Automatic adjustment of drilling fluid properties

Abstract

The primer objective of this thesis was to implement and test, in the automated drilling hydraulics laboratory at the University of Stavanger, a system for automatic adjustment of viscosity of a fluid. The fluid used to simulate the drilling fluid was to be a mixture of silicone oil and water. Due to the long waiting times and high prices of the required equipment, the project came to a halt and the nature of this study had to be changed into a more theoretical one, with limited time available.

Given that, we will look at the possibilities regarding the automation in the adjustment of drilling fluids properties, focusing only on the adjustment of density and viscosity. First, drilling fluids are described as to their functions and properties. The property known as viscosity is described in more detail for a better understanding of the work carried on this thesis.

Two implementation proposals, one for automatic density adjustment and one for automatic viscosity adjustment will be presented, using Simulink.

A proposal for the mentioned experiment in the automated drilling hydraulics laboratory will be presented, along with a third Simulink implementation, designed for the experiment.

Two experiments that were carried out in the drilling fluids laboratory will be presented and their results discussed. The objective of these experiments was to demonstrate the effect of a polymer viscosifier on a fluid and how the solubility of that viscosifier is affected by a change in other properties of the fluid, such as salinity.