Patent Publication Number: US-9410401-B2

Title: Method and apparatus for actuation of downhole sleeves and other devices

Description:
CROSS REFERENCES TO RELATED APPLICATION 
     Priority of U.S. Provisional Patent Application Ser. No. 61/778,896, filed Mar. 13, 2013, incorporated herein by reference, is hereby claimed. 
    
    
     STATEMENTS AS TO THE RIGHTS TO THE INVENTION MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT 
     None 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention pertains to an assembly having flow ports that can be selectively actuated or opened by non-mechanical interference to permit communication of fluids and pressure between a first region and a second region. More particularly, the present invention pertains to a downhole sleeve assembly, beneficially includable within a tubular string or other tool assembly, having ports capable of being selectively opened to permit fluid pressure communication and fluid flow through said ports. 
     2. Brief Description of the Prior Art 
     From time to time it is advantageous, while controlling fluid flow and/or pressure in a system having an inside and an outside, to selectively open said system to allow fluid to flow and pressure to equalize between said inside and outside of said system. Although other applications can be envisioned, one such situation in which such selective opening is particularly beneficial is in connection with oil and/or gas wells and, more particularly, the stimulation, completion and production thereof. 
     Horizontal and/or non-vertical directional wells have become common, particularly as technology for drilling, completing and stimulating such wells in shale formations and/or other low permeability reservoirs has improved. However, even with advances in drilling technology, certain limitations exist that prevent optimization of the completion and stimulation of such horizontal and/or extended reach wells. Notably, although current drilling technology has increased the length that non-vertical or horizontal well sections can be drilled, such drilling technology has generally outpaced the ability to stimulate and produce oil and gas from such extended well sections. 
     One important factor that limits or restricts recovery from extended reach wells is the number of stimulation stages or points that can be effectively deployed in order to treat or stimulate all portions of such wells. Without a viable means of stimulating substantially the entire length of an extended well, the full potential of such deeper (or longer) wells cannot be realized. Put another way, the full benefits of extended reach wells are typically not realized if such wells cannot be stimulated along substantially their entire length. 
     Several methods are currently utilized to create an opening in wellbore tubular goods in order to equalize pressure and allow fluids to flow between the inside and the outside of said tubular goods. In most instances, said openings are designed to permit: (1) flow of stimulation (such as, for example, hydraulic fracturing) materials from the inside of wellbore tubular goods to reservoir(s) surrounding the outer surface of such tubular goods, and/or (2) production of fluids from such surrounding reservoir(s) into such wellbore tubular goods. 
     One existing method of creating such openings in wellbore tubular goods involves the use perforating guns which are lowered to a desired location within a well via wireline or tubing. Such perforating guns, which typically employ directional explosive charges, are remotely triggered in order to perforate the walls of such tubular goods. Unfortunately, there are practical limits to the depths/lengths within a wellbore at which such operations can be performed such as, for example, frictional limitations on the length of wireline or tubing that can be used to convey said perforating guns into a well. 
     Yet another conventional method of establishing communication between the inside and outside of wellbore tubular goods involves use of continuous or jointed tubing equipped with a specialized cutting device(s). Such a device is lowered into a well to a desired location and sand slurry or other abrasive fluid is pumped to the bottom of the continuous or jointed tubing; the abrasive fluid exits the device and erodes opening(s) in a surrounding wellbore tubular using the abrasive effect of such fluid. However, this method is also limited by the practical length that such continuous or other concentric tubing can be conveyed within a well, primarily due to wall frictional forces generated between such continuous/jointed tubing, and said surrounding wellbore tubular goods. 
     Another method commonly used for creating such downhole opening(s) in wellbore tubular goods involves the installation of at least one ported sliding sleeve and/or other similar apparatus at desired location(s) down hole (such as, for example, on or as part of a production casing string). When desired, such sleeve(s) can be selectively opened by mechanically manipulating the devices, typically using tools that are conveyed into a well via continuous tubing or wireline, thereby exposing such ports. However, use of such sliding sleeves or other similar devices also suffer from significant operational limitations. As with tubing perforation operations described above, frictional forces also limit the length of wireline or tubing that can be used for purposes of shifting or actuating such downhole sliding sleeves. 
     Certain other conventional downhole assemblies can be selectively opened using droppable or so-called “pump-down” objects such as, for example, balls or darts. Such conventional assemblies are typically operated by a sequence in which a small ball or dart is first dropped downhole. Said first ball or dart lands on a corresponding seat assembly, thereby blocking a fluid flow bore. Application of fluid pressure to said blocked bore facilitates actuation of said sleeve assembly. Thereafter, a slightly larger ball or dart can be dropped to land on a correspondingly sized seat in order to actuate a different sleeve assembly positioned further up hole. 
     This process can be repeated (generally moving from the deepest or furthest end of the well toward the surface) with each successive ball or dart having a larger outside diameter than the immediately preceding ball or dart. It is to be observed that the overall number of balls or darts that can be used in this manner is limited by the inside diameter of the surrounding tubular. As such, the total number of selectively actuated sliding sleeve assemblies that can be used is likewise limited. 
     Certain other devices utilize a consistently-sized droppable object (such as, for example, a plurality of balls all having a uniform outside diameter) to engage and operate a selectively actuated downhole apparatus. However, such devices generally require complex mechanical assemblies to operate. Use of such mechanical assemblies are particularly problematic during cementing and stimulation operations, because cement and stimulation proppant material (such as, for example, “frac sand” used in hydraulic fracturing operations) can invade such mechanical assemblies and negatively affect their operation. 
     The equalization assembly of the present invention overcomes the limitations of existing methods, permitting wells to be drilled with longer extended sections and to be optimally stimulated for greater production rates. 
     SUMMARY OF THE INVENTION 
     The present invention comprises a ported assembly that permits selective and remote opening of at least one downhole port or pathway to allow communication of pressure and/or fluid flow between the inside of a pressure containing system (such as, for example, a tubular pipe or other separate pressure containment system) and the outside of said containment system. Although other applications can be envisioned, the ported assembly of the present invention can be utilized in connection with oil and/or gas wells and, more particularly, the stimulation, completion and production thereof. 
     In a preferred embodiment, the present invention comprises a valve assembly, sometimes referred to herein as an “equalization assembly,” that can be installed downhole at a desired location within a well bore. Although many different applications can be envisioned, the ported equalization assembly of the present invention can be installed on a production tubular (such as production casing or the like) within a vertical, directional or horizontal wellbore, and conveyed to a desired depth within said wellbore. Frequently, multiple equalization assemblies can be installed in sequence and spaced apart at desired intervals along the length of said wellbore. Further, said production tubular can be either cemented in place or left un-cemented, using packers or other sealing devices to isolate annular spaces between individual equalization assemblies. 
     Each equalization assembly has at least one transverse port or pathway extending from the inside to the outside of said assembly. When opened, said at least one port and/or pathway provides a flow path to permit fluid to flow and pressure to equalize between the inside and outside of said tubular. Moreover, when opened said port(s) and/or pathways provide a flow path for stimulation media such as fluids, gasses and proppants to be injected through said well bore and into the surrounding formation (typically during the completion phase of the well), while also providing a flow path for fluids from such formation(s) into the inside of the tubular (typically during the production phase of the well). 
     In a preferred embodiment, a control device (including, without limitation, a dart, ball, canister or threaded device) can be inserted into a well at the earth&#39;s surface and conveyed to said at least one downhole equalization assembly via various means (including, without limitation, via flowing fluid, wire line, continuous tubing and jointed pipe). Said control device contains at least one magnet or other device generating a desired magnetic field, and may optionally contain batteries or other power source(s). 
     The equalization assembly of the present invention further comprises a pressure balanced sliding sleeve. An incompressible fluid holds said sliding sleeve in a closed and locked position; in the closed position, said sliding sleeve blocks said transverse port(s) of the assembly. The equalization assembly of the present invention further comprises an electrical induction coil, an electronic counter, a valve controlling said incompressible fluid, and a magnetic solenoid. 
     When the control device passes through each equalization assembly an electrical current is generated in the induction coil of said equalization assembly. Said current eventually triggers said electronic counter. Each equalization assembly(s) can be beneficially preset with a desired counter number. When such number is reached for a specific sleeve(s), an electronic pulse will pass through the electronic counter and power said magnetic solenoid. At that point, said magnetic solenoid can open the containment valve allowing the incompressible fluid to displace into the solenoid chamber. The internal pressure inside the tubular causes the unbalanced sliding sleeve to shift, thus exposing ports and/or pathways extending between the inside and outside of the tubular through the equalization assembly(s). In one configuration an internal valve can then close to prevent fluid from flowing past the selected equalization assembly(s). In a second configuration the sliding sleeve can slide open without an internal valve closing allowing fluid to flow past the open assembly. 
     With the desired port(s) and/or pathways open, proppant and/or stimulation media can be pumped through the inner bore of the tubular goods, out the exposed port(s) or pathway(s) of the equalization assembly(s), and into the area surrounding said equalization assembly(s). Said open port(s)/pathway(s) also allow production fluids (for example, oil and/or gas) to flow from a surrounding reservoir into the inner bore of said tubular during a production phase for eventual recovery from said well. 
     The above-described invention has a number of particular features that should preferably be employed in combination, although each is useful separately without departure from the scope of the invention. While the preferred embodiment of the present invention is shown and described herein, it will be understood that the invention may be embodied otherwise than herein specifically illustrated or described, and that certain changes in form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS/FIGURES 
       The foregoing summary, as well as any detailed description of the preferred embodiments, is better understood when read in conjunction with the drawings and figures contained herein. For the purpose of illustrating the invention, the drawings and figures show certain preferred embodiments. It is understood, however, that the invention is not limited to the specific methods and devices disclosed in such drawings or figures. 
         FIG. 1  depicts a side view of multiple equalization assemblies of the present invention deployed within a well bore. 
         FIG. 2A  depicts a side sectional view of a valve sub-assembly of an equalization assembly of the present invention. 
         FIG. 2B  depicts a side sectional view of an actuation sub-assembly of an equalization assembly of the present invention. 
         FIG. 3  depicts a detailed view of the area highlighted in  FIG. 2A . 
         FIG. 4  depicts a detailed view of the area highlighted in  FIG. 2B . 
         FIG. 5A  depicts a side sectional view of a valve sub-assembly of an equalization assembly of the present invention. 
         FIG. 5B  depicts a side sectional view of an actuation sub-assembly of an equalization assembly of the present invention. 
         FIG. 6  depicts a detailed view of the area highlighted in  FIG. 5A . 
         FIG. 7  depicts a detailed view of the area highlighted in  FIG. 5B . 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
     Referring to the drawings,  FIG. 1  depicts a side view of multiple equalization assemblies  100  of the present invention deployed in sequence within in a well bore  200 . Although other applications can be envisioned without departing from the scope of the present invention, in a preferred embodiment said equalization assemblies  100  depicted in  FIG. 1  are used in connection with the stimulation and subsequent producing phase of wellbore  200  drilled for the purpose of producing hydrocarbons from surrounding subterranean formation(s). Wellbore  200  is depicted in  FIG. 1  as a substantially horizontal well; however, it is to be observed that equalization assembly  100  of the present invention can likewise be used in vertical or non-horizontal directional wellbores. 
     After a well (such as wellbore  200 ) is drilled to a desired depth, pipe or other tubular goods are installed and cemented within said well. Thereafter, openings or flow ports in wellbore tubular goods must be provided in order to equalize fluid pressure and allow fluids to flow between the inside and the outside of said tubular goods (and vice versa). Said openings can beneficially permit flow of stimulation (such as, for example, hydraulic fracturing) materials from the inside of wellbore tubular goods to reservoir(s) surrounding the outer surface of such tubular goods, as well as inflow of fluids from such surrounding reservoir(s) into said wellbore tubular goods. Equalization assembly  100  generally comprises an assembly having flow ports that can be selectively actuated via non-mechanical interference in order to allow communication of fluids and pressure between a first region and a second region. 
     As depicted in  FIG. 1 , in a preferred embodiment equalization assemblies  100  are threadably connected within a tubular string  210  and conveyed via said tubular string  210  to a predetermined position in wellbore  200 . After being properly positioned within wellbore  200 , tubular string  210  can then be cemented in place or left un-cemented. Equalization assemblies  100  can be configured in series with said assemblies being preset to actuate individually, together, or in distinct groups of two or more. 
       FIG. 2A  depicts a side sectional view of a valve sub-assembly  10  of equalization assembly  100  of the present invention, while  FIG. 2B  depicts a side sectional view of actuation sub-assembly  20  of equalization assembly  100  of the present invention. In a preferred embodiment, equalization assembly  100  is threadably connected at one end to tubular member  211  using cross-over sub  110  having threaded connections  111  and  112 . Similarly, equalization assembly  100  is threadably connected at another end to tubular member  212  using cross-over sub  120  having threaded connections  121  and  122 . 
     Tubular members  211  and  212 , which comprise components of tubular string  210 , each have central through-bore  213  which defines an internal passage through said tubular members  211  and  212 . Cross-over sub  110  has central through-bore  113  defining an internal passage through said cross-over sub  110 , while cross-over sub  120  has central through-bore  123  defining an internal passage through said cross-over sub  120 . 
     Referring to  FIG. 2A , equalization assembly  100  comprises substantially cylindrical external housing member  11  having an outer surface  12  and a central through-bore defining inner surface  13 . A plurality of transverse equalization ports  20  extend through said housing member  11  from said inner surface  13  to said outer surface  12 . Equalization ports  20  can be equipped with optional threaded or pressed nozzles that can limit the flow of liquids and gases that can pass through said equalization ports  20 , either initially or permanently. 
     Sleeve member  30 , having a central through-bore defining inner surface  31 , is slidably disposed within the central through-bore of external housing member  11 . In the “closed” configuration depicted in  FIG. 2A , sleeve member  30  obstructs equalization ports  20 . As such, in said closed position, sleeve member  30  isolates fluid pressure and flow through said equalization ports  20 . 
     Referring to  FIG. 2B , equalization assembly  100  further comprises actuation sub body member  51  having an outer surface  52  and a central through-bore defining inner surface  53 . As depicted in  FIG. 2B , sleeve member  30  only partially extends into said through-bore; however, it is to be observed that said through-bore of said actuation sub body member  51  has a sufficiently large inner diameter to receive said sleeve member  30 . 
       FIG. 3  depicts a detailed view of valve sub-assembly  10  highlighted in  FIG. 2A . Cylindrical external housing member  11  has an outer surface  12  and a central through-bore defining inner surface  13 . Sleeve member  30 , having a central through-bore defining inner surface  31 , is slidably disposed within the central through-bore of said external housing member  11 . Flapper  40  is hingedly connected to external housing member  11  using flapper hinge  41  and hinge pin  42 . As depicted in  FIG. 3 , hinge member  40  is maintained in an open or retracted position by sleeve member  30 , while flapper cover  43  extends around the external portion of said flapper  40 . 
       FIG. 4  depicts a detailed view of actuation sub-assembly  50  highlighted in  FIG. 2B . A reservoir or chamber  54  is defined between inner surface  13  of external housing member  11  and outer surface  32  of sleeve member  30 . In a preferred embodiment, said chamber  54  is filled with an incompressible liquid having desired characteristics. Said incompressible fluid is sealed within said chamber  54  using fluid pressure seals (such as, for example, elastomeric o-rings disposed around the outer surface  32  of sleeve member  30 ). Electronics housing member  70 , connected to external housing member  11 , has an outer surface  71  and a central through-bore defining inner surface  72 . Sleeve-like electronic sub cover  73  is disposed around at least a portion of said electronics housing member  70 . 
     Flow channel  55  extends from chamber  54  to control valve assembly  60 . As depicted in  FIG. 4 , control valve assembly  60  comprises a fluid pressure sealing sliding valve. However, it is to be observed that said fluid pressure sealing valve assembly can similarly comprise a gate valve, ball valve or other valve assembly. In a preferred embodiment, control valve assembly  60  comprises elongate valve body  61  having longitudinal bore  62 . Valve body  61  is slidably received within control valve seat  62 . 
     In the closed configuration depicted in  FIG. 4 , incompressible fluid is sealed within chamber  54  by valve assembly  60 . However, when valve body  61  shifts within control valve seat  62 , transverse ports extending though valve body  61  are shifted into communication with bore  62  and become open to flow channel  55 . In such a shifted or “open” configuration, incompressible fluid within chamber  54  can flow from said chamber as described more fully below. 
     Still referring to  FIG. 4 , a chamber  74  is formed between electronics housing  70  and electronic sub cover  73 . Magnetic solenoid  80  is disposed within said chamber  74 . In a preferred embodiment, said chamber  74  contains a compressible fluid maintained at or near atmospheric pressure when control valve assembly  60  is in a closed position. Magnetic solenoid  80  is beneficially electronically connected to an electronics assembly  75  also contained in chamber  74 . 
     Said electronics assembly  75  can include, but is not necessarily limited to, at least one electronic counter or processor, latch circuit, rectifier, capacitor and battery. Electronics assembly  75  is also beneficially electronically connected to induction coil  76 , also contained within electronics housing  70 . As depicted in  FIG. 4 , a wire  77  can pass through a conduit in electronics housing  70  to provide electrical connection between induction coil  76  and electronics assembly  75 . Moreover, in a preferred embodiment, magnetic solenoid  80  is configured in accordance with the magnetic solenoid apparatus disclosed in that certain pending patent application filed Feb. 14, 2013 and having Publication No. WO2013123111, which is incorporated by reference herein for all purposes. 
       FIG. 5B  depicts a side sectional view of actuation sub-assembly  50  of equalization assembly  100  of the present invention after control valve  60  has opened.  FIG. 5A  depicts a side sectional view of valve sub-assembly  10  of equalization assembly  100  of the present invention after sleeve  30  has shifted, thereby exposing equalization ports  20  and allowing flapper  40  to move into a closed position. 
     In operation, a desired number of equalization assemblies  100  are conveyed on a tubular string and deployed in place within a wellbore, as depicted in  FIG. 1 . Thereafter, an actuation control device  90  can be introduced into the inner through-bore of said tubular string, typically at the earth&#39;s surface. Said actuation control device  90  can comprise a pump-able dart, ball, canister, or container, and can be conveyed into said well by fluid flow or mechanically via coil tubing, jointed tubing or wire line. Said actuation control device  90  can include at least one encased or partially encased magnet, or other apparatus capable of generating a magnetic field. 
     Each deployed equalization assembly  100  is preset to predetermined counter number. If deployed as a series wherein each equalization assembly  100  will operate separately, then each such assembly will be preset to respond to its own unique counter number. Conversely, if deployed as a group wherein two or more equalization assemblies  100  will actuate substantially simultaneously, then each equalization assembly in said group can be preset to respond to a predetermined shared counter number. 
     Referring to  FIGS. 5A and 5B , as actuation control device  90  passes through equalization assembly  100 , the magnetic field created by said actuation control device  90  generates an electrical current as it passes by, through or in proximity to induction coil  76 . Said electrical current passes through a rectifier where said current is converted to a direct current impulse which, in turn, registers on an electronic counter included within electronic assembly  75 . This process is repeated for all equalization assemblies  100  in a sequence through which actuation control device  90  passes. 
     In the event that actuation control device  90  passes through an equalization assembly  100  that is preset to actuate when a particular counter number is reached, and that predetermined counter number is achieved, then that specific equalization assembly  100  will actuate. Specifically, referring to  FIG. 7 , an electronic counter contained within electronics assembly  75  will allow generated direct current impulse to activate a latch circuit, thereby closing an electrical connection between said capacitor, battery and magnetic solenoid  80 . When said connection is made, magnetic solenoid  80  activates and moves within chamber  74 . Said magnetic solenoid  80  will eventually contact valve body  61  of control valve assembly  60 , thereby causing said control valve assembly  60  to open and creating an open fluid flow path between chambers  54  and  74 . 
     When equalization assembly  100  is deployed downhole in a wellbore, the inner through-bore of an associated tubular string typically includes relatively heavy-weight fluids (usually due to deployment of cement slurry or stimulation materials). Elevated hydrostatic pressure from such wellbore fluids, as well as any surface pump pressure, is communicated through-bores  33  in sliding sleeve  30  and acts on fluid piston  34 . 
     While control valve assembly  60  is closed, incompressible fluid is trapped within chamber  54 , and prevents sleeve  30  from shifting or otherwise moving. However, after control valve assembly  60  is opened and a fluid flow path through control valve assembly  60  is formed, incompressible fluid contained within chamber  54  can evacuate chamber  54  and flow into chamber  74  (which is maintained at a lower fluid pressure). With said incompressible fluid no longer trapped within chamber  54 , said elevated wellbore pressure acts on piston  34  and is able to shift sliding sleeve  30 . Moreover, incompressible fluid contained within chamber  74  is prevented from flowing in the reverse direction (i.e., back into chamber  54 ) by control valve assembly  60  which, in turn, prevents sliding sleeve  30  from moving in a reverse direction. 
     Referring to  FIG. 5A , after sleeve  30  has shifted, equalization ports  20  are exposed and in fluid communication with the internal through-bore of tubular string  210 . Further, referring to  FIG. 6 , with said sleeve  30  shifted, flapper  40  is permitted to pivot about hinge pin  42  to move into a closed position. With said flapper  40  in a closed position, fluid pumped from the earth&#39;s surface through the inner through-bore of tubular string  210  is prevented from flowing past closed flapper  40  and is redirected out exposed equalization ports  20 . Although said valve mechanism is depicted as flapper  40 , it is to be observed that other valve configurations including, without limitation, flapper valves, gate valves or sliding valves, can also be used for this purpose. Moreover, in an alternative embodiment, flapper  40  can be removed; after sliding sleeve  30  has shifted, equalization ports  20  are exposed, but a fluid flow pathway also exists through the central through-bore of equalization assembly  100 . 
     In a preferred embodiment, no physical contact or mechanical interference is required between actuation control device  90  and any other components of equalization assembly  100  including, without limitation, external housing member  11  or sleeve member  30 , in order to actuate equalization assembly  100  and shift sleeve member  30 . 
     The above-described invention has a number of particular features that should preferably be employed in combination, although each is useful separately without departure from the scope of the invention. While the preferred embodiment of the present invention is shown and described herein, it will be understood that the invention may be embodied otherwise than herein specifically illustrated or described, and that certain changes in form and arrangement of parts and the specific manner of practicing the invention may be made within the underlying idea or principles of the invention.