Comparison of Methodologies for Dropped Objects Analysis in Shallow Water Drilling Rigs in the Gulf of Mexico.

The reform of the energy sector undertaken in 2013 by the Government of Mexico to empower foreign investment in the hydrocarbon sector led to the arrival of private companies with new projects and technology to the Gulf of Mexico. The projects managed in this region move continuously from the exploration stage to the production stage. During this stage transition, Offshore Projects require development of safety evaluations for the design of the platforms that were not common in the Mexican market; among these evaluations there is "Dropped Objects Analysis".

The accidental dropping of objects is considered among the main risks on offshore production platforms since its occurrence can affect personnel (injuries and / or deaths) and damage the facilities (causing spills and / or fires). Thus, as part of engineering design development, there is a need to assess the potential risk associated with impact from oscillating objects and loads that could fall during routine and non-routine lifting activities.

The analysis focuses on the possible damage to the area of operation of a given platform, structures, process equipment and subsea pipelines, evaluating the frequency of dropping combined with the type of damage that would result from the impact. However, for Dropped Object Analysis there are different methods that involve complex calculations, including solving integral equations, which for practical purposes can result in a large time investment.

This work addresses the use of a numerical method that allows a complex calculation routine to be carried out towards a solution with simple arithmetic, thus facilitating the evaluation of the frequency and impact of dropped objects on the platform and reducing the solving time.

As an application case, the Dropped Objects Analysis is presented in two offshore platforms for the exploitation and transportation of hydrocarbons installed in southeast Mexico by a private operator. During the study, the frequency and consequence of dropped objects were evaluated to issue protection recommendations in the design of both platforms and were also compared with the use of traditional calculation methods.