Product Sheet Spiral Drill Collar
Standard slip 6 3/4-in OD with NC-50 connection.
DRILCO drill collars are manufactured to specifications more stringent than API specifications. The care taken in materials specification, heat treatment, machining, and inspection is reflected in the performance of our drill collars. Drill collars are available in both standard and spiral designs. In addition, we help you select the optimum connections and the right optional features for trouble-free BHA performance.
Rolled, milled, or machined surface finishes are available. New drill collar connections are manufactured to API Specification 7. Thread roots are cold-rolled on API and H-90 connections, increasing fatigue resistance. Slip and elevator recesses are designed to cut drill collar handling time by eliminating lift subs and safety clamps. Cold-rolling the radii at the upper shoulder of each recess also extends the fatigue life of the drill collar.
An API stress-relief groove on the pin and an API bore back box are available on request, and are recommended for drill collars and all downhole tools where fatigue can occur as a result of bending. Drill collar hardbanding is the most effective way to retard OD wear.