kh(pi - Pwf) 162.6B logt + log k Qc, r 3.23) In Eq. (2-7), the skin effect must be added inside the large parentheses as 0.87s. Assum- ing that the skin effect is equal to 10, calculate the performance for 1 year and compare it with the performance of a well with zero skin. What will the ratio of the flow rates be after 6 months? Continue Problem 2-2. Assume that the price of oil is $25. The discount rate (time value of money) is 0.15. Calculate the net present value (NPV) for the expected cumulative production of the first 3 years. [NPV = (ANp)n/(1+i)", where (AND), is the cumulative production in year n and i is the discount rate.] What are the fractional contributions from each year on the 3-year NPV?