Top Oilfield Drilling Tools Categories at a Glance
BHA Components: Including Stabilizers, Drill Collars, and Integral HWDP.
Well Control Tools: Inside Blowout Preventers (IBOP) and Kelly Valves.
Drilling Optimization: Hole Openers, Underreamers, and Roller Reamers.
Fishing Tools: Downhole Fishing Magnets and Junk Baskets.
| Tool Category | Primary Function | Key Material | Size Range |
| Drill Stabilizers | Directional control & Vibration reduction | AISI 4145H Mod | 6″ – 28″ |
| Roller Reamers | Hole enlargement & Torque reduction | Forged Alloy Steel | 5-7/8″ – 26″ |
| Fishing Magnets | Retrieval of ferrous debris | High-intensity Magnetic | 3-1/8″ – 11-1/2″ |
Kelly
The kelly is located at the top of the drill string, and its main function is to transmit the torque and bear the total weight of the drill string. The end face of the driving part of the kelly is dividing into square and regular hexagonal. The square is the most used in oil drilling, and the water hole is regular hexagonal. Because the wall thickness is about three times larger than that of the drill pipe. It is made of high-strength alloy steel,so it has high tensile strength and torsional strength.
Oilfield Drilling Tool Drill pipe
Drill pipe is a commonly used drilling tool, which is mainly used to transmit torque and transport drilling fluid. The pipe body and the joint of the existing drill pipe are connecting together by butt welding. In order to increase the strength of the joint, the butt welding parts at both ends of the pipe body are thickening. And the thickening forms include inner thickening, outer thickening, and inner and outer thickening.
The inner thickening reduces the inner diameter of both ends of the pipe body to increase the thickness of the pipe wall. The outer diameter of this drill pipe is consistent, and the outer diameter of the joint is not too large. When rotating in the well, the joint has less contact with the well wall and wears less. Small, but because the inner diameter of the thickened part is smaller than the inner diameter of the pipe. The flow resistance during drilling fluid circulation is increasing.

Oilfield Drilling Tool
The Oilfield Drilling Tool inner diameter of the outer thickened drill pipe is the same. But the outer diameter at both ends of the pipe body is enlarging. The outer diameter of the drill pipe joint is larger than that of the same size drill pipe joint. And the joint is adding to the well wall when rotating in the well. The contact friction is easy to wear; since the inner diameter of the drill pipe is consistent with the inner diameter of the pipe. The flow resistance is small when the drilling fluid is circulating.
The inner and outer thickened drill pipe is to reduce the inner diameter at both ends. Of the pipe body and increase the outer diameter to increase the wall thickness of the pipe body at both ends. The drill pipe of this structure combines the advantages of the above two structure drill pipes.
Heavy weight drill pipe
The feature of theheavy drill pipe is that the wall thickness is more than twice that of the ordinary drill pipe. The joint body is longer than the ordinary drill pipe, and there is a special wear-resistant roller in the middle of the pipe body. Heavy drill pipe is mainly using in the following aspects:
- It is using in the transition zone between the drill collar and the drill pipe to ease the change of the bending stress. Of the two to reduce the damage of the drill pipe;
- It replaces drill collars in slim hole drilling and is easy to operate;
- Replace most of the drill collars in directional wells to reduce the occurrence of torque and sticking pipe sticking. Thereby reducing costs and helping to maintain the orientation of directional wells. Due to the large contact area between the drill collar and the tight seal. A large friction force occurs with the well wall when it rotates, so that the wellbore tends to deflect. When the drill collar is replacing by a heavy drill pipe. This possibility can be reducing, so there is It is beneficial to maintain the orientation of the directional well.

Oilfield Drilling Tool Drill Collar
The drill collar is one of the main components of the drill string. Its function is to provide the drilling pressure for the drill bit. And at the same time make the lower drill tool assembly have greater rigidity. So that the drill bit works stably and helps to overcome the problem of well deviation. Drill Collar Classification:
- Cylindrical type: It is made of ordinary alloy steel, and the inside and outside of the cross section of the pipe body are circular drill collars;
- Spiral type: made of ordinary alloy steel, the outer surface of the pipe has a drill collar with spiral grooves;
- Non-magnetic type: It is made of stainless alloy steel with very low magnetic permeability. And the inner and outer diameters of the cross-section of the pipe body are circular drill collars. The types of drill collars include square drill collars and non-magnetic spiral drill collars.

Spiral drill collar
The role of the helical drill collar is to reduce sticking and sticking. Three right-handed helical grooves are processing on the outer cylinder of the round drill collar. There is a section of 305-560mm in the external thread joint part and 475-mm in the internal thread end joint part. The weight of the 610mm ungrooved round drill collar section is 4% less than that of the same size round drill collar. Spiral drill collars are not including in the API standard, but many foreign manufacturers have producing them. Domestic drill collars have also been officially put into production. And their specifications and dimensions are the same as those of foreign products.
Drill stabilizer
Stabilizers are commonly known as centralizers. A certain number of stabilizers are placing at suitable positions in the drill string to form the lower drilling tool assembly. Of the drill string, which can prevent well deviation when drilling vertical wells and control the wellbore trajectory when drilling directional wells.
The use of a stabilizer can improve the working stability of the drill bit, thereby prolonging the service life of the drill bit, which is especially important for diamond drill bits.
Commonly using stabilizers are dividing into four types: three-roller stabilizers, interchangeable sleeve stabilizers, integral helical stabilizers, and integral straight-edge stabilizers.
Non-magnetic drill collar
The structure of non-magnetic drill collars is the same as that of ordinary drill collars, but the chemical composition and mechanical properties are different from ordinary drill collars. Non-magnetic drill collar is a kind of drilling tool with special function in directional well engineering. When the magnetic clinometer is using to measure the inclination Angle and azimuth Angle of the hole in a directional well, in order to prevent the compass from being affecting by the magnetic field of the drill string, the drill string must be equipping with a certain length of non-magnetic drill collar, so that the magnetic clinometer can be locating in a suitable position in the non-magnetic drill collar to measure the inclination, otherwise the correct measurement results cannot be obtaining.

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FAQ Oilfield Drilling Tool
Q: What are the must-have tools for Bottom Hole Assembly (BHA)?
A: A standard BHA typically requires Drill Collars, Stabilizers, and Heavy Weight Drill Pipes (HWDP) to provide weight-on-bit and maintain directional control.
Q: Do you provide custom-sized drilling tools?
A: Yes, we offer bespoke engineering services to manufacture oilfield drilling tools according to specific project requirements and API 7-1 standards.