Abstract
The project risk modeling - integration of organizational, human and technical factors is developing a model for quantifying barrier performance related to major risk hazards (OMT-model). The model combines knowledge related to organizational, human and technical aspects and has been tested for process leakages on both onshore and offshore plants with good results. The same methodology has now been used to identify the risk influence factors (RIF) - or performance shaping factors related to well operations. Based on a review of historical data, well incidents seem to occur most frequently during complex workover operations and well drilling. This paper outlines the OMT model and discusses it in relation to drilling and well operations of offshore production wells.