Semester of Graduation
Master of Science in Petroleum Engineering (MSPE)
Craft and Hawkins Department of Petroleum Engineering
The drilling industry has always had difficulties with staying within the mud weight window. The problems associated with failure to stay within the mud weight window include uncontrolled influxes and wellbore collapse on the low pressure side of the window, and fluid losses and wellbore damage on the high pressure side of the window. When the risk for getting outside of this mud window becomes too great, casing must be set in order to isolate formations from each other. If too many strings of casing are set, or if the damage from getting out of the mud weight window is too great, then the well must be plugged and abandoned. This thesis presents a method to more easily stay within the mud weight window, lessen or prevent uncontrolled fluid influxes into the well, and to extend the depths that can be reached before casing has to be set.
The current technique used is to increase the density of the drilling fluid, thereby increasing the pressure at greater depths, in order to stay within the mud weight window. This thesis proposes a new technique, one in which the drilling fluid has been changed to a magnetorheological fluid, which is a fluid whose apparent viscosity is modified through the application of a magnetic field. The experiments conducted have shown that a stable magnetorheological drilling fluid can be created. Using this magnetorheological fluid, in combination with a magnetic tool, it is possible to generate pseudo-chokes downhole. This allows for operator controlled pressure drops in the wellbore, increasing the pressure upstream of the tool location without affecting the pressure window downstream of the tool.
Nielsen, Garrett Lowry, "Magnetic Gradient Drilling" (2018). LSU Master's Theses. 4646.