By Jack Money Business Writer jmoney@oklahoman.comSand costs for hydraulically fractured wells can eat away at profit. But one company aims to help well operators by getting them the sand they need at a more affordable price. Pennsylvania-based Preferred Proppants, LLC (also known as Preferred Sands) is building an "in-basin" frack sand mine in Oakwood, west-northwest of Watonga, to serve well operators in Oklahoma's STACK and SCOOP plays, it has announced. Work to build the project already has started with plans for it to go online in the third quarter, and Preferred representatives said they now are filling about 100 positions needed to operate the mine. T.J.