Laboratory Instrument Developed to Measure Properties of Drilling Fluids under Extreme Geothermal Conditions: Final Report.

摘要

A test system has been built to measure the properties of drilling fluids under extreme geothermal conditions. The system has been designed to measure density, rheology, corrosion and filtration rate at temperatures up to 700/degree/F and pressures up to 20,000 psi. This one-of-a-kind drilling fluids test system was jointly funded by NL Industries, Inc. and the US Department of Energy. It has been designated the DYNAMIC HPHT(trademark) Test System. A pressure vessel composed of low-alloy carbon gun steel encloses the system's instruments during a test. The DYNAMIC HPHT drilling fluids test system makes four basic measurements of fluids under pressure and temperature: rheology, filtration rate, corrosion rate and density. Rheology is measured by a rotary drilling fluids rheometer with special methods of motivation and torque measurement. Filtration measurements are accomplished by a 5 micron stainless steel filter medium, vertically mounted in a moving mode, supplemented by a frontal shear bob and continuous external filtrate collector. Density is measured by computer comparison of the weight of a stainless steel bob to its weight in air. A specially designed electrode sensor system is combined with an electronics package to measure corrosivity. Linear polarization of the sensors provides a series of intermittent corrosion readings throughout the test period. 8 figs. (ERA citation 14:003299)