Swift multi-cycle ball-activated circulation sub

Abstract

Aspects of the present invention generally relates to downhole drilling operations. Particularly, the present invention relates to methods and apparatus to provide remote control of flow communication between inner passage flow and annulus depending on the circumstances where it might be needed. The invention is installed as part of the drilling string comprises of a body, a sleeve, a barrel cam, a restrictor, a ball, a resilient element, and a housing embodying all the elements. The ball is introduced from surface to activate the apparatus.

1 . A swift circulating sub for changing fluid flow profile within a wellbore comprising:
 A sub body having two end connections for connecting to a drilling string, an inner surface and an outer surface;   A port disposed within the sub body in a lateral position to hydraulically connect the inner surface and the annulus;   An inner flow passage within the sub body hydraulically connected to surface;   A sleeve disposed within the inner flow passage movable in at least one direction within the sub body;   An orifice disposed at one end of the sleeve;   A resilient element to bias the sleeve in one direction;   A ball having a predefined shape;   A restrictor disposed within the sleeve;   A barrel cam disposed between the sub body inner surface and the sleeve having a surface axially engaged with the sleeve;   A cam track disposed on the barrel cam surface having a first post, a second post and a ball release post   A cam follower disposed on a lateral position within the sub body linked to the cam track for controlling the movement of the barrel cam;   A ball catcher comprising:
 A catcher body connected at one end to the sub body; 
 A ball trap; 
   
     
     
         2 . The apparatus of  claim 1  wherein the all catcher further comprises an element selected from the set comprising: a ball guide, an access passage, and a ball stopper 
     
     
         3 . The apparatus of  claim 1  further comprising an energy harvesting means for forcing the sleeve to one end under the differential pressure between the inner flow passage and the annulus 
     
     
         4 . The apparatus of  claim 1  further comprising component compartment defined as the volume between a portion of the sub body inner surface and a portion of the sleeve outer surface that include the cam; the apparatus further comprises an isolation piston for restricting mud communication between the inner flow passage and the component compartment 
     
     
         5 . The apparatus of  claim 4  wherein the component compartment is filled with fluid having low solid content; 
     
     
         6 . The apparatus of  claim 5  wherein the isolation piston is movable with respect to at least one of the sleeve external surface and the sub body inner surface for equalizing pressure between the inner flow passage and the pressure within the component compartment;