An oil well in a reservoir has a drainage area of 1000 acres (assume circular cross section, 1 acre = 43560 ft2). Oil is being produced at steady state condition. The well is water driven and the hydrostatic pressure at the reservoir boundary is 6000 psi. The bottom hole (well bore) pressure is 4500 psi. The skin effect is 10. The vertical permeability of the reservoir is 10 md. The reservoir net thickness is 50 ft. The oil viscosity at the reservoir conditions is 1.7 cp (assume constant viscosity). The formation volume factor is 1.1. If well radius is 0.328 ft. calculate the steady state production rate of crude oil.
It has been decided to increase the oil production rate by 30% in two ways:
1-Decrease the well bore pressure.
2-Change the skin effect “s”.
a) Determine the reduction in wellbore pressure to increase the flow rate.
b) Determine the change in skin effect.
c) Although theoretically both methods should be applicable, which method is preferred (considering practical issues).
In above, an error was found in estimation of the drainage area. The actual drainage area was 50% lower. What would be the effect of this change in production rate? Calculate the new production rate.
Prepare a graph of production rate against drainage area and explain the result.
Is the production rate lower for a larger reservoir? Why? Explain
As a result of a number of wells drilled in the surrounding area of the well in above, the drainage area has been decreased by 20 percent and it is triangular (equilateral) in shape with the oil well at the center. Calculate the production rate. The average pressure is assumed to be 15% less than the reservoir boundary pressure.
I can see why you are having a problem with your question. You need to pay closer attention. This is not about oil refining at all but rather oil production.
February 27th, 2010 at 12:39 pm
I can see why you are having a problem with your question. You need to pay closer attention. This is not about oil refining at all but rather oil production.
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