Treatment string and method of use thereof

Abstract

A tubular member is presented for treating a subterranean formation, the tubular member being insertable in a wellbore intersecting the subterranean formation and adapted to receive a treatment fluid under pressure. The tubular member comprises at least one assembly having at least one port; a straddle system comprising an upper packer uphole of the at least one assembly and a lower packer downhole of the at least one assembly to isolate an annular interval adjacent the ported assembly between the tubular member and the wellbore; and at least one flow diverter valve positioned uphole from the upper packer for diverting fluid from within the tubular member through an annulus between the tubular member and the wellbore to surface. Methods are further provided for treating a subteranian formation

We claim: 
     
         1 . A tubular member for treating a subterranean formation, the tubular member being insertable in a wellbore intersecting the subterranean formation and adapted to receive a treatment fluid under pressure, the tubular member comprising:
 a. at least one assembly having at least one port;   b. a straddle system comprising an upper packer uphole of the at least one assembly and a lower packer downhole of the at least one assembly to isolate an annular interval adjacent the ported assembly between the tubular member and the wellbore; and   c. at least one flow diverter valve positioned uphole from the upper packer for diverting fluid from within the tubular member through an annulus between the tubular member and the wellbore to surface.   
     
     
         2 . The tubular member of  claim 1 , wherein each of the one or more flow diverter valves comprises: an inner ported sleeve shiftable within an outer ported sleeve, wherein said inner ported sleeve is shiftable from a first position in which one or more ports on the inner ported sleeve are misaligned with one or more ports on the outer ported sleeve, to a second position in which one or more ports on the inner ported sleeve are aligned with one or more ports on the outer ported sleeve. 
     
     
         3 . The tubular member of  claim 2 , wherein the inner sleeve is shiftable by hydraulic pressure. 
     
     
         4 . The tubular member of  claim 1 , further comprising at least one bypass valve located downhole of the lower packer for circulating treatment fluid from within the tubular member through the annulus between the tubular member and the wellbore downhole of lower packer. 
     
     
         5 . A method for treating a subteranian formation, comprising:
 a. inserting a tubular member into a wellbore intersecting the subterranean formation, the tubular member being adapted to receive a treatment fluid under pressure and comprising at least one ported assembly and one or more flow diverter valves positioned uphole of said ported assembly;   b. setting an isolation device in an annulus between the tubular member and the wellbore for hydraulically isolating intervals in the annulus at locations adjacent the at least one ported assembly;   c. flowing a first treatment fluid under pressure into the at least one isolated ported assembly to treat the formation in the isolated interval of the wellbore by pressurized treatment fluid flowing from the ported assembly;   d. opening one or more flow diverter valves positioned uphole of the isolated assembly; and   e. diverting the first treatment fluid from within the tubular member through the flow diverter valve, through the annulus to surface.   
     
     
         6 . The method of  claim 5 , wherein diverting the first treatment fluid through the annulus to surface balances pressure around the isolation device and prevents egress of formation fluid from treated interval into the wellbore and up to surface. 
     
     
         7 . A method for treating a subteranian formation, the method comprising:
 a. inserting a tubular member into a wellbore intersecting the subterranean formation, the tubular member being adapted to receive a treatment fluid under pressure and comprising plurality of ported assemblies spaced at intervals along a length of the tubular member and one or more flow diverter valves positioned uphole of each of said ported assemblies;   b. setting an isolation device to hydraulically isolate a first at least one interval in the annulus, said first at least one interval having at least one first ported assembly positioned therein;   c. flowing treatment fluid under pressure through the first ported assembly and allowing treatment of the formation in the first isolated interval of the wellbore by the pressurized treatment fluid; and   d. repeating the steps of:
 i. releasing treatment fluid pressure; 
 ii. opening one or more flow diverter valves positioned uphole of the isolated interval; 
 iii. circulating treatment fluid from within the tubular member through the one or more flow diverter valves into the annulus uphole of the isolated interval, to equalize annular pressure above the isolated interval with annular pressure within the isolated interval; 
 iv. simultaneously moving the tubular member to a subsequent interval of the wellbore, said subsequent interval comprising at least one subsequent ported assembly; 
 v. setting the isolation device to hydraulically isolate the subsequent at least one interval in the annulus; and 
 vi. flowing treatment fluid under pressure through the at least one subsequent ported assembly to the formation in the isolated subsequent intervals of the wellbore by the pressurized treatment fluid. 
   
     
     
         8 . The method of  claim 7 , wherein the tubular member is moved downhole for treating the wellbore therebelow. 
     
     
         9 . The method of  claim 7 , wherein the tubular member is moved uphole for treating the wellbore thereabove. 
     
     
         10 . The method of  claim 7 , wherein diverting treatment fluid from within the tubular member through the one or more opened flow diverter valves prevents migration of fluid from the isolated treated interval up the annulus to surface. 
     
     
         11 . The method of  claim 7 , further comprising, prior to moving the tubular member:
 i. opening at least one bypass valve located downhole of the isolated interval; and   ii. circulating treatment fluid from within the tubular member through the at least one bypass valve into the annulus downhole of the isolated assembly simultaneously while moving the tubular member, to equalizing annular pressure below the isolated interval with annular pressure within the isolated interval.   
     
     
         12 . A method for treating one or more isolated intervals of a subteranian formation, the method comprising:
 a. flowing treatment fluid under pressure through a first ported assembly on a tubular member and allowing treatment of the formation in a first isolated interval by the pressurized treatment fluid;   b. moving the tubular member to a subsequent interval of the wellbore, said subsequent interval comprising at least one subsequent ported assembly; and   c. simulataneously circulating treatment fluid from within the tubular member through one or more flow diverter valves into an annulus uphole of the first isolated interval while moving the tubular member.