DRILL COLLAR

The drill collar is according to SY/T5144-1997 and API 7-1 " Specification for

Rotary Drill Stem Elements" standard, the material uses AISI 4145H alloy

structural steel to carry on the deep hole processing, before thread and spiral

groove processing against the total cross-section to quenching and the tempering

heat treatment. After thread examination qualified, and carries on cold rolling

processing to the thread root and the slips, reduces the thread part fatigue failure

to increase the drill collar service life.

SPIRAL DRILL COLLAR      

The spiral drill collar is one of our product families. Three RH spiral grooves is          

made in outside surface of drill collar in order to reduce the contract area with the

well face and the steering resistance, which can prevent differential pressure    

sticking. The weight of spiral drill collar is 4% lighter than drill collar of the same

size. The shapes of both ends are the same as round drill collars. Spiral drill

collars are classified into typeⅠand type Ⅱ according to the difference of spiral

grooves.

NON-MAGNETIC COLLAR

Non-magnetic collar is a kind of low carbon chromium manganese steel, it is

through the strict chemical composition proportion by forging and after refining

and achieve its mechanical properties, good low magnetic conductivity, high

strength mechanical properties, excellent resistance to intergranular corrosion

cracking performance and excellent wear resistance.