In a open loop system, starting with well water at ~55F.  How many gallons are needed to produce X amount of BTU's.  I am looking for approximate numbers.  I know that there is other factors, like efficiently of unit.  Say 100 gl will produce 30000 per hour,  or is it 1000 or 100000?  I have found that the well needs produce from 6 to 10 gallons per Minute.  Thank you

The formula is Delta T * GPM* 500 = BTHh.

So if you take 10° out of the well water and you have 10 GPM *500 then you have 50,000 BTUh

Ok Lets say that my house by heat loss need 50,000 btu  and my well supplies 10 gpm, the heat pump removes 10F.  How much water is used per hour at a certian Oustside temp.  I know there is a lot of veriables. 
 What I am trying to wrap my head around is,  How much water output I will be dealing with.  I found on one site that output is around 6,000 gallons per day!   That is way more than I know what to do with.  Plus it sounds very high to me.  I hope this make sence to you.

So if your heat loss is 50,000 btuh and your heat pump is running non stop in the middle of the winter, then at 10 gpm * 60 minutes in an hour * 24 hours in a day .

So 10 *60 * 24 = 14,400 gallons in a day. This would only happen on a day when it was cold enough out side to keep you heat pump going non stop. This shouldn't happen very often.. If your heat pump runs 50% of the time, then you have 7,200 in a day. 25% then 3600. Any way you look at it, it is a lot of water.

Wow that is alot!   If that water is dumped on one acre that would = 1/2 inch of rain per acre per day.  That I could deal with in middle of summer, but in the winter.   Thanks for the help!

for a real world example, when i lived on the farm i heated a poorly insulated 1300 sq ft bungalow with a 3.5ton, my incoming water temps were about 58, my supply well was 47 feet deep, and i required 4 to 5 gpm early in the winter, later in the winter, close to spring i would need 5 to 6 gpms to keep it from freezing up, the well's capacity was around 6 gpm so i kept close tabs on it and ran it close to the edge most of the time, as the well also supplied my domestic water. my return well was a old wooden cribbed well that was 20 feet deep or so and only 15 feet from my supply well, i suspect the supply well was getting cooled off from the return well, this would explain why i need more water later in the winter. the return wel was not capable of accepting all the water, it over flowed daily, ran into a near by creek. this is southern saskatchewan canada, winter temps are normaly -20, sometimes dipping down to -40. this system managed to keep up but probably ran 50 minutes an hour when it was -40, or -20 and windy, so it used a considerable amount of water. in the event of a freeze up, i would switch it over to AC for a minute, you could literaly see the chunks of ice going through the flow meter. do to poor water quality this system needed regular maintainance. i had a pre filter that needed weekly cleaning, once a year i had to flush the heatpump with muriatic acid (copronickel coil required). i am much happier with my closed loop, and well insulated house.