There are many processes involved in the oil and gas industry activity cycle; exploration, appraisal, development, production and decommissioning. All these processes are complex and need the involvement of experts, a relevant financial investment, a considerable time investment and special equipment in order to reach the final objective of exploration and extraction of oil and gas, followed by the obligation of removing all or part of the equipment and installations involved once the operation is complete. Of these activities, decommissioning is one of the most difficult. The process of decommissioning consists of the removal, disposal or reuse of the installations.
There are many other factors to analyse carefully in order to decide the way the structure is going to be removed, such as the environmental impact, the costs, the potential public impact and the potential legal impact. Depending on the results of the analysis of those factors it may be made the decision of removing the whole structure, removing the structure partially or leave it in place. Deciding the method for decommissioning is a very complex issue and as was expressed before, there are many factor and agent to be considered by experts in the field followed by a combination of all the information.