Perforating gun assembly to control wellbore fluid dynamics

Abstract

A downhole tool used in the pressure isolation of adjacent subterranean formations. The downhole tool may comprise flow restriction devices along the outer circumference for impeding flow along the length of the tool. The tool may further comprise a perforating gun and an accumulator. Impeding flow along the length of the tool provides a dynamic flow restriction within the wellbore that precludes fluid flowing from one subterranean zone to an adjacent zone.

1 . A perforating system comprising:
 a perforating string;   first and second perforating guns that are spaced apart within the perforation string;   shaped charges in each of the first and second guns; and   a zonal isolation system comprising plates that are axially spaced apart and project radially outward from an outer surface of and around the perforating string for restricting fluid flow in an annular space between the member and a borehole wall and causes a pressure drop in the fluid flow in the annular space so that the pressure in a fluid flowing from a higher pressure producing zone is reduced in the annular space and does not flow into a lower pressure producing zone.   
     
     
         2 . The perforating system of  claim 1 , further comprising passages formed through the plates. 
     
     
         3 . The perforating system of  claim 1 , wherein the diameters of the plates vary. 
     
     
         4 . The perforating system of  claim 1 , wherein the zonal isolation system is disposed on one of the first or second perforating guns. 
     
     
         5 . The perforating system of  claim 1 , wherein the zonal isolation system is disposed between the first and second perforating guns. 
     
     
         6 . The perforating system of  claim 1 , further comprising a sub connected between the first and second perforating guns, wherein the zonal isolation system is disposed on the sub. 
     
     
         7 . The perforating system of  claim 1 , wherein the zonal isolation system comprises a first zonal isolation system, the perforating system further comprising a second zonal isolation system. 
     
     
         8 . A perforating system comprising:
 a. a perforating string;   b. shaped charges in the perforating string;   c. a stack of axially spaced apart plates that extend radially outward from the perforating string to define a restricted flow area between a portion of the perforating string and a wellbore wall when the perforating string is in a wellbore, so that when shaped charges in the perforating string are detonated and form perforations into formation zones adjacent the wellbore and having different pressures, fluid communication between the respective formations is impeded by the plates.   
     
     
         9 . The perforating system of  claim 8 , wherein the perforating string includes perforating guns stacked end to end. 
     
     
         10 . The perforating system of  claim 8 , wherein the plates are for directing fluid from one of the formations along a labyrinthine path for reducing pressure in the fluid. 
     
     
         11 . The perforating system of  claim 8 , further passages formed axially through the plates. 
     
     
         12 . The perforating system of  claim 11 , wherein the passages in adjacent plates are offset from one another. 
     
     
         13 . The perforating system of  claim 8 , wherein diameters of the plates varies. 
     
     
         14 . A method of dynamically isolating flow within a wellbore between a first subterranean formation zone and a second subterranean formation zone that is at a different pressure than the first subterranean formation zone, the method comprising:
 a. providing a downhole tool in a wellbore that comprises an outer surface, and a pressure isolation system that has axially spaced apart plates that extend radially outward from the outer surface of the downhole tool to define a restricted flow annulus between the member and the wellbore,   b. inducing connate fluid flow from within the first subterranean formation zone;   c. inducing connate fluid flow from within the second subterranean formation zone; and   d. dynamically creating a pressure drop between the first and second subterranean formation zones of different pressures by locating the restricted flow annulus between the first and second subterranean formation zones and reducing pressure in the connate fluid from the subterranean formation zone having a higher pressure, so that flow from the subterranean formation zone having the higher pressure does not flow into the other subterranean formation zone.   
     
     
         15 . The method of  claim 14 , wherein the plates are configured to form a labyrinthine path for connate fluid flow along the downhole tool. 
     
     
         16 . The method of  claim 15 , wherein the labyrinthine path is formed by providing passages through the plates and positioning the passages in each plate to be axially offset from passages in an adjacent plate. 
     
     
         17 . The method of  claim 15 , wherein the labyrinthine path is formed by varying the diameter of plates that are adjacent.