Cement Addetive for Oil Drilling
Since Gilsonite, a solid hydrocarbon, was introduced to the oil industry in August 1957 as a cement additive, several thousands of jobs have been performed using the material. These operations have included primary cementing through lost-circulation zones of surface, intermediate, and production pipe in both single and multiple stages as well as various remedial jobs such as squeezing, re-cementing above inadequate fill-up, and plugging back to reestablish drilling-fluid circulation. Designed primarily as a combination low-density lost-circulation slurry, Gilsonite has yielded excellent results in areas of incompetent formations as well as in other types of lost-circulation zones. Field results generally show that fill-up of 80 to 90 percent can be obtained in areas where only 50 to 60 percent fill-up was possible with other types of slurries.