Objective To provide detailed computerised procedures for the safe and reliable application of explosive cutting techniques to the removal of steel offshore jacket structures. These procedures incorporate both theoretical and practical input from a number of sources and can be used to provide designs for the essential elements of removal systems.Compilation and interrogation of a database of all North Sea UK sector fixed structures revealed that the use of explosive shaped charge cutting is most beneficial for the removal of jackets which stand in greater than 100 m of water and which weight in excess of 800 t.This will involve the use of explosive shaped cutting charges in open water. The potential market in this area was found to be significant, and analysis showed that the potential for jacket removal using shaped explosive charges will be greatest in the period 1995-2009.A review of state-of-the-art underwater initiation methods has been conducted. The reliable initiation of charges underwater has two main requirements based on the disruptive effects of through water shock waves caused by underwater explosions. The first of these is that charges in close proximity are initiated simultaneously. Secondly separate groups of charges should be initiated at intervals of long enough duration to prevent constructive interference of shock waves but of short duration to prevent shock wave disruption from other charge groups.Based on this methods of initiation involving the use of detonating cord, ordinary electric detonators, exploding bridgewire detonators and remove acoustically initiated firing modules are being assessed for suitability.Final section of initiation method will involve the trade off reliability, ease of use, cost and complexity.Detonation simulation sofware has been developed and is extended to account for explosion shock effects.The project is conducted in two phases :Phase 1 covered a review of essential results from the earlier EEC supported project EXPLOCUT and identified areas requiring further detailed attention. This has taken into account developments in high technology equipment, such as ROVs, and the evolution of legislation affecting decommissioning.Phase II has concentrated on detailed safe and reliable operating procedures to help design the key elements of the removal system, with special emphasis on detonation systems and procedures. Guidance is given on the implications to structures, vessels and the environment, of these procedures together with methods to allow for their effects. The analysis tools are in the form of interactive computer programs with sophisticated graphical output. Programme(s) ENG-HYDROCARB 1C - Programme (EEC) of Community projects in the hydrocarbons sector, 1973-1985 Topic(s) Data not available Call for proposal Data not available Funding Scheme DEM - Demonstration contracts Coordinator Advanced Mechanics and Engineering Ltd EU contribution No data Address 1 Huxley Road Surrey Research Park GU2 5RE Guildford United Kingdom See on map Total cost No data
