What is oil drill pipe? What types of oil drill pipes are there?

What is oil drill pipe?
Oil drill pipe is used for oil well drilling. Drill pipe is characterized by thin wall and light weight per unit length. It mainly provides mud passage and transmits pulling force and torque. (There is also a type of oil drill jack: thick wall, heavy weight per unit length, mainly providing mud passage, transmitting pulling force and torque and providing drilling weight for the drill bit.)

What are the steel grades of oil drill pipes?
Common oil drill pipe steel grades include E75, X95, G105, and S135. (drill pipe size)

Drill pipe is a steel pipe with a thread at the end, 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 drilling well. The purpose of the drill pipe is to transport drilling mud to the drill bit and to raise, lower or rotate the bottom hole device together with the drill bit. Drill pipe must be able to withstand tremendous internal and external pressure, twisting, bending and vibration. In the process of oil and gas extraction and refining, drill pipe can be used multiple times. Drill pipe is divided into three categories: kelly, drill pipe and weighted drill pipe. The connection sequence is kelly (1 piece) + drill pipe (n pieces, determined by the well depth) + weighted drill pipe (n pieces, determined by the design of the drill tool assembly). According to the thread type, drill pipe joints are divided into four types: IF, FH, REG, and NC.

What is the length of oil drill pipe?

The length of oil drill pipe is generally about 9 meters and the diameter is 5 inches. In addition, oil drill pipes are rolled seamless steel pipes. In order to strengthen the connection strength between the pipe body and the joints, both ends of the drill pipe body are roughened and thickened. The thickening forms are divided into internal thickening and external thickening according to API standards. There are three types: internal and external thickening. The thickening transition section is generally 20~65mm long, and the longest one can be 120~130 mm.

Types of oil drill pipes and their differences:

Oil drill pipe is an important tool in oil drilling and is mainly used for drilling and drilling operations. According to their uses and characteristics, common oil drill pipe types and their differences are as follows:

There are many types of drill pipe, among which kelly pipe, standard drill pipe, and heavy-weight drill pipe are the three most common types.

1. Kelly Pipe
The kelly pipe is located at the top of the drill string and comes in either square or hexagonal designs. It plays a crucial role.

Functions:
① During drilling, the kelly pipe works with the bushing and rotary bushing to transmit ground rotational torque to the drill pipe, thereby driving the drill string and drill bit.
② It bears the entire weight of the drill string.
③ It serves as a channel for drilling fluid circulation.

Structure:
The kelly pipe consists of upper and lower joints and a pipe body. The pipe body is either square or hexagonal (mostly square in oil drilling). The upper joint has a left-hand female thread (reverse thread) that connects to the faucet and prevents backthreading during rotation. The lower joint has a right-hand male thread that connects to the drill pipe. During operation, the upper end of the kelly pipe is always above the rotary table surface, while the lower end is below it.

2. Standard Drill Pipe
Function:
Drill pipe is a fundamental component of the drill string. Its primary functions are to transmit torque and transport drilling fluid, and its gradual lengthening allows for continuous wellbore deepening. Therefore, drill pipe plays a crucial role in oil drilling.

Structure:
Drill pipe is typically made of seamless steel pipe, with a wall thickness of 9-11 mm. Drill pipe can be summarized as consisting of two main components: the drill pipe body and the drill pipe joint. The body, as the main body of the drill pipe, provides primary support and transmission. The joint plays a crucial role in connecting multiple pieces of drill pipe to form a continuous drill string. These components are structurally connected through sophisticated craftsmanship, ensuring the stability and efficiency of the drill pipe during drilling. With the widespread application of friction butt welding technology, modern drill pipe manufacturing has reached new heights.

3. Heavy Weight Drill Pipe (HWDP)
Heavy weight drill pipe, similar to oil drill pipe, is also a hollow steel column approximately 10 meters in length. However, each piece is heavier than oil drill pipe, with a wall thickness two to three times that of drill pipe.

Function:
Heavy weight drill pipe is a downhole tool used for weighting drilling rigs. It is typically installed between the drill pipe and the drill collar, transmitting power and applying weight on bit. It prevents fatigue damage caused by changes in drill string cross-section and can also replace some drill collars. Its suspension is simple, making tripping and untripping operations easier and saving time.

Structure:
WDPP features extended joints, increased wall thickness, and externally thickened sections. Carbide-clad surfaces extend its service life.

During drilling operations, these different types of drill pipe are connected in a specific sequence to accommodate varying well depths and drill string assembly designs. Furthermore, the drill pipe's joint design, specifications, steel grade, and strength rating are key factors influencing its performance.

The drill string, another key component in drilling operations, typically consists of numerous components, including the drill bit, drill collars, drill pipe, stabilizers, specialized joints, and kelly. The coordinated operation of these components ensures efficient and safe drilling operations.

1. Drilling and workover riser (Drill Pipe): a pipe used to connect drilling tools and drill bits. It is usually made of non-magnetic steel to prevent magnetism from interfering with logging and geomagnetic exploration. According to different needs, it can be divided into standard drill pipe and high-strength drill pipe.
2. Drill Collar: used to connect two sections of drill pipe to increase the total drill pipe weight, enhance drilling and stabilize the wellbore. According to the shape and use, it can be divided into straight drill string and turbulent drill string.
3. Anchor (Stabilizer): used to stabilize the well wall during drilling and prevent well wall collapse and diameter expansion. According to the form and function principle of stabilizing the well wall, it can be divided into cutting type stabilizer and sliding type stabilizer.

4. Magnetic pressure change detector (MWD) in the drill string: By installing a measuring device in the drill string, downhole drilling parameters, including pressure, temperature, vibration, etc., can be monitored in real time to guide drilling operations. These oil drill pipes play different roles in the oil drilling process and are suitable for different working conditions and needs. Based on the well depth, formation properties and work requirements, drilling engineers will select the appropriate oil drill pipe model to complete the drilling task.

The functions of drill pipe:
Drilling drill pipe is a multi-segmented tool on the drilling platform that hangs down with the drill string. It is mainly used to lower the drill bit and other materials to the bottom of the well, and at the same time bring away the oil, natural gas, water and other substances at the bottom of the well. Come up. In drilling operations, drilling drill pipe is one of the indispensable tools because it can complete the following important tasks:

1. Provide necessary strength and stiffness
Drilling drill pipe needs to bear the weight of tools such as drill bits and the torsional and lateral forces generated during drilling. Therefore, it needs to have a certain strength and stiffness to ensure the stability and safety of drilling.

2. Transfer power and torque
Drilling drill pipe not only needs to bear the weight of tools such as drill bits, but also needs to transfer the power and torque generated by the drilling rig to ensure smooth drilling.

3. Transfer fluids and samples
The inner hollow of the drilling drill pipe can be used to transport fluids such as drilling fluids and fracturing fluids, as well as materials such as rock and soil samples, so as to facilitate timely collection and analysis of geological exploration work.

Importance of drill Pipe:
Drilling drill pipe plays a very important role in drilling operations. It is not only the core component of the entire drilling system, but also a necessary tool to complete drilling tasks. In addition, drilling drill pipe also has the following important functions:

1. Ensure drilling safety and stability
Drilling drill pipe needs to bear the weight and torsion force of drill bits and other tools, and must have a certain strength and stiffness to ensure the safety and stability of drilling.

2. Collect geological samples and fluids
The inner hollow of the drilling rod can be used to transport rock, soil and other samples and liquids, and can provide reliable support for drilling geological exploration work.

3. Solve drilling problems
The tool boxes and equipment provided by the drilling pipe and drilling platform can deal with various drilling problems, such as the drill bit getting stuck in the drilling hole, formation collapse, etc.

Read more: Drill Pipe Connection Method or Casing pipe vs Drill pipe