Drilling fluid, definition

The classification of drilling fluid additives is based on the definitions of the International Association of Drilling Contractors [30]. 

Figure 4-162 shows a natural diamond drill bit which has a long outer taper and medium inner cone, radial flow fluid courses, and five to six stones per carat (spc) diamonds set with a medium placement density. Using the definitions in Figures 4-156, 4-158, 4-159, and 4-160, the characteristics of this bit are coded D 2 R 5 as follows ... 

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