Application of polyvinyl alcohol drilling fluid in core drilling construction of Tengjia Gold Mine in Zhaoyuan

Abstract:

In order to complete the evaluation of the gold resource potential of the Linglong-Shuiwangzhuang mining area， Zhaoyuan， two drill holes with a total of 4000 m coring task were designed and carried out in the relevant mining area. In the construction of ZK1603 hole， the research on solid-free anti-collapse drilling fluid based on polyvinyl alcohol（PVA） as an inhibitor was carried out， aiming at the problems of hole wall collapse， mud-making， and mud cake buildup on the inner wall of the drill pipe in the mudstone formations in the process of diamond wire-line core drilling. Compared with conventional inhibitors such as potassium humate and sulfonated asphalt， polyvinyl alcohol had strong inhibition， which was positively correlated with the degree of polymerization. Through comparative tests， it was determined that polyvinyl alcohol（PVA） was used as a viscosifying cutting agent， sulfonated lignite resin （SPNH） and sulfonated asphalt （FT-342） were used as water loss reducing agents to prepare the drilling fluid， which achieved good results in the actual practice.