Quiz (Rock-Fluid)

Q-1 Special core analysis tests are performed on core samples regarding physical properties of reservoir rocks; a) b) c) d) e) f)

Porosity, Permeability & Saturation Capillary pressure, Relative permeability, Wettability Surface and Interfacial Tension, Electrical Conductivity, Pore size Distribution Only c Only d c and d

Q-2 Define Anisotropy? Q-3 The porosity of consolidated materials depends on: a) Grain shape & Grain packing b) Grain sorting & Grain size distribution c) Compaction, degree of cementation and consolidation d) a and b e) b and c f) a, b and c Q-4 Define absolute, average, effective, and relative Permeability? Q-5 Calculate the porosity of packing of uniform spheres (Figure attached), if the unit cell is a cube and r is the radius of sphere.

Q-6

One of the Bulk Volume laboratory determination methods is coating the rock sample with paraffin. Find the Bulk Volume of the coated sample that is immersed in water. If; Weight of dry sample in air = 30.0 g Weight of the sample after coating with paraffin = 31.8 g Paraffin density = 0.9 g/cm3 Weight after immersing of the coated sample in the water = 20 g Water density = 1 g/cm3 Q-7 The following data obtained during a routine permeability test at 70 oF. Find the permeability. Flow rate = 2000 cc of air at 1 atm in 400 sec Downstream pressure = 1atm Viscosity of air at test temperature = 0.02 cP Core cross sectional area = 3 cm2 Core length = 5 cm Upstream Pressure = 1.75 atm Q-8 Define The Klinkenberg Effect. Q-9 The “Klinkenberg Effect” is a function of; a) Type of the testing fluid (gas) b) Test conditions (pressure and temperature) c) Molecular size of the gas d) Kinetic energy of the gas e) Both a & b f) None of above Q-10

The permeability of a core plug is measured by air. Only one measurement is made at a mean pressure of 2.25 psi. The air permeability is measured as 46.6 md. Estimate the absolute (liquid) permeability of the core sample. Where, b = constant for the air in the medium is 6.75 and both fluids permeability relationship is given as;

Q-11 Various methods of measuring capillary pressure (Pc) on small core samples are; a) The Porous Diaphragm Method & The Centrifugal Method b) The Mercury Injection Method & Dynamic capillary pressure method c) Both a & b d) None of above Q-12 A stratified aquifer contains 2 ft of 200-md sand, 3 ft of 100-md sand, 2.5 ft of 250-md sand and 3.5 ft of 100-md sand. What is the average permeability of this stratified water reservoir? The general expression for average permeability of a parallel layered formation with n layers is:

Q-13 Define wettability and which of the following factors effect wettability; a) Oil composition and rock mineralogy b) Brine composition and pH c) Reservoir Pressure and Temperature d) Thickness of connate water layer e) All of above

f) None of above Q-14 A laboratory air-brine capillary pressure of 1.25 bars has been measured in a reservoir core sample at residual water saturation. The air-brine interfacial tension is 0.070 N/m and the brineoil interfacial tension for the reservoir fluids is 0.022 N/m. What is the height of the water-oil

transition zone? Use relation;

and

.

Q-15 What is the flow rate of a horizontal rectangular system when the conditions are as follows? Permeability = k = 1 darcy Area = A = 6 ft2 Viscosity = m = 1.0 cp Length = L = 6 ft Inlet pressure = P1 = 5.0 atm Outlet pressure = P2 = 2.0 atm

Q-16 Express answer in reservoir capillary pressure by using the following laboratory data.

ϭAW = 72 dynes/cm & θAW = 0o Reservoir data: ϭOW = 24 dynes/cm & θOW = 20o Lab data:

(Air-water system) (Oil-water system)

Q-17 A glass tube is placed vertically in a beaker of water. The interfacial tension between the air and water is 72 dynes/cm and the contact angle is 0 degree. Calculate the capillary rise of water in the tube if the radius of the tube is 0.01 cm. Q-18 Determine the porosity for a sandstone using Archie's equation.

The formation water's

resisitivity is 0.5 ohm-meters. The formation rock 100% saturated with this water was 21.05 ohm-meters.

Q-19