[石油英语5.ppt

Drawworks A drawworks is the same general type of mechanism that is known in other industry as hoist. The two main purposes of the drawworks are To lift the pipe out of the hole. To lower the pipe back into the hole. Drill stem（钻柱） Drill stem consists of three main parts: drill collar（钻铤）, which are heavy, thick-walled, hollow steel tubes; drill pipe（钻杆）, which like the drill collars, is a hollow steel (sometimes aluminum) tube, not as heavy as the collars; a kelly（方钻杆）, which is a hollow, squared-sided or hexagonal-sided length of steel tubing. Main functions of drill stem 1.It lowers the bit into the hole and withdraws it. 2. Part of the drill stem puts weight on the bit so that the bit can penetrate the formations more effectively. 3.It transmits a turning or rotating action to the bit. 4. It conducts the drilling fluid under pressure from the surface to the bit. The lengths of steel tube that make up the drill pipe are also expensive. The drill pipes are known as a string, consisting of many sections of pipe joined together. Each pipe section is about thirty feet long. Two sections, three sections, or four sections at a time are known as doubles, thribbles, or fourbles, respectively. Rotary table the rotary is the piece of equipment on a rotary rig that gives the rig its name. The rotary serves two main functions: 1. To rotate the drill stem and 2. To hold devices called slips that support the weigh of the drill stem when the latter is not supported by the hook and elevators. Swivel a swivel is a remarkable mechanical device. The swivel does not rotate, but it supports the kelly which does. Furthermore, the entire load is introduced into the drill stem is carried by the swivel whenever drilling is in progress. Rotary Drilling Bits: the only part of the rotary-rig equipment that actually makes hole. The drilling bits are especially designed for the different kinds of underground layers that they have to cut through. And no matter how strong or shar