Patent ID: 6296055
Filing Date: 2001-10-02
Classification: E21B

Abstract:
A drill collar based retrievable drilling fluid filter and drill string wiper tool for subterranean drilling operations, comprising;a) a filter collar dimensioned for inclusion within a drill string with a central bore forming a drilling fluid passageway and a receiver for a filter and wiper unit,b) the filter and wiper unit include a filter insert slidably received by an elongated wiper carrier, the filter insert and filter collar includes a plurality of longitudinally positioned splines and interruptions which fragment the drilling fluid passageway into numerous drilling fluid passageways which block a flow of particles in the drilling fluid, the splines and interruptions vary in number and alignment from an upper end of the tool where the numerous drilling fluid passageways are largest to a lower end of the tool where the numerous drilling fluid passageways are smallest,c) the elongated wiper carrier includes numerous wiper brushes that are enclosed within a wiper brush receiving cylinder when the tool is in an operational position and removed from the wiper brush receiving cylinder before the wiper brushes are removed from the filter collar.