Abstract:
A method of determining the position of a valve includes, measuring pressure at a first location within a bore and measuring pressure at a second location within the bore wherein the first location and the second location are positioned on opposing longitudinal sides of the valve. The method further includes analyzing values from the measuring and attributing characteristics of the analyzing to specific valve positions.

Description:
BACKGROUND 
       [0001]    Tubular valves, such as flapper valves used in the downhole completion industry, for example, are often configured to automatically actuate in response to changes in environmental conditions surrounding the valve. Although such actuations are effective at quickly preventing unwanted flow under specific conditions, it is sometimes difficult to ascertain an actual position a valve is in at any particular time. Although mechanical monitoring devices exist that serve this function adequately, the industry is always receptive to new devices and methods of determining position of valves. 
       BRIEF DESCRIPTION 
       [0002]    Disclosed herein is a method of determining the position of a valve. The method includes measuring pressure at a first location within a bore and measuring pressure at a second location within the bore wherein the first location and the second location are positioned on opposing longitudinal sides of the valve. The method further includes analyzing values from the measuring and attributing characteristics of the analyzing to specific valve positions. 
         [0003]    Further disclosed herein is a method of determining positions of a valve. The method includes, measuring differences in pressure between locations on opposing longitudinal sides of a valve in operable communication with a bore, and attributing values of differential pressure measured to positions of the valve. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
           [0005]      FIG. 1  depicts a quarter cross sectional view of a pressure monitoring arrangement configured to enable determination of a position of a valve within a bore as disclosed herein; and 
           [0006]      FIG. 2  depicts a quarter cross sectional view of an alternate embodiment of a pressure monitoring arrangement configured to determine a position of a valve within a bore as disclosed herein; and 
           [0007]      FIG. 3  depicts a quarter cross sectional view of an alternate embodiment of a pressure monitoring arrangement also configured to determine a position of a valve within a bore as disclosed herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
         [0009]    Referring to  FIG. 1 , a pressure monitoring arrangement employed in methods disclosed herein is illustrated generally at  10 . The arrangement  10  includes, a tubular  14  with a bore  18  therethrough having a valve  22 , illustrated in this embodiment as a flapper, configured to be moveable between an open position and a closed position (shown in the Figures in the closed position). When in the open position the valve  22  substantially provides no restriction to flow through the bore  18 . In contrast, when the valve  22  is in the closed position, flow through the bore  18  is essentially fully blocked. A first pressure transducer  24  is in fluidic communication with a first location  28  defined as being beyond the valve  22  in a first longitudinal direction, while a second pressure transducer  34  is in fluidic communication with a second location  38  defined as being beyond the valve  22  in a second longitudinal direction. In this embodiment the valve  22  is positioned within a borehole  42  in an earth formation  46  and the first location  28  is uphole of the valve  22  while the second location  38  is downhole of the valve  22 . It should be noted that the notations of uphole and downhole are arbitrary and do not limit the currently disclosed methods to these orientations. 
         [0010]    The foregoing pressure monitoring arrangement  10  allows an operator thereof to determine positions of the valve  22  by the following methods. When the valve  22  is open, the pressure drop across the valve  22  is substantially negligible and thus the pressure reading at the first location  28  is substantially equal to the pressure at the second location  38 . An operator, could therefore, attribute similar pressure values at the locations  28 ,  38 , as measured by the respective pressure transducers  24 ,  34 , to the valve  22  being in an open position. Alternately, when the valve  22  is closed, the pressure values at the two locations  28 ,  38  can vary from one another. Thus, an operator could attribute different pressures at the two locations  28 ,  38  to the valve  22  being closed. 
         [0011]    Depending upon the application within which the pressure monitoring arrangement  10  is employed, additional information or confidence in the position of the valve  22  can be determined. For example, in applications, such as for that of the instant embodiment wherein the pressure monitoring arrangement  10  is employed within the borehole  42  of the earth formation  46 , known conditions of pressures within the borehole  42  can be employed to increase confidence in the determination of the position of the valve  22 . An operator can estimate or calculate the hydrostatic pressure within the borehole  42  corresponding to the depth at which the valve  22  is located. If, for example, pressure at the first location  28  corresponds to the estimated/calculated hydrostatic pressure and pressure at the second location  38  is greater than that at the first location  28 , the operator can attribute these conditions to the valve  22  being in the closed position with significant confidence. Additionally, unstable values of pressure at the first location  28  as determined by the first pressure transducer  24  can be attributed to leakage by the valve  22  since such leakage could cause momentary increases in pressure at the first location  28  whenever higher pressure from the second location  38  leaks by the valve  22 . 
         [0012]    Accuracy of the pressure readings from the pressure transducers  24 ,  34  can also affect confidence with which an operator determines positions of the valve  22 . Since accuracy of the pressure transducers  24 ,  34  can vary with temperature a first temperature gauge  54  is mounted near the first pressure transducer  24  and a second temperature gauge  58  is mounted near the second pressure transducer  34 . With the temperatures measured by the temperature gauges  54 ,  58  the outputs of the pressure transducers  24 ,  34  can be compensated for based on actual temperatures and effects of such temperatures on the pressure transducers  24 ,  34 . Although each of the pressure transducers  24 ,  34  illustrated in this embodiment have a temperature gauge  54 ,  58  positioned nearby, a single temperature gauge may sufficiently monitor the temperature in the area of both of the pressure transducers  24 ,  34  to allow a single temperature gauge to be employed instead of two as shown herein. 
         [0013]    Referring to  FIG. 2 , an alternate embodiment of a pressure monitoring arrangement employed to practice the methods disclosed herein is illustrated generally at  110 . The arrangement  110  is similar to that of the arrangement  10  with the primary difference being that the pressure transducers  24 ,  34  in the arrangement  110  are collocated on a same longitudinal side of the valve  22 . The fact that the transducers  24 ,  34  are collocated does not alter the fact that they still measure pressure at the first location  28  and the second location  38 . A fluidic passageway  62 , shown herein as a tubular, provides fluidic communication between the second location  38  and the second pressure transducer  34 . Although this fluidic passageway  62  is illustrated herein as a separate tubular it should be noted that porting the fluidic passageway  62  by other means, such as through a wall  66  of the tubular  14  is also contemplated. Routing the passageway  62  in this manner may protect the passageway  62  from damage during running of the tubular  14 , for example. Additionally, one or both of the pressure transducers  24 ,  34  could be welded to the housing  14  directly to reduce the chances of leaks between the bore  18  and an annulus  78  defined between the tubular  14  and the borehole  42 . 
         [0014]    Additionally, collocating the pressure transducers  24 ,  34  may facilitate usage of a single temperature gauge  70 , since temperature in the proximity of both of the pressure transducers  24 ,  34  would be substantially similar. 
         [0015]    Alternately, the collocated pressure transducers  24 ,  34  could be replaced with a single differential pressure transducer  74 . The differential transducer  74  could be configured to measure the difference in pressure between the first location  28  and the second location  38 . A sign (positive or negative) of the output of the differential transducer  74  could be indicative of which location  28 ,  38  is exhibiting a greater pressure. An advantage of using the single differential pressure transducer  74  over the two separate transducers  24 ,  34  is that it could automatically compensate for variations in absolute pressure encountered in the locations  28 ,  38 . In a manner similar to that of the arrangement  10  the arrangement  110  can be used to determine various positions of the valve  22 . For example, values of differential pressure that are substantially negligible could be attributed to the valve  22  being open, while greater values of differential pressure could be attributed to the valve  22  being in a closed position. Additionally, values of pressure differential, such as having a negative value, for example, indicative of a greater pressure below the valve  22  than above can increase confidence that the valve  22  is indeed closed, while unstable values of differential pressure can be attributed to leakage by the valve  22 . 
         [0016]    Referring to  FIG. 3 , an alternate embodiment of a pressure monitoring arrangement employed to practice the methods disclosed herein is illustrated generally at  210 . The arrangement  210  is similar to that of the arrangement  110  with the primary differences being that a third pressure transducer  82  is collocated with the pressure transducers  24 ,  34 , and a control line  86 , illustrated herein as a tubing encapsulated conductor, is a feed through control line. The third pressure transducer  82  can be configured to monitor pressure in the annulus  78  or in the control line  86  to provide further analysis and troubleshooting capabilities. The feed through nature of the control line  86  will permit the use of multiple devices on the same control line  86 . 
         [0017]    While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.