Drillbacks: Nevada Test Site, fiscal year 1984

Technical Report · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6104296

Dean, R

This report is a compilation of operational and cost data for the 16 drillbacks completed during fiscal year 1984. Its purpose is to summarize major elements of costs in significant categories and to show their relative contribution to total costs. Productivity data and cost summaries for fiscal years 1978 through 1984 are included in the report to indicate any trends in each laboratory's drillback practices and costs. Current drillback practices include setting 13-3/8-inch conductor pipe for the Los Alamos National Laboratory (LANL) holes and 10-3/4-inch conductor pipe for Lawrence Livermore National Laboratory (LLNL) holes. Both laboratories utilize 9-7/8-inch bits for drillbacks. The Los Alamos program uses the Skytop drill rig to drill holes that are deeper than 1200 feet. For holes 1200 feet deep or less, Los Alamos uses the Boyles drill rig. Holes for LLNL are drilled with the Hycalog drill rig. Air foam and sepiolite mud are used on drillbacks for LLNL events and bentonite mud is used on holes for Los Alamos events. Sepiolite mud is favored over bentonite mud in hole conditioning at depth. During fiscal year 1984, the costs of plugging prior year drillbacks near event locations were $20,547 for LLNL and $8,226 for Los Alamos. These costs are charged to separate work orders and were not used in determining drillback costs. Costs incurred for general construction support of drillbacks are not directly comparable for LLNL and Los Alamos because charges for similar tasks are accounted for differently by each laboratory. Containment equipment costs for LLNL and Los Alamos are shown.

• Research Organization: Reynolds Electrical and Engineering Co., Inc., Las Vegas, NV (USA)
• DOE Contract Number: AC08-84NV10327
• OSTI ID: 6104296
• Report Number(s): DOE/NV/10327-15; ON: DE85006898
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
422000* -- Engineering-- Mining & Underground Engineering-- (1980-)
COST
DRILLING
NATIONAL ORGANIZATIONS
NEVADA TEST SITE
US DOE
US ORGANIZATIONS