Reverse Circulation Rotary Drilling Sample Clauses

Reverse Circulation Rotary Drilling. The RC drilling conducted by Atna was completed by D▇▇▇▇▇ Construction & Drilling of Winnemucca, Nevada using a S▇▇▇▇▇▇ 1500 truck mounted drill, supported by a water truck, pipe truck, and service truck, and staffed by a driller, helper and sampler. RC drilling was used principally for pre-collaring core holes. The pre-collar portion consisted of drilling through non- or weakly-mineralized rock and stopping at a known depth above target mineralization. After drilling, the hole was cased using 4 5/8 inch threaded steel pipe to maintain the integrity of the hole until the core rig arrived to finish the hole to target depth. Drilling started out using a 5 5/8 inch hammer bit. The hammer bit used a pounding action along with rotation to break the rock into pieces, and air pressure to lift the cuttings up out of the hole, and into the sample splitter. When the air system was no longer powerful enough to drive the hammer in the presence of high downhole water pressure, the hammer bit was replaced with a tri-cone bit. A tri-cone uses three rotating wheels with pointed carbide buttons to grind the rock into little pieces. Air pressure is used, as with the hammer bit, to lift the ground-up cuttings to the sampling apparatus.
View Source

Related to Reverse Circulation Rotary Drilling

  • PREVAILING WAGE RATES - PUBLIC WORKS AND BUILDING SERVICES CONTRACTS If any portion of work being Bid is subject to the prevailing wage rate provisions of the Labor Law, the following shall apply:

  • Compressed Work Week The Company and Union recognize the concept of the compressed work week. It is further understood that the compressed work week conditions will apply only to those departments that are on the compressed work week.

  • Drainage Systems (1) Clear culvert inlets, outlets, and sediment catching basins. (2) Maintain waterbars, drainage dips, and other water diversion measures. (3) During active use, patrol and maintain functional drainage. (4) Repair damaged culvert ends.

  • Standard Work Week (a) Except as provided below, the standard work week for Full-time Employees shall normally consist of 35 hours per week, which shall normally consist of 5 equal Shifts of 7 hours. (b) The standard work week for certain Full-time Employees, including but not limited to, technical Employees, shall normally consist of 37.5 hours per week, which shall normally consist of 5 equal Shifts of 7.5 hours.

  • Completion of Concrete Pours and Emergency Work (a) Except as provided in this sub-clause an Employee shall nor work or be required to work in the rain. (b) Employees shall not be required to start a concrete pour in Inclement Weather. (c) Where a concrete pour has been commenced prior to the commencement of a period of Inclement Weather Employees may be required to complete such concrete pour to a practical stage and for such work shall be paid at the rate of double time calculated to the next hour, and in the case of wet weather shall be provided with adequate wet weather gear. (d) If an Employee’s clothes become wet as a result of working in the rain during a concrete pour the Employee shall, unless the Employee has a change of dry working clothes available, be allowed to go home without loss of pay. (e) The provisions of clauses 32.7(c) and 32.7(d) hereof shall also apply in the case of emergency work where the Employees concerned and their delegates agree that the work is of an emergency nature and can start and/or proceed.