3 Quiz PGE 424 20 minutes Name:
1. State multiphase Darcys law for oil and water flow.
qw=-kkrwwdPwdx ; qo=-kkroodPodx
2. Why is typically (krw+kro) < 1?
Immiscible fluids block each other in the pore network.
3. What does krw, relative permeability of water depend on?
Water saturation Sw, Sw-history, wettability, pore structure
4. What is capillary number a ratio of?
Viscous forcesCapillary forces
5. Define fractional flow of water. What does it depend on?
fw= qwqw+qo = krwwkrww
depends on krw, kro, w, o.
+kroo
(neglecting Pc and gravity effect);
6. What are the advantage and disadvantages of the steady state method of relative
permeability? accurate, Advantage: needs no interpretation; Disadvantage: time-consuming, capillary end effect.
7. In three phase flow, gas relative is usually a function of only the gas saturation
(independent of oil saturation). Why? Gas is the most non-wetting fluid; it occupies largest pores. Occupation of pores depends only on Sg.
8. Name two techniques to measure water saturation in the steady state technique?
--Separator level for re-circulating system; --Weight of core --X-ray or -ray attenuation
9. What is the unit of resistivity?
Ohm-m
10. What is Formation Factor?
F = R0Rw = Resistivity with 100% brine saturation resistivity
of the brine