Drilling Hole-Stemming

The existence of fresh water beneath the Atlantic Ocean, to the edge of the U.S.A. continental shelf, has been well documented in the JOIDES and AMCOR drill holes (Manheim, 1967 Hathaway et al., 1979 Kohout, 1981 Pauli and Dillon, 1981). New electrical-logging data from the COST GE-J well confirm the existence of brackish water in the upper 900 m. Moreover, a special agreement by Tenneco Oil Co. permitted the U.S. Geological Survey to run a drill-stem test at 350-m depth, in a wildcat well (Fig. 1, T) 85km seaward of Jacksonville, Florida. A drill-stem test confirmed presence of brackish water having less than half the salinity of seawater (R. Johnston, pers. commun., 1979). 

A series of percutaneous implant devices with three stem/flange ratios (1 1, 1 2 and 1 4) was fabricated from three materials (Dacron velour - silicone, porous PU and porous metal). The implants were totally porous (coarse, 150-250 ym) with 1.5 mm diameter holes drilled throughout the device. Figure 6 shows the mold and the polyurethane percutaneous devices with three stem/ flange ratios and 1.5 mm diameter drilled holes. 

To encourage lots of beneficial insects such as ladybugs, lacewings, and bees to stay on in your gardens or yard, you can easily make hibernation homes for them. Cut up short lengths of bamboo poles or hollow plant stems, cram them into an open-fronted box or tube, and hang the tube in a sheltered spot. There are also ready-made versions of these shelters available to buy. For solitary bees and wasps, drill holes of different sizes in pieces of wood. Then position your bee and wasp homes in areas where the insects activities will not disturb you while you are in the garden. 

Decoking is a routine daily occurrence accomplished by a high-pressure water jet. First the top and bottom heads of the coke drum are removed then a hole is drilled in the coke from top to hottom.. A rotating stem is lowered through the hole, spraying a jet high-pressure water sidewavs... 

BHA — Change bottom hole assembly DMF — Down hole motor failure DSF — Drill string failure DST — Drill stem test DTF — Down hole tool failure LOG — Run logs CM — Condition mud CP — Core point DP — Drill plug FM — Formation change... 

Downhole drilling tools are the components of the lower part of a drill string used in normal drilling operations such as the drill bits, drill collars, stabilizers, shock absorbers, hole openers, underreamers, drilling jars as well as a variety of drill stem subs. 

Figure 14.10 illustrates the method of seismic prospecting on land by what is known as reflection shooting. A hole usually 10 to 12 cm in diameter is drilled to a depth of 15 to 30 m. The charge of explosive is likely to be 5 to 12-5 kg and the stemming used is usually water. As the explosive must fire under a depth of water which may exceed 45 m, special varieties of gelatines are employed (see p. 53). Alternatively, a powder explosive can be sealed into pressure-resistant metal containers. Special detonators are also employed, not only to withstand the possible head of water, but also to have a specially short bursting time (see p. 113). 

Decoking by Drilling. For this method of decoking, a hydraulically controlled, rotating drill stem is mounted in a well below the coke drum. At the end of the cycle, the bottom from the coke drum is removed and a hole is drilled upward through the coke bed. The drill is then removed from the stem and knocker-bars are mounted in its place. The knocker-bars swing out from the drill stem when it is rotated, hit the coke, and break it loose from the drum. The coke falls out and is recovered (5,40). 

Generally, a drill stem test is carried out—either in the Open hole or after the hole has been cased. However, the case bole test is the most reliable. 

Basically, the drill stem test involves attaching a tubing assembly to the end of the drill pipe, isolating the lest zone with rubber packers, and perforating the zone. The tool is then opened so that the fluids or gas in die formation can How up the drill pipe for metering at the surface. During this process, extensive pressure measurements are taken, which can help to indicate the extent of the reservoir and the rate at which the hydrocarbons could be recovered. Prior to describing how a well is finally completed (if the hole is not dry ), it is in order to describe the forces utilized to transfer the oil from the reservoir to the surface. 

First, a hole was drilled to allow the string to be passed through, and then the stem was carved to keep the holes parallel and facilitate threading them while in the sorting device (see Fig. 4). The modified stems can be... 

A method of blasting in which an air space is left between the explosive charge and the stemming, or in which the blast hole is purposely drilled lager than the diameter of the explosive cartridge to be loaded - Contour Blasting. 

In large-scale blasting processes in open pit mining and quarrying, rows of nearly vertical boreholes are drilled parallel to the quarry face the diameter of each borehole is 3-8 in. (in Germany more often 3-4 in.), while the borehole length is over 10 m. The holes are filled with explosive and stemmed. -> Free-flowing Explosives or pumped -> Slurries can be applied. 

The usual procedure is to drill the hole, remove the core barrel or other tool, seat the packer, make the test, remove the packer, drill the hole deeper, set the packer again to test the newly drilled section, and repeat the test (see Fig. 15.2a). If the hole stands without casing, a common procedure is to drill it to final depth, fill with water, surge it, and bail out. Then set two packers on pipe or drill stem as shown in Figs. 15.2c and d. The length of packer when expanded should be 5 times the diameter of the hole. The bottom of the pipe holding the packer must be plugged, and its perforated portion... 

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