by Xenophobe » Sat 29 Jan 2011, 17:58:13
$this->bbcode_second_pass_quote('dsula', '
')Try this: My diesel powered pump is pumping oil from my backyard well. When do you think I will shut-off the pump?
A point in time between immediately, and some time in the future?
If you are really asking an honest question about a standard oilfield pumpjack, we need more information. What is the cost of diesel fuel? How often do you run the motor? How many oil changes do you normally do on the surface diesel engine? If this is a standard oilfield pumpjack, we need to know the cost of the lubricating oil in the gearbox and the frequency of maintenance? Grease for the stuffing box? How often does the downhole pump need replaced, and the costs? Do we wish to include the costs related to the MTBF of the rods themselves? What is the expected capital cost of replacement with an electric motor and attendant windmill? What is the oil worth? What are the severance and ad valorum taxes in your state? How do you value your time? Have you fully depreciated the equipment yet? Do you wish to factor in the salvage costs, and revenue, in this calculation? In which case, could we have information on the size and configuration of the casing string? How many strings? Tagged in, or cemented to surface? On which strings? What is the size and overall shape of the tubing and rods? Which cementing company do you prefer, and how do you wish to free the casing, ripping it or shooting it?
If we knew all of this operating level information, we still wouldn't know for sure exactly when, or why, you might wish to stop pumping this oil. And therefore, the original answer is still valid.