WoldWide Drilling Resource

Well Screens ~ Keeping it Clean Adapted from Information by Alloy Machine Works, Inc. Every day, 83.3 billion gallons of groundwater are pumped in the United States. In fact, nearly half of the U.S. population depends on groundwater for its drinking water supply. One issue many wells contend with is sand and gravel intrusion. Well screens can help alleviate those problems by acting as a filtering device, allowing water to move into the well, while keeping out gravel and sand. Alloy Screen Works, a division of Alloy Machine Works, Inc. has been producing industrial-quality screens since 1998. The company’s Drive Point Screens are rod-based, wedge-wire wrapped screens. The large inlet area provides maximum water flow, while the continuous slot allows more open area than conventional gauze-type drive points made on pipe. The nonclogging slots are formed by wedge-shaped wire, wrapped spirally around preset vertical base rods, and specially welded at each point of contact. The wire wraps are precision spaced giving uniform slot tolerance throughout the length of the screen. Wedge- shaped wire forms “V” shaped openings between wraps, which provide self-cleaning action and greatly reduce flow friction. Small particles are easily passed through the continuous slot, while larger ones are held out without inhibiting the total inlet area. The Alpha rod-based, wedge-wire wrapped sand screen provides more open area than other well screen designs. It is versatile and easily adapted to several types of in- dustrial and water well applications. Its continuous slot design reduces encrustation and helps prevent plugging while preventing sand from damaging pumps. The wire-wrapped design produces flow rates almost three times higher than bridge- slot screens, and almost ten times higher than slotted pipe. These screens are customized to exact specifications using a sophisticated, electron- ically-controlled fusion welding process. It provides maximum flow, improved well effi- ciency, and superior tensile strength for dependability and long well life. With over 150 years of combined industry experience, the company’s technical staff has knowledge specific to the screen industry. Their unique problem-solving skills have assisted companies in the gas and oil, water well, environmental, and other industries. A. Support Rods The structure and number of support rods provide strength. The rods are made of the same material as the wrap wire to prevent corrosion. C. End Fittings All standard and custom-made fittings are rigidly secured to the screen body. B. Screen Wrap Wire V-shaped wire welded at each junction with a support rod provides a self-cleaning action for better flow and less chance of plugging. WTR Alpha Drive Point 49 WorldWide Drilling Resource ® JULY 2019