Patent Publication Number: US-10329894-B2

Title: Base gauge and multiple remote sensors

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND 
     Some oil and gas production rigs employ an artificial lift electrical submersible pump (ESP) to increase pressure within a reservoir to thereby encourage oil to the surface. When the natural drive energy of the reservoir is not sufficient to push the oil to the surface, artificial lift is employed to recover more production. If an ESP fails during operation, the ESP must be removed from the pumping environment and replaced or repaired, either of which results in a significant cost to an operator. 
     In various applications, sensors or other detectors are used to monitor aspects of the pumping system, for example to detect or predict pumping system failure, or to provide surveillance engineers with a richer observable dataset upon which to make decisions regarding pumping system operation. In some cases, a base gauge may serve as a “hub” between surface monitoring equipment and one or more remote sensors positioned along the ESP string. However, the downhole environment is space constrained with respect to the ability to provide connectors to more than a small number of remote sensors. Further, the base gauge is often incapable of providing sufficient power for more than a small number of remote sensors. 
     SUMMARY 
     Embodiments of the present disclosure are directed to a system for monitoring one or more downhole parameters. The system includes a downhole base gauge configured to receive power from a surface power drive and to communicate data with a surface computing device and a plurality of downhole remote sensors coupled to the base gauge in series and configured to generate data indicative of one or more observable parameters. The base gauge is further configured to query one of the remote sensors and, in response to such a query, the remote sensor is configured to transmit data indicative of the observable parameter associated with that sensor to the base gauge. 
     Other embodiments of the present disclosure are directed to a method of monitoring one or more downhole parameters. The method includes providing downhole a base gauge configured to receive power from a surface power drive and to communicate data with a surface computing device and providing downhole a plurality of remote sensors coupled to the base gauge in series and configured to generate data indicative of one or more observable parameters. The method also includes querying one of the remote sensors and, in response to such a query, transmitting, by the remote sensor to the base gauge, data indicative of the observable parameter associated with that sensor. 
     This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the disclosure are described with reference to the following figures: 
         FIG. 1 a    is an illustration of a prior art electric submersible pump (ESP) including a base gauge coupled to two remote sensors; 
         FIG. 1 b    is an illustration of a block diagram of the prior art base gauge coupled to two remote sensors; 
         FIG. 2 a    is an illustration of an example of an ESP system deployed in a wellbore, according to an embodiment of the present disclosure; 
         FIG. 2 b    is an illustration of an example of an ESP system deployed in a wellbore, where a base gauge is coupled to a plurality of remote sensors in series, according to an embodiment of the present disclosure; 
         FIG. 2 c    is an illustration of a block diagram of the base gauge coupled to a plurality of remote sensors in series, according to an embodiment of the present disclosure; 
         FIG. 3  is an illustration of various views of a base gauge and connector, according to an embodiment of the present disclosure; 
         FIGS. 4 a  and 4 b    are illustrations of a remote sensor having a smallest effective outer diameter, according to an embodiment of the present disclosure; 
         FIGS. 5 a  and 5 b    are illustrations of a clamp-mounted remote sensor, according to an embodiment of the present disclosure; and 
         FIG. 6  is an illustration of a tubing-mounted remote sensor, according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     One or more embodiments of the present disclosure are described below. These embodiments are merely examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such implementation, as in any engineering or design project, numerous implementation-specific decisions are made to achieve the developers&#39; specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such development efforts might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure. 
     When introducing elements of various embodiments of the present disclosure, the articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements. The embodiments discussed below are intended to be examples that are illustrative in nature and should not be construed to mean that the specific embodiments described herein are necessarily preferential in nature. Additionally, it should be understood that references to “one embodiment” or “an embodiment” within the present disclosure are not to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. The drawing figures are not necessarily to scale. Certain features and components disclosed herein may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. 
     The terms “including” and “comprising” are used herein, including in the claims, in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first component couples or is coupled to a second component, the connection between the components may be through a direct engagement of the two components, or through an indirect connection that is accomplished via other intermediate components, devices and/or connections. If the connection transfers electrical power or signals, the coupling may be through wires or other modes of transmission. In some of the figures, one or more components or aspects of a component may be not displayed or may not have reference numerals identifying the features or components that are identified elsewhere in order to improve clarity and conciseness of the figure. 
     Electric submersible pumps (ESPs) may be deployed for any of a variety of pumping purposes. For example, where a substance does not readily flow responsive to existing natural forces, an ESP may be implemented to artificially lift the substance. Commercially available ESPs (such as the REDA™ ESPs marketed by Schlumberger Limited, Houston, Tex.) may find use in applications that require, for example, pump rates in excess of 4,000 barrels per day and lift of 12,000 feet or more. 
     To improve ESP operations, an ESP may include one or more sensors (e.g., gauges) that measure any of a variety of phenomena (e.g., temperature, pressure, vibration, etc.). A commercially available sensor is the Phoenix MultiSensor™ marketed by Schlumberger Limited (Houston, Tex.), which monitors intake and discharge pressures; intake, motor and discharge temperatures; and vibration and current leakage. An ESP monitoring system may include a supervisory control and data acquisition system (SCADA). Commercially available surveillance systems include the LiftWatcher™ and the LiftWatcher™ surveillance systems marketed by Schlumberger Limited (Houston, Tex.), which provides for communication of data, for example, between a production team and well/field data (e.g., with or without SCADA installations). Such a system may issue instructions to, for example, start, stop or control ESP speed via an ESP controller. 
     As explained above, sensors or other detectors are used to monitor aspects of the ESP, for example to detect or predict ESP failure, or to provide surveillance engineers with a richer observable dataset upon which to make decisions regarding ESP operation.  FIG. 1 a    shows a prior art ESP string  100 , including a base gauge  102  coupled to remote sensors  104   a ,  104   b  by way of control lines  106   a ,  106   b , respectively.  FIG. 1 b    shows a corresponding block diagram of the elements of  FIG. 1 a   , in which surface equipment  150  is coupled to the base gauge  102 , which in turn couples to each of the remote sensors  104   a ,  104   b  by way of dedicated control lines  106   a ,  106   b . The surface equipment  150  may include a topside power drive such as a VSD to provide power to the base gauge  102  as well as various computing equipment to transmit to and receive from the base gauge  102  data, messages, and the like. 
     Requiring a separate control line  106  for each remote sensor  104  has several drawbacks. For example, additional control lines  106  consume additional space, which is limited to begin with. Additional control lines  106  in the downhole environment also increase complexity and may be more cumbersome to install, as well as introduce increased likelihood of failure. Further, in prior systems such as those shown in  FIGS. 1 a  and 1 b   , the base gauge  102  supplies power to both remote sensors  104   a ,  104   b . However, the total amount of power the base gauge  102  is able to supply is limited, and thus prior systems may be limited to one remote sensor  104 , two remote sensors  104   a ,  104   b , or an otherwise-limited number of remote sensors  104  due to constrains on the base gauge&#39;s  102  ability to supply power concurrently. 
     Embodiments of the present disclosure address these and other issues by providing a system and method for monitoring one or more downhole parameters in which a downhole base gauge is coupled to a plurality of downhole remote sensors in series. In particular, the base gauge receives power from a surface power drive such as a VSD and communicates data with a surface computing device. For example, the surface computing device may send commands to the base gauge to poll various sensors, while the base gauge may return data indicative of measurements of those sensors to the surface computing device. Since the base gauge is coupled to the remote sensors in series, the problems associated with requiring multiple control lines  106  is eliminated, since a single control line will be present between the base gauge and a proximate remote sensor, and between that remote sensor and another proximate remote sensor, and so on. Thus, unlike the prior art system  100 , the base gauge in accordance with embodiments of the present disclosure only directly couples to one remote sensor, which then may couple to one other remote sensor, and so on. 
     In addition to eliminating the problem of dedicated control lines  106  for each remote sensor  104 , embodiments of the present disclosure also permit a single base gauge to power any number of remote sensors. In particular, remote sensors according to embodiments of the present disclosure are configured to operate in either a standby mode or in an awake mode. In the standby mode, a remote sensor consumes a minimal amount of power, sufficient to receive and process a query or message from the base gauge, but insufficient to power its sensor to receive or acquire measurements and the like. In the awake mode, which the remote sensor enters after receiving a query from the base gauge, the remote sensor functions normally, and is able to acquire and transmit data indicative of an observable parameter to the base gauge. Once such a transmission is complete, the remote sensor reenters standby mode. As a result, and since the base gauge may only query one or a limited number of remote sensors at a time, a much larger number of remote sensors may be deployed along the ESP string without concern about the ability of the base gauge to power the various sensors, since polling may occur on an as-needed basis. Other embodiments and details thereof will be explained below, with reference to the accompanying figures. 
     Turning to  FIG. 2 a   , an example of an ESP system  100  is shown. The ESP system  100  includes a network  101 , a well  103  disposed in a geologic environment, a power supply  105 , an ESP  110 , a controller  130 , a motor controller  150 , and a VSD unit  170 . The power supply  105  may receive power from a power grid, an onsite generator (e.g., a natural gas driven turbine), or other source. The power supply  105  may supply a voltage, for example, of about 4.16 kV. 
     The well  103  includes a wellhead that can include a choke (e.g., a choke valve). For example, the well  103  can include a choke valve to control various operations such as to reduce pressure of a fluid from high pressure in a closed wellbore to atmospheric pressure. Adjustable choke valves can include valves constructed to resist wear due to high velocity, solids-laden fluid flowing by restricting or sealing elements. A wellhead may include one or more sensors such as a temperature sensor, a pressure sensor, a solids sensor, and the like. 
     The ESP  110  includes cables  111 , a pump  112 , gas handling features  113 , a pump intake  114 , a motor  115  and one or more sensors  116  (e.g., temperature, pressure, current leakage, vibration, etc.). The well  103  may include one or more well sensors  120 , for example, such as the commercially available OpticLine™ sensors or WellWatcher BriteBlue™ sensors marketed by Schlumberger Limited (Houston, Tex.). Such sensors are fiber-optic based and can provide for real time sensing of downhole conditions. Measurements of downhole conditions along the length of the well can provide for feedback, for example, to understand the operating mode or health of an ESP. Well sensors may extend thousands of feet into a well (e.g., 4,000 feet or more) and beyond a position of an ESP. 
     The controller  130  can include one or more interfaces, for example, for receipt, transmission or receipt and transmission of information with the motor controller  150 , a VSD unit  170 , the power supply  105  (e.g., a gas fueled turbine generator or a power company), the network  101 , equipment in the well  103 , equipment in another well, and the like. The controller  130  may also include features of an ESP motor controller and optionally supplant the ESP motor controller  150 . 
     The motor controller  150  may be a commercially available motor controller such as the UniConn™ motor controller marketed by Schlumberger Limited (Houston, Tex.). The UniConn™ motor controller can connect to a SCADA system, the LiftWatcher™ surveillance system, etc. The UniConn™ motor controller can perform some control and data acquisition tasks for ESPs, surface pumps, or other monitored wells. The UniConn™ motor controller can interface with the Phoenix™ monitoring system, for example, to access pressure, temperature, and vibration data and various protection parameters as well as to provide direct current power to downhole sensors. The UniConn™ motor controller can interface with fixed speed drive (FSD) controllers or a VSD unit, for example, such as the VSD unit  170 . 
     In accordance with various examples of the present disclosure, the controller  130  may include or be coupled to a processing device  190 . Thus, the processing device  190  is able to receive data from ESP sensors  116  and/or well sensors  120 . The controller  130  and/or the processing device  190  may also monitor surface electrical conditions (e.g., at the output of the drive) to gain knowledge of certain downhole parameters, such as downhole vibrations, which may propagate through changes in induced currents. 
       FIG. 2 b    shows a system  200  in accordance with embodiments of the present disclosure, with particular focus on ESP string  202  and its base gauge  204  coupled to a plurality of remote sensors  206   a - n  in series. The remote sensors  206   a - n  may generate data indicative of any number of observable parameters, such as pressure, temperature, vibration, flow rate, proximity to the wellbore, and the like. As explained above, the base gauge  204  receives power and data from a surface power drive and computing device  201  and transmits data to the same. A single control line  208  directly couples the base gauge  204  to proximate remote sensor  206   a , while a single control line  208  directly couples the proximate remote sensor  206   a  to another proximate remote sensor  206   b , and so on. The control line  208  may comprise a coaxial cable having a single inner core. The control line  208  transmits power from the base gauge  204  to the remote sensors  206   a - n , as well as carries messages transmitted between the base gauge  204  and the remote sensors  206   a - n . In other words, the base gauge  204  both sends commands/queries to the remote sensors  206   a - n  by way of the control line  208  and the remote sensors  206   a - n  send messages to the base gauge  204  by way of the control line. By utilizing only a single control line between any two neighboring remote sensors  206   a - n  (and between one remote sensor  206   a  and the base gauge  204 ), space constraints are loosened, while the overall connection scheme is simplified. 
     In addition to eliminating the problem of dedicated control lines for each remote sensor as explained with respect to  FIGS. 1 a  and 1 b   , the base gauge  204  is able to power any number of remote sensors  206   a - n . In particular, remote sensors  206   a - n  are configured to operate in either a standby mode or in an awake mode. In the standby mode, a remote sensor  206  consumes a minimal amount of power, sufficient to receive and process a query or message from the base gauge  204 , but insufficient to power its sensor to receive or acquire measurements and the like. In the awake mode, which the remote sensor  206  enters after receiving a query from the base gauge  204 , the remote sensor  206  functions normally, and is able to acquire and transmit data indicative of an observable parameter to the base gauge  204 . Once such a transmission is complete, the remote sensor  206  reenters standby mode. As a result, and since the base gauge  204  may only query one or a limited number of remote sensors  206   a - n  at a time, a much larger number of remote sensors  206   a - n  may be deployed along the ESP string  202  without concern about the ability of the base gauge  204  to power the various sensors  206   a - n , since polling may occur on an as-needed basis. 
     Further, in certain embodiments, the base gauge  204  may be configured to address various issues that commonly arise from electrical imbalances that occur in the ESP system  100 . Electrical imbalances arise as a result of mismatches between various components of the ESP system  100 . For example, mismatches in resistance or inductance between phases of the motor  115  contribute to electrical imbalances. Electrical imbalance causes a normally-DC power supply that powers the base gauge  204  to become alternating, or AC. However, in the certain embodiments, the base gauge  204  is configured to utilize the imbalance condition, or the AC voltage, as a power supply for its internal circuitry and components. Thus, in these embodiments, the base gauge  204  is able to communicate with remote sensors  206   a - n  immune from issues that might otherwise arise in the presence of an imbalance condition. 
       FIG. 2 c    shows a block diagram of the system  200  to illustrate the single control line  208  that directly couples each pair of neighboring remote sensors  206   a - n  (and directly couples one remote sensor  206   a  to the base gauge  204 ). 
       FIG. 3  shows a perspective view of the base gauge  204  and in particular illustrates that only a single control line  208  from the base gauge  204  is needed to communicate with and supply power to a plurality of remote sensors. The base gauge  204  may house its internal electronics (e.g., for power provision and communications between the surface and the remote sensors) on a bracket, which is enclosed by an outer housing as shown. Various o-ring or other type seals (not shown) maintain a certain pressure inside the base gauge  204  during operation. A head  302  of the base gauge  204  is where the control line  208  terminates into the base gauge  204 , and power and communication connections are provided between the termination of the control line and the internal electronics of the base gauge  204 . 
       FIG. 4 a    shows a remote sensor  206  in further detail, including a termination  401  for the control line  208  and an exemplary welded electronics compartment  403  to protect the circuitry and power and communication electronics of the remote sensor  206 . Similar to a base gauge  204 , the remote sensor  206  houses electronics and transducer(s) to generate data indicative of observable parameters, although in a more compact arrangement.  FIG. 4 b    shows another exemplary remote sensor  206  having a control line input  402  (e.g., to receive power and communications from the base gauge  204 ) and a control line output  404  (e.g., to transmit power and communications to another remote sensor  206 ). Of course, one of ordinary skill will appreciate that while these are referred to as “input” and “output,” data in the form of indications of observable parameters will flow in the opposite direction. That is, data from a downstream remote sensor  206  (i.e., in the “up” direction in  FIG. 4 b   ) will be received at the output  404  and transmitted back to the base gauge  204  (or intermediary remote sensor(s)  206 ) by way of the input  402 . Of importance is the fact that only a single control line  208  is required between sensors to couple a plurality of remote sensors  206  to the base gauge  204 . 
       FIG. 4 a    also demonstrates that the base gauge  204  may include a flange  406  to couple to the ESP string, for example. The flange  406  includes a recess  405 , which receives the control line  208  to ensure that the outer diameter of the base gauge  204 , including the control line  208 , is no greater than the outer diameter of the flange  406  itself, which is particularly useful when casing drift may be an issue. Similar flanges with recesses may be utilized on remote sensors as appropriate, to likewise ensure that their outer diameter does not exceed the outer diameter of the ESP string or the associated flanges, further reducing borehole clutter. 
       FIGS. 5 a  and 5 b    show examples of clamp-mounted remote sensors  502 . In particular, in  FIG. 5 a   , the remote sensor  502  houses various electronics and transducers or other measurement devices to generate data indicative of an observable parameter. Further, and as described above, the remote sensor  502  includes an input termination  504  and an output termination  506  for the transfer of power and data between the remote sensor  502  and its neighbors (i.e., either another remote sensor or a base gauge, as explained above).  FIG. 5 b    depicts one embodiment  510  in which the remote sensor  502  is integrated into the clamp itself, or is formed as part of a clamp to clamp to a portion  508  of an ESP string, for example.  FIG. 5 b    depicts another embodiment in which the remote sensor  502  is coupled to a clamp device  512 , for example by one or more fasteners, which is then in turn clamped to a portion  514  of an ESP string. Regardless of the particular style of clamping, the clamp-mounted remote sensors  502  offer the flexibility to monitor parameters (e.g., vibration) at very specific locations along an ESP string. Further, in some cases, clamps of varying diameter may be employed to permit mounting to various sections of the ESP string having different outer diameters. 
       FIG. 6  shows another example implementation of a remote sensor  602  in accordance with embodiments of the present disclosure. In particular, in  FIG. 6 , the remote sensor  602  is integrated to a portion of production tubing  604 , for example to measure various tubing pressures (e.g., inlet and/or outlet pressures), temperatures, flow rates, vibration, and the like. The production tubing  604  also includes a coupling  606  to connect to other sections of tubing. 
     In addition to the foregoing, it should be appreciated that the scope of the present disclosure also extends to methods of use and/or installation of the various described systems for monitoring one or more downhole parameters. For example, certain methods may include providing a downhole base gauge configured to receive power from a surface power drive and to communicate data with a surface computing device and providing a plurality of downhole remote sensors coupled to the base gauge in series and configured to generate data indicative of one or more observable parameters. The method may also include querying one of the remote sensors and, in response to such a query, transmitting data from the remote sensor to the base gauge indicative of an observable parameter associated with that sensor. 
     Although only a few example embodiments have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the example embodiments without materially departing from the electrical connector assembly. Features shown in individual embodiments referred to above may be used together in combinations other than those which have been shown and described specifically. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. 
     The embodiments described herein are examples only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the disclosure. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims.