Question

The total oil production rate (measured at the bottom hole conditions) from a volumetric reservoir is 200 bbl/day (1 bbl = 5.615 ft\(^3\)) at the flowing bottom hole pressure (FBHP) of 3000 psi. The reservoir has the following properties:

Considering a radial flow under pseudo steady state, the bottom hole pressure after 180 days is ________________ psi (rounded off to two decimal places).

Hint:

In pseudo steady state, the bottom hole pressure depends on the production rate, reservoir properties, and drainage area.

Answer 1

Correct Answer: 2280

The bottom hole pressure in a radial flow system under pseudo steady state can be calculated using the following formula: \[ P_{\text{bh}} = P_{\text{wf}} + \frac{141.2 \times q \times \mu}{k \times h \times r^2} \times \left( \ln \left(\frac{r}{r_w}\right) + s \right) \] Where:
- \( P_{\text{bh}} \) = bottom hole pressure
- \( P_{\text{wf}} \) = flowing bottom hole pressure (3000 psi)
- \( q \) = production rate (200 bbl/day)
- \( \mu \) = fluid viscosity
- \( k \) = permeability (35 mD)
- \( h \) = pay zone thickness (10 ft)
- \( r \) = drainage radius (1000 ft)
- \( r_w \) = wellbore radius (0.25 ft)
- \( s \) = skin factor (0)
The calculated bottom hole pressure after 180 days is between 2280.00 and 2290.00 psi. Final Answer: 2280.00–2290.00 psi