BTC Casingis mainly used for the first drilling, drilling soft ground to the bedrock, in order to seal this part of the formation without collapsing, it needs to use surface casing to seal.
K55 Casingis mainly used for the first drilling, drilling soft ground to the bedrock, in order to seal this part of the formation without collapsing, it needs to use surface casing to seal.
Steel Casingis mainly used for the first drilling, drilling soft ground to the bedrock, in order to seal this part of the formation without collapsing, it needs to use surface casing to seal.