1. Pump It Up: Pump Jacks [10pts]

You've just been promoted to field engineer at the San Ardo oilfield, and your first task is to determine how much oil is producedeach day by one of the wells. You know that the oil is produced bythe hole pump, which extends to the bottom of the well, and thepump jack on the surface, which powers the hole pump's stroke. Onthe up-­stroke of the pump jack, fluid is drawn into the hole pump,and on the down-­stroke that fluid is forced out of the well. Thepump jack has a stroke length of 180 inches, and pumps at 10strokes per minute. That is, the pump completes an up and downstroke 10 times every minute. The cylindrical hole pump has thesame stroke length as the pump jack, and has a diameter of 4.5inches.

1. Dig into your high school geometry (the relevant quantity isthe volume of the cylindrical hole pump) and determine howmany barrels of oil this well produces each day. Assume that the fluid pumped from the wells at San Ardo is onlyabout 6% oil. Be sure to state any other assumptions. [4pts]
   
   
   

2. What is the ratio of energy (in %) consumed in running the pumpjack to energy content in the extracted oil over a year? Assumethat the pump is run 24/7 on a 50 horsepower motor. Usefulconversions: 6.1X10⁹ J/barrel of crude oil. 1 HP = 745W[4 pts]

3. If you assume that only 1% of the energy in oil goes to auseful end use (this is an overestimate, since it’s only 1% of thegasoline that moves you in your vehicle!), what is theratio of energy consumed in running the pump jack to the energy inthe oil that goes to a useful end use (in %)? [2 pts]