Question 2) The unsteady state partial differential diffusivity equation could also be written as follows: + 2 1 1 r dr at 0.000264k n = The units are k [mD], r[ft], P[psia],c[1], t[hrs], and [cp]. Assuming the initial reservoir pressure is P; at all points before the production initiate and an infinite acting reservoir (reco) and constant flow rate in a cylindrical reservoir the following analytical solution would be obtained: P(r,t) = P + [70.6QBo kh -9480cr2 E( kt The units are k [mD],r[ft], P[psia],c[+], t[hrs], Q[ST], and [cp]. Day Using the above equation, the reservoir pressure could be calculated at different times for each point in the reservoir. E is simply a mathematical function that is represented by the following graph. Therefore, by -9480cr2 -9480cr2 calculating the term and locating it on the x-axis of the graph, E( kt kt could be read from the y-axis. 10 8 6 43 2 1 EXPONENTIAL INTEGRAL VALUES 9-C E;(-x) = -du x For x