Patent Publication Number: US-9404335-B2

Title: Annular barrier system with flow lines

Description:
This application is the U.S. national phase of International Application No. PCT/EP2012/073918 filed 29 Nov. 2012 which designated the U.S. and claims priority to EP 11191287.9 filed 30 Nov. 2011, the entire contents of each of which are hereby incorporated by reference. 
     FIELD OF THE INVENTION 
     The present invention relates to an annular barrier system connected with a well head via a well tubular structure, comprising a first annular barrier and a second annular barrier to be expanded in an annulus between the well tubular structure and an inside wall of a casing or a borehole downhole for providing zone isolation between a first zone and a second zone. Furthermore, the present invention relates to a well completion system and method. 
     BACKGROUND ART 
     In known annular barrier solutions, the well casing is pressurised in order to expand the annular barriers, but not all components of a completion can withstand such high pressure, and therefore an alternative solution is needed in order to protect these components while expanding the annular barriers. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved annular barrier system, wherein the expansion of the expandable sleeve of the annular barrier provides a solution which is safer than known solutions in order to avoid pressurising the casing from within to expand the annular barriers. 
     The above objects, together with numerous other objects, advantages, and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by an annular barrier system connected with a well head via a well tubular structure, comprising:
         an annular barrier to be expanded in an annulus between the well tubular structure and an inside wall of a casing or a borehole downhole for providing zone isolation between a first zone and a second zone, the annular barrier comprising:   a tubular part extending in a longitudinal direction for mounting as part of the well tubular structure;   an expandable sleeve surrounding the tubular part and defining a space;   an opening for letting fluid into the space to expand the sleeve; and   a first connection part and a second connection part connecting the expandable sleeve with the tubular part, and wherein the first connection part is arranged nearest to the well head,
 
wherein the system further comprises a flow line fluidly connecting the well head with the opening for supplying fluid to the opening for expanding the expandable sleeve.
       

     In another embodiment, the annular barrier system may be connected with a well head via a well tubular structure, and comprises:
         a first annular barrier and a second annular barrier to be expanded in an annulus between the well tubular structure and an inside wall of a casing or a borehole downhole for providing zone isolation between a first zone and a second zone, each annular barrier comprising:   a tubular part extending in a longitudinal direction for mounting as part of the well tubular structure;   an expandable sleeve surrounding the tubular part and defining a space;   an opening for letting fluid into the space to expand the sleeve; and   a first connection part and a second connection part connecting the expandable sleeve with the tubular part, and wherein the first connection part is arranged nearest to the well head,
 
the system further comprising a flow line fluidly connecting the well head with the opening for supplying fluid to the opening for expanding the expandable sleeve, and the second connection part of the first annular barrier having a second opening and the second opening of the second connection part being fluidly connected with an opening arranged in the first connection part of the second annular barrier via a second flow line part for expanding the expandable sleeve of the second annular barrier, wherein a second valve is arranged in the second opening, the second valve being a two-way valve which, at a predetermined pressure, disconnects communication to the second annular barrier and opens fluid communication to an annular space between the annular barriers in their expanded condition to pressurise the annular space.
       

     In one embodiment, a valve may be arranged in the opening. 
     Also, the valve may be adapted to close at a predetermined pressure. 
     In another embodiment, the flow line may extend along an outer face of the well tubular structure. 
     Moreover, the flow line may extend inside or in a groove in the well tubular structure. 
     In yet another embodiment, the opening may be arranged in the connection part or in the tubular part. 
     Furthermore, the flow line may have an overall outer diameter which is substantially smaller than an overall outer diameter of the tubular part. 
     The outer diameter of the flow line may be less than 50% of the outer diameter of the tubular part, preferably less than 30% of the outer diameter of the tubular part, more preferably less than 15% or less of the outer diameter of the tubular part. 
     In one embodiment, the well head may comprise a well head valve. 
     Said well head valve may be connected to a pumping unit. 
     In another embodiment, the first connection part may have the opening fluidly connected to the well head via the flow line. 
     The annular barrier system as described above may further comprise a second annular barrier comprising a tubular part extending in a longitudinal direction for mounting as part of the well tubular structure, an expandable sleeve surrounding the tubular part and defining a space, an opening for letting fluid into the space to expand the sleeve, and a first connection part and a second connection part connecting the expandable sleeve with the tubular part, and the first connection part may be arranged nearest to the well head. 
     Moreover, the second connection part may have a second opening and the second opening of the second connection part may be fluidly connected with an opening arranged in the first connection part of the second annular barrier via a second flow line part for expanding the expandable sleeve of the second annular barrier. 
     In one embodiment, a second valve may be arranged in the second opening. 
     Also, the second valve may be adapted to close at a predetermined pressure. 
     Furthermore, the annular barrier system may comprise a second flow line in order to let fluid into an annular space between the annular barriers in their expanded condition to pressurise the annular space, and the system may comprise a switch valve fluidly connecting the first flow line with the second flow line when the fluid reaches a predetermined pressure. 
     Moreover, the second flow line may be connected with a fluid channel in the first annular barrier, and the channel extends through the first annular barrier in order to let fluid into the annular space. 
     In one embodiment, the switch valve may be a hydrostatic switch. 
     Further, the second valve may be a two-way valve which, at a predetermined pressure, may disconnect communication to the second annular barrier and may open fluid communication to an annular space between the annular barriers in their expanded condition to pressurise the annular space. 
     In another embodiment, the system may comprise a release device arranged in connection with the opening for disconnecting the flow line after expansion of the sleeve. 
     In yet another embodiment, a cutting device may be arranged in connection with the well head. 
     Furthermore, the system may comprise a pressure sensor tool. 
     Moreover, the tool may comprise a gas detection unit and/or a pressure measuring unit. 
     Also, the annular barrier system as described above may comprise a third annular barrier comprising:
         a tubular part extending in a longitudinal direction for mounting as part of the well tubular structure;   an expandable sleeve surrounding the tubular part and defining a space;   an opening for letting fluid into the space to expand the sleeve; and   a first connection part and a second connection part connecting the expandable sleeve with the tubular part, and wherein the first connection part is arranged nearest to the well head,
 
the system further comprising a flow line fluidly connecting the opening in the second connection part of the second annular barrier with an opening in the first connection part of the third annular barrier for supplying fluid to the opening for expanding the expandable sleeve of the third annular barrier,
       

     The annular barrier system as described above may further comprise a second flow line for letting fluid into an annular space between the first and second annular barriers in expanded condition to pressurise the annular space. 
     In addition, the annular barrier system as described above may further comprise a switch valve fluidly connecting the first flow line with the second flow line when the fluid reaches a predetermined pressure. 
     In one embodiment, the second flow line may be connected with a fluid channel in the first annular barrier, and the channel may extend through the first annular barrier in order to let fluid into the annular space. 
     Furthermore, the switch valve may be a hydrostatic switch. 
     In one embodiment, the opening may be arranged in the tubular part and the flow line may extend in the tubular part. 
     In another embodiment, the second valve of the second connection part may be fluidly connected with an opening in a first connection part of the second annular barrier. 
     In yet another embodiment, a plurality of annular barriers may be serially connected via flow lines. 
     Furthermore, the present invention relates to a well completion system comprising an annular barrier system according to the invention, a well tubular structure and a well head. 
     Said well head may comprise a well head valve. 
     Also, the well head valve may be connected to a pumping unit. 
     In one embodiment, a cutting device may be arranged in connection with the well head for cutting the flow line after expansion of the sleeves. 
     Moreover, the invention relates to a method for expanding an annular barrier according to the invention in an annulus between a well tubular structure and an inside wall of a casing or a borehole downhole, the method comprising the steps of:
         pressurising a fluid, and   leading the fluid into the space of the annular barrier via the flow line so that the expandable sleeve is expanding.       

     Said method may further comprise the step of leading the fluid through the annular barrier into an expandable space of a second annular barrier for expanding the sleeve of the second annular barrier. 
     In one embodiment, the flow line may be cut off after the annular barrier(s) has/have been expanded. 
     Finally the invention relates to a method for arranging an annular barrier system according to the present invention in a well completion system, comprising the steps of:
         mounting an annular barrier as part of the well tubular structure,   connecting a flow line to the opening of the annular barrier, and   lowering the well tubular structure with the mounted annular barrier into a casing and/or a borehole while feeding the flow line.       

    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which 
         FIG. 1  shows an annular barrier system, 
         FIG. 2  shows the annular barrier system of  FIG. 1  in an enlarged view, 
         FIG. 3  shows another embodiment of the annular barrier system, 
         FIG. 4  shows the annular barrier system of  FIG. 3  in an enlarged view, 
         FIG. 5  shows another embodiment of the annular barrier system, 
         FIG. 6 a    shows a cross-sectional view of the tubular part, and 
         FIG. 6 b    shows a cross-sectional view of another embodiment of the tubular part. 
     
    
    
     All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  shows an annular barrier system  100  in which the system is connected with a well tubular structure  3  which is again connected to a well head  40 . The well tubular structure  3  is surrounded by an intermediate casing  20  forming an annulus  2  between the well tubular structure  3  and the intermediate casing  20 . The annular barrier system  100  comprises an annular barrier  1  to be expanded in the annulus  2  between the well tubular structure  3  and an inside wall  4  of the intermediate casing  20  for providing zone isolation between a first zone  8  above the annular barrier  1  and a second zone  9  below the annular barrier  1 . Hereby, the annulus  2  above the annular barrier  1  is isolated from the reservoir  28 . 
     The annular barrier comprises a tubular part  6  extending in a longitudinal direction for mounting as part of the well tubular structure  3 . The annular barrier further comprises an expandable sleeve  7  surrounding the tubular part  6  and surrounding a space  13  defined between the tubular part  6  and the expandable sleeve  7 . The annular barrier further comprises an opening  11  for letting fluid into the space to expand the sleeve. The expandable sleeve is connected with the tubular part by means of a first connection part  15  and a second connection part  16 , wherein the first connection part  15  is arranged nearest to the well head  40 . In order to expand the sleeve, the system further comprises a flow line  17  fluidly connecting the well head  40  with the opening  11  for supplying fluid to the opening for expanding the expandable sleeve. In this way, the annular barrier  1  can be expanded from the rig via the well head by pressurising the flow line. In case of a subsea well head, the well head may comprise a pumping unit  35  which can be activated by means of a remote operated vehicle (ROV) (not shown) and thus, indirectly from the rig. In case of an on-shore well head, a pumping unit may be connected with one or more well heads for providing pressurised fluid down through the flow line  17 . 
     By having the flow line  17  connecting the pumping unit  35  and the space  13 , openings in the tubular part can be avoided and the well tubular structure does no longer have to be pressurised to a pressure large enough to expand the expandable sleeve  13 . In this way, other components forming part of the well tubular part are not exposed to the high expansion pressure, and the components can therefore be selected irrespectively of whether they can withstand such high pressure. Furthermore, expansion of the annular barrier uses less energy as the whole well tubular structure does not have to be pressurised in order to expand the annular barrier but only have a substantially smaller volume being that of the flow line. 
     As shown in  FIG. 1 , the flow line  17  extends along an outer face  19  of the well tubular structure  3 . In another embodiment, the flow line extends inside the well tubular structure, as shown in  FIG. 6A , or in a groove  50  in the well tubular structure, as shown in  FIG. 6B . 
     Firstly, the annular barrier of the annular barrier system shown in  FIG. 1  is mounted as part of the well tubular structure, and then the flow line is connected with the opening of the annular barrier before the well tubular structure with the mounted annular barrier is lowered into the intermediate casing and/or borehole while feeding the flow line so that the flow line stays connected with the opening. 
     Subsequently, the expandable sleeve of the annular barrier is expanded in the annulus  2  between the well tubular structure  3  and the inside wall  4  of a casing  20  or a borehole  5  downhole by activating the pumping unit  35  and pressurising a fluid and leading the fluid into the space of the annular barrier via the flow line, so that the expandable sleeve is expanding. 
     As shown in  FIG. 2 , the opening  11  of the annular barrier is arranged in the first connection part  15 . The flow line  17  is connected with the opening  11  for expanding the expandable sleeve  7  of the annular barrier so that an opening in the tubular part is avoided. Furthermore, having the opening in the connection part increases the sealing ability of the connection parts towards the tubular part. By avoiding the opening in the tubular part, the seal between the connection parts and the tubular part is of less importance to the well integrity. In another embodiment, the opening may be arranged in the tubular part so that the flow line extends within the well tubular structure. Hereby, the annular barrier system may fit existing systems on the market as only smaller adjustments need to be made. 
     In  FIG. 2 , the annular barrier comprises a valve  18  arranged in the opening  11  so as to let fluid in through the opening, but prevent said fluid from flowing into the flow line again. In other words, the valve may be a one-way valve. Furthermore, after the expandable sleeve has been expanded, the flow line is released from the well head and dumped into the annulus. Alternatively, the flow line  17  is released by a release device  30  shown in  FIG. 1  in connection with the opening of the connection part  15  and is pulled up through the well head  40 . The valve may be adapted to close at a predetermined pressure so that, when the expandable sleeve has been expanded, the valve closes at a pressure just above the expansion pressure securing that the expandable space  13  is closed when the flow is disconnected or cut by the release device  30 . Thus, the release device  30  may be arranged in connection with the well head or in connection with the valve or the opening. 
     The flow line shown in  FIG. 2  has an overall outer diameter D fl , which is substantially smaller than an overall outer diameter D tp  of the tubular part. The outer diameter D fl , of the flow line is thus less than 50% of the outer diameter of the tubular part, preferably less than 30% of the outer diameter of the tubular part, more preferably less than 15% or less than the outer diameter of the tubular part. The flow line is thus easily placeable in the annulus between the well tubular structure and the intermediate casing. 
     In  FIG. 3 , the annular barrier system further comprises a second annular barrier  21  comprising a tubular part  6  mounted as part of the well tubular structure  3 , an expandable sleeve  7  surrounding the tubular part and defining a space  13 , an opening  11  for letting fluid into the space to expand the sleeve, and a first connection part  15  and a second connection part  16  connecting the expandable sleeve with the tubular part, wherein the first connection part of the second annular barrier is arranged nearest to the well head. 
     The second connection part  16  of the first annular barrier  1  comprises the second opening  22  being in fluid connection with an opening  11  arranged in the first connection part  15  of the second annular barrier  21  via a second flow line part  25  for expanding the expandable sleeve of the second annular barrier. A second valve  23  is arranged in the second opening  22  which is adapted to close at a predetermined pressure. 
     As shown in  FIG. 3 , the annular barrier system may further comprise a third annular barrier  43  which is connected with the second connection part of the second annular barrier  21  via a flow line part  44  so that when the first annular barrier is expanded or set, the high pressurised fluid is led into the expandable space of the second annular barrier and further into the space of the third annular barrier. The expansion of several annular barriers may thus occur simultaneously or approximately simultaneously. 
     In  FIG. 4 , a first annular barrier  1  and a second annular barrier  21  are shown where the first annular barrier is connected with the top of the well or the well head by means of a flow line  17 , and the first annular barrier is fluidly connected with the second annular barrier  21  by means of a second flow line part  25  of the flow line  17 . A second valve  23  may be arranged in the second opening  22  in the second connection part of the first annular barrier. In  FIG. 4 , the second valve  23  is a two-way valve which, at a predetermined pressure, disconnects communication to the second annular barrier and opens fluid communication to an annular space  29  between the annular barriers in their expanded condition to pressurise the annular space. By being able to pressurise the annular space between the first and the second expanded annular barriers, the first annular barrier can be pressure-tested to determine whether the first annular barrier has sealed off the annulus providing a zone isolation between the first zone above the first annular barrier and a second zone below the first annular barrier. Some kind of recognisable chemicals may be added in the fluid flowing in the flow line or a pressure sensing tool  31  may be inserted in the well tubular structure as shown in  FIG. 5 . The pressure testing tool comprises a gas detection unit  36  and/or a pressure measuring unit  37 . 
     In another embodiment, the annular barrier system comprises a third flow line  52  for letting fluid into an annular space between the annular barriers in their expanded condition to pressurise the annular space. The third flow line may extend from the pumping unit to the first annular barrier and is connected with a channel in the first barrier, through the first barrier to the second opening in the second connection part. In another embodiment, the channel may extend through the tubular part of the first barrier in order to let fluid into the annular space. In another embodiment, the system comprises a switch valve fluidly connecting the first flow line with the second flow line when the fluid reaches a predetermined pressure. In this way, only the first flow line is connected with the pumping unit and the second flow line is connected with the first flow line further down the annulus. In one embodiment, the switch valve is a hydrostatic switch. 
     The invention relates to a well completion system comprising the annular barrier system described above, the well tubular structure and the well head as shown in  FIG. 1 . The well head may comprise a well head valve  53  connected to a pumping unit. The well completion system may comprise a cutting device  54  arranged in connection with the well head for cutting the flow line after expansion of the sleeves. 
     The present invention is susceptible to embodiments of different forms. Specific embodiments are described in detail and are shown in the drawings with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognised that the different teachings of the different embodiments discussed above may be employed separately or in any suitable combination to produce desired results. 
     By a flow line is meant a tubular pipe extending from the top of the well down along and on the outside of the casing in the annulus between the intermediate casing surrounding the casing and the intermediate casing. The flow line is supplying pressurised fluid, such as sea water, down to the expandable space of the annular barrier in order to expand the sleeve. The flow line is therefore made in a material, such as metal, capable of withstanding such high pressure, i.e. a pressure difference of up to 10,000 PSI. 
     An annular barrier may also be a packer or similar expandable means. The well tubular structure can be the production tubing or casing or a similar kind of tubing downhole in a well or a borehole. As mentioned above, the annular barrier can be used both in between the inner production tubing and an outer tubing in the borehole, or between a tubing and the inner wall of the borehole. A well may have several kinds of tubing and the annular barrier of the present invention can be mounted for use in all of them. 
     The valves that may be utilised to control the flow through the first and second fluid passages may be any kind of valve capable of controlling flow, such as a ball valve, butterfly valve, choke valve, check valve or non-return valve, diaphragm valve, expansion valve, gate valve, globe valve, knife valve, needle valve, piston valve, pinch valve, or plug valve. 
     The expandable tubular metal sleeve may be a cold-drawn or a hot-drawn tubular structure. 
     The fluid used for expanding the expandable sleeve may be any kind of well fluid present in the borehole surrounding the tool and/or the well tubular structure. Also, the fluid may be cement, gas, water, polymers, or a two-component compound, such as powder or particles mixing or reacting with a binding or hardening agent. Part of the fluid, such as the hardening agent, may be present in the cavity between the tubular part and the expandable sleeve before injecting a subsequent fluid into the cavity. 
     By fluid or well fluid is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By gas is meant any kind of gas composition present in a well, completion, or open hole, and by oil is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil, and water fluids may thus all comprise other elements or substances than gas, oil, and/or water, respectively. 
     By a casing is meant any kind of pipe, tubing, tubular, liner, string, etc., used downhole in relation to oil or natural gas production. 
     In the event that the tools are not submergible all the way into the casing, a downhole tractor can be used to push the tools all the way into position in the well. A downhole tractor is any kind of driving tool capable of pushing or pulling tools in a well downhole, such as a Well Tractor®. 
     Although the invention has been described in the above in connection with preferred embodiments of the invention, it will be evident for a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.