Automatic Drilling Fluid Measurements

Abstract

The drilling fluid properties are critical for drilling parameters such as ECD (equivalent circulating density), surge and swab pressures and hole cleaning properties. To be able to optimize drilling parameters and improve drilling efficiency also the drilling fluid must be at optimum specifications. To have a more proactive fluid engineering where the drilling fluid at all times is as desired continuous measurements of drilling fluid properties are necessary. This paper will present the development of new equipment for offshore use for automatic viscosity and density measurements. The paper will discuss the technology in use, the implementation and qualification into harsh offshore environment as well as the resulting data obtained, transformed into digital data received at onshore operation centers. The measurements of drilling fluids properties and chemical compositions have been more or less unchanged for decades. The tests in use are manual and performed by the mud engineer normally four times a day. Based on these tests the fluid properties are engineered within given set points of selected parameters. This limited number of tests will often drive the fluid engineering into a reactive mode, where fluid properties must be adjusted due to drift in measured values. In this paper the experiences from introducing continuous measurements of drilling fluids density and rheology will be presented. Automatic measurements have been introduced by an operator on several offshore installations, both semi-submersible drilling rigs as well as jack-ups and fixed platforms. The use of the data in the fluid engineering process as well as in the drilling process will be discussed. Drilling Fluid parameters can now be measured automatically on the rig. The fluid properties can then be monitored from operation centers 24/7.This ensure improved quality of drilling fluid. When this is performed in combination with online hydraulic calculations improved drilling performance is obtained.