Patent Publication Number: US-2020284366-A1

Title: Choke valve with internal sleeve for erosion protection

Description:
CLAIM OF PRIORITY 
     This application is a Continuation of and claims priority to U.S. patent application Ser. No. 15/995,293, filed on Jun. 1, 2018, the entire contents of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This disclosure relates to controlling fluid flow through flow lines, for example, using valves. 
     BACKGROUND 
     Flow lines carry fluids over long distances. The fluids can include multiple phases including liquids, gases and suspended solids. For example, the fluids can include hydrocarbons extracted from a hydrocarbon reservoir in a subterranean zone via a wellbore. In some instances, the hydrocarbons can include solid particulates, for example, sand or other debris, that flowed from the subterranean zone via the wellbore to the surface together with the hydrocarbons. 
     Flow lines implement valves to control the flow of fluid. In instances in which the flowing fluids include solid particulates, the particulates can erode internal regions of the valves over time. Such erosions, left untreated, can damage, for example, rupture, the flow lines causing leaks. 
     SUMMARY 
     This specification describes technologies relating to choke valves with internal sleeves for erosion protection. 
     An aspect relates to a choke valve assembly including an inlet body configured to receive fluids flowed through an upstream flow line, and an outlet body fluidically coupled to the inlet body, the outlet body configured to discharge fluids received at the inlet body out of the choke valve assembly into a downstream flow line. The assembly includes a choke valve body positioned between and attached to each of the inlet body and the outlet body, the choke valve body having a choke valve configured to be opened or closed to control flow of the fluids from the inlet body to the outlet body. In addition, the assembly includes a sleeve positioned in and attached to an inner region defined by the choke valve body, the sleeve defining an inner sleeve region internal to the sleeve and an outer sleeve region external to the sleeve and internal to the inner region of the choke valve body. The sleeve is configured to flow the fluids from the inlet body through the inner sleeve region instead of the outer sleeve region. 
     Another aspect relates to a method including receiving, from an upstream flow line, fluids at an inlet body of a choke valve assembly, the inlet body fluidically coupled to an outlet body of the choke valve assembly, the outlet body configured to flow the fluids to a downstream flow line. Further, the method includes forming, by a sleeve positioned in and attached to a choke valve body positioned between the inlet body and the outlet body, an inner region internal to the sleeve and an outer region external to the sleeve and internal to the choke valve body, the choke valve body comprising a choke valve configured to be open or closed to control flow of the fluids from the inlet body to the outlet body. The method also includes flowing, by the sleeve and in response to the choke valve being open, the fluids received at the inlet body through the inner region instead of through the outer region and to the outlet body. 
     Yet another aspect relates to a hydrocarbon flow line assembly having an upstream flow line configured to flow well fluids comprising hydrocarbons extracted from a hydrocarbon reservoir in a subterranean zone, and a choke valve assembly downstream of the upstream flow line, the choke valve assembly fluidically coupled to an outlet of the upstream flow line to receive the well fluids from the upstream flow line. The choke valve assembly includes a sleeve positioned in and attached to an inner region of the choke valve assembly, the sleeve defining an inner sleeve region internal to the sleeve and an outer sleeve region external to the sleeve and internal to the inner region of the choke valve assembly. The sleeve is configured to flow the fluids from the inlet body through the inner sleeve region instead of the outer sleeve region. The hydrocarbon flow assembly also includes a downstream flow line downstream of the choke valve assembly and configured to receive the well fluids from an outlet of the choke valve assembly. 
     The details of one or more implementations of the subject matter described in this specification are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the subject matter will become apparent from the description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of example flow lines fluidically coupled by a valve assembly. 
         FIG. 2  is a schematic diagram of an example choke valve assembly in a closed state. 
         FIG. 3  is a schematic diagram of an example choke valve assembly in an open state. 
         FIG. 4  is a flowchart of an example of a process of controlling fluid flow through flow lines. 
     
    
    
     Like reference numbers and designations in the various drawings indicate like elements. 
     DETAILED DESCRIPTION 
     Choke valve assemblies are used to control flow of fluids through flow lines. The fluids can include hydrocarbons extracted from a hydrocarbon reservoir. Such fluids can include liquid, gas and solid particulates, for example, sand particles or other solid particulates from the hydrocarbon reservoir. The outlet portions of the choke valve assemblies experience high fluid velocities due to the volumetric flow rates of the fluids flowed through the flow lines. The outlet portions experience pin-hole leaks resulting from erosion caused by the solid particles. In the case of hydrocarbon carrying flow lines, such erosion can result in oil spills which can be catastrophic. 
     This disclosure describes a modified choke valve assembly that includes an internal sleeve within the choke valve assembly. As described later, the internal sleeve defines an inner sleeve region through which the flow line fluid is flowed and an outer sleeve region that is external to the sleeve and internal to the choke valve assembly. The outer sleeve region defines a void space in which the fluidic pressure is sensed. If the fluidic pressure in the outer sleeve region fails to satisfy a fluidic pressure threshold (for example, is greater than the fluidic pressure threshold), that indicates that the internal sleeve has been eroded. In response, flow through the flow lines can be stopped and the internal sleeve of the choke valve assembly can be replaced without needing to replace the entire choke valve assembly. Alternatively or in addition, in response to detecting that the internal sleeve has eroded, an emergency shutdown (ESD) system can be activated to shut off flow through the flow lines to prevent any spillage while the sleeve is being replaced. 
     In some implementations, the sleeve is attached in or near an outlet body of the choke valve assembly. Because any erosion is absorbed by the sleeve, the choke valve body is protected, thereby extending its life. By sensing the fluidic pressure in the void space defined by the outer sleeve region, a failure (such as rupture) of the sleeve due to erosion by solid particulates can be detected before the choke valve assembly itself fails. In this manner, leaks or spills can be prevented and the associated damage avoided. Therefore, asset integrity and reliability may be enhanced, decreasing interruption of oil/gas production and thus increasing production, and also reducing undesired release of oil/gas to the environment, and so on. 
       FIG. 1  is a schematic diagram of example flow lines fluidically coupled by a valve assembly. A choke valve assembly  100  controls flow of the fluids through the flow lines, in particular, an upstream flow line  102  upstream of the choke valve assembly  100  and a downstream flow line  104  downstream of the choke valve assembly  100 . In some implementations, the flow lines can carry hydrocarbons (for example, oil, gas, or combinations of them) extracted from a hydrocarbon reservoir in a subterranean zone via a wellbore. The fluids in the flow lines can carry solid particulates, for example, sand or well debris that flowed into the flow lines from the hydrocarbon reservoir via the well. 
     The choke valve assembly  100  is described in the context of hydrocarbons received from a wellbore or carried through a flow line. The choke valve assembly  100  can be implemented in any flow line through which fluids that carry solid particulates. Specifically, the solid particulates, for example, sand, rock, or other solid particulates, can be of a size and toughness that can erode inner regions of the choke valve assembly when flowed through the choke valve assembly. Also, the choke valve assembly  100  is described in the context of an upstream flow line  102  that is substantially perpendicular to a downstream flow line  102  such that the fluid flow path turns by substantially ninety degrees. As used in this disclosure, the term “substantially” represents a variance from a numerical value by up to and including around 5%. For example, by “substantially perpendicular,” it is meant that an angle between the upstream flow line  102  and the downstream flow line  104  can range between 85 degrees and 95 degrees. In alternative implementations, the choke valve assembly  100  can be implemented when the upstream flow line  102  and the downstream flow line  104  are at different angles from that shown in  FIG. 1 . For example, the upstream flow line  102  and the downstream flow line  104  can be co-axial with the choke valve assembly  100  positioned in between. Indeed, the choke valve assembly  100  may accommodate or incorporate various arrangements of the flow lines  102  and  104 . Again, in some examples, the angle for the choke valve between the upstream line  102  and downstream line  104  is about 90 degrees. 
       FIG. 2  is a schematic diagram of an example choke valve assembly  100  in a closed state. The choke valve assembly  100  includes an inlet body  202  that can receive fluids flowed through an upstream flow line, for example, the upstream flow line  102  ( FIG. 1 ). The inlet body  202  can include a hollow tubular member that can be fluidically interfaced with and seal to an outlet of the upstream flow line  102 , for example, via a coupling or other interface structure. The choke valve assembly  100  includes an outlet body  204  fluidically coupled to the inlet body  202 . The outlet body  204  can discharge fluids received at the inlet body  202  out of the choke valve assembly  100  into a downstream flow line, for example, the downstream flow line  104 . Like the inlet body  202 , the outlet body  204  can include a hollow tubular member that can be fluidically interfaced with and seal to an inlet of the downstream flow line  104 , for example, via a coupling or other interface structure. In some implementations, a longitudinal axis  224  of the inlet body  202  can be substantially perpendicular to a longitudinal axis  226  of the outlet body  204  such that the fluids entering the choke valve assembly  100  via the inlet body  202  are turned by substantially ninety degrees in the outlet body  204 . 
     A choke valve body  206  is positioned between and attached to each of the inlet body  202  and the outlet body  204 . The choke valve body  206  includes a choke valve  208  that can be opened or closed to control flow of the fluids from the inlet body  202  to the outlet body  204 . In  FIG. 2 , the choke valve  208  is shown in a closed state. That is, the choke valve stem  211 , which can be moved between open and closed states, for example, by rotating the hand wheel  209 , seals the outlet body  204  from the inlet body  202 , thereby preventing fluid flow from the inlet body  202  to the outlet body  204 . 
     The choke valve body  206  defines an inner region  212  within the choke valve assembly  100 . Fluids from the upstream flow line  102  can flow through portions of the inner region  212  to the downstream flow line  104 . The choke valve assembly  100  includes a sleeve  210  positioned in and attached to the inner region  212 . The sleeve  210  defines an inner sleeve region  214  internal to the sleeve  210  and an outer sleeve region  216  external to the sleeve  210  and internal to the inner region  212  of the choke valve body  206 . The sleeve  210  can flow the fluids from the inlet body  202  through the inner sleeve region  214  instead of the outer sleeve region  216 . In other words, the sleeve  210  is attached to the inner region  212  of the choke valve body  206  such that, when the choke valve assembly  100  is in an open state and is operating as intended, fluids from the inlet body  202  can only flow through the inner sleeve region  214 , but not through the outer sleeve region  216 . 
     In some implementations, the inner sleeve  210  is positioned in and attached to a portion of the choke valve body  206  that is attached to the outlet body  204 . A portion of the inner sleeve  210  extends into the outlet body  204 , for example, into the outlet trim of the choke valve assembly  100 . By this arrangement, fluids can flow from the upstream flow line  102  into the choke valve body  206 . Fluids exiting the choke valve body  206  are constrained to flow through the inner sleeve region  214 , but not the outer sleeve region  216 , toward the downstream flow line  104 . 
     In certain implementations, the sleeve may be placed in the inlet trim instead of the outlet trim. In other implementations, two sleeves includes one sleeve at the inlet trim and the other sleeve at the outlet trim, respectively. In some instances, the pressure in the void area of the inlet trim can be sensed similarly to pressure sensing in the void area of the outlet trim. Lastly, while the inlet trim may be implemented, disposing the trim at the choke outlet portion may be beneficial because the trim would be generally exposed to higher fluid velocity at the outlet portion than at the inlet portion. 
     The sleeve  210  is fixedly and sealingly attached to the inner region  212  defined by the choke valve body  206  to prevent the fluids from flowing through the outer sleeve region  216 . To do so, the choke valve assembly  100  includes a ring-seal  218  that affixes the sleeve to the inner region  212  and seals the outer sleeve region  216  from the rest of the inner region  212 . Various structural features, locks, seals, etc. may attach the sleeve to the valve outlet trim and, in examples, some of these features if employed may be attached to and removable from the valve body. The mechanisms may create a seal that prevents fluid from flowing into the void space. In one example, a seal may be at the upstream end of the inlet or at other locations. 
     In some implementations, the sleeve  210  can be a tubular member that is concentric with the outer body  204 . The sleeve  210  can be made of a material that can withstand (physically and chemically) the fluids flowed through the choke valve assembly  100 . For example, the sleeve  210  can be made of tungsten carbide or high super duplex stainless steel material. 
     As described earlier, the choke valve assembly  100  is shown in a closed state in  FIG. 2 . That is, the hand wheel  209  has been turned to lower the valve stem  211  onto an end of the sleeve  210 . The ring-seal  218  prevents fluids received through the inner body  202  from flowing to the outer body  204 . 
       FIG. 3  is a schematic diagram of an example choke valve assembly, for example, the choke valve assembly  100 , in an open state. In the open state, the hand wheel  209  has been turned to raise the valve stem  211  away from the end of the sleeve  210 . Fluids from the inner body  202  can flow through the choke valve body  206  towards the outer body  204 . However, the ring-seal  218  forces the fluids to flow through the inner sleeve region  214  and seals the outer sleeve region  216  to the fluid flow. Any erosion or other damage that is caused by solid particulates or other components of the fluids is experienced by the inner surface of the sleeve  214  rather than the inner surface of the choke valve body  206  in the outer sleeve region  216 . In this manner, the choke valve body  206  is protected even if the sleeve  210  is ruptured due to the erosion or damage. 
     Over time, as fluids flow through the choke valve assembly  100 , the sleeve  210  is likely to be ruptured and damaged as explained above. To determine if the sleeve  210  has ruptured or has been damaged, a pressure sensor  222  can be connected to the void space defined by the outer sleeve region  216 . For example, tubing  223  made from a fluidic pressure resistant material (such as stainless steel) can connect the void space defined by the outer sleeve region  216  to the pressure sensor  222 . The pressure sensor  222  can sense a fluidic pressure in the void space, and, generate and transmit a signal representing the sensed fluidic pressure. 
     An ESD system  220  can be operatively coupled to the outer sleeve region  216  and to the pressure sensor  222 . The ESD system  220  can be implemented as a computer-readable medium storing computer instructions executable by one or more computer processors to perform operations including shutting down flow through either the upstream flow line  102  or the downstream flow line  104  or both. Alternatively, the ESD system  220  can be implemented as processing circuitry, firmware, hardware, software or combinations of them to perform the operations. If the fluidic pressure in the void space defined by the outer sleeve region  216  fails to satisfy a fluidic pressure threshold, that is an indication that the sleeve  210  has failed. Upon such an occurrence, the ESD system  220  can shut down the flow through the upstream flow line  102  or the downstream flow line  104  or both to prevent leakage of the fluids out of the flow lines. 
     In some implementations, the ESD system  220  stores a fluidic pressure threshold, for example, 100 pounds per square inch (PSI). The ESD system  220  includes or is operatively coupled to a valve (for example, a solenoid valve or other valve). In operation, the ESD system  220  receives fluidic pressure sensed by the pressure sensor  222 , for example, continuously, periodically (for instance, at a frequency of 1 pressure signal per second or other frequency) or upon the pressure sensor  222  sensing a pressure value greater than the fluidic pressure threshold. The ESD system  220  compares the fluidic pressure value represented by the pressure signal from the pressure sensor  222  to the stored fluidic pressure threshold. Upon determining that the sensed pressure fails to satisfy the fluidic pressure threshold (for example, is greater than the fluidic pressure threshold), the ESD system  220  activates the valve, such as a safety valve, to close the upstream flow line  102  (or the downstream flow line  104 , or both) to which the ESD system  220  is fluidically coupled. 
       FIG. 4  is a flowchart of an example of a process  400  of controlling fluid flow through flow lines. The process  400  can be implemented, in part, by a choke valve assembly such as the choke valve assembly  100  and, in part, by a ESD system such as the ESD system  220 . At  402 , fluid is received at a choke valve assembly inlet body. For example, fluids from an upstream flow line are received at the inlet body  202  of the choke valve assembly  100 . At  404 , fluidic pressure is sensed in a void space defined by a sleeve in the choke valve assembly. For example, the sleeve  210  positioned in and attached to the choke valve body  206  positioned between the inlet body  202  and the outlet body  204  forms a void space defined by the outer region  216  external to the sleeve  210  and internal to the choke valve body  206 . At  406 , a determination is made to check if a fluidic pressure threshold is satisfied. For example, the ESD system  220  checks if the pressure sensed by the pressure sensor  222  in the void space satisfies the fluidic pressure threshold stored by the ESD system  220 . If the fluidic pressure is satisfied (decision branch “YES”), then the fluidic pressure is continued to be sensed by implementing step  404 . If the fluidic pressure is not satisfied (decision branch “NO”), then, at  408 , emergency shutdown of the flow line is initiated. For example, the ESD system  220  triggers a valve to shut down flow through the flow line to which the ESD system  220  is operatively coupled, which can be the upstream flow line  102  or the downstream flow line  104  or both. 
     In sum, some implementations of the subject matter described here are directed to a hydrocarbon flow line assembly. The assembly includes an upstream flow line, for example, the upstream flow line  102 , to flow well fluids that include hydrocarbons extracted from a hydrocarbon reservoir in a subterranean zone. The assembly includes a choke valve assembly, for example, the choke valve assembly  100 , downstream of the upstream flow line. The choke valve assembly is fluidically coupled to an outlet of the upstream flow line to receive the well fluids from the upstream flow line. The choke valve assembly includes a sleeve positioned in and attached to an inner region of the choke valve assembly. The sleeve defines an inner sleeve region internal to the sleeve and an outer sleeve region external to the sleeve and internal to the inner region of the choke valve assembly. The sleeve can flow the fluids from the inlet body through the inner sleeve region instead of the outer sleeve region. The assembly includes a downstream flow line, for example, the downstream flow line  104 , downstream of the choke valve assembly that can receive the well fluids from an outlet of the choke valve assembly. 
     Thus, particular implementations of the subject matter have been described. Other implementations are within the scope of the following claims.