Made by machining solid bars of steel, drill collars are thick-wall tubulars that help break up the rock below by adding weight to the lower end of the assembly. Available in a variety of designs and specifications, all of our drill collars are composed of AISI 4145-modified alloy steel, heat-treated to meet API standards.
Each of our drill collar’s connections is cut in-house using constant profile cutting tools and applying standard API relief features—cold rolled and kemplated. Meticulous product inspections are applied at every step to ensure zero surprises. Stabil Drill collars are available in a variety of designs that include:
Also known as a Short Drill Collar (SDC), pony collars measure less than the standard drill collar length. While our average drill collar length is 31’ 6”, pony collars can measure between just five and 15 feet.
Thicker portions of the pipe wall are known as upsets. Used in high-stress applications, these collars feature center upsets which reduce hole drag—improving overall rate of penetration and maintaining drill string steer-ability.
These drill collars are designed with a smooth surface that comes just as they were mill rolled. These designs are preferable when you need more weight and contact with the wellbore wall.
These collars are machined with spiral grooves throughout their length to help minimize wall contact, which dramatically reduces the risk of sticking during operations.
Our non-magnetic drilling collars are typically made slick, but can be spiral-machined as needed. These collars are often used in directional drilling applications to avoid interference.
For enhanced resistance to corrosion on non-magnetic collars, Stabil Drill applies a mechanical bore treatment (RSC or roller burnishing) and shot peening on outside diameters. Stabil Drill's exclusive MAGCOAT process can also be applied to extend tool life and reduce galling by up to ninety-nine percent.