Hydrocarbon Exploration Potential in Migration Pathways

Abstract Part of the hydrocarbons generated in the mature kitchens migrate into the conventional traps while the other portions remain in the kitchens as unconventional resources. However, significant part of the generated hydrocarbons could be available in the migration pathways. Hydrocarbons in the migration pathways are either retained in the rocks in migration routes or accumulated in subtle traps due to the presence of heterogeneities along the migration pathways. The migration pathways traps are envisaged to be developed in response to the presence of an equilibrium state between the buoyancy forces that are trying to move the hydrocarbon through the rocks and the capillary pressures in the low permeable layers that are resisting these movements (figure 1). The only requirement to develop such traps is for the capillary pressure to be greater than the migration buoyancy force. Smaller pore throat sizes will greatly enhance the seal capacity, especially for the larger oil molecules that are expelled during early oil migration and result in longer oil columns. The Upper Thamama migration pathways, in east and central Abu Dhabi may represent one of the most potential areas for the secondary migration pathways oil accumulations. Some of the well-known conventional fields in these areas in reality were developed in response to the presence of heterogeneities along the migration pathways. Also, the stratigraphic traps of Mishrif and Mauddud formations in west onshore Abu Dhabi are other examples of the migration pathways hydrocarbon exploration potential. The exploration activities in the migration pathways will rely heavily on technological improvements in seismic imaging, basin modeling, horizontal drilling, frac testing and steam injection. These will result in discovering a commercial volume of hydrocarbons along the migration pathways.