Analysis Fraction Flow of Water versus Cumulative Oil Recoveries Using Buckley Leverett Method

To derive the fractional flow equation oil displacement will be assumed to take place under the so-called diffusive flow condition. The constraints are that fluid saturations at any point in the linear displacement path are uniformly distributed with respect to thickness; this allows the displacement to be described mathematically in one dimension. The simultaneous flow of oil and water can be modeled using thickness averaged relative permeability, along the centerline of the reservoir. The condition for fluid potential equilibrium is simply that of hydrostatic equilibrium for which the saturation distribution can be determined as a function of capillary pressure and therefore, height. That is the fluids are distributed in accordance with capillary-gravity equilibrium. This paper focused on the fraction flow of water versus cumulative oil recoveries using Buckley Leverett method. Several field cases have been developed to aid in analysis. Producing watercut (at surface conditions) will be compared with the cumulative oil recovery at breakthrough for the flowing fluid.

Authors:

• Reza Cheraghi Kootiani
• Ariffin Bin Samsuri

Keywords:

• Fractional Flow
• Fluid Saturations
• Permeability
• Cumulative Oil Recoveries
• Buckley Leverett Method.

References:

[1] Leveret, M.C.:"Capillary Behavior in Porous Solids", Trans., AIME
(1941) 142, 152-169.
[2] Buckley, S.E. and Leverett, M.C.: "Mechanism of Fluid Displacement in
Sands", Trans., AIME (1942) 146, 107-116.
[3] Welge, H. J.: "A Simplified Method for Computing Oil Recovery by
Gas or Water Drive", Trans., AIME (1952) 195, 91.
[4] Craig, F. C. Jr.: "The Reservoir Engineering Aspects of Waterflooding,
Society of Petroleum Engineering", Monograph Series, SPE,
Richardson, TX (1971) 3, 35-38
[5] Willhaite, G. Paul: "Waterflooding, SPE Textbook Series", Volume 3,
Richardson, TX (1986) 3, 64-67
[6] Higgins, R. V. and Leighton A.J.: "A Computer Method to Calculate
Two-Phase Flow in Any Irregularly Bounded Porous Medium", Jour.
Pet. Tech. (Jun, 1962) 679.
[7] Cole,F.:"Reservoir Engineering Manual", Gulf Publishing Company,
Houston Texas. 1969. p. 249.
[8] Dake, L.P.:"Fundamentals of Reservoir Engineering", Elsevier 1978. P.
357.
[9] Amaefule, J. O., Altunbay, M., Tiab, D., Kersey, D. and Keelan, D.,
paper SPE 26436, 1993: Enhanced Reservoir Description: Using Core
and Log Data to Identify Hydraulic (Flow) Units and Predict
Permeability in Uncored Intervals/Wells.
[10] Blomberg, J.R., "History and Potential future of Improved Oil recovery
in the Appalachian Basin", SPE 51087, Proceedings of the Eastern
Regional Meeting, 1998.