Multiphase correlations References

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Multiphase correlations References:

n° Correlation Description Reference
1 Anand, et al Predicting Thermal Conductivities of Formations from Other Known Properties. JPT (Oct. 1980).
2 Ashford, F.E, & Pierce, P.E. The Determination of Multiphase Pressure Drops and Flow Capacities in Downhole Safety Valves (Storm Chokes). SPE 5161 1974 SPE Annual Fall Meeting, Houston Oct. 6-9.
3 Beggs, H.D. & Brill, J.P. A Study of Two Phase Flow in Inclined Pipe. JPT (May 1973), 606-617.
4 Churchill-Chu Correlating Equations for Laminar and Turbulent Free Convection from a Horizontal Cylinder. International Journal Heat Mass Transfer (1975) 18, 1049-1053.
5 Fancher, & Brown, G.G. Prediction of Pressure Gradients for Multiphase Flow in Tubing. SPE Journal (Mar. 1963), 59-64.
6 Fortunati Two Phase Flow Through Well-head Chokes. SPE 3742 1972 SPE European Spring Meeting, Amsterdam, May 17-18.
7 Hagedorn, A.R. & Brown, K.E. Experimental Study of Pressure Gradients Occurring During Continuous Two-Phase Flow in Small-Diameter Vertical Conduits. JPT (Apr. 1965), 475-484.
8 Mandhane et al A Flow Pattern Map for Gas-liquid Flow in Horizontal Pipes. International Journal Multiphase Flow, 1, 537-541.
9 Moody Friction Factor for Pipe Flow. Trans., AIME (1944), 66, 671-675.
10 Mukherjee, H. & Brill, J.P. Liquid Holdup Correlations for Inclined Two-Phase Flow. JPT (May 1983), 1003-1008.
11 Oranje Condensate Behaviour in Gas Pipeline is Predictable. Oil and Gas Journal (July 1973), 39-43.
12 Orkiszewski Predicting Two Phase Pressure Drop in Vertical Pipes. JPT (June 1967), 829-833.
13 Duns, H. Jr & Ros, N.C.J. Vertical Flow of Gas and Liquid Mixtures in Wells. Proc., Sixth World Petroleum Congress, Frankfurt (1963) 451.
14 Tansev, E. Startzman, R. & Cooper, A. Predicting Pressure Loss and Heat Transfer in Geothermal Wellbores. SPE 5584 1975 SPE Annual Fall Meeting, Dallas, Sept. 28-Oct. 1.
15 Gould, T.L, Tek, M.R. & Katz, D.L. Two-Phase Flow Through Vertical, Inclined, or Curved Pipe. JPT, August, 1974, 915-925.

Reference: PROSPER Use’s Guide.

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Rod Rotator extends the life of rod-pumped wells

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The constant up-and-down movement of a sucker rod creates excessive friction between rods and tubing which can result in premature rod and tubing failures due to excessive wear. If left unchecked, this generally requires a costly intervention to make repairs.

To extend the sucker rod run life, one of the widely used techniques is the use of rod rotators. A rod rotator is a mechanical device installed on the polished rod between the carrier and the polished rod clamp. It incrementally rotates the rod with each stroke. A rotating mechanism with an actuator lever arm is connected to the walking beam with a metal string. As the surface unit moves up and down, it pulls and releases this metal string so that, moves the actuator lever arm up and down. The rotation mechanism is activated and this slowly rotates the polished rod and the rod string below.

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Outflow Performance Correlation Selection

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There is no universal rule for selecting the best flow correlation for a given application. When an outflow performance simulator is used, it is recommended that a Correlation Comparison always be carried out. By inspecting the predicted flow regimes and pressure results, the User can select the correlation that best models the physical situation. Refer to the article titled “Multiphase flow correlations” for more details about flow correlations and their use.

Fancher and Brown is a no-slip correlation, with no flow regime map. Therefore, this correlation cannot be recommended for general use and should not be used for quantitative work. on the other hand, Duns and Ros Modified gives the highest pressure drops in the slug flow regime for oil wells. This is why Fancher Brown (no slip) and Duns and Ros Modified can serve only as quality check boundaries for downhole measurements.

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Slickline Service Tools – part 1

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Slickline operations have been in use since the early days of the oil and gas industry. The development of equipment and technology for slickline operations has kept pace with the development of new methods and tools used in well completion, remedial and work-over operations. Slickline is used for depth determination, deviated hole surveys, temperature and pressure surveys, paraffin cutting, and cementing operations.  Slickline may also be used to set, retrieve, and manipulate chokes, circulating plugs, gage cutters, swaging tools, safety valves and gas-lift valves.

Various tools frequently used in slickline operations are described in this article.

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Multiphase flow correlations

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The primary purpose of a multiphase flow correlations is to predict the liquid holdup (and hence the flowing mixture density) and the frictional pressure gradient.  This article details the most widely used correlations for the prediction of the Vertical Lift Performance.

The oil and water are lumped together as one equivalent fluid. Thus flow correlations in common use consider liquid/gas interactions.  They are therefore more correctly termed two-phase flow correlations.  Depending on the particular correlation, flow regimes are identified and specialized holdup and friction gradient calculations are applied for each flow regime.

There is no universal rule for selecting the best flow correlation for a given application. When an outflow performance simulator is used, it is recommended that a Correlation Comparison always be carried out. By inspecting the predicted flow regimes and pressure results, the User can select the correlation that best models the physical situation.

Multiphase flow correlations:

Fancher & Brown:

  • Fancher and Brown is a no-slip correlation, with no flow regime map. Therefore, this correlation cannot be recommended for general use and it is provided for use as a quality control (should not be used for quantitative work).
  • It gives the lowest possible value of Vertical lift Performance (VLP). Therefore, Measured data falling to the left of Fancher Brown on the correlation comparison plot indicates a problem with fluid density (i.e PVT) or field pressure data.
  • According to Brown, it is only suitable for 2-3/8 – 2-7/8 inch tubing.
  • It is for GLR less than 5000 scf/bbl and flow rates less than 400 bpd.
  • It has its own friction factor model, which is independent of pipe roughness.

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