Abstract:

After large-scale volume fracturing of deep shale gas wells, there comes the difficulty of wellbore plugging, which affects long-term production. The common methods to remove the wellbore plugging by coiled tubing and drill pipe are simple. It lacks of the pertinence measures to treat the diameter shaft and the mixed stemming. For example, Well-WY23-1HF can not produce normally due to the fracturing of adjacent well. The formation collapses and the cuttings enter the wellbore, causing serious plugging. The trajectory of its plugging section is of the complex situation of warped, casing deformation and so on. The measures of plugging removal and resuming production are drill-grinding string, drill-grinding process, well killing fluid design, etc. The field application shows that the same type of bridge plug should be used to reduce the impact of tapering, ensure the smooth trajectory, prevent the accumulation of plugging material, and avoid the complication of wellbore conditions for multi-stage fracturing of horizontal wells. At the same time, combined with the comprehensive application of soluble bridge plug and large diameter non-easy-to-drill bridge plug, the combination of pipe string with oil flushing with nibs+drill pipe with bit （or milling shoe） is adopted to remove plug, and the recovery of production is successfully achieved. This technology provides a reference for similar shale gas wells.

Key words: drilling bridge plug, plugging, plugging removal, recovery production, horizontal well, shale gas