Reservoir Connectivity Analysis – Defining Reservoir Connections and Plumbing

Abstract Gas, oil, and water fluids in channelized or faulted reservoirscan create complex reservoir plumbing relationships. Variable hydrocarbon contacts can develop when some, but not all, fluids are in pressure communication. Reservoir Connectivity Analyis (RCA) is a series of analyses and approaches to integrate structural, stratigraphic, and fluid pressure and composition data into permissible but non-unique scenarios offluid contacts and pressures. RCA provides the basis for fluid contact and pressure scenarios at all business stages, allowing the creation of fluid contact and segmentation scenarios earlier in an exploration or development setting, and the identification of by-passed pays or new exploration opportunities in aproduction setting. Combining conventional structural and fault juxtaposition spill concepts with a renewed appreciation of fluid breakover (contacts controlled by spill of pressure-driven, denser fluid, like water over a dam) and capillary leak (to define the ratio of gas and oil where capillary gas leak determines the GOC), we define permissible but non-unique scenarios of the full fluid fill/displacement/spill pathways of ahydrocarbon accumulation comprised of single or multiple reservoir intervals. This new analytical approach has been used in a wide range of reservoirs, including clastic (from fluvial to shoreface to deepwater) and carbonate reservoirs, in fields around the world.RCA models have been used to predict fluid contacts in faulted reservoirs where other approaches failed, to locateby-passed pay opportunities for in fill drilling in mature fields,and to condition connections in reservoir simulation models. RCA is an integrated technology that challenges the interpreter to evaluate and incorporate fluid property, composition, and pressure data with stratigraphic and structural interpretations of a reservoir to achieve a deeper, more comprehensive understanding of reservoir compartments and the connections between them.