178A interrogate the database of case histories and select the most suitable simulation model. The functions of each component are demonstrated.
Rock Breakage and Excavation
boundaries early enough to make the necessary orientation changes during drilling. The use of a full service MWD tool with dual propagation resistivity (DPR), gamma, and directional sensors has allowed trajectory planning, real-time stratigraphic control, and evaluation of the reservoir without the need for openhole wireline logs in the horizontal section. 933308
Single equation simpt~es horizoatat,directienal~ m ~ Wiggins, M L; Choc, J; Juvkam-Wold, H C Oil Gas J V90, N44, Nov 1992, P74-79
Drilling See also: 933228, 933280 933304
Dry dcim~ in endergroendpredeceon De Souza, E M CIM Bull V8S, N963, Sept 1992, P46-50 Surface and underground evaluation of dry drilling with a dust control system at Inco's Crean Hill Mine is described. A series of 165ram holes was drilled at the surface using low and high pressure air drilling plus conventional wet drilling for comparison. Penetration rate and bit wear were monitored. Underground testing used high pressure air and a dust collection system designed for large diameter holes. Initial economic assessment favours dry drilling, but further development of the dust control system is necessary for its application in production drilling. 933305 Directional drilli~ Engng Min J V193, N9, Sept 1992, P70-75 Four case studies which demonstrate the benefits of directional drilling are described. The Navi-Drill, a hydraulically driven downhole motor which allows smooth change of trajectory, was used. Deflection shoes cause pressure forcing the drill to sidetrack, whilst springs determine the amount of deflection. The advantages of knowing the precise location and orientation of the hole in areas of uncertain geology and the ability to hit targets inaccessible by conventional drilling are discussed. 933306 Horizontal sUm-hole drilling with coiled tabing: an operator's experience Ramos, A B; Fahel, R A; Chatfm, M G; Pulis, K H J Pet Teclmol V44, NIO, Oct 1992, P1119-1125 Production occurs through natural fractures in the Austin Chalk of the Pearsall Field in Texas, and care must be taken in drilling to prevent prolific flow of oil or complete lost circulation. The first horizontal well drilled using directionally controlled coiled tubing has recently been completed in this Cretaceous limestone. The drilling equipment is illustrated: 50ram coiled tubing, downhole mud motors, wireline steering tools, mechanical downhole orienting tool, and 98ram drill bit. A 1325m vertical section was drilled, and build rate of 15 deg/30m achieved in the curve. 933307 Stratigral~k control and formafien evaluation of herizeatal wel~s with MWD Hammons, L R B; Sellers, D H; Fisher, E K J Pet Teelmol V44, NIO, Oct 1992, Pl134-1140 Gulf of Mexico sandstone reservoirs do not typically form horizontal planes. In order to keep horizontal wells within the producing interval, it is necessary to detect approaching bed
Horizontal and extended reach wellbores have many applications in hydrocarbon recovery. A large number of factors must be considered in deviating a borehole, and careful planning is necessary. A single equation has been developed for planning, which can be adapted to any two dimensional wellbore trajectory and aids identification of start and end of build up and drop off. 933309 Preliminary plan for the continental scientific drilling, in China (CSDC) Lin Guangzhi Sei Driili~ V3, NS, 1992, P215-219 The design philosophy for the scientific drilling program in China is outlined. A pilot hole will be sunk through hard to very hard crystalline rock to depth of at least 3000m, hopefully 5000m. Details are given of the drill rigs to be used and the reason for their selection, the Super Series drill rods, diamond coring bits, and wireline coring system. 933310 New concepts in percussive Beccu, R Worm Min F.qaip VI6, N7/8, July/Aug 1992, P39-42 Developments in hydraulic tophammers have enabled the amplitude of the shock wave which transmits energy through the drill rods to be reduced whilst the energy content is increased. This advance must be matched by tool systems suited to the rock to be drilled. Alternatives to experience in bit selection have been proposed using the parameter rock penetration resistance (RPR), the relation between force and penetration. When the correct bit is coupled to rods designed for maximum energy transmission, high efllciency percussion drilling is possible.
Blasting 933311 related to bimthole ~ m e t e r i reek Idmting Kou, S Q; Rustan, A lnt J Rock Meek MiR Sei V29, N6, Nov 1992, P543-533 On the basis of energy conservation in a single blasthole, a complete relation is developed between burden and either biasthole diameter or specific charge. It consists of terms related to surface energy for the two side cracks, fragmentation of the rock prism released, and energy required to move the rock. Four approximate formulae are derived for burden as a power function of blasthole diameter, the exponent decreasing (2, 1, 5/6, 2/3) with increased scale of blasting. The coefficients of these formulae are expressed in terms of rock and explosive properties. The linear relation, a special case with relatively small blasthole diameters, is in good agreement with the wellknown Langefors formula. The formulae are tested against empirical relations.
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