The Role of Hydrocarbon Production on Land Subsidence and Fault Reactivation in the Louisiana Coastal Zone

Abstract

We use a simple analytical model of reservoir compaction and a numerical model incorporating both reservoir compaction and fault slip to investigate surface subsidence in the area of the Lapeyrouse Field in southern Louisiana. A releveling survey shows approximately 20 m of elevation change over a 30 years time period that includes the period of extensive oil and gas production from a number of reservoirs at depth. The degree and extent of subsidence estimated from a simple analytical model of compaction predicts approximately half of the elevation change measured from the releveling surveys. Incorporating the impact of compaction-induced slip along the Golden Meadow Fault, located at the northern edge of the Lapeyrouse Field, on surface subsidence still does not account for all of the measured subsidence. Coastal wetland loss is a result of complicated process and it is difficult to isolate the impact of specific mechanisms. This study suggests that land subsidence induced by hydrocarbon production is one of several mechanisms that need to be considered when evaluating localized subsidence and wetland loss in the Louisiana coastal zone.