Dear Wayne ...
I get e-mails and phone calls from drillers from all over asking me questions about different things. And because I would rather talk to drillers than most anyone else, I have a good time on the phone - or the net - most evenings. My wife wonders what the heck I'm doing in here anyway. Of course, she's in the den watching Vanna turn the letters, so I have to wonder what the heck she's doing.
Most of the drilling questions and answers are covered in pretty short order; then we can get down to swapping lies for an hour or so. I've decided to write up some of the most common questions and answers - "Dear Abby" style - and pass them along.
Dear Wayne: What is specific capacity and how do I use it?
Bubba, in Texas
Dear Bubba: First of all, it's not the amount of beer your brother-in-law can drink and still walk.
Specific capacity is the relationship we find between the amount of water a well will produce and the drawdown. It is expressed by dividing the pumping rate by the drawdown. For example: A well produces 20 gpm and draws down 5 feet (from static). Twenty divided by five equals 4 gallons of water for each foot of drawdown. If you pumped the well at 40 gpm, you could expect a drawdown of 10 feet. The specific capacity still would be 4 gpm/ft. of drawdown. This explanation is pretty simplified and there are plenty other things to take into account, such as sustained rate, recovery, etc.
I hope this information helps. If not, go back to trying to figure out you brother-in-laws' specific capacity (if he's buying).
Dear Wayne: How do I decide what slot-size screen to run?
Jim, in South Carolina
Dear Jimbo: At my house, I use a screen that keeps the blue-bottle flies out. The occasional gnat slips through, but they usually head for my wife (she bathes more often).
Actually, a screen is used to keep out most of the formation, while allowing maximum production. Too large and the well makes sand; too small and the well doesn't produce enough. The trick is to get good samples. You don't need to keep all of the sand out; development will pull the fines out and make a better well. If you get good, clean samples, you can send them to your screen company and those people can recommend a slot size. After a while, you'll have a good idea what size to run in a given formation.
Dear Wayne: My wife wants to keep my books for me. Do you think this is a good idea?
Ansle, in West Virginia
Dear Ansle: If she's a pretty sharp bookkeeper, you can't get a better partner. But if she's like one of my ex-wives, it'd be like putting the liberals in charge of the treasury!
These, and many more, are the kind of questions I get every day. In the coming months, I'll try to pass along the more interesting ones. If you have any questions, or want to disagree with anything I write, you can e-mail rockbit@compuserve.com, call me at 912-265-1839, or write your own letter or column for publication.
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