Difference between casing pipe and drill pipe

The difference between casing and drill pipe:

Casing pipe: It is an important component of well cementing. It plays the role of fixing the well wall and oil pipe in the well hole to prevent oil and gas from leaking in the well.
Drill pipe: refers to a long rod used when drilling holes in rock formations. The drill bit or drill bit assembly can be sent down the hole for use.

1. Different uses
Casing and drill pipe play different roles in the drilling process. Casing is a pipe that is put into the wellbore to ensure the stability of the well wall and prevent oil and gas leakage. It is also a pipe that connects the surface equipment and the wellhead. The drill pipe is used to send the drill bit to the bottom of the well and perform detection and sampling work.

2. Different materials

The materials of casing and drill pipe also vary. Casings are generally made of steel or plastic to withstand the challenges of high pressure and high temperature in underground environments. The drill pipe is made of high-strength steel or aluminum alloy to ensure that it can withstand the high pressure at the bottom of the well and the strong geological reaction.

3. Different structures
There are also differences in the construction of casing and drill pipe. Casings are generally immersed tubes with different wall thicknesses and different cross-sectional dimensions and collapse pressures. The upper part of the casing has a smaller diameter and the lower part has a larger diameter in order to reduce the diameter of the wellbore and withstand geological pressure. Drill pipe, on the other hand, is a series of long tubes and rods, sometimes using different types of steel and connectors. A weight is often added to the lower part to facilitate the downward push by gravity. The length of drill pipe is determined by the well depth and drilling target, while the casing length is basically equal to the well depth.

4. Contact between the two
Although casing and drill pipe are different in structure and purpose, they are related to each other. That is, during the drilling process, the casing is fed into the wellbore layer by layer through the drill pipe, and penetrates the drill pipe. It serves as a bridge between surface equipment and bottom-hole work, and the two are closely related to each other.

Summarize:
Casing and drill pipe are essential tools in oil drilling. Although their uses, materials and structures are different, the two are related to each other. Only the correct use of casing and drill pipe can ensure safe, efficient and successful drilling.