Entwicklung und Einsatz einer mechanischen bsperrung fur grosskalibrige Kavernenhalse - Der Spider Plug

摘要

A hydraulic Separation of a well and the cavern can be necessary for differ-ent workover applications, e. g. casing mill-ing or underreaming. The Separation is needed to ensure a mud circulation during such Operations. In that case a barrier is set ofter flooding the cavern, which will then be used as a mechanical abutrnent for the ce-ment bridge. If the diameter of the cavern neck has been enlarged due to e. g. unwanted leaching processes or unstabilized underreaming processes, it might get impossible to set a Standard plug with the available tech-nologies into those diameters. Therefore UGS GmbH has developed a mechanical plug, which is set hydraulically. The so called "Spider Plug " is used as basis for a cement bridge,and can be removed by drilling after the workover has been done. Depending on the dimension of the setting tool a cavern neck up to 50" diameter can be plugged by the "Spider Plug". Up to now a number ofsuccessful Operations on different locations has shown, that the "Spider Plug" is a practicable and cost-efficient Solution for a mechanical abutrnent of large cavern necks.