An Integrated Study on Fossil Mangrove Carbonates on Mallorca, Spain
Delft University of Technology, Department of Applied Earth Sciences.
Delft, The Netherlands.
Several oil reservoirs around the world are producing from carbonate mangrove deposits. Little previous research has been undertaken on fossil mangroves, especially regarding their lateral heterogeneity, structure, permeability and porosity. This has resulted in a relatively poor understanding of reservoir mechanisms and consequent reservoir performance of such reservoirs. A new integrated study on outcropping mangrove deposits provides insight into the properties of mangrove carbonate reservoirs.
A series of Miocene carbonate outcrops along the southeastern coast of Mallorca include fossil mangrove deposits. These rooted intervals are part of the Santanyi Limestone. Three weeks of fieldwork were undertaken during which sedimentological and petrographical data were collected from 12 logged outcrops in order to examine petrophysical properties and lateral heterogeneities. Rock samples were taken and were analysed to elucidate their porosity, permeability and petrophysic characteristics. From these data, a sedimentological model was established.
The outcrop data was used as a framework to build a three-dimensional static reservoir model in the software package Petrel. Rock properties measured from the rock samples were used to populate the facies with porosity and permeability data. Several well placement scenarios were simulated with Eclipse. It was found that the low horizontal and high vertical permeabilities of the mangrove facies strongly favor field development using horizontal wells.
AAPG Search and Discovery Article #90060©2006 AAPG Foundation Grants-in-Aid