This Continuous slot screen are manufactured by a v or wedge shape wire around an internal array of longitudinal support rods . Each intersecting point of these wire is fusion welded , the v or wedge shaped profile wire wraps around the support rods over the full length of the screen creating a continuous slot opening . Hence the screen allows water or oil to enter well freely in ample quantities while at the same time keeps the majority of sand and gravel out of the well .