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全断面钻井法在打竖井中愈来愈显得重要。在欧洲,用全断面钻井法打的竖井,直径已达25呎,在美国也已达16.5呎。全断面钻井法的许多技术,是由打油井和天然气井的技术发展而来的。在必须穿透含水量大、不稳定地层(用普通凿井法非常困难或者费用昂贵)以及在需要快速打井等种种情况下,采用全断面钻井法十分经济。在沉积岩中打直径大约12呎或小于12呎的井,采用全断面钻井法和采用普通凿井法的费用不相上下。在条件适合于采用天井钻井法的地方,全断面钻井法就比不上天井钻井法。但是,全断面钻井法较之天井钴井法,适应性确实更大。而且全断面钻井法还可用于不可能采用天井钻井法或采用天井钴井法效率不高的地方。现已采用全断面和天井联合钻机,以便在竖井表土阶段不宜采用天井钴井法的情况下,能充分发挥这种设备的作用。用于钻直径达30呎的竖井的全断面钻井设备的研制工作,现正得到美国矿业局的支持。
Full-face drilling is increasingly important in vertical shafts. In Europe, shafts drilled by full-face drilling have reached 25 feet in diameter and have reached 16.5 feet in the United States. Many techniques of full-face drilling are developed from the technology of oil and gas wells. Full-face drilling is very economical when it is necessary to penetrate large and unstable water-bearing formations (which are very difficult or expensive to use for normal drilling) and where quick drilling is required. Filling wells of about 12 feet in diameter or less in sedimentary rocks is more costly than using full face drilling and conventional drilling. Where condition is suitable for use of the well drilling method, the full cross-section drilling method can not compare with the well drilling method. However, the full face drilling method compared to the patio cobalt well method, the adaptability is indeed greater. Full-face drilling can also be used in areas where it is not possible to use a well drilling method or to use a low-cost cobalt well method. Has been used full-face and the co-drilling rig, so that in the shaft topsoil stage is not suitable for using the case of the cobalt well method, can give full play to the role of such equipment. The development of full cross-section drilling equipment for vertical shafts up to 30 feet in diameter is now being supported by the U.S. Bureau of Mines.