Method for mitigating barite sag in water-based mud with thermochemical fluid
AssigneesSaudi Arabian Oil Company, King Fahd University of Petroleum and Minerals
InventorsAyman R Al-Nakhli, Olalekan Alade, Mohamed Mahmoud
Life of this patent
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Abstract
Described is a method for mitigating particulate settling in a drilling fluid. A set of rheological data for a first drilling fluid is obtained, where the set of rheological data includes a measured viscosity value. A thermal effect of the measured viscosity value is determined, and a predicted viscosity value for a second drilling fluid having a similar composition as the first drilling fluid is determined based on the thermal effect. Based on the predicted viscosity value, an amount of a thermochemical fluid to add to the second drilling fluid is determined to increase a temperature and a viscosity of the second drilling fluid such that settling of a particulate is mitigated.
Claims14
A method for mitigating particulate settling in a drilling fluid, comprising:
- obtaining, by measuring a viscosity of a first drilling fluid, a set of rheological data for the first drilling fluid having a composition, wherein the set of rheological data comprises a measured viscosity value;
- determining a thermal effect of the measured viscosity value;
- determining, based on the thermal effect, a predicted viscosity value for a second drilling fluid having a composition that is similar to the composition of the first drilling fluid;
- determining an amount of a thermochemical fluid to add to the second drilling fluid;
- adding the determined amount of the thermochemical fluid to the second drilling fluid, thereby increasing a temperature and a viscosity of the second drilling fluid such that settling of a particulate is mitigated;
- and
- determining a flow consistency index K and a flow behavior index n for the first drilling fluid according to the following:
- μ
- a
- =
- K
-
- γ
- .
- n
- -
- 1
-
- and
-
- ln
-
- μ
- a
- =
- ln
-
- K
- +
- (
- n
- -
- 1
- )
-
- ln
-
- γ
- .
- ,
- where μa is the measured viscosity value and {dot over (γ)} is a shear rate,
- wherein the predicted viscosity value μp is determined according to the following:
- μ
- p
- =
- K
- 0
-
- exp
-
- (
- E
- a
- R
-
- T
- )
-
- γ
- .
- n
- -
- 1
- ,
- where Ko is the thermal effect, Ea is a flow activation energy, R is a universal gas constant, and T denotes temperature.
A system for mitigating particulate settling in a drilling fluid, comprising:
- a processor configured to perform operations of:
- obtaining, by measuring a viscosity of a first drilling fluid, a set of rheological data for the first drilling fluid having a composition, wherein the set of rheological data comprises a measured viscosity value;
- determining a thermal effect of the measured viscosity value;
- determining, based on the thermal effect, a predicted viscosity value for a second drilling fluid having a composition that is similar to the composition of the first drilling fluid;
- determining, based on the predicted viscosity value, an amount of a thermochemical fluid to add to the second drilling fluid to increase a temperature and a viscosity of the second drilling fluid such that settling of a particulate is mitigated,
- wherein the system is configured to add the determined amount of the thermochemical fluid to the second drilling fluid,
- wherein the processor is configured to perform an operation of determining a flow consistency index K and a flow behavior index n for the first drilling fluid according to the following:
- μ
- a
- =
- K
-
- γ
- .
- n
- -
- 1
-
- and
-
- ln
-
- μ
- a
- =
- ln
-
- K
- +
- (
- n
- -
- 1
- )
-
- ln
-
- γ
- .
- ,
- where μa is the measured viscosity value and {dot over (γ)} is a shear rate, and
- wherein the predicted viscosity value μp is determined according to the following:
- μ
- p
- =
- K
- 0
-
- exp
-
- (
- E
- a
- R
-
- T
- )
-
- γ
- .
- n
- -
- 1
- ,
- where Ko is the thermal effect, Ea is a flow activation energy, R is a universal gas constant, and T denotes temperature.
Dependencies are inferred from the claim text.