WorldWide Drilling Resource

23 WorldWide Drilling Resource ® APRIL 2015 Environmental Monitoring by Thomas Kwader, Ph.D., P.G. Developing Wells with Compressed Air Developing wells is an important task all well drilling professionals should do before they complete any type of well. Development “repairs or restores” the damage done during the drilling of a well, often associated with smearing, compacting, and plugging the borehole wall. A properly developed well will cre- ate more water and clearer water than an undeveloped well. If a well is prima- rily used for supply, the amount of money saved in energy costs due to develop- ment, over the life of the well can be more than the price of the well. There are many methods of well development, including: surge block, bailing, rawhiding, overpumping, sonic- bursts, jetting, and compressed air. Personally, I have used and seen all these methods, and their effectiveness depends on actual well construction, depth, and physical characteristics of the well. The best way of developing a well involves stressing it by pumping out of the well with an occasional surge or a slug of water flowing into the borehole formation. This “surging” action allows for clearing the passageways (or screen slots) at and near the borehole wall. If the water is only pumped out of the well, bridging will occur in the formation or screen, and will tend to plug the openings. The flow must be reversed occasional- ly to “break the bridges” for subsequent removal of the particles from the well. Development by air alone is gen- erally not effective. Assuming an airline is placed near the bottom of the well and a pulse of air is suddenly released, the column of water will begin to rise from the bottom and actually force water out of the well at higher elevations, below the bottom of the casing, decreasing the velocity and volume upwards. In larger wells, the air bubbles may “train” along one side of the casing, lifting very little water (and sediment) out of the well. At the top of the well it may look like a lot of development is taking place, but actu- ally it is not. Pulsing the air will allow the water to fall and have some rever- sal of flow or surging. It is recommended to alternate air bursts with a surge block (snug-fitting disc) to break the bridges by forcing water back into the formation, then hitting it with air again, to create the surging action. Tom Tom Kwader may be contacted via e-mail at michele@ worldwidedrillingresource.com DEADLINES: Space Reservation - A PRIL 25 TH Display & Classified Ad Copy - M Ay 1 ST GOT TANKS? Don’t miss an opportunity to be in WWDR ’s June issue all about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