In situ injection or production via a well using dart-actuated valve assemblies and related system and method

Abstract

An actuation dart for deployment down a tubing string installed within a wellbore and provided with one or more valve assemblies is provided. The actuation dart includes a dart body adapted to be carried down the tubing string to the valve assembly via fluid flow. The dart body has a shifting head provided at a first end of the dart body, the shifting head being configured to engage and shift the valve assembly in the open configuration to enable fluid injection in a reservoir surrounding the wellbore. A method for hydrocarbon recovery from a wellbore using the actuation dart is also provided, along with a wellbore system adapted to receive the actuation dart.

1 . A method for treating a hydrocarbon bearing reservoir, comprising:
 running a tubing string into an existing well previously operated for primary production to define an annulus between the tubing string and a wellbore, and defining a plurality of wellbore intervals isolated from one another along the well defined by isolation devices deployed in spaced-apart relation to each other within the annulus;   for multiple wellbore intervals, installing a corresponding valve assembly along the tubing string, the valve assembly comprising at least one valve, each valve being operable in at least one of a closed configuration for preventing fluid flow into the surrounding reservoir and an open configuration for establishing fluid communication between the tubing string and the surrounding reservoir via respective fluid passages, the fluid passage of at least one valve being elongated and configured such that the open configuration of the corresponding valve is a flow restricted configuration where fluid flowrate from the tubing string into the reservoir is restricted;   deploying an actuation dart within the tubing string; and   injecting at least one fluid down the tubing string to carry the actuation dart along the tubing string via fluid flow so as to pass through the wellbore intervals and operate the valves in the open configuration for allowing the at least one fluid to flow along the fluid passage and enter the reservoir at the corresponding wellbore interval.   
     
     
         2 . The method of  claim 1 , wherein each valve comprises a corresponding valve housing provided with a valve sleeve slidably mounted therein, the valve housing comprising a fluid outlet communicating with the fluid passage of the valve for allowing injection fluid to flow from the tubing string to the surrounding reservoir. 
     
     
         3 . The method of  claim 2 , wherein each valve sleeve is operable in a central position, an uphole position and a downhole position, the position of the valve sleeves within their respective valve housings corresponding to an operational configuration of the respective valves. 
     
     
         4 . The method of  claim 3 , wherein each valve sleeve is initially in the central position when the valves are installed along the tubing string and while the tubing string is run into the wellbore, and wherein the actuation dart is configured to shift the valve sleeve downhole and into the open configuration. 
     
     
         5 . The method of any one of  claims 2 to 4 , wherein the valve sleeve comprises a fluid passage inlet communicating with the fluid passage, and wherein the fluid passage is defined by a channel in an outer surface of the valve sleeve and an inner surface of the housing that overlays the channel. 
     
     
         6 . The method of any one of  claims 1 to 5 , wherein the injected fluid used to carry the actuation dart includes water, diesel, drilling mud, produced water, produced gas, methane, CO 2 , nitrogen or a combination thereof. 
     
     
         7 . The method of any one of  claims 1 to 6 , wherein the fluid used to carry the actuation dart is injected within the tubing string via a pump. 
     
     
         8 . The method of  claim 7 , wherein the pump is located at surface. 
     
     
         9 . The method of  claim 7 or 8 , wherein the pump is adapted to generate fluid flow between about 20 L/min and about 1200 L/min. 
     
     
         10 . The method of  claim 9 , wherein the injected fluid is adapted to exert a pressure between about 20 psi and about 3000 psi on the actuation dart. 
     
     
         11 . The method of any one of  claims 2 to 10 , wherein the actuation dart comprises a dart head having an outer surface with a portion thereof being configured to engage a complementarily shaped portion of an inner surface of the valve sleeve and shift the valve sleeve in the open configuration. 
     
     
         12 . The method of  claim 11 , wherein the injected fluid is adapted to exert a pressure between about 100 psi and 3000 psi on the valve sleeve via the actuation dart to shift the valve sleeve in the open configuration. 
     
     
         13 . The method of  claim 11 or 12 , wherein the actuation dart comprises a dart tail connected to the dart head, the dart tail comprising an engagement surface for engaging an inner surface of the tubing string in order to guide the actuation dart as it is carried down the wellbore. 
     
     
         14 . An actuation dart for deployment down a tubing string installed within a wellbore and provided with one or more valve assemblies, comprising:
 a dart body adapted to be carried down the tubing string to the valve assembly via fluid flow, the dart body comprising:
 a shifting head provided at a first end of the dart body, the shifting head being configured to engage and shift the valve assembly in an open configuration to enable fluid injection in a reservoir surrounding the wellbore. 
   
     
     
         15 . The actuation dart of  claim 14 , wherein the shifting head comprises an abutment portion shaped and sized to engage a complementarily shaped portion of the valve assembly and shift the valve assembly in the open configuration. 
     
     
         16 . The actuation dart of  claim 15 , wherein the abutment portion is configured to compress inwardly when engaged with the valve assembly via pressure exerted on the actuation dart via fluid flow, thereby enabling the actuation dart to disengage from the valve assembly and allow the actuation dart to flow further downhole along the tubing string. 
     
     
         17 . The actuation dart of  claim 15 , wherein the dart body further comprises a dart tail connected to the shifting head, the dart tail comprising an engagement surface adapted to engage an inner surface of the tubing string in order to guide the actuation dart as it is carried down the wellbore. 
     
     
         18 . The actuation dart of  claim 16 , wherein the dart body comprises a crossover segment extending between and connecting the dart tail and the shifting head together. 
     
     
         19 . The actuation dart of  claim 17 , wherein the dart tail comprises a tubing cup connected to an uphole end of the crossover segment and having an uphole rim extending outwardly therefrom, and wherein the uphole rim includes the engagement surface for engaging the inner surface of the tubing string. 
     
     
         20 . The actuation dart of  claim 18 , wherein the dart body comprises a plurality of tubing cups connected together in an end-to-end manner. 
     
     
         21 . The actuation dart of  claim 18 or 19 , wherein the tubing cup comprises a cupped region extending generally transversely with respect to a passage of the tubing string, the cupped region being shaped and adapted to have fluid exert pressure thereon to push the actuation dart downhole. 
     
     
         22 . The actuation dart of  claim 21 , wherein the uphole rim substantially surrounds the cupped region of the tubing cup. 
     
     
         23 . A well system comprising:
 a tubing string installed in a wellbore;   a valve assembly provided along the tubing string, the valve assembly comprising at least one valve, each valve being operable in at least one of a closed configuration for preventing fluid flow into the surrounding reservoir and an open configuration for establishing fluid communication between the tubing string and the surrounding reservoir via respective fluid passages, the fluid passage of the at least one valve being elongated and configured such that the open configuration of the valve is a flow restricted configuration where fluid flowrate from the tubing string into the reservoir is restricted;   an actuation device adapted for deployment down the tubing string via fluid flow for engaging the valve assembly and shifting each valve in the open configuration; and   a pump for pumping fluid down the tubing string to carry the actuation device via fluid flow toward the valve assembly,   
       the actuation device being configured to engage and shift each valve of the valve assembly subsequently. 
     
     
         24 . The well system of  claim 23 , wherein each valve comprises a corresponding valve housing provided with a valve sleeve slidably mounted therein, the valve housing comprising a fluid outlet communicating with the fluid passage of the valve for allowing injection fluid to flow from the tubing string to the surrounding reservoir. 
     
     
         25 . The well system of  claim 24 , wherein each valve sleeve is operable in a central position, an uphole position and a downhole position, the position of the valve sleeves within their respective valve housings corresponding to an operational configuration of the respective valves. 
     
     
         26 . The well system of  claim 25 , wherein each valve sleeve is initially in the central position when the valves are installed along the tubing string and while the tubing string is run into the wellbore, and wherein the actuation dart is configured to shift the valve sleeve downhole. 
     
     
         27 . The well system of  claim 26 , wherein the central position corresponds to a first open configuration of the valve assembly defining a first fluid flowrate through the fluid outlet, and wherein shifting the valve sleeve in the downhole position operates the valve assembly in a second open configuration defining a second fluid flowrate through the fluid outlet. 
     
     
         28 . The well system of  claim 27 , wherein the first fluid flowrate is greater than the second fluid flowrate. 
     
     
         29 . The well system of  claim 27 or 28 , wherein when in the first open configuration, the fluid outlet is provided with a breakable barrier adapted to occlude the fluid outlet and prevent fluid communication between the fluid passage and the surrounding reservoir 
     
     
         30 . The well system of any one of  claims 25 to 29 , wherein the valve sleeve comprises a fluid passage inlet communicating with the fluid passage, and wherein the fluid passage is defined by a channel in an outer surface of the valve sleeve and an inner surface of the housing that overlays the channel. 
     
     
         31 . The well system of any one of  claims 23 to 30 , wherein the pumped fluid used to carry the actuation dart includes water, diesel, drilling mud, produced water, produced gas, methane, CO 2 , or nitrogen or a combination thereof. 
     
     
         32 . The well system of any one of  claims 23 to 31 , wherein the pump is located at surface. 
     
     
         33 . The well system of any one of  claims 23 to 32 , wherein the pump is adapted to generate fluid flow between about 20 L/min and about 1200 L/min. 
     
     
         34 . The well system of any one of  claims 23 to 33 , wherein the injected fluid is adapted to exert a pressure between about 20 psi and about 3000 psi on the actuation dart. 
     
     
         35 . The well system of any one of  claims 23 to 34 , wherein the injected fluid is adapted to exert a pressure between about 100 psi and 3000 psi on the valve sleeve via the actuation dart to shift the valve sleeve in the open configuration. 
     
     
         36 . The well system of any one of  claims 23 to 35 , wherein the actuation device comprises an actuation dart as defined in  claims 14 to 22 . 
     
     
         37 . The well system of any one of  claims 23 to 36 , wherein the wellbore is provided in a geothermal reservoir, and wherein fluids are produced as part of geothermal operations. 
     
     
         38 . A method for injecting fluids into a reservoir via a well system as defined in  claims 23 to 37 , comprising:
 deploying the actuation dart within the tubing string;   pumping fluid within the tubing string for carrying the actuation dart toward the valve assembly via fluid flow;   engaging the actuation dart with the valve assembly; and   pumping additional fluid within the tubing string for exerting pressure on the actuation dart and shifting the valve assembly in the open configuration.   
     
     
         39 . A method for injecting fluids into a reservoir via a well system comprising a wellbore provided with a tubing string, the tubing string comprising one or more valve assemblies operable between a closed configuration for preventing fluid flow into the surrounding reservoir and an open configuration for establishing fluid communication between the tubing string and the surrounding reservoir via respective fluid passages, the fluid passage of at least one valve assembly being elongated and configured such that the open configuration of the corresponding valve is a flow restricted configuration where fluid flowrate from the tubing string into the reservoir is restricted, the method comprising the steps of:
 deploying an actuation dart within the tubing string;   pumping fluid within the tubing string for carrying the actuation dart toward the valve assembly via fluid flow;   engaging the actuation dart with the valve assembly; and   pumping additional fluid within the tubing string for exerting pressure on the actuation dart and shifting the valve assembly in the open configuration.   
     
     
         40 . The method of  claim 39 , wherein the actuation dart is as defined in any one of  claims 14 to 22 . 
     
     
         41 . The method of  claim 39 or 40 , further comprising the step of monitoring a tubing string pressure to determine when a shifting pressure profile is recorded indicative of a shifted valve assembly in the open configuration. 
     
     
         42 . The method of  claim 41 , wherein monitoring the tubing string pressure comprises recording pressure samples at a predetermined sample frequency to enable the collection of pressure data and the creation of a pressure graph. 
     
     
         43 . The method of  claim 42 , wherein the creation of the pressure graph is facilitated by at least one of increasing the predetermined sample frequency at which the tubing string pressure is recorded, and lowering a rate at which fluids are pumped downhole. 
     
     
         44 . The method of  claim 42 or 43 , wherein the predetermined sample frequency is between about 10 and 100 pressure samples per second. 
     
     
         45 . The method of any one of  claims 42 to 44 , further comprising the step of analyzing the pressure data and/or pressure graph to determine a number of times the shifting pressure profile is recorded, indicative of a number of shifted valve assemblies in the open configuration. 
     
     
         46 . The method of  claim 45 , wherein the shifting pressure profile comprises a pressure build up to a shifting pressure threshold, followed by a pressure drop indicative of the actuation dart releasing from the valve assembly following a shift in the open configuration. 
     
     
         47 . The method of any one of  claims 41 to 46 , wherein the tubing string pressure is monitored using a pressure sensor located at surface. 
     
     
         48 . The method of any one of  claims 39 to 47 , wherein fluids are injected into the reservoir as part of a waterflooding operation. 
     
     
         49 . The method of any one of  claims 39 to 47 , wherein fluids are injected into the reservoir as part of a CO 2  flooding operation. 
     
     
         50 . The method of any one of  claims 39 to 47 , wherein fluids are injected into and produced from the reservoir as part of acid solution mining operations. 
     
     
         51 . A method of injecting fluids into a reservoir via a well system comprising a wellbore provided with a tubing string, the tubing string comprising one or more valve assemblies operable between a closed configuration for preventing fluid flow into the surrounding reservoir and an open configuration for establishing fluid communication between the tubing string and the surrounding reservoir via respective fluid passages, the method comprising the steps of:
 deploying an actuation dart within the tubing string;   pumping fluid within the tubing string for carrying the actuation dart toward the valve assembly via fluid flow;   engaging the actuation dart with a valve sleeve of the valve assembly;   continuing pumping fluid to build tubing string pressure for exerting pressure on the actuation dart up to a shifting pressure threshold adapted to shift the valve sleeve for operating the valve assembly in the open configuration;   monitoring the tubing string pressure to determine when the tubing string pressure reaches the shifting pressure threshold indicative of a shifted valve sleeve to operate the valve assembly in the open configuration; and   pumping additional fluid in the tubing string for injection into the reservoir via the valve assembly.