Well 201H1 is located in Dazu District of Chongqing city. It is a key horizontal exploratory well laid by Chongqing shale gas company. The well drilled in August 20, 2016, by the CCDC 70016 drilling team bearing drill. The drilling fluid company's ZY5064 team provides drilling fluid technical services.

As the "prefix" new block first level straight wells, the wells data of the wells is almost zero, the horizontal section facing the fracture formation, the density window is narrow, bottom temperature up to 132 degrees Celsius and other multiple problems. In order to ensure the oil base drilling fluid to the fractured formation and in strong sealing to ensure horizontal fracture zone formation leakage does not collapse, shale gas project manager department and R & D center research team, through the indoor experiment proves the feasibility of 201H1 wells of oil based drilling fluid formula, in the actual drilling process called density the adjustment is fine, the final accident occurred under the condition of well drilled in the underground. It is reported that the oil based drilling fluid in the horizontal section of this well all Chuanqing independent research and development.