1、套管钻井使用标准的油井套管，并使钻井和下套管作业同时进行；2、井底

1, use standard casing drilling the well casing, and drilling and casing operations simultaneously; <br>2, bottom hole assembly to the lower end of the casing string, can be withdrawn quickly through the wire rope inside the sleeve. In the extraction process can be maintained continuously circulating mud; <br>3, throughout the drilling process, has been maintained through the sleeve to the bottom, to improve well control situation; <br>4, only a single direction of the sleeve engaging the formation, no longer play out. After the confirmation is finished well, unless the dry well, may be pulled out of the last paragraph of the casing string; <br>5, casing drilling may follow a number of conventional drilling techniques, such as directional drilling, cementing, logging, coring and well testing operations; <br>6, application of these techniques is the main difference compared to the original no longer rely on drill pipe, drill bit replacement operation but by rope; <br>7, using standard oilfield casing casing drilling is performed, the only difference is, casing cuff or thread needs to be improved in order to provide the torque required to drilling;

1, casing drilling using standard well casing, and make drilling and casing operations at the same time;<br>2, well bottom drill combination installed in the lower end of the casing column, can be used wire rope through the casing inside quickly removed. The mud can be kept circulating continuously during the removal process;<br>3, the whole drilling process, has always maintained the casing straight to the bottom of the well, improve the well control situation;<br>4, casing is only a single direction into the formation, no longer out. Unless it is confirmed that it is a dry well after completion, the last sleeve column may be erected;<br>5, casing drilling can follow many existing drilling technology, such as directional drilling, cement injection, logging, core extraction and test wells and other operations;<br>6, the application of these technologies and the original comparison of the main difference is no longer rely on the drill pipe, but rely on wire rope to replace the drill bit operation;<br>7, casing drilling using standard oil field casing, the only difference is that the casing hoop or thread needs to be improved in order to provide the torque required for drilling;

1. Casing drilling uses standard well casing, and enables drilling and casing operation to be carried out simultaneously;<br>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 steel wire rope. The continuous circulation of mud can be maintained during the extraction process;<br>3. During the whole drilling process, the casing is kept straight to the bottom of the well to improve the well control condition;<br>4. The casing is only drilled into the formation in one direction and is no longer pulled out. Unless it is confirmed that the well is dry after drilling, the last casing string may be pulled out;<br>5. Many existing drilling techniques can be used in casing drilling, such as directional drilling, cement injection, logging, coring and well testing;<br>6. The main difference between the application of these technologies and the original one is that they no longer rely on drill pipe, but on wire rope to replace drill bit;<br>7. Casing drilling is carried out with standard oilfield casing. The only difference is that casing coupling or thread needs to be improved to provide the required torque for drilling;