Mid-string mud cap downhole tool and methods of use

Abstract

A well system includes a drillstring extended within a wellbore penetrating first and second lost circulation zones, a drill bit arranged at a downhole end of the drillstring, and a mid-string mud cap tool included in the drillstring and arranged uphole from the drill bit. The mid-string mud cap tool includes a body that defines an interior, one or more ports defined in the body to facilitate fluid communication between the interior and the annulus, and a ball seat provided within the interior. A wellbore projectile is conveyable into the drillstring to land on the ball seat. The mid-string mud cap tool is arranged at a location between the lost circulation zones, and landing the wellbore projectile on the ball seat causes a portion of drilling fluid circulating within the drillstring to circulate into the annulus via the ports and between the lost circulation zones.

1 . A well system, comprising:
 a drillstring extended within a wellbore such that an annulus is defined between the drillstring and the wellbore, the wellbore penetrating a formation including first and second lost circulation zones;   a drill bit arranged at a downhole end of the drillstring;   a mid-string mud cap tool included in the drillstring and arranged uphole from the drill bit, the mid-string mud cap tool including:
 a body that defines an interior; 
 one or more ports defined in the body to facilitate fluid communication between the interior and directly into the annulus; and 
 a ball seat provided within the interior downhole from the one or more ports; and 
   a wellbore projectile conveyable into the drillstring and sized to land on the ball seat,   wherein the mid-string mud cap tool is arranged within the wellbore at a location between the first and second lost circulation zones, and   wherein landing the wellbore projectile on the ball seat causes a portion of drilling fluid circulating within the drillstring to circulate into the annulus via the one or more ports and at the location between the first and second lost circulation zones.   
     
     
         2 . The well system of  claim 1 , wherein the drill bit and the mid-string mud cap tool form part of a bottom hole assembly. 
     
     
         3 . The well system of  claim 1 , wherein the mid-string mud cap tool further includes a sleeve arranged within the interior and operatively coupled to the ball seat such that landing the wellbore projectile on the ball seat causes the ball seat to shift and thereby transition the sleeve between a closed position, where the sleeve occludes the one or more ports, and an open position, where the one or more ports are exposed. 
     
     
         4 . The well system of  claim 3 , wherein increasing a pressure within the drillstring causes the ball seat and the sleeve to shift within the interior. 
     
     
         5 . The well system of  claim 3 , wherein the sleeve is actuated using at least one of a motor, a servo, a hydraulic actuation system, and any combination thereof. 
     
     
         6 . The well system of  claim 3 , wherein transitioning the sleeve to the open position causes a first portion of the drilling fluid within the drillstring to be diverted through the one or more ports, while a second portion of the drilling fluid bypasses the wellbore projectile and is discharged into the annulus at the drill bit. 
     
     
         7 . The well system of  claim 6 , wherein the first portion of the drilling fluid comprises about 10% to about 20% of the drilling fluid within the drillstring. 
     
     
         8 . The well system of  claim 6 , wherein a second volume of drilling fluid is pumped into the annulus from a well surface and migrates into the first lost circulation zone, wherein the second portion of the drilling fluid migrates into the second lost circulation zone, and wherein the first portion of the drilling fluid maintains a hydrostatic column of the drilling fluid within the annulus between the first and second lost circulation zones. 
     
     
         9 . The well system of  claim 1 , wherein the first and second lost circulation zones exhibit a pore pressure that is less than a hydrostatic pressure of the drilling fluid circulating in the drillstring. 
     
     
         10 . The well system of  claim 1 , wherein the diameter of the ball seat is sized smaller than the diameter of the wellbore projectile. 
     
     
         11 . A method, comprising:
 extending a drillstring into a wellbore penetrating a formation including first and second lost circulation zones, the drillstring including a drill bit and a mid-string mud cap tool arranged uphole from the drill bit, the mid-string mud cap tool including:
 a body that defines an interior; 
 one or more ports defined in the body to facilitate fluid communication between the interior and directly into an annulus defined between the drillstring and an inner wall of the wellbore; and 
 a ball seat provided within the interior; 
   advancing the drillstring until the mid-string mud cap tool is positioned within the wellbore to axially interpose the first and second lost circulation zones;   pumping a first volume of drilling fluid through the drillstring;   conveying a wellbore projectile into the drillstring and landing the wellbore projectile on the ball seat; and   diverting a portion of the first volume of the drilling fluid directly into the annulus via the one or more ports and at the location between the first and second lost circulation zones.   
     
     
         12 . The method of  claim 11 , wherein the mid-string mud cap tool further includes a sleeve arranged within the interior and operatively coupled to the ball seat, and wherein landing the wellbore projectile on the ball seat comprises:
 increasing a fluid pressure within the drillstring; and   moving the ball seat downhole within the interior and thereby transitioning the sleeve from a closed position, where the sleeve occludes the one or more ports, to an open position, where the one or more ports are exposed.   
     
     
         13 . The method of  claim 11 , wherein the portion of the first volume of the drilling fluid comprises a first portion, the method further comprising:
 bypassing the ball seat and the wellbore projectile with a second portion of the first volume of the drilling fluid; and   discharging the second portion of the first volume of the drilling fluid from the drill bit and into the annulus.   
     
     
         14 . The method of  claim 13 , wherein the first portion of the first volume of the drilling fluid comprises about 10% to about 20% of the drilling fluid within the drillstring. 
     
     
         15 . The method of  claim 13 , further comprising:
 pumping a second volume of drilling fluid into the annulus from a well surface;   flowing the second volume of the drilling fluid to the first lost circulation zone;   flowing the second portion of the first volume of the drilling fluid to the second lost circulation zone; and   maintaining a hydrostatic column of the drilling fluid within the annulus between the first and second lost circulation zones with the first portion of the first volume of the drilling fluid.   
     
     
         16 . The method of  claim 11 , wherein the mid-string mud cap tool further includes a sleeve arranged within the interior and operatively coupled to the ball seat, and wherein landing the wellbore projectile on the ball seat comprises:
 actuating the sleeve with at least one of a motor, a servo, and a hydraulic actuation system and thereby moving the ball seat downhole within the interior to transition the sleeve from a closed position, where the sleeve occludes the one or more ports, to an open position, where the one or more ports are exposed moving the.