Drill pipe is a steel pipe with threads at the tail end, 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 well. The purpose of the drill pipe is to transport drilling mud to the drill bit and raise, lower or rotate the bottom hole device together with the drill bit. So how many types are there?

Classification of drill pipes
Drill pipe is an indispensable tool in drilling operations. According to the shape of its rod body and the quality of its material, it can be divided into the following types:
1. Spiral drill pipe
The threads are usually tight, very durable and easy to connect and disassemble. This type is suitable for use as a down-the-hole drill and specific drilling.
2. Straight wall drill pipe
It has many shapes and sizes. It is mainly made of high-quality steel and is suitable for deep well drilling and some special types of drilling.
3. Flat drill pipe
Flat drill pipe is also called square rod drill pipe. It is mainly used for drilling mudstone and soft rock and other soft formations. Its cross section is divided into two shapes: square and round.
4. Wire rope drill pipe
Mainly used for drilling water wells and environmental drainage, the material is high-strength steel wire, with good retreat and small hole spacing.

Application of drill pipe
Different types of drill pipes have different characteristics and application scopes. The following are the main characteristics and application scopes of various types of drill pipes:
1. Spiral drill pipe
Suitable for various drilling rigs and various well depths, it can adapt to the well depth environment and operating conditions of various situations, and is the most common type of drill pipe.
2. Straight wall drill pipe
Due to its high strength and excellent mechanical properties, it is usually used for drilling operations at great depths or encountering harder formations.
3. Flat drill pipe
Due to its shape and material properties, it is suitable for drilling soft rocks and other non-hard formations, and is also used for drilling construction and engineering drilling.
4. Wire rope drill pipe
Mainly used for drilling light sandstone and mudstone layers, especially for areas with large water flow, wire rope drill pipes are also widely used in sewage and flood discharge and environmental protection.

Summary
In summary, it is very important to choose the appropriate drill pipe according to the different needs and geological environment of drilling operations. Each type of drill pipe has its advantages and disadvantages and applicable scope, and needs to be selected based on actual conditions.