Environmental impact assessment and HazOp study of the drilling cuttings confinement process into non-productive wells in marine platforms in Campeche, Mexico

摘要

Potential risk and environmental impacts associated with the cuttings re-injection process as an alternative method for drilling wastes disposal were identified and assessed in two marine platforms facilities located in Campeche, Mexico. Environmental impacts were identified and assessed on physicochemical, biological-ecological, socio-cultural and economical elements using the Rapid Impact Assessment Matrix (RIAM). Drilling cuttings re-injection can cause negative effects with light changes. Most of negative impacts were on the physicochemical and biological-ecological elements, whereas positive impacts were on the socio-cultural and economical elements. The most critical negative impacts were: effects due to extreme events, persistent substances presence, effects on aquatic fauna, and changes in biodiversity. The most important positive impacts were those that generated changes in the regional and local economy. By applying the correct mitigation measures it would be possible to decrease the impacts, and in some cases, to eliminate them. Risks were evaluated using the HazOp methodology, deviations in the process were analyzed, recommendations were provided and each risk analyzed was categorized as tolerable or non-tolerable. Consequences analysis from an accidental spill of slurry and/or cuttings was carried out by the YAXUM-3D mathematical model. The results of the consequences analysis showed that even the concentrations in the discharge point exceed the recommended criteria for protection of marine life and marine water quality; the spill is rapidly dispersed complying with the permitted levels in a period of 8 h as a maximum. Keywords: environmental assessment, HazOp, drilling cuttings disposal, re-injection, platforms.