When drilling commences and the top of the BHA is completely in the borehole, the first piece of the drill pipe is screwed into to the top of the BHA. Note that the mud pumps are shut off prior to making any connection. This drill pipe is stored in a pipe rack near the pipe ramp (sometimes called a “catwalk”). Drillers secure chains around each joint of drill pipe and use either auxillary hoists on the draw works or separate hoists to lift the drill pipe up the pipe ramp, through the “v-door” (the opening between the mast supports – caution: never respond to anyone asking for the keys to the v-door) and onto the rig floor. The pipe is inserted into the mousehole for temporary storage or stood up and racked in a stand of single , double , or triple joints on newer rigs.
From the mouse hole or stand, the pipe is hoisted and aligned with the top of the drill string already in the hole. The two pipes are screwed together (“made up” in drilling terms), using the rotary table and the tongs (big wrenches that are hung in the mast – they usually show up in classic rig crew photos) or top drive and robotic pipe-handler, sometimes called an “iron roughneck”. The pumps are restarted, circulation established, and the drive system is reengaged, allowing drilling to continue. Remember, whenever the bit is progressing, the mud circulation system is also hard at work.
In a table drive setup, the kelly is screwed into the top of the new pipe, which is lowered into position. For a top drive system, the drive itself is lowered until it engages the new drill pipe.
Drilling can now continue until the new pipe is completely in the hole.
The process is repeated many times – hundreds of 30-foot drill pipe joints or 90-foot stands of drill pipe are required to complete a well several thousands of feet long.
Images: “Doping” by Michael Black; “Threads” by Michael Black