High Temperature, high pressure equation of state density correlations and viscosity correlations

• Main Authors: Tapriyal, D., Enick, R., McHugh, M., Gamwo, I., Morreale, B.
• Other Authors: United States. Office of Fossil Energy.
• Format: Report
• Language: English
• Published: National Energy Technology Laboratory (U.S.) 2012
• Subjects: Natural Gas; Hydrocarbons; 02 Petroleum; Flow Rate; Deserts; Simulation; Petroleum; Production; Drilling; 97 Mathematical Methods And Computing; Mixtures; Gulf Of Mexico; 03 Natural Gas; Equations Of State; Viscosity; Arctic Regions; Transport; Design; Arctic; Psi
• Online Access: https://doi.org/10.2172/1047835; https://digital.library.unt.edu/ark:/67531/metadc844559/

Global increase in oil demand and depleting reserves has derived a need to find new oil resources. To find these untapped reservoirs, oil companies are exploring various remote and harsh locations such as deep waters in Gulf of Mexico, remote arctic regions, unexplored deep deserts, etc. Further, the depth of new oil/gas wells being drilled has increased considerably to tap these new resources. With the increase in the well depth, the bottomhole temperature and pressure are also increasing to extreme values (i.e. up to 500 F and 35,000 psi). The density and viscosity of natural gas and crude oil at reservoir conditions are critical fundamental properties required for accurate assessment of the amount of recoverable petroleum within a reservoir and the modeling of the flow of these fluids within the porous media. These properties are also used to design appropriate drilling and production equipment such as blow out preventers, risers, etc. With the present state of art, there is no accurate database for these fluid properties at extreme conditions. As we have begun to expand this experimental database it has become apparent that there are neither equations of state for density or transport models for viscosity that can be used to predict these fundamental properties of multi-component hydrocarbon mixtures over a wide range of temperature and pressure. Presently, oil companies are using correlations based on lower temperature and pressure databases that exhibit an unsatisfactory predictive capability at extreme conditions (e.g. as great as {+-} 50%). From the perspective of these oil companies that are committed to safely producing these resources, accurately predicting flow rates, and assuring the integrity of the flow, the absence of an extensive experimental database at extreme conditions and models capable of predicting these properties over an extremely wide range of temperature and pressure (including extreme conditions) makes their task even more daunting.