Patent Publication Number: US-11377341-B2

Title: Mobile distribution station with additive injector

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present disclosure is a continuation of U.S. patent application Ser. No. 15/795,697 filed Oct. 27, 2017. 
    
    
     BACKGROUND 
     Hydraulic fracturing (also known as fracking) is a well-stimulation process that utilizes pressurized liquids to fracture rock formations. Pumps and other equipment used for hydraulic fracturing typically operate at the surface of the well site. The equipment may operate semi-continuously, until refueling is needed, at which time the equipment may be shut-down for refueling. Shut-downs are costly and reduce efficiency. More preferably, to avoid shut-downs fuel is replenished in a hot-refueling operation while the equipment continues to run. This permits fracking operations to proceed fully continuously; however, hot-refueling can be difficult to reliably sustain for the duration of the fracking operation. 
     SUMMARY 
     A distribution station according to an example of the present disclosure includes a mobile trailer, a delivery system that has a pump on the mobile trailer, a manifold on the mobile trailer and fluidly connected with the pump, a plurality of reels on the mobile trailer, and a plurality of hoses connected, respectively, with the reels. The reels are fluidly connected with the manifold and each of the valves are situated between the manifold and a respective different one of the hoses. Each of the sensors is associated with a respective different one of the hoses. An additive injector is fluidly connected with the delivery system and operable to introduce controlled amounts of an additive into the delivery system. 
     A distribution station according to an example of the present disclosure includes an injection system that has a controller and an additive injector fluidly connected with the delivery system. The controller is configured to operate the additive injector and introduce controlled amounts of an additive into the delivery system. 
     A distribution station according to an example of the present disclosure includes a container that has an additive and an additive injector fluidly connected with the container. The delivery system is operable to introduce controlled amounts of the additive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description. The drawings that accompany the detailed description can be briefly described as follows. 
         FIG. 1  illustrates an example mobile distribution station. 
         FIG. 2  illustrates an internal layout of a mobile distribution station. 
         FIG. 3  illustrates an example of a connection between a manifold, a control valve, and a reel. 
         FIG. 4  illustrates an example of an integrated fuel cap sensor for a mobile distribution station. 
         FIG. 5  illustrates another example mobile distribution station. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a mobile distribution station  20  and  FIG. 2  illustrates an internal layout of the station  20 . As will be described, the station  20  may serve in a “hot-refueling” capacity to distribute fuel to multiple pieces of equipment while the equipment is running, such as fracking equipment at a well site. As will be appreciated, the station  20  is not limited to applications for fracking or for delivering fuel. The examples herein may be presented with respect to fuel delivery, but the station  20  may be used in mobile delivery of other fluids, in other gas/petroleum recovery operations, or in other operations where mobile refueling or fluid delivery will be of benefit. 
     In this example, the station  20  includes a mobile trailer  22 . Generally, the mobile trailer  22  is elongated and has first and second opposed trailer side walls W 1  and W 2  that join first and second opposed trailer end walls E 1  and E 2 . Most typically, the trailer  22  will also have a closed top (not shown). The mobile trailer  22  may have wheels that permit the mobile trailer  22  to be moved by a vehicle from site to site to service different hot-refueling operations. 
     In this example, the mobile trailer  22  has two compartments. A first compartment  24  includes the physical components for distributing fuel, such as diesel fuel, and a second compartment  26  serves as an isolated control room for managing and monitoring fuel distribution. The compartments  24 / 26  are separated by an inside wall  28   a  that has an inside door  28   b.    
     The first compartment  24  includes one or more pumps  30 . Fuel may be provided to the one or more pumps  30  from an external fuel source, such as a tanker truck on the site. On the trailer  22 , the one or more pumps  30  are fluidly connected via a fuel line  32  with a high precision register  34  for metering fuel. The fuel line  32  may include, but is not limited to, hard piping. In this example, the fuel line  32  includes a filtration and air eliminator system  36   a  and one or more sensors  36   b . Although optional, the system  36   a  is beneficial in many implementations, to remove foreign particles and air from the fuel prior to delivery to the equipment. The one or more sensors  36   b  may include a temperature sensor, a pressure sensor, or a combination thereof, which assist in fuel distribution management. 
     The fuel line  32  is connected with one or more manifolds  38 . In the illustrated example, the station  20  includes two manifolds  38  that arranged on opposed sides of the compartment  24 , with an aisle A in between. As an example, the manifolds  38  are elongated tubes that are generally larger in diameter than the fuel line  32  and that have at least one inlet and multiple outlets. Each hose  40  is wound, at least initially, on a reel  42  that is rotatable to extend or retract the hose  40  externally through one or more windows of the trailer  22 . Each reel  42  may have an associated motor to mechanically extend and retract the hose  40 . The reels  42  and motors may be mounted on a support rack in the station  20 . The station  20  may include twenty hoses  40 , although fewer or more hoses could be used. Most typically, some of the hoses  40  are deployable from one side of the station  20  and other hoses are deployable from the other side of the station  20 . 
     Referring also to  FIG. 3 , each hose  40  is connected to a respective one of the reels  42  and a respective one of a plurality of control valves  44 . For example, a secondary fuel line  46  leads from the manifold  38  to the reel  42 . The control valve  44  is in the secondary fuel line  46 . The control valve  44  is moveable between open and closed positions to selectively permit fuel flow from the manifold  38  to the reel  42  and the hose  40 . For example, the control valve  44  is a powered valve, such as a solenoid valve. 
     In the illustrated example, the first compartment  24  also includes a sensor support rack  48 . The sensor support rack  48  holds integrated fuel cap sensors  50  (when not in use), or at least portions thereof. When in use, each integrated fuel cap sensor  50  is temporarily affixed to a piece of equipment (i.e., the fuel tank of the equipment) that is subject to the hot-refueling operation. Each hose  40  may include a connector end  40   a  and each integrated fuel cap sensor  50  may have a corresponding mating connector to facilitate rapid connection and disconnection of the hose  40  with the integrated fuel cap sensor  50 . For example, the connector end  40   a  and mating connector on the integrated fuel cap sensor  50  form a hydraulic quick-connect. 
       FIG. 4  illustrates a representative example of one of the integrated fuel cap sensors  50 . The integrated fuel cap sensor  50  includes a cap portion  50   a  and a fluid level sensor portion  50   b . The cap portion  50   a  is detachably connectable with a port of a fuel tank. The cap portion  50   a  includes a connector port  50   c , which is detachably connectable with the connector  60  of the hose  40 . The sensor portion  50   b  includes a sensor  50   d  and a sensor port  50   e  that is detachably connectable with a connector. The fuel cap sensor  50  may also include a vent port that attaches to a drain hose, to drain any overflow into a containment bucket and/or reduce air pressure build-up in a fuel tank. Thus, a user may first mount the cap portion  50   a  on the fuel tank of the equipment, followed by connecting the hose  40  to the port  50   c.    
     The sensor  50   d  may be any type of sensor that is capable of detecting fluid or fuel level in a tank. In one example, the sensor  50   d  is a guided wave radar sensor. A guided wave radar sensor may include a transmitter/sensor that emits radar waves, most typically radio frequency waves, down a probe. The probe serves as a guide for the radar waves. The radar waves reflect off of the surface of the fuel and the reflected radar waves are received into the transmitter/sensor. A sensor controller determines the “time of flight” of the radar waves, i.e., how long it takes from emission of the radar waves for the radar waves to reflect back to the transmitter/sensor. Based on the time, the sensor controller, or the controller  52  if the sensor controller does not have the capability, determines the distance that the radar waves travel. A longer distance thus indicates a lower fuel level (farther away) and a shorter distance indicates a higher fuel level (closer). 
     At least the control valves  44 , pump or pumps  30 , sensor or sensors  36   b , and register  34  are in communication with a controller  52  located in the second compartment  26 . As an example, the controller  52  includes software, hardware, or both that is configured to carry out any of the functions described herein. In one further example, the controller  52  includes a programmable logic controller with a touch-screen for user input and display of status data. For example, the screen may simultaneously show multiple fluid levels of the equipment that is being serviced. 
     When in operation, the integrated fuel cap sensors  50  are mounted on respective fuel tanks of the pieces of equipment that are subject to the hot-refueling operation. The hoses  40  are connected to the respective integrated fuel cap sensors  50 . Each integrated fuel cap sensor  50  generates signals that are indicative of the fuel level in the fuel tank of the piece of equipment on which the integrated fuel cap sensor  50  is mounted. The signals are communicated to the controller  52 . 
     The controller  52  interprets the signals and determines the fuel level for each fuel tank of each piece of equipment. In response to a fuel level that falls below a lower threshold, the controller  52  opens the control valve  44  associated with the hose  40  to that fuel tank and activates the pump or pumps  30 . The pump or pumps  30  provide fuel flow into the manifolds  38  and through the open control valve  44  and reel  42  such that fuel is provided through the respective hose  40  and integrated fuel cap sensor  50  into the fuel tank. The lower threshold may correspond to an empty fuel level of the fuel tank, but more typically the lower threshold will be a level above the empty level to reduce the potential that the equipment completely runs out of fuel and shuts down. The controller  52  can also be programmed with a failsafe measure related to the operation of the fuel cap sensors  50 . As an example, once a control valve  44  is open, if the controller  52  does not detect a change in fuel level from the fuel cap sensor  50  associated with the control valve  44  within a preset time period, the controller  52  shuts the pump  30  off and closes the control valve  44 . Thus, if a hose  40  were to rupture, spillage of fuel is limited to the volume of fuel in the hose  40 . For instance, the preset time period may be three seconds, six seconds, ten seconds, or fifteen seconds, which may limit spillage to approximately fifteen gallons for a given size of hose. 
     The controller  52  also determines when the fuel level in the fuel tank reaches an upper threshold. The upper threshold may correspond to a full fuel level of the fuel tank, but more typically the upper threshold will be a level below the full level to reduce the potential for overflow. In response to reaching the upper threshold, the controller  52  closes the respective control valve  44  and ceases the pump or pumps  30 . If other control valves  44  are open or are to be opened, the pump or pumps  30  may remain on. The controller  52  can also be programmed with an electronic stop failsafe measure to prevent over-filling. As an example, once an upper threshold is reached on a first tank and the control valve  44  is closed, but the pump  30  is otherwise to remain on to fill other tanks, if the fuel level continues to rise in the first tank, the controller  52  shuts the pump  30  off. 
     Multiple control valves  44  may be open at one time, to provide fuel to multiple fuel tanks at one time. Alternatively, if there is demand for fuel from two or more fuel tanks, the controller  52  may sequentially open the control valves  44  such that the tanks are refueled sequentially. For instance, upon completion of refueling of one fuel tank, the controller  52  closes the control valve  44  of the hose  40  associated with that tank and then opens the next control valve  44  to begin refueling the next fuel tank. The controller  52  may perform the functions above while in an automated operating mode. Additionally, the controller  52  may have a manual mode in which a user can control at least some functions through the PLC, such as starting and stopped the pump  30  and opening and closing control valves  44 . For example, manual mode may be used at the beginning of a job when initially filling tanks to levels at which the fuel cap sensors  50  can detect fuel and/or during a job if a fuel cap sensor  50  becomes inoperable. Of course, operating in manual mode may deactivate some automated functions, such as filling at the low threshold or stopping at the high threshold. 
     In addition to the use of the sensor signals to determine fuel level, or even as an alternative to use of the sensor signals, the refueling may be time-based. For instance, the fuel consumption of a given piece of equipment may be known such that the fuel tank reaches the lower threshold at known time intervals. The controller  52  is operable to refuel the fuel tank at the time intervals rather than on the basis of the sensor signals, although sensor signals may also be used to verify fuel level. 
     The controller  52  also tracks the amount of fuel provided to the fuel tanks. For instance, the register  34  precisely measures the amount of fuel provided from the pump or pumps  30 . As an example, the register  34  is an electronic register and has a resolution of about 0.1 gallons. The register  34  communicates measurement data to the controller  52 . The controller  52  can thus determine the total amount of fuel used to very precise levels. The controller  52  may also be configured to provide outputs of the total amount of fuel consumed. For instance, a user may program the controller  52  to provide outputs at desired intervals, such as by worker shifts or daily, weekly, or monthly periods. The outputs may also be used to generate invoices for the amount of fuel used. As an example, the controller  52  may provide a daily output of fuel use and trigger the generation of an invoice that corresponds to the daily fuel use, thereby enabling almost instantaneous invoicing. 
     For diesel fuels used in re-fueling operations, others fuels, or other liquids, additives may be used to modify one or more properties of the fuel or liquid. Examples based on diesel fuels may include additives that modify handling, gelling, thermal stability, engine protection, and combustion. Example handling additives may include additives that modify freezing, flow, clouding, foaming, static electricity, dyes, odorants, deodorants, and the like. Example stability additives may include anti-oxidants, metal deactivators, biocides, dispersants, and the like. Example engine protection additives may include corrosion inhibitors, cleaners, lubricants, and the like. Example combustion additives may include ignition modifiers, such as cetane boosters, smoke suppressants, catalysts, and the like. 
     The fuel, as-received, may not initially include such additives. Although such additives may, in some cases, be included during refining or prior to delivery of fuel to the site, not all customers may want to incur the expense of the additive, nor may such additives be needed or required for a particular operation. In order to provide such additives on-site and on-demand, as customers or operations may require, the station  20  includes an additive injector  60  ( FIG. 2 ) fluidly connected with the delivery system of the station  20  and operable to introduce controlled amounts of an additive into the delivery system. The pump(s)  30 , manifold(s)  38 , hoses  40 , reels  42 , control valves  44 , and fuel cap sensors  50  collectively make up the delivery system of the station  20 . 
     The additive injector  60  may be mounted inside the trailer  22 , such as on one of the side walls W 1 /W 2 . As shown, the additive injector  60  is fluidly connected with a container  62  that contains an additive  64 . In this example, the container  62  is separate from the station  20 , although it may alternatively be inside or mounted inside the trailer  22 . The additive injector  60  is also fluidly connected, by delivery line  66 , to the fuel line  32 . The delivery line  66  may be a flexible hose, hard piping, or the like. In this example, the delivery line  66  opens into the fuel line  32  at a location between the pump(s)  30  and the manifold(s)  38 . In this case, where there are two manifolds  38 , the delivery line  66  opens into the fuel line  32  at a location upstream from a split in the fuel line  32  to each manifold  38 . This ensures that the additive  64  is distributed to both manifolds  38 . 
     In this example, the additive injector  60  is or includes a metering pump. A metering pump moves a precise volume of fuel or liquid in a specified time period to provide a controlled volumetric flow rate. The amount of the additive  64  can thus be precisely controlled, monitored, and tracked. Example metering pumps may include, but are not limited to, piston pumps, diaphragm pumps, and parastaltic pumps. 
     The metering pump may further be a variable speed metering pump, the speed of which can be adjusted to change and control the amount of additive introduced into the delivery system. In this regard, the metering pump can have an integrated controller that can be used to program, adjust, and control introduction of the additive. Additionally or alternatively, the metering pump may be in communication with the controller  52 , which may control operation of the metering pump. 
     The metering pump may introduce the additive  64  continuously or by batch. For continuous introduction the integrated controller or controller  52  operates the metering pump to continuously introduce, i.e., inject, the additive  64  into the delivery system when the pump or pumps  30  are active. For instance, as one or more tanks are being filled, the additive  64  is injected so that the fuel delivered to the tanks has a known, controlled amount of the additive  64 . The timeframe over which the additive is injected is equal to or substantially equal to (within about 10%) the timeframe over which the tank is filled. For batch introduction, the integrated controller or controller  52  operates the metering pump to introduce a defined dose amount of the additive  64  over a defined timeframe. For instance, as a tank is being filled, the defined dose of the additive  64  is injected so that the tank has a known, controlled amount of the additive  64 . The timeframe over which the dose is injected is less than the timeframe over which the tank is filled. 
     In one further example, the integrated controller or controller  52  includes a memory that is used to record how much of the additive  64  is delivered into the delivery system. In this regard, the integrated controller or controller  52  can be used to track the amount of additive  64  used over a time period to generate invoices for the amount used. As an example, the integrated controller or controller  52  may provide a daily output of additive use and trigger the generation of an invoice that corresponds to the daily use, thereby enabling almost instantaneous invoicing. 
       FIG. 5  illustrates another example of the station  20 . In this example, rather than the delivery line  66  of the additive injector  60  opening into the fuel line  32 , the delivery line  66  opens into the manifold  38 . In this regard, if more than one manifold  38  is used, the additive injector  60  may also be connected to open into the other manifold  38 . Alternatively, the additive injector  60  may open into only one of the manifolds  38 , while the other manifold  38  does not have the additive  64 . Of course, an additional additive injector  60  could be provided and fluidly connected with the other manifold  38  so that both manifolds can provide fuel with the additive  64 . 
     Although a combination of features is shown in the illustrated examples, not all of them need to be combined to realize the benefits of various embodiments of this disclosure. In other words, a system designed according to an embodiment of this disclosure will not necessarily include all of the features shown in any one of the Figures or all of the portions schematically shown in the Figures. Moreover, selected features of one example embodiment may be combined with selected features of other example embodiments. 
     The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from this disclosure. The scope of legal protection given to this disclosure can only be determined by studying the following claims.