Milling of Cast-Iron Bridge Plug With Electric-Line-Conveyed Technology

摘要

Abstract A new application of well tractor robotics in combination with well milling technology has been proven in the UKCS. In June 2007 on a North Sea platform, well tractor robotics in conjunction with a well milling rotational unit, using an electric wire line cable, were used to remove a cast iron bridge plug at 16,000-ft. A cast iron bridge plug run for a water shut off was set at an incorrect depth. Through evaluation, milling tests onshore confirmed that the concept of using a well miller with a well tractor was viable. The total operational time from rig up to rig down was 67 hours, with an actual milling time of 16 hours. During this unique operation all milled material was recovered and the challenges of controlling rate and milling penetration were achieved. This new application for milling well completions hardware and other well bore obstructions offers a cost efficient alternative technology to existing methods. The proven technology, normally used for production logging in highly deviated wells, also offers HSE benefits and logistical advantages. The article will describe the actual process from testing to completion of the offshore operation.