Drill pipe

Earlier on when we described the cutting action of the drill bit we learned about the drilling fluid or mud. The mud cools the bit and also removes the cuttings by carrying them up the hole outside the drill pipe. At the surface the mud runs over a number of moving screens, the shale shakers (Fig. 3.11) which remove the cutting for disposal. The fine particles which pass through the screens are then removed by desanders and desilters, usually hydrocyclones. 

Some clay minerals may absorb some of the water contained in the drilling mud. This will cause the clays to swe//and eventually reduce the borehole size to the point where the drill pipe becomes stuck. Prevention mud additives which prevent clay swelling e.g. potassium salt. 

Coring is performed in between drilling operations. Once the formation for which a core is required has been identified on the mud log, the drilling assembly is pulled out of hole. For coring operations a special assembly is run on drill pipe (Fig. 5.33) comprising a core bit and a core barrel. 

The Research-Production Company (RPC) Zond (city of Ivano-Frankivsk) now is a well-known centre for development, fabrication and introduction of the technologies and methods of NOT of oil and gas equipment and tools Its experts developed and introduced the technologies and equipment which enables control of the drill pipes, especially their threaded joints, oil and gas equipment, sort out the pipes into groups by the strength and yield point of the pipes material, etc. 

Two suppliers to the U.S. market are Bayer and Nippon Zeon. The estimated volume used in the United States is 500 700 t/yr. Hydrogenated nitrile mbber (HSN or HNBR) compounds compete with EKM, EVMQ, ECO, ACM, and high ACN content nitrile mbbers. Big applications include automotive timing belts, blowout preventors, drill pipe protectors, and numerous oil and fuel pump components. 

The drill string, consisting of a drill bit, drill collars, drill pipe, and kelly, is assembled and lowered into the conductor pipe. Drilling fluid, better known as drilling mud, is circulated through the kelly and... 

To reduce drilling and development costs, slimhole drilling is increasingly being used. Slimhole wells are considered wells in which at least 90 percent of the hole has been drilled with a bit fewer than six inches in diameter. For example, a typical rig uses a 8.5-in bit and a 5-in drill pipe, whereas a slimhole rig may use a 4-in bit and a 3.7-in drill pipe. Slimhole drilling is especially valuable in economically marginal fields and in environmentally sensitive areas, since the fuel consumption can be 75 percent less (mud pumps, drill power), the mud costs 80 percent less, the rig weight is 80 percent less, and the drill site is 75 percent smaller. 

Drill Collar 716. Drill Pipe 735. Tool Joints 748. Heavy-Weight Drill Pipe 749. Fatigue Damage of Drill Pipe 763. Drill String Design 765. 

The derrick or mast must also be designed to withstand wind loads. Wind loads are imposed by the wind acting on the outer and inner surfaces of the open structure. When designing for wind loads, the designer must consider that the drill pipe or other tubulars may be out of the hole and stacked in the structure. This means that there will be loads imposed on the structure by the pipe weight (i.e., setback load) in addition to the additional loads imposed by the wind. The horizontal forces due to wind are counteracted by the lattice structure that is firmly secured to the structure s foundation. Additional support to the structure can be accomplished by the guy lines attached to the structure and to a dead man anchor some distance away from it. The dead man anchor is buried in the ground to firmly support the tension loads in the guy line. The guy lines are pretensioned when attached to the dead man anchor. 

In general, the drawworks is rated by its input horsepower. But it used to be rated by depth capability along with a specific size of drill pipe to which the depth rating pertains. The drawworks horsepower input required HP. for hoisting operations is... 

Elevator links The elevator is a hinged clamp attached to the hook and is used to hoist drill pipe, tubing, and casing. The actual clamp is in a pair of links that in turn attaches to a bail supported on the hook. 

Kelley spinners, when used as tension members An adapter between the swivel and the kelley that spins the kelley for rapid attachment and disattachment to joints of drill pipe. 

Drill pipe elevators for taper shoulder and square shoulder weld-on tool joints shall have bore dimensions as specified in Table 4-6. 

Drill Pipe Elevator Bores (All dimensions In Inches) [9]... 

Tool Joint Designation Reference Drill Pipe Size and Style (All Weights and Grades) Weld On Too) Joints Elev. Marking... 

Figure 4-26a. Casing, tubing, and drill pipe elevators, side door elevators [10].

The effective weight per foot of casing may be estimated from data given on Figure 4-78 for drill pipe (using the approximate Ib/ft), or calculated as... 

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