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Applications of Dual‐Wall Reverse‐Circulation Drilling in Ground Water Exploration and Monitoring
Author(s) -
Strauss M. Fred,
Story Steve L.,
Mehlhorn Norman E.
Publication year - 1989
Publication title -
groundwater monitoring and remediation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 47
eISSN - 1745-6592
pISSN - 1069-3629
DOI - 10.1111/j.1745-6592.1989.tb01140.x
Subject(s) - drilling , borehole , drill , hammer , petroleum engineering , drill cuttings , geology , drilling fluid , drilling rig , mud logging , geotechnical engineering , mining engineering , engineering , mechanical engineering
Dual‐wall reverse‐circulation drilling uses flush‐threaded double‐wall drill pipe and high‐pressure air to provide continuous return of formation and water samples. Cuttings and formation waters are not contaminated with drilling additives or mixed with other borehole material. Up‐hole velocity of about 70 ft/sec provides reliable logging of water, mineral or contaminant‐bearing strata. Water samples representative of specific strata may be airlifted or bailed to the surface. In the percussion hammer system, dual‐wall drill pipe is advanced through chiefly unconsolidated material by the percussion action of an above‐ground pile hammer. The borehole is drilled and temporarily cased in one pass. Wells or monitoring devices are installed as the drill pipe is hydraulically retracted during construction. A rotary head may be adapted as an option to allow dual‐wall rotary drilling into consolidated or crystalline formations through a percussion hammer drill string temporarily left in place as a conductor. The complex geology and variety of geoenvironmental problems in southern California has provided a testing ground for dual‐wall drilling on hazardous material site investigations. Several case histories have demonstrated the capabilities and versatility of this method, including: (1) the installation of 4‐inch and 6‐inch diameter gasoline monitoring and recovery wells through gravels and cobbles at a filling station where hollow‐stem auger drilling failed; (2) the confirmation of a dry borehole initially drilled by direct rotary at a landfill; and (3) multiple installations of monitoring devices through municipal refuse at a city of Los Angeles landfill.