Abstract:
Due to its mountainous topography,the Weiyuan Shale Gas Block suffers from unfavorable transportation conditions and high costs for drilling operations.Drilling operations in the sparsely populated area face significant challenges in logistics,health,safety and environmental protection.To cope with specific features in topography and shale gas development in the Weiyuan Block,research well pattern design in mountainous regions,well trajectory design,trajectory control,collision-proof cluster wells and application of the TI-350T hydraulic smart rig were conducted to establish the "well pad" drilling processes for high-efficiency development of shale gas.Applications of the drilling mode in Pad W204H11 reached the technical index:an average ROP of 7.13 m/h,inter-well mobilization time of 2.0 h and drilling fluid utilization rates over 80%.It can be seen that application of the technique can effectively minimize down time and cut drilling cost.Research results show the "well pad" drilling mode in mountainous regions may provide guides and form an example for high-efficiency development of shale gas in similar blocks in China.