四川石油管理局钻采工艺研究所研制的川6-外返孔取心工具,进行了两口井的试验,均取得了预期的效果。1983年8～9月,在川南矿区董6井第1次下井试验。试验井段3078.78～3246米,岩性是二迭系阳新灰岩;泥浆比重2.30～2.40克/厘米~3,粘度50～80秒;钻井参数是:钻 Sichuan Petroleum Administration Bureau Institute of drilling technology developed by Sichuan 6-hole return hole coring tools, conducted two wells test, have achieved the desired results. From August to September 1983, the first downhole test was conducted at Dong 6 well in the southern Sichuan mining area. The test interval is 3078.78 ~ 3246 meters with lithology of Yangxin limestone of Permian system. The mud weight is 2.30 ~ 2.40 g / cm ~ 3 and the viscosity is 50 ~ 80 seconds. The drilling parameters are: