Differences between Oil Casing Pipe and Oil Drill Pipe

There are two main differences between oil casing and oil drill pipe: 1. Different uses; 2. Different materials; 3. Different functions.

Petroleum casing is a steel pipe used to support the walls of oil and gas wells to ensure the normal operation of the entire oil well after drilling and completion. Each well uses several layers of casing according to different drilling depths and geological conditions. Cement is used to cement the well after the casing is run down. Unlike tubing and drill pipe, it cannot be reused and is a disposable material. Therefore, casing consumption accounts for more than 70% of all oil well pipes. Casings can be divided into pipes, surface casings, technical casings and oil casings according to their usage.
　　
The essence of oil casing is:

1. During the drilling process, as the depth of the well increases, the required mud density will increase, and the upper and bottom layers may leak. The role of the casing is to prevent the upper layer from leaking when drilling the lower layer.

2. The last oil pipe and tail pipe are oil passages. The purpose is to stabilize the formation and prevent collapse. If the formation is hard, the well can be completed in the open hole.
Open hole completion can only be applied to a single oil and gas layer with hard and tight rock formations, no water-bearing interlayers, no collapsible interlayers, or certain oil and gas layers with the same properties and similar pressures.

A rod connected in a drilling tool to transmit power. The usual components of a drill string are: drill bit, drill collar, drill pipe, stabilizer, special joint and kelly. The basic functions of the drill string are: (1) start the drill bit; (2) apply weight on bit; (3) transmit power; (4) transport drilling fluid; (5) perform special operations: squeeze cement, deal with underground accidents, etc.
　　
API standard E75 to S135 steel grades, series of oil drill pipes with outer diameters from 2 3/8" to 6 5/8", double shoulder joint drill pipes with high torsion resistance and special steel for sulfur-containing oil wells Grade BNK C95S drill pipe. It is mainly suitable for the construction of deep wells, horizontal wells and extended reach wells in the process of oil and gas exploration and development.