Oil well Drilling pipes& Heavy Weight Drilling Pipes API Standard

Heavy weight drill pipe is the most commonly used in the vertical section of the hole and provides weight on the bit for directional drilling while maintaining more flexibility than a drill collar. Heavy weight is also knows as hevi-wate or HWDP in the industry.

Heavy weight drill pipe has a "center upset", also known as wear pad, that increases tube life by protecting the tube from wearing on the outer diameter by keeping the tube away from the hole wall. It also reduces hole drag and differential sticking problems. The walls of heavy weight drill pipe are thicker and have longer upsets compared to conventional drill pipe, as well as being stronger with high tensile strength. There are a variety of specifications of heavy weight drill pipe.

Heavyweight drill pipe (HWDP) may be used to make the transition between the drill collars and drill pipe. The function of the HWDP is to provide a flexible transition between the drill collars and the drill pipe. This helps to reduce the number of fatigue failures seen directly above the BHA.

Specification: