The properties of reservoir fluids are critical for the successful exploitation of petroleum oil and gas reservoirs. Integrated PVT sampling and testing programs are key to successful reservoir development applications. Recently developed laboratory measurements and advanced computational tools have enhanced knowledge of phase behavior and physical properties of reservoir fluids. However, many aspects of phase behavior remain unresolved.
This poster session highlights the integrative aspects of PVT programs and provides insights and solutions for unresolved problems. Issues covered include the following:
RESERVOIR FLUIDS SAMPLING COMPLEXITIES
Sampling Under Dynamic Reservoir Conditions: Petroleum reservoirs are continually in a dynamic state. Thus, obtaining representative samples during any stage of depletion or development presents its own unique challenges. Case histories are provided of the pros and cons of bottomhole vs. surface sampling.
Sour Crude Oil System Sampling: Sampling and laboratory testing of systems which contain hydrogen sulfide (H2S) deserve special consideration as absorption of H2S on the surface of sampling vessels can occur. This is of particular importance in studies of minimum miscibility pressure (MMP) since H2S is beneficial in lowering MMP for miscible hydrocarbon gas displacements.
Condensate Fluids Sampling: Well conditioning for sampling of condensate fluids are critical in ensuring that representative fluids are obtained. The difficulty in obtaining representative samples results from liquid dropout of the condensate in the near wellbore region.
Compositional Variation Within a Reservoir, Oil Fingerprinting: Utilization of oil fingerprinting, a chromatographic technique, represents a significant stride for reservoir surveillance and reservoir management of fields which contain multiple crude oils. The technique can be used as a production allocation tool for reservoir surveillance and is much more accurate and cost effective over conventional production logging techniques.
FLUID PROPERTIES AND PHASE BEHAVIOR PROBLEM DEFINITION AND POTENTIAL RESOLUTIONS
Near Critical Fluids: When oil and gas equilibrium compositions vary considerably with spatial position and time, the assumption of solubility of gas in oil being dependent on pressure alone is not valid.