Application of low density anti-sloughing drilling fluid in Jie-207 well

Jie - 207 well is the first long open hole evaluation well in Yingzijie facture zone of Huimin sag in Jinyang depression. The aim of drilling is to evaluate Upper Sha3 segment oil and gas content condition in Jinyang depression Huimin sag Yingzijie facture zone slope 2 nose structure. According to serious sloughing happened in neighbour well slope 2 shale rock, we applied MMH, polymeric alcohol, high polymer PAM, high temperature anti -sloughing lubricating agent RS- 2 and binary protect nano emulsion SDJ - 2 low density anti - sloughing drilling system to prevent Jie 207 well loss and hole collapse. This system has stable sidewall, sand carrying and lubricating performance, which has good effect of stable sidewall, anti- sloughing, improving penetration rate and decreasing drilling fluid soaking time.