Abstract: Methods for cleaning sand from a helical spring sand filter, methods for assembling a self-cleaning helical spring sand filter, and a self-cleaning helical spring sand filter for use at the petroliferous unconsolidated sand strata of an oil well are disclosed. The filter comprises a helical spring connected in tension at each end to an elongated perforated sleeve for spacing apart all convolutions by a predetermined distance for forming the filter. One or more washer shaped cleaning rings with square holes therein are mounted between adjacent convolutions at one end of the spring for being rotated by a square ended rod supported by a sucker rod in a well between all of the convolutions to the spring other end for scraping off all foreign material from between the convolutions. The spring sand filter can be cleaned for as many times as there are cleaning rings instead of making trips to the surface for unclogging.