【正文】 l steam and water. Drilling boreholes for fluid resource recovery requires boreholes drilled to depths of 3,000 ft to as much as 20,000 ft. Rotary drilling is highly versatile. The rotary drilling applications given aboverequire the drilling of igneous, metamorphic, and sedimentary rock. However, the deep drilling of boreholes for the recovery of crude oil and natural gas are almost exclusively carried out in sedimentary rock. Boreholes for the recovery of geothermal steam and water are constructed in all three rock types. The rotary drilling method requires the use of a rock cutting or crushing drill bit. Figure 11 shows a typical mill tooth tricone roller cone bit. This type of drill bit uses more of a crushing action to 論文翻譯 3 advance the bit in the rock (see Chapter 3 for more details).This type of bit is used primarily in the drilling of sedimentary rock. To advance the drill bit in rock requires the application of an axial force on the bit (to push the bit into the rock face), torque on the bit (to rotate the bit against the resistance of the rock face), and circulating fluid to clear the rock cuttings away from the bit as the bit generates more cuttings with its advance (see Figure 12). Rotary drilling is carried out with a variety of drilling rigs. These can be small論文翻譯 4 “ single” rigs, or larger “ double” and “ triple” rigs. Today most of the land rotary drilling rigs are mobile units with folding masts. A single drilling rig has a vertical space in its mast for only one joint of drill pipe. A double drilling rig has a vertical space in its mast for two joints of drill pipe and a triple drilling rig space for three joints. Table 11 gives the API length ranges for drill collars and drill pipe [6]. Figure 13 shows a typical single drilling rig. Such small drilling rigs are highly mobile and are used principally to drill shallow (less than 3,000 ft in depth) water wells, environmental monitoring wells, mining related boreholes, and other geotechnical boreholes. These single rigs are usually selfpropelled. The selfpropelled drilling rig in Figure 13 is a Gee E. Failing Company Star 30K. These rigs typically use Range 1 drill collars and drill pipe. 論文翻譯 5 Single rigs can be fitted with either an onboard air pressor, or an onboard mud pump. Some of these rigs can acmodate both subsystems. These rigs have either a dedicated prime mover on the rig deck, or have a powertakeoff system which allows utilization of the truck motor as a prime mover for the drilling rig equipment (when the truck is stationary). These small drilling rigs provide axial force to the drill bit through the drill string via a chain or cable actuated pulldown system, or hydraulic pulldown system. A pulldown system transfers a portion of the weight of the rig to the top of the drill string and then to the drill bit. The torque and rotation at the top of the drill string is provided by a hydraulic tophead drive (similar to power swivel systems used on larger drilling rigs) which is moved up and down the mast (on a track) by the chain drive pulldown system. Many of these small single drilling rigs are capable of drilling with their masts at a 45? angle to the vertical. The prime mover for these rigs is usually diesel fueled. Figure 14 shows a typical double drilling rig. Such drilling rigs are also mobile 論文翻譯 6 and can be selfpropelled or trailer mounted. Figure 15 shows the schematic of a selfpropelled double drilling rig. The trailer mounted drilling rig in Figure 14 is a Gee E. Failing Company SS40. These double rigs have the capability to drill to depths of approximately 10,000 ft and are used for oil and gas drilling operations, geothermal drilling operations, deep mining and geotechnical drilling operations, and water wells. Double rigs typically use Range 2 drill collars or drill pipe. These rigs are fitted with an onboard prime mover which operates the rotary table, drawworks, and mud pump. The axial force on the drill bit is provided by drill collars. The torque and rotation at the top of the drill string is provided by the kelly and the rotary double drilling rigs have a “ crows nest” or “ derrick board” nearly midway up the mast. This allows these rigs to pull stands of two drill collar joints or two drill pipe joints. These rigs can carry out drilling operations using drilling mud (with the onboard mud pump) or using pressed air or gas drilling fluids (with external pressors). A few of these drilling rigs are capable of drilling with their masts at a 45? angle to the vertical. The prime mover for these rigs is usually diesel fueled,but 論文翻譯 7 can easily be converted to propane or natural gas fuels. Triple drilling rigs are available in a variety of configurations. Nearly all of these drilling rigs are assembled and erected from premanufactured sections. The vertical tower structure on these drilling rigs are called derricks. The smaller triple land rigs can drill to approximately 20,000 ft and utilize Range 2 drill collars and drill pipe. Very large triple drilling rigs are used on offshore platforms. These rigs can utilize Range 3 drill collars and drill pipe. The schematic layout in Figure 15 shows a typical selfpropelled double drilling rig. This example rig is fitted with a mud pump for circulating drilling mud. There is a vehicle engine that is used to propel the rig over the road. The same engine is used in a powertakeoff mode to provide power to the rotary table,drawworks, and mud 論文翻譯 8 pump. For this rig, this powertakeoff engine operates a hydraulic pump which provides fluid to hydraulic motors to operate the rotary table, drawworks, and mud pump. The “ crows nest” on the mast indicates that the rig is capable of drilling with a stand of two joints o