Selection and Application of Hydraulic DTH Hammer Flushing Fluid for Loose and Fractured Formation in Gansu

Abstract:

Caojiakou gold deposit is located in Shandan County of Gansu Province. In the drilling construction in 2015, 2 full hydraulic power head drilling rigs were used, 4 drilling holes have been scrapped because of formation fracture, collapse and serious leakage. In order to improve the construction efficiency and quality, SYZX96 type wire-line coring hydraulic DTH hammer was adopted, and the evaluation analysis was carried out on the types of matching flushing fluid to ensure the best effect of the hydraulic DTH hammer. The field application results show that the footage per round trip increased by 68%, the core recovery rate was up to more than 95.5% in total and the average monthly efficiency increased by 21% with no downhole accident, which reduces the drilling cost and improves the construction quality and construction efficiency.