method of claim 2, wherein the dimer fatty acid is selected from the group consisting of a C16 dimer fatty acid, a C18 dimer fatty acid and mixtures thereof.
The method of claim 1, wherein the carboxylic acid unit is derived from a mixture of a dimer fatty acid and a trimer fatty acid.
The method of claim 1, wherein the polyamine unit is derived from a polyethylene polyamine.
The method of claim 6, wherein the polyamine is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetriamine and tetrayethylenepentamine.
The method of claim 6, wherein the polyamine is diethylenetriamine.
The method of claim 1, further comprising adding one or more emulsifiers to the drilling fluid.
The method of claim 1, further comprising adding an organoclay to the drilling fluid.
The method of claim 1, further comprising adding to the drilling fluid one or more of:
- a fluid loss reducing additive and a weight agent.
The method of claim 1, comprising adding less than about 2 ppb drilling fluid additive to the drilling fluid.
The method of claim 1, wherein the polyamide has an average molecular weight of about 2,000 to about 2030.
Dependencies are inferred from the claim text.