Drilling Technology for Adjustment Wells of the Jiaoshiba Block in the Fuling Shale Gas Field

With the Jiaoshiba Block in the Fuling Shale Gas Field entering into the development and adjustment period, the recoverable reserves of single well are reduced. To develop the field economically, it is necessary to shorten the drilling cycle and reduce the drilling cost. Therefore, with the optimum design of drilling, drilling of ultra-long horizontal sections, increasing rate of penetration by optimization in drilling parameters, a “one-trip drilling” technique based on equal-life idea, integration of drilling, reaming and flushing in well completion, and long-term sealing technology in cementing, the drilling technology for adjustment wells of Jiaoshiba Block of the Fuling Shale Gas Field was formed. Field application results showed that the average length of horizontal sections in adjustment wells was 2 096 m, 37.8% longer than that in drilling the first phase drilling there. The average penetration rate reached 9.49 m/h, 26.2% higher than that in the first phase drilling and the drilling cycle was 62.27 d, which was 26.0% shorter than in the past. The percentage of wells with annular pressure lowered from 70.0% to 4.6%. The results show that the proposed key drilling technology could meet the technical needs of adjustment wells of Jiaoshiba Block of the Fuling Shale Gas Field, and provide supports for a stable production and more effective development of the Fuling Shale Gas Field.