Drill pipe heavy-weight

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

In highly deviated holes, an excessive torque is encountered with conventional drill collars therefore, a heavy wall drill pipe can he used to supply pan of the required weight. 

This explains why heavy-weight drill pipe is successfully used for creating weight on the bit in highly deviated holes. However, in drilling a vertical or nearly vertical hole, a drill pipe must never be run in effective compression or, in other words, the neutral point must always reside in the drill collar string. 

Selection Chart—Tool Joints Applied to Heavy-Weight Drill Pipe—Grade E [30]... 

Geometrical and mechanical properties of heavy-weight drill pipe (Hevi-Wate ) manufactured by Drilco are given in Table 4-90. 

From offset wells, it is known that six joints of heavy-weight drill pipe are desirable... 

Determine size of heavy-weight drill pipe. 

To maintain BSR of less than 5.5, selection 5-in. heavy-weight drill pipe with unit weight of 49.3 Ib/ft (see Table 4-91) and section modulus of 21.4 in . 

Heavy-Weight Drill Pipe or Drill Collar Weight Above Jars (lbs. x 1,000)... 

Early drilled wells were made by a cable-tool system in which a heavy tool, about 10 cm in diameter by 1.5-2 m long and with a sharpened end, was alternately lifted and then let drop in the hole by a cable and winch system. At intervals the loosened material, suspended in a few centimeters of water at the base of the well, was lifted out with a bailer fastened to the end of the cable system. The bailer consisted of a length of pipe fitted with a weighted valve at the lower end, which opened when the pipe was lowered to the end of the hole, and which reclosed on lifting. Then the percussion drilling could be resumed. This method, which had been used by the Chinese for water and brine wells for more than a thousand years, was effective, simple, inexpensive, and could reach depths as great as 1,100 m [4]. It was virtually the only method used to drill oil wells in the nineteenth century and the predominant method for the first two decades of the twentieth century. 

The usual method for obtaining samples at significant depths below the surface is to push or drive a pipe or tube into undisturbed soil at the bottom of a drill hole. Of course, this process disturbs the soil, particularly when the pipe is heavy walled. Many different kinds and sizes of samplers are used, and the most common is shown in Figure 1.1. This sampler is commonly called a split spoon. When used with the dimensions shown, and hammered into the soil by a free falling, 140 pound weight, dropping 30 inches, this is the Standard Penetration Test (see ASTM Standard D.1586,... 

---