Preacher,
I found a website to calculate the number of gallons in a vertical cylinder. Based on the cylinder (well) being 49 feet deep, 8 feet in diameter and filled only 25 feet deep: the well would have a "filled volume" of 9400.30 gallons. Total volume, if filled to the top, the well would contain 18,424.59 gallons.
Thank you NALT it was suppose to be 8" though not 8 Feet. RTR!