What is the difference between drill pipe and drill string?
The drillstring means the tubulars and the accessories used to run the drill bit to the bottom. The drill string is composed of drill pipe, heavy weight drill pipe, drill collars and other components like stabilizers and drilling jars.
How are drill collars made?
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.
Why do we use drill collar?
The drill collar is used to concentrate a heavy mass near the lower end of the drill column. A drill collar is a thick tubular piece at the bottom of a drillpipe, which concentrates the weight on the rotating drill bit.
What is a flex collar in drilling?
Flex. 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.
What is a drilling jar?
Drilling jar is a equipment that runs in the bottom-hole assembly to free the drill string when it gets stuck during drilling operations. It is used to deliver an impact to the stuck point by releasing strain energy stored in the drill string, acting like a hammer.
What are non-magnetic drill collars made of?
Non-magnetic drill collar is a kind of drill collar made of high quality stainless steel in drilling tool. It is widely used in oil fields, but its failure rate is rising directly, and the oil well is safe.
What is the difference between drill pipe and drill collars?
While drill pipe makes up the majority length of a drill string, drill collars make up only a small amount. For example: a 10,000ft drill string may be comprised of 9,000ft of drill pipe, and only 500ft of drill collars. Much like drill pipe, drill collars are made in 31ft lengths and are screwed together vertically on the drilling rig.
What is drdrill collar material and process traceability?
Drill collar material and process traceability are maintained from receipt of mill-certified raw material to completion of all manufacturing. Serial numbers are die-stamped on drill collar bodies. We inspect all our drill collars to comply with API standards and Grant Prideco specifications.
What is a stock drill collar?
Stock collars are drill collars that have so much external wear that the outside diameter and weight of the drill collar are less than acceptable. Once this has occurred, certain size drill collars can be cut up and used as “stock” material to build subs, stabilizers, and various other specialty drilling tools.
Why use a non-Mag drill collar?
As you drill in areas closer to the earth’s magnetic poles, it is essential to use a non-magnetic drill collar. Our non-mag drill collars offer strength and hardness while neutralizing magnetic inference. Compatible with standard drill string tools and stabilizers, our non mag drill collars are manufactured to API Spec 7-1.