Characteristics of oil casing drilling

Compared with conventional drill pipe drilling, oil casing drilling has obvious advantages. It is a technical revolution in drilling engineering, and it can bring huge economic benefits to oil field operators. Casing drilling has the following characteristics:

1. Standard oil well casing is used for oil casing drilling, and the drilling and casing operations are carried out at the same time;
2. The bottom hole assembly is installed at the lower end of the casing string and can be quickly taken out through the inside of the casing with a wire rope. Continuous mud circulation can be maintained during the extraction process;
3. During the whole drilling process, keep the casing straight to the bottom of the well to improve the well control condition;
4. The oil casing is only drilled into the formation in one direction and will not be pulled out again. Unless it is confirmed to be a dry well after drilling, the last casing string may have to be pulled out;
5. Oil casing drilling can continue to use many existing drilling technologies, such as directional drilling, cementing, logging, coring, and well testing;
6. The main difference between the application of these technologies and the original one is that it no longer relies on the drill pipe, but relies on the wire rope to replace the drill bit;
7. Oil casing drilling uses standard oilfield casing. The only difference is that the casing collar or thread needs to be improved to provide the torque required for drilling; the thread selected by other overseas companies when drilling the first test well is (Hydrill 511 Premium Thread), and the coupling is a modified reinforced coupling (Modified Buttress Coupling).