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                            Provisions on the use of vertical hole freezing method for the excavation of inclined wellbore

                            Source: xe1x.com Author: admin Date: 2019-09-07 15:32 heat:
                            Article 46 of the Coal Mine Safety Regulations When using a vertical hole freezing method to drill a deviated well shaft, the following provisions shall be observed
                            (1) The freezing terminal position along the inclined length shall ensure that the wellbore top plate of the inclined well is located at a relatively stable water-proof stratum above 5m, and the freezing depth of each vertical hole shall pass through the wellbore bottom plate of the frozen section of the inclined well above 5m.
                            (2) The working face excavated in the direction of the shaft of the inclined well shall not be less than 5m from the frozen terminal of each section.
                            (3) The maximum distance between the initial support and permanent support of the freezing section and the excavation face, and the interval between the excavation and the completion of the permanent support must be specified in the design of the construction organization, and special measures for handling frozen pipes and water prevention after thawing must be formulated After the permanent support is completed, the wellbore freezing can be stopped.
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