There are two main types of sand

    In Choosing a filter size it is important  to know what type of sand is causing the problem.

       Formation Sand:   

        This sand is smaller than other sands and is usually irregular in size.

Frac Sand:

        This Sand is larger than the formation sand and is very uniform.

        Frac sand is usually the most abrasive.

What is a slot Size ?

    A slot size is the opening or gap between the Vee-wires, which determines the filtration size.

    (Example: an 18 slot screen has an opening of 18/1000ths)

How do I determine a slot size ?

    Larger slot openings will have less plugging. Ideally, you want to filter out 70% of the sand.

    Normal recommendations are 18-25 slot for fracture sand and 12 slot for formation sand.

How do I determine the length ?

    Length is a critical factor in sand screen use. Most plugging occurs when the sand velocity

    is too fast, causing sand to become wedged in the opening. The longer the length, the slower the velocity.

    Six to eight foot lengths are recommended.