Table 4: Parameters of Velocity-pressure drop curves with different oil viscosities in different permeable sand packs

Temperature°C Kg
/(10-3μm2)		 Viscosity
/mPa.s		 Non-Linear Segment Linear Segment
a b c Slope α Intercept β
60 8000 237600 0.0035 -0.0026 0.0003 0.0057 -0.0043
2000 237600 0.0198 -0.0337 0.0143 — —
80 8000 25127.5 0.2537 -0.097 0.0092 0.0472 -0.011
2000 25127.5 0.0118 -0.0014 -0.0002 0.0093 -0.0027
450 25127.5 0.0014 0.0001 -0.0004 0.0028 -0.0016
110 8000 2258.3 20.072 0.5354 -0.0115 2.7543 -0.0716
2000 2258.3 0.042 0.0126 -0.0003 0.0588 -0.0129
450 2258.3 0.0092 0.0218 -0.0012 0.0342 -0.0055
140 8000 365.12 230.02 0.7476 -0.0095 7.322 -0.0542
2000 365.12 0.7338 0.0835 -0.0015 0.2493 -0.0121
450 365.12 0.0583 0.1722 -0.0042 0.2106 -0.0081

In this paper, a large number of experiments were conducted, permeability was measured with perm-plug method and fluid viscosity was found to have an impact on the start-up pressure gradient of oil and the velocity-pressure drop curve shape. Therefore, the relational expressions between a, b, c, α, β and Kg / µo were established, whose results are shown in Table 5. Then for a real heavy oil reservoir, velocity-pressure drop curve can be acquired by empirical formula mentioned above when the permeability and fluid viscosity are known.