Mallman, E.P. and Zoback, M.D., 2007. Subsidence in the Louisiana Coastal Zone due to Hydrocarbon Production. Journal of Coastal Research, SI 50 (Proceedings of the 9th International Coastal Symposium), 443 – 449. Gold Coast, Australia, ISSN 0749.0208

Coastal wetland loss in southern Louisiana poses a great threat to the region's ecologic and economic stability. Wetland loss in the Louisiana Coastal Zone is caused by the interactions of multiple natural and human induced mechanisms, and it has been suggested that subsurface oil and gas production may be a large contributing factor. We model the effect of oil and gas production in Lafourche Parrish, Louisiana on surface subsidence using a first-order leveling line along highway Louisiana 1 to constrain our model. Using geologic and pressure data, we estimate the amount of compaction in modeled reservoirs. We find the subsidence predicted from reservoir compaction is consistent with observations of localized subsidence between 1982 and 1993. Both modeling and observations show that subsidence due to reservoir compaction is a highly localized signal that is not consistent with observations of regional subsidence. Interestingly, while predictions of subsidence from compaction of the reservoir sands fit the observed subsidence in one time epoch, the leveling data shows an increasing rate of subsidence from the 1965-1982 to 1982-1993 epoch – a time when production rates decreased. This indicates the potential for a time-dependent mechanism for production-induced subsidence. This work is a critical part in the development of an integrated model of subsidence and wetland loss in southern Louisiana.