In offshore drilling operations, accidental loads such as dropped objects pose a high potential threat to human safety, asset integrity, environment as well as reputation and business of the operator. A safe design of offshore exploration and production facilities for accidental collisions requires the risk assessment of such accidental events. This paper proposes the methodology to assess such risk. For the frequency assessment part of the risk, the paper proposed an extended version of the approaches outlined in industry guidelines such as DNV-RP-F107. For the consequence analysis, it has been demonstrated that advanced analysis method is capable and suitable for understanding the response of structures to accidental loadings, not only to remove conservatism inherent in simplified approach but also to assure a safer and economical design. Furthermore, this paper has demonstrated that by accounting for fluid-structure and structure-soil interactions, more detailed insight can be obtained of the response of the subsea pipeline protection system that otherwise could be easily missed without consideration of the fluid and foundation and can lead to ineffective design and connection details.