The image above represents the radial flow rate.

To compute for the radial flow rate, eight essential parameters are needed and these parameters are **External Pressure (P _{e}), Flowing Bottom-Hole Pressure (P_{wf}), Formation Thickness (h), Oil Viscosity (μ_{o} ), Permeability (k), Oil Formation Volume Factor (B_{o}), Drainage Radius (r_{e}) **and

**Well Bore Radius (r**

_{w}).The formula for calculating the radial flow rate:

Q_{o} = ^{0.00708kh[Pe – Pwf]} / _{μo Bo In[re / }_{rw}]

Where;

Q_{o} = Radial Flow Rate

P_{e} = External Pressure

P_{wf} = Flowing Bottom-Hole Pressure

h = Formation Thickness

μ_{o} = Oil Viscosity

k = Permeability

B_{o} = Oil Formation Volume Factor

r_{e} = Drainage Radius

r_{w} = Well Bore Radius

Let’s solve an example;

Find the radial flow rate when the External Pressure is 14, Flowing Bottom-Hole Pressure is 21, Formation Thickness is 7, Oil Viscosity is 35, Permeability is 50, Oil Formation Volume Factor is 13, Drainage Radius is 26 and Well Bore Radius is 15.

This implies that;

P_{e} = External Pressure = 14

P_{wf} = Flowing Bottom-Hole Pressure = 21

h = Formation Thickness = 7

μ_{o} = Oil Viscosity = 35

k = Permeability = 50

B_{o} = Oil Formation Volume Factor = 13

r_{e} = Drainage Radius = 26

r_{w} = Well Bore Radius = 15

Q_{o} = ^{0.00708kh[Pe – Pwf]} / _{μo Bo In[re / rw]
}Q_{o} = ^{0.00708 x 50 x 7 [14 – 21] }/ _{35 x 13 In[26 / 15]
}Q_{o} = ^{0.00708 x 50 x 7 [-7] }/ _{35 x 13 In[26 / 15]
}Q_{o} = ^{0.00708 x 50 x 7 [-7] }/ _{35 x 13 In[1.73]
}Q_{o} = ^{0.00708 x 50 x 7 [-7] }/_{35 x 13 x 0.55
}Q_{o} = ^{2.478 [-7] }/ _{35 x 13 x 0.55
}Q_{o} = ^{-17.346 }/ _{250.27
}Q_{o} = -0.069

Therefore, the **radial flow rate** is **-0.069** ^{STB}/_{day}.