What is the most economical diameter of a pipeline that is required to transport crude oil ( ¼ 30 cP, SG ¼ 0:95) at a rate of 1 million bbl/day using ANSI 1500# pipe if the cost of energy is $0.05/kWh...

What is the most economical diameter of a pipeline that is required to transport crude oil ( ¼ 30 cP, SG ¼ 0:95) at a rate of 1 million bbl/day using ANSI 1500# pipe if the cost of energy is $0.05/kWh (in 1980 dollars), the economic lifetime of the pipeline is 40 yr, and the pumps are 50% efficient.