Application of Fiber Additives in HDD Drilling Fluids

摘要

The presence of gravel and cobble during Horizontal Directional Drilling (HDD) operations is one of the mostrnchallenging situations encountered by contractors. An unexpected encounter with this soil condition oftenrnresults in difficultly or even failure in completing the bore. This paper presents the results of field research inrnwhich three 61 m (200 ft.) installations of 100 mm (4”) High Density Polyethylene pipe were performed inrngravel/cobble conditions. Each of the bores was completed using various combinations of drilling fluids torndemonstrate the effectiveness of using fibers in increasing the chances of success. The first installation wasrncompleted using a traditional bentonite/polymer drilling fluid mixture, while the second and third installationsrnwere performed with fiber additives mixed into the drilling fluid. The results demonstrated that increasedrnproductivity and flow of returns could be achieved with proper drilling fluid considerations. Overall, a 25%rnincrease in productivity from the second installation and a 67% increase from the first installation wasrnachieved through the used of two fiber additives; BAROLIFT? and N-SEAL?. The results of this researchrnshould assist HDD contractors in improving the success rate of installations in gravel/cobble conditions andrnresult in significant cost savings in fluid usage, mixing time, and problems associated with inadvertentrnreturns.