Drilling Specialist, There Are Various

¶ … drilling specialist, there are various rig types, each with its advantages and disadvantages. The success and improvement of drilling technology often means that drilling can occur in increasingly deep ocean waters. In relatively shallow waters, the professional has the choice between a built platform or a jack-up rig. The advantage of the latter is that it can be moved to different locations, as desired. In deeper water, the rig cannot practically be placed upon the seabed. Instead, a floating device such as a semisubmersible rig or a drill ship is used. These devices float, but contain stabilizing devices to help the rig remain in place while drilling takes place. In more recent times, the tension-leg platform has been developed, which is fixed to the sea-bed with cables. Op to 5000 feet of water can then stand bewteen the rig and the sea-bed without significant problems.

The drilling rig contains several components, creating a technologically sound environment for drilling while also ensuring the safety of the personnel involved. Like the drilling rig in general, these have been developed over time, in keeping with drilling technology. At the top of the rig, there is the crown and crown block. The traveling block is about halfway down the rig, underneath which the standpipe and swivel are found. The rotary hose is connected to the swivel and standpipe. The Kelly connects these to the turntable lower down, which in turn is connected to the conductor pipe and drill pipe, which goes into the borehole. The bit is at the bottom of the drill pipe and is most directly connected to the borehole being drilled. To the right hand side is a pipe rack. To the left are the draw works and engine, as well as fuel/water tanks. The mud pump and mud pit are next to the draw works.

Generally, drill rigs use the block and tackle system. The crown block is connected to the drum and dead line anchor by means of the fast line and dead line, respectively. There are eight wire lines that connect it with the Travelling block and the drilling hook below it. The drum is located in the draw-works and is operated with a drum brake. The dead line anchor is connected to the storage reel.

The swivel is connected to the rotary drilling hose, which is used to pump drilling fluid into the drill string. Below the ocean surface, various components are of importance, including the gamma ray, directional survey, pressure, temperature, and the weight on the bit. Communication regarding these components occurs via mud pulsing and other methods. Drill collars are used to exercise weight on the bit for penetration into the ocean bed. The weight of the drill string contributes to this. The downhole motor is especially helpful when directional drilling is involved.

In deep ocean situations Grant Prideco's extreme Torque Drillpipe allows high tongue for Extended Reach Drilling (ERD) wells. The Kelly pipe functions as a connecting device between the rotary table and the drill string. The casing spool holds the upper end of the casing strings, while the pipe ram seals around the pipe. In a flowing well, the shear ram can cut the pipe as a last resort to avert spills. The annular BOP is a rubber donut that seals around the pipe or open hole. The bell nipple adds drilling fluid into the drillstring. This includes a return line. The mud motors are in operation while the drillstring does not rotate.