Pre-Collar Casing
Primarily used in diamond coring applications. On large coring projects with heavy overburden a rotary drill is used to pre-collar the borehole to bedrock, as a rotary drill is much more adept and efficient in drilling the overburden geology verses a diamond core drill. Once bedrock is reached by the rotary drill, it stops drilling and cases the bore hole with pre-collar casing. A diamond coring rig is then brought in to core the borehole to its termination point while working inside the pre-collar casing. The pre-collar casing typically uses a “WT” taper thread profile and often times a lesser grade of steel due to the fact that many times it is set to a shallow depth and dedicated to the bore hole. Matrix offers a choice of steel grades to match the project application (shallow or deep.) Available sizes: NWT – HWT – PWT. Lengths: 10’, 20’, and 30 ft. or as required.