Study on Applicability of a Newly-Developed Biodegradable Polymer to Fiber Mud in Geothermal Drilling

Abstract

Hole cleaning in geothermal well drilling, where unweighted thin mud or water is usually used as a drilling fluid, is much more challenging if the well is deviated or lost circulation with less return to the surface occurs. In some situations of oil and gas drilling, fiber-containing sweep mud is used to improve the hole cleaning efficiency and provides good results. Fiber sweep mud basically consists of base drilling fluid mixed with fibrous materials as drilling fluid additive. In this study, a newly-developed biodegradable polymer (TM) was tested whether it is suitable for a sweep fiber and is effective for hole cleaning in geothermal drilling. First, rheological properties of the prepared fiber sweep muds and dispersibility of the fibers were evaluated for various combinations of base fluid, fiber concentration and the shape of fiber. Then, experiments to investigate cuttings transport ability of the fiber seep mud were conducted. Based on these experimental results, applicability of the newly-developed environmental-friendly polymer to fiber sweep mud in geothermal drilling is discussed.