Control of drilling fluid composition

Abstract

A method of controlling composition of a drilling fluid involves receiving desired values of one or more properties of a drilling fluid; inputting the one or more desired values to a first fluid model to determine a preliminary desired concentration of each of one or more components of the drilling fluid, wherein the first fluid model is configured to output, for a given input of said one or more desired values, a concentration of each said component of the drilling fluid that corresponds to said input; using a second model to correct the one or more preliminary desired concentrations to determine one or more desired concentrations, wherein the second model is configured to output, based on a concentration of each of said one or more components, a correction to a corresponding output of the first fluid model; determining a concentration of each of said one or more components in the drilling fluid; and based on a difference between the one or more desired concentrations and the determined concentrations, determining a quantity of one or more additives to be added to the drilling fluid to achieve the desired concentration of each of the one or more components. Fig 3