Drill pipe, Heavy Weight Drill Pipe

Drill Pipe

Drill pipe, is hollow, thin-walled, steel or aluminium alloy piping that is used on drilling rigs. It is hollow to allow drilling fluid to be pumped down the hole through the bit and back up the annulus. It comes in a variety of sizes, strengths, and wall thicknesses, but is typically 27 to 32 feet in length.Drill pipe is a steel pipe with a threaded end that is used to connect the surface equipment of the drilling rig to the drilling and grinding equipment or bottom hole device at the bottom of the well. Its main function is to transport drilling mud to the drill bit and to lift, lower or rotate the bottom hole device together with the drill bit. Drill pipe must be able to withstand huge internal and external pressure, twisting, bending and vibration. Drill pipe can be reused in the process of oil and gas extraction and refining. According to the use and characteristics, drill pipe can be divided into three types: square drill pipe, standard drill pipe and heavy drill pipe.

What Are The Specific Types Of Drill Pipe?

Drill pipe can be customized according to different drilling requirements. Drill pipe is mainly divided into three categories: kelly, standard and weighted drill pipe. Usually, the connection sequence is one kelly plus several standard and weighted drill pipes, the number of which depends on the well depth and the drill string assembly design. Common drill pipe types include conventional drill pipe and heavy-duty drill pipe, spiral pipe can enhance torque transmission, and special pipe is used for directional and horizontal drilling.

Conventional drill pipe

Conventional drill pipe or standard drill pipe comes in a variety of sizes and outer diameters, with the most common outer diameter range being approximately 2 3/8 inches to 6 5/8 inches. Standard drill pipe generally has fixed lengths, with 30 feet (about 9 meters) and 45 feet (about 14 meters) being the most common. For deeper drilling projects, longer drill pipe may be used.

Heavy-duty drill pipe

Heavy-duty drill pipe (HWDP) is characterized by thicker walls and significantly higher weight per foot than standard drill pipe. These characteristics make HWDP particularly suitable for harsh drilling environments. HWDP is designed to address challenges such as borehole control, wellbore stability and high-pressure environments in deep well drilling. The added weight helps maintain drilling accuracy.

Kelly

The Kelly is located at the top of the drill string and is available in square and hexagonal shapes. In rotary drilling operations, the Kelly works with the square bushing and the rotary bushing to transmit the torque of the ground rotary table to the drill rod, thereby driving the drill bit to rotate and bearing the suspended weight of the drill string. The main function of the Kelly is to convert the rotation of the rotary table into the rotation of the entire drill string and drill bit to break the formation, that is, to transmit torque and bear the entire weight of the drill string.

What Are The Uses And Functions Of Drill Pipe?

The main uses of drill pipe are as follows:

Tripping the drill bit: sending the drill bit from the wellhead to the bottom of the well or lifting it from the bottom of the well.

Applying drilling pressure: applying the necessary pressure to the drill bit through the drill pipe to achieve drilling.

Transmitting power: transmitting the rotational power generated by the ground drilling rig to the drill bit downhole.

Transporting drilling fluid: transporting drilling fluid to the bottom of the well through the drill pipe to cool the drill bit and carry the cuttings back to the ground.

Special operations: such as squeezing cement and handling downhole accidents.

API 5CT standard E75 to S135 steel grades, a series of oil drill pipes with outer diameters ranging from 2 3/8″ to 6 5/8″, as well as double shoulder joint drill pipes with high torsion resistance and BNK C95S drill pipes with special steel grades for sulfur-containing oil wells, are mainly suitable for the construction of deep wells, horizontal wells and large displacement wells in the process of oil and gas exploration and development.

Drill pipe is a steel pipe with threads at the tail, which is used to connect the surface equipment of the drilling rig and the drilling and grinding equipment or bottom hole device at the bottom of the drilling well. Drill pipe is used for the following purposes:

Transport drilling mud: It carries drilling mud to the drill bit and raises, lowers or rotates the bottom hole device together with the drill bit.
Withstands pressure and force: It must be able to withstand tremendous internal and external pressure, twisting, bending and vibration.
Drill pipe can be used many times during the extraction and refining of oil and gas. Drill pipe has two main functions:
Torque transmission: It is designed to transmit drilling torque from the surface of the drilling rig to the drill bit over long distances, often across miles.
Fluid circulation: It serves as a conduit for drilling fluid (also known as "drilling mud") to flow down from the surface and back into the wellbore. Drilling fluid is essential for cooling the drill bit, transporting cuttings to the surface, and maintaining pressure in the well.
Because drilling operations can reach depths of nearly 15,000 feet, different sections of drill pipe must be connected. This connection process usually involves welding threaded drill pipe joints (including female and male drill pipe joints) together to form a continuous length of drill pipe.

What Are The Common Materials For Drill Pipes?

Drill pipe is usually made of high-strength low-alloy steel (HSLA), which can withstand the harsh conditions such as high stress, corrosion and wear during drilling. Sometimes, lightweight aluminum is also selected, especially when weight is a key factor, such as remote drilling or when the weight of the equipment is limited. In addition, the drill pipe may be coated with nickel or other anti-corrosion coatings to provide additional corrosion protection.

The best choice of drill pipe material is seamless steel pipe, which is suitable for oil industry and geological special drill pipe.

Drill pipe has high process requirements. The end of the steel pipe needs to be hydraulically upset by medium frequency heating to increase the wall thickness of the pipe end, and then threaded and properly processed. Geological drill pipe is connected by threading, while oil drill pipe is friction welded.

The drill string components include drill bits, drill collars, drill pipes, stabilizers, special joints and square drill pipes. Commonly used API standard steel grades are E75 to S135, with outer diameters ranging from 2-3/8" to 6-5/8". In addition, there are double shoulder joint drill pipes with high torsion resistance and special steel grade BNKC95S drill pipes for sulfur-containing oil wells, which are suitable for the construction of deep wells, horizontal wells and large displacement wells.

The drill pipes we produce meet the API international standards. The threaded drill pipe material is 35CrMo and has undergone high-quality heat treatment and nitriding treatment to ensure the hardness and service life of the drill pipe. Each drill pipe has been pier-thickened, and the maximum inner and outer pier thickness can reach 24mm, which increases the friction welding area and ensures the stability of the welded joint. Choose us baowi-steel, we will provide you with the best service.