Casing and Tubing - Drilling

A bit attached to a drill string that rotates into the earth, is used to create a well 127.0 mm to 914.4 mm (5-36 inches). Technical Data used in the field explained in drilling courses in rawalpindi. Following the hole drilling process, casing is placed is placed into the hole. Casing and tubing is used for two main purposes, the first of which is to strengthen the newly drilled well, and secondly, to reduce the potential hazards of high pressure zones below the surface.

With the well now safely secured by the casing, a smaller drill bit can be used to drill deeper into the earth. Smaller casing is then used to secure the smaller hole as it is drilled into more-potentially unstable formations. Most wells have 2 to 5 sets of subsequent holes drilled inside itself, each level being strengthened by cemented casing. Some more details of drilling courses in Rawalpindi  are as under.

The sheer weight of the drill string and collars break up the earth as the drill bit digs down. The breakup of the rock is helped by having drilling fluid pumped down the drilling shaft and exiting at the drill bit. This also keeps the drill bit cool, clean and lubricated. The rock cuttings generated by the drill bit are carried back up to the surface by the drilling fluid. The drilling fluid is filtered through shakers to remove all of the rock fragments before being reused. Watching for abnormalities in the returning cuttings and volume of returning fluid are imperative to catch "kicks" (when the pressure below the bit is more than that above, causing gas and mud to come up uncontrollably) early. The pipe or drill string to which the bit is connected is little by little lengthened as the well gets deeper by screwing in several 30-foot (10 m) joints of pipe at surface. Usually joints are combined into 3 joints equaling 1 stand. Some smaller rigs only use 2 joints and newer rigs can handle stands of 4 joints.

This operation is all facilitated by a drilling rig which contains all necessary equipment to circulate the drilling fluid, hoist and turn the casing and tubing, control downhole pressures, remove cuttings from the drilling fluid, and generate onsite power for these operations. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join drilling courses in Islamabad.