Real-time control of drilling fluid properties using predictive models

Patent metadata

Field	Value
Publication number	US-10901377-B2
Application number	US-201415527652-A
Country	US
Kind code	B2
Filing date	Dec 31, 2014
Priority date	Dec 31, 2014
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A method for controlling drilling fluid properties, in some embodiments, comprises determining a predictive model for a fluid circulation system that routes drilling fluid downhole to a drill bit to remove debris from said drill bit; determining a cost function associated with the fluid circulation system; using the predictive model and the cost function to determine a set of input values for the predictive model; operating a controlled device according to at least some of the set of input values, said controlled device changes properties of the drilling fluid in the fluid circulation system; and obtaining measurements of the properties.

First claim

What is claimed is:

1. A method for controlling drilling fluid properties, comprising:
determining a predictive model for a fluid circulation system that routes drilling fluid downhole to a drill bit to remove debris from said drill bit, wherein the predictive model is a dynamic model that is a function of the time delay between an addition of one or more substances to the drilling fluid and a change of one or more properties of the drilling fluid in response to the addition of the one or more substances to the drilling fluid;
determining a cost function associated with the fluid circulation system wherein said cost function accounts for multiple parameters associated with the fluid circulation system, and wherein one or more operations performed using one or more of said multiple parameters is weighted;
wherein the weight applied to an operation involving an equivalent circulating density measurement and an equivalent circulating density setpoint are increased when a difference between a pore pressure gradient and a fracture pressure gradient is less than a predetermined threshold;

using the predictive model and the cost function to determine a set of input values for the predictive model by using the input values in tandem with the predictive model to produce output values that minimize the cost function;
operating a controlled device according to at least some of the set of input values, said controlled device changes properties of the drilling fluid in the fluid circulation system; and
obtaining measurements of said properties.

2. The method of claim 1 , wherein the input values for the predictive model include:
quantities of chemicals to be added to the drilling fluid; and
a pump rate at which the drilling fluid is to be pumped in the fluid circulation system.

3. The method of claim 1 , wherein the cost function comprises a summation of a plurality of calculations, each calculation associated with a different time k, at least one of said calculations comprising measured viscosity and density values for the drilling fluid, and one or more of said calculations comprising calculated viscosity and density values for the drilling fluid.

4. The method of claim 1 , wherein the cost function accounts for parameters selected from the group consisting of:
drilling fluid density and viscosity measurements;
setpoints for said drilling fluid density and viscosity measurements;
energy consumption;
equivalent circulating density; and
a setpoint for said equivalent circulating density.

5. The method of claim 1 , wherein the predictive model describes a relationship between quantities of chemicals added to the drilling fluid, a pump rate at which the drilling fluid is pumped, and actual or predicted measurements of density and viscosity of the drilling fluid.

6. The method of claim 5 , wherein the predictive model describes said relationship using a matrix of dynamic transfer functions.

7. The method of claim 5 , further comprising updating the predictive model based on said obtained measurements by adjusting a transfer function used to describe said relationship.

8. The method of claim 5 , further comprising updating the predictive model based on said obtained measurements by using one or more of said measurements of the properties to adjust an initial condition associated with a differential equation transfer function used to describe said relationship.

9. The method of claim 1 , wherein the controlled device comprises a chemical additive apparatus.

10. The method of claim 1 , wherein the properties include drilling fluid viscosity and density.

11. A system to control drilling fluid properties, comprising:
a measurement device to determine drilling fluid properties of drilling fluid in a fluid circulation system;
a processor that determines input values to a predictive model using the predictive model and a cost function, wherein the predictive model and cost function are associated with the fluid circulation system, wherein the predictive model is a dynamic model that is a function of the time delay between an addition of one or more substances to the drilling fluid and a change of one or more properties of the drilling fluid in response to the addition of the one or more substances to the drilling fluid;
wherein the processor determines said input values by using the input values in tandem with the predictive model to produce output values that minimize the cost function;
wherein the cost function accounts for multiple parameters associated with the fluid circulation system, and wherein one or more operations performed using one or more of said multiple parameters is weighted;
wherein the processor increases a weight applied to an operation involving an equivalent circulating density measurement and an equivalent circulating density setpoint when a difference between a pore pressure gradient and a fracture pressure gradient is less than a predetermined threshold; and

a controlled device that adjusts parameters associated with the fluid circulation system based on said input values,
wherein the measurement device determines new drilling fluid properties after said adjustment, and wherein the processor updates the predictive model using said new drilling fluid properties.

12. The system of claim 11 , wherein the processor increases a weight applied to an operation that has a result exceeding a predetermined threshold.

13. The system of claim 11 , wherein the processor decreases a weight applied to an operation that has a result within a predetermined range.

14. The system of claim 11 , wherein the processor further determines the input values using a set of constraints pertaining to one or more of:
parameters used in the cost function;
values used in the predictive model;
a predicted fluid tank level; and
a pipeline pressure.

15. The system of claim 11 , wherein the cost function accounts for parameter setpoints, and wherein the processor determines the setpoints using a setpoint cost function associated with the fluid circulation system and a setpoint predictive model associated with the fluid circulation system.

16. The system of claim 11 , wherein said controlled device comprises a chemical additive apparatus, and wherein said parameters associated with the fluid circulation system include the rates at which multiple chemicals are added to said drilling fluid in the fluid circulation system.

Assignees

• Halliburton Energy Services Inc

Inventors

• Dykstra Jason D
• Sun Zhijie
• Xue Yuzhen
• Bu Fanping

Classifications

• E21B44/00 Primary

  Automatic control systems specially adapted for drilling operations, i.e. self-operating systems which function to carry out or modify a drilling operation without intervention of a human operator, e.g. computer-controlled drilling systems; Systems specially adapted for monitoring a plurality of drilling variables or conditions · CPC title

• E21B21/08

  Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10) · CPC title

• E21B21/06 Primary

  Arrangements for treating drilling fluids outside the borehole · CPC title

• G05B13/042 Primary

  in which a parameter or coefficient is automatically adjusted to optimise the performance · CPC title

• E21B44/005

  Below-ground automatic control systems · CPC title