CA2722369C - System and method for land application of waste fluids - Google Patents

Abstract

A system and method are provided for automated control of application of fluid to a surface. A surface map is annotated with shapes designating zones for spraying, and excluding others. A control system in a vehicle uses the annotated map and GPS to assist the operator of the vehicle avoid spraying on excluded zones, and provides a record of the spraying operation including locations sprayed and fluid spray rates. The control system operates valves to control spraying from a container on the vehicle, based on several parameters, so as to avoid spraying excluded zones and steep slopes, to avoid overlaps, and to limit fluid spray rates below pre-determined maximums. The system further assists the operator by providing a visual guide on a display. A kit can be provided to retrofit a vehicle for landspraying.

Description

2

3 FIELD OF THE INVENTION

4 The present invention relates to techniques for land application of waste streams generally and more particularly to controlling and monitoring the 6 disposal or landspraying of drilling waste to comply with applicable government 7 regulations.

Drilling wells for oil and gas exploration invariably produces waste 11 material. The drilling process typically involves the use rotary drill bits that are 12 lubricated by drilling fluids sometimes called mud. As the drill bit grinds downward 13 through soil and rock formation, large amounts of ground-up materials called drill 14 cuttings and drilling fluids are generated, requiring environmentally safe disposal.

Many methods exist for disposing drill waste. These include on-site 16 disposal methods, off-site disposal methods, land-treatment methods and other 17 alternatives. Two of the well known methods for disposing of water-based drilling 18 waste off-site are "land spraying" and "land spraying while drilling". In the present 19 document, "land spraying", and "land spraying while drilling", may be referred to individually and collectively as "landspraying". Under suitable conditions, drill waste 21 can be safely and beneficially sprayed over agricultural land.

22 However, excessive amounts of drill waste disposed within a given 23 area of land, may lead to undesirable environmental side effects. Not surprisingly, 1 governments at provincial/state and federal levels have instituted strict regulations 2 regarding drill waste disposal methods. Compliance with the regulations requires 3 tight control over where the drill waste fluid is sprayed and the amount of fluid 4 sprayed over a given area.

Care must be taken to avoid spraying on sensitive areas such as 6 bodies of water, steep hills, bales of hay, physical structures and the like. In addition 7 one attempts to limit the amount of waste deposited in any given unit of area to safe 8 amounts. What is deemed safe can be based on the chemical properties of the 9 waste fluid.

Current conventional methods require a technician to physically scout 11 and review the land. The technician calculates the total land area required for 12 disposal based on the volume and chemical properties of drill waste fluid.
The 13 technician assesses the suitability of the land by taking representative soil samples 14 to establish baseline soil chemistry of zones to be sprayed. The technician excludes areas that have high slopes, bodies of water, and other zones made unsuitable for 16 spraying by seasonal factors.

17 After the boundaries of zones to be sprayed are determined, the 18 operator of a truck loaded with drill waste fluid, is provided with information regarding 19 approved zones to be sprayed, and the excluded areas.

The operator of the truck must either visually inspect the land being 21 sprayed, or remain in communication with a technician, to avoid spraying outside the 22 approved marked zones. It should be noted that the technician is not on-site during 1 the entirety of each spraying operation, and thus the operator of the truck is 2 responsible for spraying only on approved zones.

3 Drilling mud is a difficult fluid to handle. Drill cuttings in the fluid make it 4 difficult to exercise flow control, other than fully opening to allow fluid discharge or fully closing to disallow fluid discharge. Often, vacuum trucks or similarly equipped 6 vehicles, are used for landspraying. After the vacuum system is pressurized, the 7 spraying operation is started and stopped manually using a simple valve operated by 8 the truck operator depending on the location of the truck relative to zones 9 designated for spraying. After disposal, manual mapping of the sprayed areas is performed for reporting purposes to comply with regulations.

11 There are many problems with these current conventional practices.
12 During winter months, the technician scouting the land is often hampered by snow 13 and uses, at best, dated aerial photographs for assessment. Further, post spraying 14 mapping may be impaired by rain, snow and agricultural activities, which may lead to inaccuracies in the reported data. Trucks that discharge the drill waste fluid have no 16 engineered environmental safeguards in place to ensure regulatory compliance.
17 Accordingly, the onus is on the truck operator to perform landspraying in a compliant 18 manner, relying largely on visual inspection, during good or poor weather, daytime 19 and night conditions. As the truck operator is often among the least trained persons with regard to regulatory compliance requirements, reliance on the operator entails a 21 high risk of non-compliance as a result of human error, weather conditions, poor 22 visibility and the like.

1 Systems and methods for dispensing fluids on agricultural land are 2 known. US Patent 7,370,589 to Wilkerson et al. for example, discloses a fluid 3 dispenser aimed at improving in-furrow chemical application. The dispenser is 4 operable to dispense fluid at a second location, after detecting that an object has passed a first location. Such known systems however, are aimed at improving 6 efficiency and do not provide adequate safeguards to avoid overlap of zones on 7 which fluids are dispensed, and require physical marker objects to be present on the 8 target surface prior to applying the fluid. The requirement for physical markings may 9 be costly and may limit available candidate land surfaces for Iandspraying.
Moreover, the operation of known systems and methods does not take the slope of 11 the terrain into account, which is a limiting factor for suitability for landspraying.

12 Accordingly, a system and method is needed to overcome the 13 deficiencies of the conventional landspraying methods for drill waste disposal 14 namely to better manage compliance with regulations for controlled placement, concerning where sprayed and amount sprayed.

2 Apparatus and method are provided for controlled spraying of a 3 surface with fluid from a mobile container. Spraying is controlled to avoid exclusion 4 zones, such as boundaries, hazards and environmentally sensitive areas. A
vehicle, such as a vacuum truck, supports and transports the container. A navigation unit 6 determines a current position of the vehicle and a speed indicator determines a 7 speed of the vehicle. A valve-operated spray nozzle is mounted on the container for 8 controllably delivering fluid to the spray nozzle. A control unit determines spatial 9 coordinates of the surface including boundary coordinates defining one or more exclusion zones on the surface which are not to be sprayed. The control units 11 determines a current position of the vehicle, and conditions including whether the 12 current position is outside the exclusion zones; and a minimum speed Vmin for the 13 vehicle for spraying an areal spray rate less than a predetermined maximum spray 14 rate RMAX. If the conditions are satisfied, the controller automatically signals an actuator interconnected to the valve for controllably delivering spray fluid.

16 The apparatus enables practising of a method comprising obtaining a 17 plurality of spatial coordinates for the surface and establishing boundary coordinates 18 defining one or more exclusion zones on the surface which are not to be sprayed.
19 One traverses at least a portion of the surface with the container along a path, the container having a spray nozzle for controllably delivering a spray width W of fluid at 21 an areal spray rate R (volume/area) to the surface along the path For each current 22 position of the container along the path, the method further comprises obtaining 23 position coordinates; determining the areal spray rate R; and automatically spraying

5 1 the spray width W at a sprayed position along the path with the fluid from the 2 container, if the following spray conditions are met, including the spray width is 3 outside the exclusion zones, and the areal spray rate R is less than a 4 predetermined maximum spray rate RMAX.

While entire systems can be provided, vehicles can be retrofitted for

6 automatic control of landspraying including provision of a kit to supply that which is

7 not already on such as vehicle. A kit might include an actuator assembly a

8 navigation unit, a control unit comprising: a processor in communication with

9 memory, a control unit comprising a processor in communication with the navigation unit, the actuator; and memory storing processor-executable instructions adapting 11 the control unit to assess the aforementioned spray conditions and spray 12 accordingly. The kit may also include an actuator assembly to manipulate the 13 discharge valve, a pneumatic cylinder connected to the valve and a solenoid-piloted 14 pneumatic actuator for alternating control between the control unit and manual control.

16 Use of various of the embodiments disclosed herein will better effect 17 compliance and costs associated therewith including avoiding spraying: in the wrong 18 field, outside the appropriate area; in unacceptable proximity to identified water 19 bodies and identified pipelines. Further, one avoids use of improper sloped terrain, overflow and excessive spray rates, and overlap of spraying. The disclosed 21 embodiments control liquid discharge in accordance with assessed rules that ensure 22 the above risks are eliminated. Further, using the annotated display provides the 23 driver or operator with a form of night vision and steering assistance for field 1 navigation and aesthetics. The drivers can focus on driving versus assessing fields 2 and compliance matters. High mapping accuracy results and technicians can be 3 more efficient, with more time focused on quality assessments and details.

BRIEF DESCRIPTION OF THE DRAWINGS

6 Fig. 1 is a schematic diagram of an embodiment of a system for 7 landspraying, depicting a vehicle with a control unit for operating a container 8 mounted thereon;

9 Fig. 2 is a schematic block diagram of one embodiment of a relay board forming part of the interface circuit in the control unit of Fig. 1;

11 Figs. 3A-3D are schematic block diagrams of one embodiment of the 12 valve actuator of Fig. 1 illustrating controlled valve operation and operations with 13 control bypassed for manual operation;

14 Fig. 4 is a flowchart depicting steps to operate the valve depicted in Fig. 1;

16 Fig. 5 is a flowchart diagram depicting a set of criteria evaluated within 17 step S404 of Fig. 4;

18 Fig. 6 is a diagram of a screenshot of the display in Fig. 1, when the 19 system of Fig. 1 is in operation;

Fig. 6A is sample listing of latitude/longitude GPS coordinates provided 21 as data defining a polygon boundary for an exclusion zone, the actual coordinates 22 having being disguised 23 Fig. 6B is a plot of the exclusion zone data of Fig. 6A;

1 Figs. 7A-7D are schematic side views of a vehicle, depicting possible 2 orientations for its container and spray plate;

3 Figs. 7E-7H are schematic plan views of the spray corresponding to 4 the container and spray plate orientations depicted in Figs. 7A-7D
respectively;

Fig. 8A is a graphical representation of inclusion and exclusion zones 6 overlying a color photograph of a surface including mapping data; and 7 Fig. 8B is a graphical representation of mapping data and sprayed 8 areas on a color photograph of a land surface incorporated into a report illustrating 9 land characteristics and recorded landspraying data.

12 A system and control unit provide automated control and monitoring 13 system for maximizing regulatory compliance in landspraying operations.
While 14 described herein in the context of landspraying of waste fluids such as drilling fluid, the apparatus and methods herein can be applied to the controlled deposition of 16 other materials and waste fluids.

17 The control unit is typically installed in a vehicle having a fluid 18 container mounted thereon. The container has a valve, operable by the control unit, 19 to regulate discharge of waste fluid typically containing solid particle debris. The control unit obtains coordinate data for land surface to be sprayed, including 21 boundaries of exclusion zones on the surface that should not be sprayed.
The 22 control unit then employs a navigation system and valve control to avoid spraying 1 within the exclusion zones, to avoid overspraying in approved zones and to capture 2 the exact mapping of deposited material for analysis and reporting.

3 The control unit operates the valve to spray the waste fluid based on 4 safety and environmental regulatory criteria. The control unit makes use of various parameters to evaluate if compliance criteria are met before initiating spraying of the 6 waste fluid. The criteria are selected to avoid spraying on sensitive zones such as 7 bodies of water and, when spraying in approved zones, to limit areal spray rate, i.e., 8 the volume of fluid sprayed per unit area of surface. The system assists the 9 operator of the vehicle by providing automated spraying control, and can further provide visual guides, and automated steering for the vehicle as needed.

11 A management system, including application software, may be used to 12 assist in identifying the boundaries for zones within the land surface that should not 13 be sprayed. The application software may be used to select a map of the land 14 surface from a database of maps or photographic/satellite images containing coordinate data. Application software may then be used to annotate the selected 16 map with polygons or other shapes distinguishing boundaries of exclusion zones not 17 to be sprayed. The annotated map is then provided to the control unit. The overall 18 area of the land surface to be sprayed, less the exclusion zones provides a rough 19 net area available for spraying.

Accordingly, and with reference to Fig. 1, one embodiment of a land 21 spraying system 100 is provided for use in drill waste fluid disposal. The land 22 spraying system 100 comprises a vehicle 102, a fluid container 104 mounted 23 thereon, a control unit 106 and peripherals described later which support operations.

1 An onsite or offsite surface pre-spray and post-spray management system 210 2 enables surface selection, zone determination and post-spraying reporting functions.
3 The fluid-handling apparatus comprises the vehicle 102, container 104, 4 and fluid discharge equipment including discharge valve 115, valve actuator 114 and nozzle 200. The container 104 can be a standard tank suitable for transporting 6 liquids. The container 104 is fit with a fluid discharge or duct 116 adjacent its base.
7 The container 104 is filled with the waste fluid and may be pressurized with an air 8 pad to aid in the discharge of the waste fluid through duct 116. As the fluid level in 9 the container 104 drops, the hydrostatic head also drops and the flow rate diminishes. Due to variable hydraulic head of the waste fluid, the flow rate or 11 discharge rate can vary, being maximum when the container 104 is full and the fluid 12 hydrostatic head is additive in the container pressure. The variability in hydrostatic 13 head is somewhat lessened by the use of the air padding over the waste liquid.

14 A hydraulic mechanism 109 in the vehicle 102 may be used to tilt the container 104 for maximal discharge of fluid though duct 116. A relief valve may be 16 present in the container 104 to protect against excessive pressure build up. In one 17 specific embodiment, a Kunkle relief valve supplied by Tyco International Ltd of 18 Princeton, New Jersey, USA may be used.

19 Nozzle 200 is formed by the discharge opening of the duct 116 and a spray plate 117 to disperse the fluid in a fan pattern (See also Figs. 7A and 7E). A
21 typical discharge opening of the duct 116 for a vacuum truck is about 4 inches in 22 diameter. The sprayed fluid thus lands onto the surface below having a spray width 1 W. As the vehicle 102 traverses the land surface, the spray width W and a traversed 2 distance over the surface establishes the sprayed area over time.

3 An on-off discharge valve 115 in the duct 114 controls the flow of fluid 4 from the container 104 to the nozzle 200. Waste fluids have characteristics which interfere with fine variable flow control. Thus, on-off valves are used as they mitigate 6 intermittent blockages in the duct 116 that can occur with variable flow control 7 valves. Periodic blockages are undesirable as they can lead to unpredictable 8 drought and flood discharge. While crude, the controlled discharge of a on/off valve 9 is predictable and step-wise controllable. The valve 115 can have a fail-safe, closed mode.

11 An actuator 114 may be used to actuate the on-off valve 115. The 12 actuator 114 may include one or more pneumatic/hydraulic actuators and cylinders 13 controlled by a solenoid, as will detailed later. The actuator 114 may be triggered by 14 a control signal to the solenoid.

A pressure switch 112 may be used to monitor air pressure in the 16 container 104 and to provide a signal when the container 104 is empty or very nearly 17 empty. Alternatively, a pressure switch might be used to measure liquid pressure 18 with corresponding changes in setpoints for assessing liquid conditions. In one 19 specific embodiment, the pressure switch 112 may be an Ashcroft B-Series general purpose pressure switch provided by Ashcroft Inc, of Stratford, Connecticut, USA.
21 Pressure switches are more suitable than alternatives such as load sensors, due to 22 reduced costs and relative immunity to sediment build-up in the container 104.
23 Further, the pressure switch 112 can be used to monitor pressure variations to 1 ensure rate compliance, as variations in pressure, or without applied air pressure, 2 the pattern is poor and over-spraying could occur.

3 The vehicle 102 further includes position and automation controls 4 comprising a human interface device or tablet 138, and inputs including a navigation unit 118, a speed indicator 136, pressure switch 12 and a slope measurement unit 6 134. The tablet 138 includes a control unit 106 for managing inputs and controlling 7 landspraying operations including actuation of the valve 115 and even steering 8 assist 110.

9 The navigation unit 118 may be a global positioning system (GPS) device, a differential GPS (DGPS) device, a precision GPS (PGPS) device or a 11 similar navigation unit having a corresponding antenna. The speed indicator 12 may be part of the navigation unit 118 or a separate dedicated speedometer with a 13 digital input-output (I/O) interface.

14 The slope measurement unit 134 may be an inertial measurement device that provides independent measurements of both the roll and the pitch for 16 vehicles. Accordingly, the slope measurement unit 134 may include accelerometers 17 and gyroscopes coupled to a digital signal processor with appropriate I/O
interfaces.
18 Digital signal processing algorithms may be used to identify and smooth out minor 19 bumps and depressions from genuine underlying slopes of land surfaces using digital filtering and the like. In other embodiments, measurement unit 134 may 21 alternately be implemented as a modified steering-assist unit, as will be detailed 22 later.

1 The tablet 138 comprises the control unit 106 and a display 108. The 2 control unit 106 provides automated control of the spraying operation. The control 3 unit 106 may include a general purpose processor 105 interconnected to a block of 4 memory 107 and an interface circuit 120. The memory 107 may include volatile and non-volatile parts that store processor-executable instructions for execution by the 6 processor 105. The stored instructions may, in some embodiments, include 7 instructions for implementing parts of the navigation unit 118. The display 108 is 8 interconnected with the control unit 106. The display 118 may be a touch screen that 9 allows touch based user inputs in addition to its visual display functions.
Alternately, a separate keyboard or keypad (not shown) interconnected to control unit 106 may 11 be used for data entry. The tablet 138 can be a hardware unit such as a computer, 12 handheld device, a laptop computer. The tablet may also physically house both the 13 display 108 and components of the control unit 106.

14 The control unit 106 may further interconnect the steering-assist unit 110, the navigation unit 118, the slope measurement unit 134, the speed indicator 16 136, and the actuator 114. The control unit 106 interconnects to the solenoid in 17 actuator 114. The control unit 106 can thus automatically open and close valve 115 18 via actuator 114 by transmitting an electrical signal to the solenoid.

19 The interface circuit 120 of the control unit 106 may include various specific hardware interfaces for receiving and outputting digital and analog signals.
21 The interfaces may provide specific interconnections to the display 108, the steering-22 assist unit 110, the navigation unit 118, the actuator 114, the pressure switch 112, 23 the speed indicator 136 and the like. The interface circuit 120 may further include 1 USB interfaces, a wireless interface (such as WiFi or Bluetooth) and other input-2 output (I/O) interfaces.

3 The control unit 106 is able to receive data from and send data to the 4 various components of the land spraying system 100 interconnected with it.
This allows the control unit 106 to perform various monitoring and control functions. For 6 example, the control unit 106 can determine if the container 104 is empty such as by 7 comparing pressure data from the pressure switch 112 with a predefined minimum 8 pressure. The control unit 106 can determine the speed (or velocity) of the vehicle 9 102 by receiving data from the speed indicator 136 or navigation unit 118.
The control unit 106 may determine its current location by receiving current location 11 coordinates from the navigation unit 118, and may determine the slope at the current 12 location using data from the slope measurement unit 134. Further, as will be detailed 13 later, the control unit can open and close the valve 115 by signalling the solenoid in 14 the actuator 114.

The system 100 further includes management system 210, which can 16 comprise a computing device 124 which may be any one of the commonly available 17 personal computers or workstations having a processor, volatile and non-volatile 18 memory, and an interface circuit for interconnection to one or more peripheral 19 devices for data input and output. Processor-executable instructions, in the form of application software, may be loaded into the memory in computing device 124 to 21 adapt its processor to read an input map 122, to process the map including the 22 overlaying of exclusion shapes and zones, and to output an annotated coordinate 23 map 126. The input map 122 is typically a satellite image, an aerial photograph, a 1 topographical map or the like. Exclusion shapes can be defined by vector graphics 2 and the like, including simple geometric shapes like circles or polygonal 3 representations.

4 A detailed record of spraying operation by vehicle 102 may be kept by the control unit 106 as a data file 128 for export to and processing by the computing 6 device 124 of the management system 210 and subsequent transmission to a 7 designated reporting database 132 by way of a wide area network 130 such as the 8 Internet. The recorded mapping data can be used to avoid overlaps and may be 9 used to compile formal reports for regulatory compliance and/or for custom internal record keeping.

11 Turning to Fig. 2, an embodiment of an interface circuit 120 between 12 the control unit 106 and the peripherals includes interconnections to one or more 13 USB devices. The interface circuit 120 may include a relay board 140 similar to a 14 JSB-252 USB relay board from J-Works Inc., of Granada Hills, California, USA. The relay board 140 may be housed in a separate enclosure. The relay board 140 may 16 have a first relay 142 interconnecting the pressure switch 112 and the processor 105 17 of control unit 106; and a second relay 144 interconnecting the actuator 114 to an 18 override switch 152. The override switch may be a two position, keyed switch.

19 A circuit breaker 154 may be used to limit current into relay 144 from a power supply 156. The relay board 140 may also include a USB port 146 to allow a 21 host controller such as processor 105 to perform host control functions, via standard 22 programming languages. The relay board 140 may further include one or more LED
23 indicators 148 to provide status information.

1 In one embodiment, the first relay 142 relays an electrical signal from 2 the pressure switch 112 to processor 105 whenever the pressure inside container 3 104 has fallen below a specified threshold, indicating that container 104 may be 4 approaching empty. This allows processor 105 to determine that actual spraying has effectively stopped and thus close the valve 115.

6 A factor in determining the minimum velocity of the vehicle is based 7 upon specific spray pattern expectations, those spray patterns being affected by the 8 pressure in the tank. Thus, in another embodiment, the first relay 142 relays an 9 electrical signal from the pressure switch 112 to processor 105 to keep valve 115 from opening until a suitable pressure has been created in the tank to ensure 11 complaint spray patterns and prevent overspray.

12 The second relay 144 may be used to override the signal from 13 processor 105 and to open or close the valve 115 via the solenoid in actuator 114.
14 Of course many alternative implementations for overriding a control signals and for communicating status information will be known to those of ordinary skill in the art.
16 With reference to Figs. 3A through 3D, an otherwise conventional 17 vacuum truck can be retrofitted for automated landspraying, yet convertible back to 18 conventional uses thereafter. If convertibility is not employed, air and electrical 19 controls would be simplified.

Simply, on/off control of the valve 115 is placed under automated 21 control or manual control. In one mode, the actuator 114 enables the control unit 22 106 to open and close the valve 115 under automated control for use in 23 landspraying. In a second mode, the control unit 106 is bypassed, such as via keyed 1 bypass switch 152, and the valve 115 is actuated by some other means, such as by 2 direct operator manual control, not related to landspraying use as contemplated 3 herein.

4 Figs. 3A and 3B depict one such embodiment of the actuator 114. As shown, the actuator 114 may include a pneumatic-actuated, double-acting cylinder 6 114B, for manipulating the valve 115, and a spread valve such as an air toggle 7 switch 114C. The switch 114C may be that already available as part of the 8 unmodified vehicle 102, or provided anew as part of this embodiment. For 9 automation, a solenoid-piloted actuator 114A and a shuttle valve 114D are incorporated with the switch 114C and cylinder 114B. An air supply unit 150 such as 11 an air compressor provides compressed air for use by the actuator 114. The 12 cylinder 114B is mechanically coupled to the discharge valve 115. Power is 13 provided for operating electrical components including the solenoid-piloted actuator 14 114A. A suitable solenoid-piloted actuator 114A is model MAC series 800 by MAC
valves Inc., Michigan, US.

16 With the bypass switch 152 off, the control unit 106 is in control of the 17 solenoid-piloted actuator 114A. When the air toggle switch 114C is open, 18 automated control is enabled. Simply, the control unit 106 controls solenoid-piloted 19 actuator 114A to alternate between directing air through air toggle switch 114C to open the valve 115 (Fig. 3A) and directing air through a closing bypass line to 21 bypass the air toggle switch 11 4C and close the valve 115 (Fig. 3B). A
shuttle valve 22 114D isolates the air toggle switch 114C from the closing bypass line. In this 23 convertible embodiment, the air toggle switch 114C is a manual spread valve which 1 is always available to manually close the valve 115. In automated control mode, the 2 air toggle switch 114C is left in the open position and control unit 106 can open and 3 close the valve 115 with the air toggle switch 114C in the open position.

4 As shown in Fig. 3A, the control unit 106 can open and close the valve 115 by sending a signal to the solenoid-piloted actuator 114A. A first output of the 6 air toggle switch 114C connects to a first port the cylinder 1146. A second output 7 port of the air toggle switch 114C connects to the shuttle valve 114D. The shuttle 8 valve 114D interconnects the switch 114C with a second port of the cylinder 1146.
9 With the toggle switch 114C is one or open, air is directed from its input to its first output. Conversely, when the toggle switch 114C is off or closed, the first output is 11 blocked and a second output is opened for manual closing of the valve 115.
Toggle 12 switch 11 4C can thus be used to override control unit 106 and close the valve 115.
13 The solenoid-piloted actuator 114A has at least one input and two 14 output ports. The air supply unit 150 is connected to the input of actuator 114A and the first output of actuator 11 4A is connected to an input of the toggle switch 11 4C.
16 The second output of actuator 114A is connected to another input of the shuttle 17 valve 114D. Electrical input to the actuator 114A alternates directing air from the 18 input port to the first output port to supply switch 11 4C, and from the input port to the 19 second output connected to the shuttle valve 114D. Not shown in the general schematics of Figs. 3A to 3D, the solenoid in actuator 11 4A may be electrically wired 21 through relay board 140 of Fig. 2.

22 The cylinder 114B is typically a double-acting cylinder having a piston 23 that moves between two positions, the piston being mechanically coupled to valve 1 115 which is fully open in a first position and fully closed in a second position. Air 2 flow into the first input of cylinder 114B moves the piston to an open position thereby 3 opening the coupled valve 115. Conversely, air flow into the second input of cylinder 4 114B retracts the piston back to the closed position, thereby closing the coupled valve 115. In alternate embodiments, the cylinder 114B may be single-acting 6 cylinder having a normally-closed position, spring-biased return. Venting of the 7 opposing cylinder inputs is not detailed.

8 Actual air flow within the actuator 114 is depicted by the thick solid 9 lines in Figs. 3A-3C. The direction of air flow is indicated by arrows.

In Fig. 3A, the toggle switch 114C is switched on (set to an open or 11 enable position) to enable the control unit 106 to operate valve 115. The control unit 12 106 signals the actuator 11 4A to open the valve 115. Accordingly air flows through 13 the first output of the actuator 114A and moves the piston in the cylinder 114B to the 14 open position, thereby opening valve 115. Piston extension and retraction functions may be reversed depending on the mechanical coupling of the valve 155 and 16 cylinder 114B. Typical of double-acting cylinders, extension typically has greater 17 actuating force than retraction and thus one might arrange the cylinder accordingly 18 to advantage.

19 In Fig. 3B, while the toggle switch 114C remains on or open, the control unit 106 signals the solenoid-piloted actuator 114A to close the valve 115.
21 Accordingly air now leaves from the second output of the actuator 114A, through the 22 shuttle valve 114D, and moves the piston in the cylinder 114B to the closed position, 23 thereby closing valve 115. It is clear from Figs. 3A-3B, that while toggle switch 114C

1 remains open, the control unit 106 is able to automatically operate the valve 115 via 2 the solenoid-piloted actuator 11 4A and the cylinder 1146.

3 As discussed, the vehicle 102 can be converted to normal operation 4 without having to remove the retrofit components. As shown in Figs. 3C and 3D, the keyed bypass 152 can be set to disable control unit 106 communication with the 6 solenoid-piloted actuator 114A and instead continuously powers actuator 114A.
7 Accordingly air is continuously directed to toggle switch 114C.

8 As shown in Fig. 3C, with toggle switch 114C switched on or open, air 9 is directed to open cylinder 1146. As shown in Fig. 3D however, with toggle switch 114C switched off or closed, air is directed through shuttle valve 114D to close 11 cylinder 114B.

12 As discussed above, the actuator 114 can be used to selectively 13 operate an appropriately equipped vacuum truck either normally via toggle switch 14 11 4C or using the control unit 106.

Availability of a bypass could result in inappropriate use. Thus a 16 bypass lockout can be provided. Lockout tags also avoid the overhead associated 17 with issuance and tracking of keys for a keyed bypass. While a keyed bypass can 18 still be used with a lockout tag, a bypass switch also be provided without individual 19 keys and instead lockout tags are used of irreversibly indicate actuation or use of the bypass. The lockout tag can further list appropriate contacts or phone numbers as 21 well as additional contacts for the current technician applied thereon when installing 22 the tag. When the technician arms the system for controlled spraying the lockout tag 23 is installed in such a manner that to disarm would require breaking the tag. This 1 allows for no interruption to a landspraying consultant, can be bypassed without 2 keys, and forces the operator to break a seal to bypass which should encourage the 3 operator to call the contact numbers before bypassing or at least afterwards.
4 Further, regardless of contact, there is evidence the bypass was used.

A person of ordinary skill in the art will readily appreciate that 6 numerous other alternative implementations for the actuator 114 may be used in 7 alternate embodiments of the present invention.

With reference to Fig. 1, in preparation, an input image or map 122, 11 which corresponds to a land surface to be sprayed with drill waste fluid, may be 12 chosen from an image database 121 of candidate maps. Application software 13 forming part of computing device 124 may be used to retrieve the maps and select a 14 suitable input map 122. The maps in the database 121 may be in the form of satellite images, topographic maps, aerial photographs, or other digital 16 representations of geographical coordinate data.

17 Fig. 6 illustrates a schematic representation of an annotated image 18 integrate with steering control overlaid thereon. Fig. 8A depicts a satellite image 19 annotated with exclusion and inclusion zones. Fig. 8B depicts a report for an example sprayed land surface having a satellite image embedded in a report format 21 annotated with the identified exclusion zones, sprayed paths, sprayed area and 22 various land spraying data.

1 The selection of a suitable land surface may depend on the net area 2 available for disposal, and proximity to the drill site. Land surfaces situated close to 3 the drill site often result in reduced disposal costs. Accordingly, a search for suitable 4 land may be conducted in an ever-increasing radius starting from the drill site, the source of the waste fluids. Determination of the net area may in turn depend on the 6 volume of waste to be disposed, the maximum allowable spray rate (or maximum 7 fluid application rate), waste fluid chemistry and soil chemistry.

8 The suitability of the selected land surface may be verified by onsite 9 inspection performed by a technician. Soil samples may be taken for analysis (See Fig. 8B) of applicable spray rates, and physical measurements using laser range 11 finders for example, may be made to confirm the location and perimeters of 12 exclusion zones such as bodies of water.

13 Once a land surface corresponding to a selected map is verified to be 14 suitable for landspraying, the selected map 122 identifies a plurality of spatial coordinates for the surface. The map 122 may be annotated using the application 16 software executing in the computing device 124. Shapes (e.g., polygons, circles, 17 ovals, etc) are superimposed or overlaid to define boundaries in map 122 that 18 correspond to zones that should not be sprayed called exclusion zones E.
The 19 technician may use the software on device 124 to apply the exclusion zone shapes to the map or a separate data file can be used which linked by the geo-coordinates 21 or other coordinate reference for use by the control unit 106.

22 As shown in Fig. 6A, one embodiment for a subset of data that can be 23 provided to define a zone, being an exclusion zone E or inclusion zone S, for 1 annotation of the mapping data is being to list latitude/longitude GPS
coordinates 2 which are then in the same coordinate system as the mapping data for accurate 3 superposition thereover. One can see, from the plot of Fig. 6B, that the data of Fig.
4 6A defines a generally rectangular zone. Further, the data can include whether the zone is exclusion or inclusion, the nature of the zone such as water or obstacle, job 6 and contact details. Besides exclusion and inclusion zone data, one can include 7 projected start, end and path data.

8 The remaining area of the selected map (outside of the exclusion 9 zones) may be considered allowable or inclusion zones S that may be sprayed.
Alternately, inclusion zones S may be explicitly designated and annotated on map 11 122. Of course, inclusion and exclusion zones S,E may be marked differently, for 12 easy identification by devices and human operators, for example by using different 13 colors or patterns. A shown in the color photograph portion of Fig. 8A, inclusion 14 zone(s) S may be indicated with a yellow or green overlay and exclusion zones E in a red overlay.

16 Exclusion zones E can simply be boundaries to an identified area 17 including that within a leased or rented land area. Other exclusion zones E, which 18 are typically regulated, can include bodies of water (such as sloughs, dugouts, and 19 ponds shown in Figs. 8A, 8B), steeply sloped areas that could funnel or concentrate the sprayed fluid to undesirable locations and appropriate safety buffer zones from 21 such sensitive locations. The buffers can be obtained from appropriate regulations 22 and may be dependent on seasonal conditions. For example, under current 23 regulations in western Canada, spraying should not occur within 100 m of a body of 1 water in summer. In winter, that margin doubles to 200 m in part to account for 2 reduced absorption or permeability of the ground, and the potential presence of ice.
3 As may be appreciated, low absorption can result in a rapid runoff of fluid and into 4 surrounding low lying areas including excluded areas or result in overconcentration of waste fluid.

6 Exclusion zones E may also include other sensitive locations that 7 should not be exposed to the sprayed fluid as specified in relevant government 8 regulations and/or by landowner request. Examples of relevant government 9 regulations include Directive-050 published by the Energy Resources Conservation Board (ERCB) of the Government of Alberta; the Saskatchewan Drilling Waste 11 Management Guidelines (GL99-01) from the Saskatchewan Ministry of Energy and 12 Resources (SMER); Landspraying While Drilling (LWD) Application and Approval 13 Guidelines from the Manitoba Petroleum Branch; and the British Columbia Oil and 14 Gas Handbook from the Government of British Columbia.

The computing device 124 thus outputs the annotated coordinate map 16 126 which is partitioned into exclusion zones E where no spraying should occur and, 17 by difference, inclusion zones S where spraying may take place.

18 In one embodiment, the user of computing device 124 may account for 19 safety buffers or margins when marking the exclusion zone E. For example, to protect a pond in the winter, the corresponding exclusion zone E may be drawn to 21 encompass the pond, as well as any point within 200 m from the edge of the pond.
22 In an alternate embodiment, the user of computing device 124 may 23 simply identify a feature, draw boundaries of the exclusion zones over each feature 1 and let the control unit 106 add the appropriate safety margins prior to opening valve 2 115 during operation. Such features can include transient presence of equipment, 3 storage of crops, rock piles, well heads and the like.

4 In one alternate embodiment, such as in cases of missing satellite data or failure of computing device 124, an operator can physically identify exclusion 6 zones on the ground (e.g., using pylons) to outline the boundaries or perimeters of 7 specific land features. The control unit 106 may then be set to a recording mode, 8 where it records current position coordinates, and sprayed position, as provided by 9 navigation unit 118 while the vehicle 102 is driven. The operator may then drive vehicle 102, along particular desired paths while remaining well outside the pylon 11 marked exclusion zones, simulating a spraying dry run while the control unit 106 12 records coordinates of the paths followed. During the dry run, the valve 115 remains 13 closed and the container 104 may preferably be empty. Thereafter, the container 14 104 may be filled with waste fluid and the control unit 106 may be used to help the operator of vehicle 102 retrace the recorded path, using automated controls 16 including the steering-assist unit 110, while spraying fluid.

17 The annotated coordinate map 126 may contain additional data such 18 as slope logs, roads, pipelines, contours, and other geographic information system 19 (GIS) layers. The coordinate system used in coordinate map 126 may be the Latitude/Longitude coordinate system used in GPS devices, the Universal 21 Transverse Mercator (UTM) coordinate system, or another coordinate system.

22 The annotated coordinate map 126 may be provided to the control unit 23 106 on the vehicle 102 by way of a USB device attached to a USB port in interface 1 circuit 120 of the control unit 106. Of course other interfaces such as a Bluetooth 2 interface, serial or parallel port interface, Wi-Fi interface, an Ethernet interface or the 3 like may be used by interface circuit 120 of the control unit 106 for I/O
purposes.

CALIBRATION

6 Each vehicle and/or container has different characteristics that affect 7 the spraying operation including frame height, container volume, discharge rate, 8 pressure and the like. Thus, to prepare the vehicle 102 for landspraying, a number 9 of calibration and testing steps may be performed to provide appropriate vehicle-specific parameters for use by control unit 106, to determine if and when spraying 11 should be started, continued or stopped.

12 For example, depending on the type of valve 115 and actuator 114 13 used, the signal to open or close may be sent at different times to account for 14 varying delays (e.g., air system delays in pneumatic-actuators) in opening or closing the valve 115 as the vehicle 102 is in motion. Typical delay times of about 4 16 seconds from actuation have been noted for opening. When closing this time delay 17 was approximately 2 seconds. As a result, a signal to open/close the valve 115 may 18 be issued slightly before the moving vehicle 102 reaches a designated boundary at 19 which it should start/stop spraying. Given a vehicle travelling at speed VT, and a closing air system delay time of Tc, the signal to close the valve 115 may be issued 21 at a distance of DCLOSE = VTTc before the actual boundary. Similarly, for an opening 22 air delay time of To, the signal to open the valve may be issued at a distance of 23 DOPEN = VTTo before the actual boundary is reached.

1 As noted above, hydrostatic pressure and applied air padding pressure 2 may be used to expel fluid out of the container 104 through its duct 116.
The 3 padding pressure may be dependent on the vehicle 102 and may be set accordingly.
4 For example, a padding pressure of about 12 psig to about 15 psig may be applied for a specific vehicle and container.

6 The amount of fluid volume Fõ discharged per unit time t, out of the 7 duct 116 of the container 104, gives the flow rate C. The instantaneous flow rate 8 may thus be expressed as C = dFõ/dt.

9 An average fluid flow rate may be computed by filling the container 104 with test fluid (e.g., waste fluid, water etc.) of predetermined volume FV1 and 11 measuring the time t1 required to discharge it though the duct 116. The applied 12 pressure during calibration should be the same pressure as that which would be 13 used in operation. The average flow rate may then be computed as C =
Fvi/ti.
14 Alternately, as will be discussed later, a real-time measure for the instantaneous flow rate C = dFv/dt may be determined during operation.

16 Referring also to Figs. 7A - 7H, the spray plate 117 of nozzle 200 17 disperses the fluid in a fan-like shaped manner onto the land surface below with a 18 particular spray width W. The actual spray width W, W1 - W4 is affected by different 19 factors including the height of the spray nozzle 200 from the ground, the dimension of the duct 116 and spray plate 117, and the applied pressure in container 104. The 21 spray width W of the test fluid can be obtained by measuring the width of a sprayed 22 path as the vehicle 102 traverses a path while spraying.

1 The pressure switch 112 may be tested and calibrated by inspecting its 2 pressure reading just before and just after the container 104 empties its fluid 3 contents under combined hydrostatic and applied pressure. In some embodiments, a 4 pressure reading below 7 psig may indicate an empty or nearly empty tank or a potentially unacceptable variability in spray rate.

6 The navigation unit 118 provides current location coordinates for its 7 antenna or the antenna coordinates. The antenna is typically in a front of the 8 vehicle, adjacent the operator. However, the location of interest for spraying 9 operations is the target or current position on the surface below and typically well-behind the vehicle. To determine the position coordinates for the target position of 11 the spray, the relative location of the target position with respect to the antenna, 12 which may be called the spray-to-antenna offset or spray-to-antenna setback, may 13 be measured. The position coordinates of the target position can thus be obtained 14 by offsetting the antenna coordinates, by the spray-to-antenna offset.

A total-antenna-offset parameter may be determined as the greater of 16 the measured spray-to-antenna offset, and the distance travelled during the delay 17 involved in actuating the valve 115 (i.e., DOPEN or DCLOSE).

18 A maximum fluid areal spray rate R, may be specified in units of 19 fluid volume per sprayed surface area (e.g., in m3/m2 or in m3/ha) by a technician, after analyzing applicable regulations, agreements with the land owner, the fluid 21 chemistry and the soil chemistry. The areal spray rate R is the rate of fluid volume Fõ
22 sprayed per unit area A of the sprayed surface. The instantaneous areal spray rate 23 may thus be expressed as R = dFõ/dA.

1 Examples of parameters which may be determined during calibration 2 are shown in TABLE I. The measured values listed are of course only exemplary 3 and vary from one vehicle and/or components to another.

TABLE I
Parameter Value Unit Volume of container 104 19.1 m Spray Width W 13 m Time t to empty container 213.6 s Delay to open valve 115, DOPEN 4 s Delay to close valve 115, DCLOSE 2 s Spray-to-Antenna offset 21 m Total-Antenna-setback 21 m RMAX 15 m3/ha 4 To ensure that the areal spray rate R does not exceed the maximum areal spray rate RM,X, a minimum speed for vehicle 102 can be computed, below 6 which one cannot spray. For a vehicle travelling at speed V (in m/s), with a container 7 having a fluid flow rate C (in m3/s) and a spray width W (in m), the instantaneous 8 areal spray rate R (in m3/m2) is:

9 R = dFõ/dA = Cdt/(WVdt) = C/(WV).

Thus, ensuring that R < RMAx requires that V > C/(WRM,) Vm;n. The 11 vehicle 102 must maintain a minimum speed of Vm;n = C/(WRMAX) before spraying 12 can start or resume, in order to ensure that the spray rate does not exceed the 13 maximum (i.e., R < RMAX).

14 Accordingly, TABLE II depicts an exemplary concordance of spray rates (or fluid application rates) and corresponding minimum vehicle velocities 16 required, for a uniform spray width W = 13m and a fluid flow rate of C =
0.09 m3/s.

1 TABLE II further includes offset distances to compensate for delays in closing the 2 valve 115.

TABLE II
Fluid Areal Spray Rate R Speed Doffset to (m3/ha) (km/h) close valve m 24.76 14 16.51 9 12.38 7 9.91 6 8.25 5 7.07 4 6.19 4 4.95 3 4.13 3 3.54 2 3.1 2 5 After calibration, the container 104 may be filled with drilling waste 6 fluid. Vacuum pumps may be used. Other, low cost methods of pumping fluid waste 7 such as the use of impeller pumps are often not suitable due to debris found in 8 drilling waste known as cuttings or shale. Impeller pumps often wear out quickly 9 when used for pumping drilling waste.

10 The annotated coordinate map 126 is provided to the control unit 106,

11 which may be accomplished via its interface circuit 120 using a USB flash memory,

12 wired or wireless network transmission or the like.

13 Upon receiving the annotated coordinate map 126, the control unit 106

14 reads the map or otherwise obtain a digital representation of the surface to be

15 sprayed containing coordinate data (e.g., GPS coordinates). Included therewith or in 1 a separate data file are boundary coordinates identifying exclusion zones E
in the 2 surface which are not to be sprayed. The boundary coordinates can be vector data 3 including polygons and the like which are geo-referenced to the geo-coordinates of 4 the image of the surface.

The control unit 106 is used to open and close valve 115 to discharge 6 fluid onto the target surface below, based on a set of conditions, rules, or criteria 7 designed to avoid non-compliance.

8 Several modes of operation can result in non-compliance. These 9 include spraying into the exclusion zone; spraying too much waste fluid onto an area of the surface (areal spray rate R); spraying onto steep inclines; and spraying onto 11 areas previously sprayed (overlap). The control unit 106 is thus used to avoid non-12 compliance by automatically preventing any spraying at all unless all rules or criteria 13 for spraying have been met.

14 Fig. 4 depicts a flowchart of the basic steps performed by the control unit 106. Initially (step S402) the control unit 106 reads the coordinate map 126 to

16 obtain spatial coordinates defining the land surface to be sprayed, including or

17 accompanied by boundary coordinates identifying and defining one or more

18 exclusion zones E.

19 The operator of vehicle 102 traverses at least a portion of the surface to be sprayed along a path P. As shown in Fig. 6, the path P, taking the spray width 21 W into account, may be displayed onto the display 108 to assist the operator of the 22 vehicle 102. Exclusion zones E, as well as the current location of the vehicle 102, 23 may be displayed. As shown on Fig. 6, the exclusion zones E are shown as circular, 1 or portions of circular boundaries. Additionally, the steering-assist unit 110 may be 2 fed with corresponding data to provide assisted or automatic steering.

3 As the vehicle 102 traverses the surface, the control unit 106 obtains 4 the GPS coordinates for its current position from the navigation unit 118 and further obtains threshold parameters determined during calibration to determine if the 6 criteria for opening (or keeping open) the valve 115 are satisfied (step S404). If the 7 conditions for opening the valve 115 are satisfied, such as avoiding exclusion zones, 8 maintaining minimum speed to ensure are spray rates less than a maximum rate, 9 and others including sustaining minimum pressure, the control unit 106 automatically signals the valve 115 to open (step S408).

11 Otherwise (i.e., if any one of the specified criteria is not met) then 12 control unit 106 automatically signals the valve 115 to close or remain closed (step 13 S406). Criteria determination loops, keeping the valve 115 closed until such time as 14 the criteria are satisfied. No operator input is required to open or close the valve 115. Operator error is virtually eliminated.

16 Each time the criteria is satisfied and spraying commences, real-time 17 mapping of the sprayed areas can be performed (step S410). The mapping data 18 preferably includes a record of sprayed regions and the corresponding spray rate.
19 The mapping data may also optionally include a record of the terrain (e.g., slope).
The data may be optionally transmitted (step S412) to a recipient in real-time.

21 If the operation is completed (step S414), the process terminates, 22 otherwise it starts back at S402. The conditions or rules or criteria can be varied that 23 must be satisfied prior to opening the valve 115.

1 Fig. 5 is a more detailed depiction of various criteria (of step S404 of 2 Fig. 4) according to one embodiment. Having obtained current position coordinates, 3 the control unit 106 may initially check if the current target position to be sprayed is 4 in an exclusion zone using the supplied annotated coordinate map (step S404-1).
This may be determined by comparing the current GPS coordinates of the target 6 position (determined from the current antenna coordinates offset by the antenna-to-7 spray offset), to the boundary coordinates of the exclusion zones obtained by the 8 control unit 106. If the target position is in an exclusion zone, then the criteria for 9 opening the valve 115 are deemed not to have been satisfied.

Further, the control unit 106 may determine if the current target 11 position has been previously sprayed. Automatic spraying only occurs if the current 12 position is not in the record of previously sprayed positions. If the target position has 13 already been sprayed, known from identifying previously sprayed positions in the 14 records, then overlap would occur, the maximum areal spray rate would be exceeded and thus the criteria for spraying would not be satisfied. The control unit 16 106 may ensure (via steering-assist unit 110) that the target position is at least a 17 minimum distance away (e.g., 50 cm) from a previously sprayed path. This 18 minimizes overlaps. If the current target position is closer than a predetermined 19 minimum distance from a previously sprayed path, or is already sprayed (step S404-2), then the criteria for spraying are not satisfied.

21 Otherwise the control unit 106 may further determine if the slope (i.e., 22 the pitch or the roll) at the current target position is greater than the maximum 1 allowed (e.g., 5%) (step S404-3). If the slope is greater than the maximum limit, the 2 criteria for spraying are not satisfied.

3 Otherwise, the control unit 106 may further determine if the speed of 4 the vehicle 102 (indicating the rate of change of the target position for spraying), is above the prescribed minimum speed (step S404-4). If this speed is less than the 6 predetermined minimum speed, then the areal spray rate (the same volume of fluid 7 discharged onto a smaller traversed area) would exceed the maximum areal spray 8 rate lam, and thus the criteria are not satisfied. As noted above, the predetermined 9 minimum speed is derived from to the maximum desired areal spray rate and other spray characteristics.

11 Otherwise the control unit 106 may further determine if the pressure in 12 container 104 remains greater than the predetermined minimum pressure required 13 (e.g., about 9 psi) (step S404-5) using the pressure switch 112. A pressure reading 14 less than the predetermined minimum pressure required indicates that the tank is empty or approaching empty, and thus the criteria for spraying are not satisfied. A
16 pressure reading less than the predetermined minimum pressure can also indicate 17 that the spray pattern may no longer be equivalent to that which was used during 18 calibration of minimum velocity, negatively affecting the spray rate.

19 If each of the required criteria are satisfied, including the pressure being above the prescribed minimum, the control unit 106 has determined that the 21 criteria for opening the valve 115 are met and may signal the solenoid in actuator 22 114 to open the valve 115. Otherwise the control unit 106 has determined that the 1 criteria for opening the valve 115 are not met and would signal the solenoid in 2 actuator 114 to close valve 115.

3 Of course other embodiments may include more or less of the 4 conditions outlined in Fig. 5. The set of conditions illustrated in Fig. 5 is only one example, of many possible permutations of criteria or rules may be evaluated by the 6 control unit 106 to determine if the spraying should be started or stopped.

9 The actual spray rate should be monitored to ensure that it is within prescribed limits. Too high a spray rate may result in non-compliance and 11 environmental harm. On the contrary, too low a spray rate would require a much 12 larger land surface to be sprayed for a given amount of fluid resulting in increased 13 disposal costs. The maximum areal spray rate RMAx may depend on seasonal 14 weather conditions. For example the maximum allowed spray rate may be 40 m3/ha in summer, but only 20 m3/ha in winter. These again reflect relative fluid absorption 16 rates of the ground under different seasonal conditions.

17 As above, a base or average flow rate C for a given container may be 18 computed during calibration, obtained by dividing a known volume of fluid in the 19 container Fv1 by amount of time t1 required to discharge it. The use of an average flow rate may be adequate in operations where the flow rate C is roughly constant 21 for the duration of the spraying operation. However, in embodiments where flow rate 22 may vary substantially during operation, a real-time measure of the instantaneous 23 flow rate C(t) might also be obtained.

1 A flow meter, such as an ultrasonic flow meter, may be used to 2 measure the real-time flow rate C(t) as fluid is expelled through duct 116.
One form 3 of ultrasonic flow meter, also called an ultrasonic gauge, are known and some of 4 which ultrasonic gauges use a pair of ultrasonic transducers placed outside and on opposing sides of the duct, and spaced axially. In a stationary fluid (i.e., flow rate 6 C = 0), the time taken by an ultrasonic pulse to travel diagonally from the first 7 transducer to the second and vice versa should be the same. However, when fluid 8 is flowing, the time taken by the ultrasonic pulse to travel diagonally along the 9 direction of flow would be shorter than the time needed to travel diagonally against the fluid flow in the opposite direction. This difference can be used to determine the 11 fluid flow rate (i.e., the flow rate C(t)). Unlike mechanical flow meters, ultrasonic 12 gauges have the advantage of not interfering with the flow of fluid.

13 Once the real-time flow rate C(t) is known, the spray width W, the 14 vehicle speed V(t) may be used to obtain the real-time areal spray rate R(t) =
C(t)/[WV(t)]. The control unit 106 may thus limit the areal spray rate R(t) <
RMM by 16 ensuring that the speed V(t) > C(t)/[WR xJ while spraying.

17 The areal spray rate R may be mapped by the control system 106.
18 Given a real-time logs (digital samples) of the flow rate C; (from the flow meter) and 19 the vehicle speed V; (from the speed indicator 136) at small intervals of time At. The real-time spray rate may be logged as R. = [C;]/[WV1].

21 In addition to the flow rate C, the spray width W may also vary during 22 operation depending on parameters including waste fluid and nozzle characteristics.
23 Further, even once basic characteristics are set, additional variations can be 1 introduced in operation due to: orientation of the spray plate 117, the height of 2 nozzle or the spray plate 117 from the ground surface, and the tilt of container 104.
3 The minimum speed may Vm;n therefore change as the spray width W changes.

4 Figs. 7A-7D depict schematic diagrams of a vehicle 102' with the nozzle for container 104', i.e., the duct 116' and spray plate 117', at its rear. The 6 vehicle 102' may be substantially the same as the vehicle 102 of Fig. 1.
Figs. 7E-7H
7 depict plan views of the spray from container 104' corresponding to the Figs. 7A-7D
8 respectively.

9 With reference to Figs. 7A and 7E, in Fig. 7A the container 104' lies in a horizontal position on the vehicle's frame with its spray plate 117' oriented 11 upwardly at a height of H, from the ground, forming an upward orientation angle a =
12 a, with the horizontal plane. The arrangement in Fig. 7A corresponds to a spray 13 width of W, depicted in Fig. 7E.

14 With reference to Figs. 7B and 7F, in Fig. 7B, the container 104' is in a tilted position (indicated by the tilt angle R) with its spray plate 117' at a height of H1 16 from the ground, tilting the spray plate 117' to form -a shallower angle a2 < a, with the 17 horizontal plane. The arrangement in Fig. 7B corresponds to a spray width of W2 18 depicted in Fig. 7F.

19 With reference to Figs. 7C and 7G, in Fig. 7C, the container 104' is in a horizontal position as in Fig. 7A but the spray plate 117' is oriented downwardly to 21 form an angle a3 below the horizontal plane. The arrangement in Fig. 7C
22 corresponds to a smaller spray width of W3 depicted in Fig. 7G.

1 With reference to Figs. 7D and 7H, in Fig. 7D, container 104' is again 2 in a horizontal position as in Fig. 7A and is once again positioned to form an angle a, 3 with the horizontal plane. However, the container 104' is loaded on a lower truck 4 frame, and the spray plate 117' is at a lower height of H2 < H,. The arrangement in Fig. 7D may thus correspond to a spray width of W4 depicted in Fig. 7H.

6 As shown in Figs. 7E-7H, the spray width W may depend on the 7 orientation angle a of the spray plate 117' and the height h of the spray plate 117' 8 from the ground. Additionally the spray width may depend on the tilt angle 0 of 9 container 104' as shown in Fig. 7B. The spray width may thus be described as a multivariable function W = W(a,h,[3).

11 The spray width dependence on a, h, [3 may be described as a table of 12 values determined during calibration. The calibrated values may be used to compute 13 an accurate spray rate. For example, as the spray width is reduced from Wi to W2, it 14 is necessary to increase the minimum speed Vmin of vehicle 102' (from C/[WiRmAA to C/[W2Rn,,,J), in order to ensure that maximum areal spray rate RMM is not 16 exceeded.

17 In alternate embodiments, it may be desirable to increase the 18 efficiency of spraying - i.e., increase the areal spray rate R as close to the maximum 19 rate Rwx as possible without exceeding Rkw. Accordingly, the control 106 with possible use of steering-assist unit 110 may decrease the speed of vehicle 102, in 21 response to either a reduced flow rate or an increased spray width, to boost spraying 22 efficiency while maintaining a compliant spray rate below the maximum spray rate.

2 As noted above and generally, overlap of spraying is avoided (step 3 S404-2) on those parts of the land surface designated for spraying. In contrast to 4 agricultural applications (e.g. fertilizer spraying), overlaps are avoided for drill waste disposal and missed areas are tolerated. Overlaps generally lead to spray rates that 6 may exceed the maximum spray rate limits set by regulations.

7 The control unit 106 takes the spray width into account, when 8 monitoring the path P traversed by the vehicle 102, so as to avoid overlaps when 9 encountering or approaching previously sprayed positions. To avoid overlaps, a clearance gap between the region defined by the periphery of the current path and a 11 previously sprayed strip (or region or pass) of the path should be non-zero. For 12 example, in some embodiments, a 50 cm clearance gap is a good practical 13 separation. As shown in Fig. 6, sprayed regions may be displayed on the display 14 108 for the benefit of the operator of vehicle 102.

When the vehicle 102 approaches the perimeter of an inclusion zone S
16 at an angle, (i.e., diagonally), one end/edge of the sprayed area approaches an 17 already sprayed strip or path P earlier than the opposite end/edge of the sprayed 18 area. In this case, the control unit 106 signals the valve 115 to close to avoid 19 overlap from either end of the spray width. Similar problems are known in the agricultural industry, and are typically solved using precision agricultural guidance 21 technologies, employing section and boom controls to reduce or eliminate overlap 22 spraying that may result when the angle of vehicle approach is less than 90 . In 23 embodiments of the present invention, overlaps are completely eliminated.

3 As noted in step S404-3 of Fig. 5, control unit 106 avoids spraying on 4 sloped surfaces or inclines that have a rise to run ratio of greater than a predetermined maximum SL,.. Steep slopes risk run off and localized 6 concentration and an equivalent areal spray rate greater than the maximum.
This 7 maximum slope may be expressed as an angle using simple trigonometry, 8 Stan-'(SL,r,)I. Thus a maximum rise over run slope value of SL,,,aX = 5%
corresponds 9 to a maximum magnitude of about tan"1(0.05) = 2.86 for both the roll angle cp and the pitch angle 8.

11 Slope data can be provided by slope measurement unit 134. The slope 12 measurement unit 134 may include one or more inclinometers, and/or 13 accelerometers. Independent measurements of both the roll angle cp and the pitch 14 angle 8 of vehicle 102 may be obtained from the slope measurement unit 134.
Commercial systems exist for measuring the pitch and roll of vehicles.

16 The control unit 106 will thus signal a cessation of spraying (i.e., closes 17 valve 115) if either of the roll or pitch measurements indicate an incline greater than 18 the maximum allowed slope. That is, no spraying should take place unless both the 19 roll and pitch are less than the maximum slope allowed.

Slope measurement unit 134 may also be implemented as a modified 21 steering-assist unit. Algorithms used in steering-assist can be modified to detect 22 steep slopes. Auto-steer technology uses a measure of the vehicle roll, to 23 compensate by steering in the opposite direction to ensure a straight vehicle path on 1 hilly terrain. By slightly modifying the algorithm used for steering-assist, roll measure 2 data to may be converted to slope data.

3 In one embodiment, for simplicity or economy, only one inclinometer 4 might be provided providing one of either the pitch angle 6 or roll measurement cp.
When there is only one measurement available, such as pitch, the other 6 measurement, roll cp, may also be assumed not to exceed the maximum allowed 7 slope. This is a reasonable simplification as avoidance of rollover ensures that 8 vehicle 102 is also always driven at a low roll angles, well within the maximum slope 9 allowed.

In yet other embodiments, where a topographical map is used as input 11 map 122, then slope measurement unit 134 may not be required. As may be 12 appreciated, topographical maps contain contour date that identify contiguous 13 positions having the same altitude. This allows slope data to be determined by 14 computation using simple trigonometry. For example, the pitch angle 6 at a given position may be computed as 6 = tan-'(Ay/Ax) where Ay is the altitude difference 16 between the closest two contour lines and Ax is the horizontal distance between 17 them along the direction of travel. Accordingly, a separate hardware slope 18 measurement unit such as slope measurement unit 134 need not be present.
The 19 computation of slope data from contours may be performed by computing device 124 or control unit 106. Alternately, the slope measurement unit 134, if present, may 21 be used by control unit 106 to verify computed slope data.

2 The control unit 106 may record or map various data including vehicle 3 location, vehicle speed, spray rate, and the like in mapping data file 128.
A record 4 actual spray rates and locations where fluids are applied can be used to demonstrate compliance with applicable regulations, and commercial agreements 6 with landowners.

7 As noted above, upon receiving a signal from pressure switch 112, the 8 control unit 106 determines that there is little or no fluid left to spray, regardless of 9 the status of valve 115. This helps prevent areas from being erroneously logged as having been sprayed, when the container is empty even if the valve 115 may be 11 open.

12 The control unit 106 may store its real-time mapping data file 128 13 locally, or provide it to a remote computing device for real-time monitoring (see S412 14 in Fig. 5).

Accordingly, one alternate embodiment of system 100 may include a 16 wireless data communication antenna (e.g., Wi-Fi antenna, Bluetooth antenna) 17 attached to a wireless port in interface circuit 120. The control unit 106 may thus 18 transmit real-time mapping data to a remote computer located at a remote site using 19 the data communication antenna. Real time mapping data may be encapsulated and transmitted as extensible mark-up language (XML) data, using web-services or 21 using proprietary formats and network transport protocols. Further, alerts can be 22 transmitted including that the system was bypassed alerting the need for system 23 troubleshooting.

1 In one specific embodiment, a nearby gateway device such as a 2 wireless router or a nearby computer, in wireless communication with control unit 3 106, may receive real-time mapping data and retransmit it to across a wide area 4 network 130 such as the Internet, to a remote monitoring device, via a modem such as a cable modem, a DSL modem, ISDN modem, a dial-up modem, satellite modem 6 or the like.

7 In a variation of the above embodiment, the control unit 106 may 8 optionally receive control commands and data (e.g., in XML format) sent from a 9 remote computer. Control unit 106 may interpret control commands and parameter data, and locally execute the commands (e.g., to stop spraying altogether, to change 11 a particular threshold parameter value, update a map, etc). Such capabilities may be 12 used to remotely override spraying operations in case of an emergency; or to update 13 a few parameters on an already calibrated vehicle.

14 The system 100 may be used compile reports as required by applicable regulations. The mapping data file 128 may include graphical reports on 16 sprayed surfaces as depicted in Fig. 8. In addition, a concordance of spray rates 17 and slope data may be provided along with the graphical representation. A
final map 18 of activity depicting detailed information interspersed within the photographic map 19 (e.g., satellite image) of the land surface sprayed may be produced by device 124 as depicted in Fig. 8B. The information may include, for example, waste generator 21 licensee, unique drilling location identifier, surface location of the waste generating 22 site, well license number, name of technician, the disposal location, the ground 23 and/or soil condition, the type of land, landowner information, source water 1 chemistry, source water location, soil sample data, GPS coordinates and drilling 2 waste, soil and source water salinities/chemistry, owner information, various 3 compliance flags, and the like.

4 In addition to the final map of activity, the computing device 124 may also compile detailed reports on fluid waste chemistry's, analyse loading rates, total 6 analyse loads, calculated spray rates, and all other data applicable for regulatory 7 compliance and good record keeping practices. Customized reports may be 8 generated for internal purposes landowners, clients, regulatory agencies and the 9 like.

12 In one alternative embodiment of the present invention, components 13 for retrofitting a vehicle may be provided in kit form. A kit can be provided to reliably 14 and conveniently retrofit a vacuum truck so that it can be used for landspraying. The vacuum truck may already have container with a pneumatically actuated discharge 16 valve (similar to valve 115 coupled to cylinder 114B), or will be fitted with one as 17 required herein.

18 A typical vacuum truck will have a remote-actuated on-off (open-19 closed) dump valve. A kit will interject into the on/off control for the existing dump valve, or it absent, provide a valve, duct and nozzle. Accordingly, a typical kit for 21 retrofitting a vehicle for use in landspraying, may include provision of control unit 22 106, and navigation unit 118 and an automation or kit interface to enable both 1 controlled landspraying pursuant to embodiments disclosed herein, and manual 2 operation according to the original uses of the vehicle.

3 The control unit 106 can include the touch-screen display 108. The 4 navigation unit 118 may include an antenna, an antenna cable for interconnecting the antenna to the unit, and an antenna mount (e.g., magnetic mount). The kit may 6 also include various connection hardware including a plurality of pipes such as 7 plastic air lines, and a variety of fittings or interconnects. The fittings may include 8 push-in and/or threaded connects.

9 The kit may also include some or all of the actuator assembly 114 including the solenoid-piloted actuator 114A and the shuttle valve 114D. The kit 11 may also include the fluid pressure switch 112 and relay 142. If not already supplied 12 on the vehicle, or unsuitable for integration, the air toggle switch 114C
is also 13 provided.

14 The kit may additionally include a weather proof box for housing the assembled components; a breather vent; and a plurality of framing nuts. The kit 16 may include relay 144, a relay cable, the lockable override switch 152, LED
148 and 17 circuit breaker 154. The kit may also include a variety of electrical connection 18 conveniences including a relay harness, a strain relief, a plurality of crimp and shrink 19 ring connectors and a terminal block.

The kit may further include an adapter and actuator connector between 21 the actuator 114 and valve 115.

22 The kit may further include a vehicle-specific steering-assist unit 110 23 and a cable for interconnecting steering-assist unit 110 to the control unit 106.

1 In some embodiments, a basic kit may be provided without control unit 2 106 and display 108. Accordingly, a vacuum truck retrofitted using the smaller kit 3 without the control unit 106 and the display 108, may be operated in manners 4 exemplary of the present invention by temporarily acquiring a tablet device, such as hardware unit 138 that includes both control unit 106 and display 108, by way of a 6 lease or rental arrangement.

7 As noted, the retrofitted truck may contain a discharge valve like valve 8 115 with an actuating mechanism similar to double-acting cylinder 114B. If not, in 9 some embodiments, the cylinder 11 4B and the valve 115 may be included in the kit, to adapt a container for landspraying use. A nozzle, such as in the form of a 11 standardized duct 116 and spray plate 117, may also be included in the kit.
12 Standardization can assist in simplifying calibration and range of control issues. Yet 13 other embodiments may also provide the container 104, and air supply unit 150 to 14 upgrade an ordinary truck for landspraying use.

The components in the kit may, of course, are only exemplary and in 16 no way limiting. In alternate embodiments, the kit may use hydraulic actuators or 17 electric actuators and/or pneumatic actuators to actuate the valve.

18 The memory 107 of the control unit 106 may be preloaded with 19 processor-executable instructions adapting the control unit 106 to operate as described herein for automatic control of the spraying operation of system 100.

21 Alternately, the kit may include firmware on a processor readable 22 medium such as a USB memory stick, for loading into memory 107.

1 In addition, the kit may include an application software program, 2 provided on a processor readable medium such as a CD, DVD, flash memory, USB
3 memory stick or the like. The application program contains a set of processor-4 executable instructions for loading to a generic computing device (such as device 124). The set of instructions adapt the computing device to accept an input map 6 representative of a surface to be sprayed, and to outline exclusion zones on the 7 input map, to form an annotated coordinate map for use by the control unit 106.
8 Installation and use instructions for the software may also be provided on the CD or 9 optionally as a booklet.

As may now be appreciated, embodiments disclosed herein provide a 11 robust regulatory compliance management system and an accurate drill waste fluid 12 disposal data collection. Powerful mapping functions and controls automate much of 13 the process involved in landspraying and reporting, thereby reducing human error.
14 Reliable data can be provided to various stakeholders including governments, residents, land owners and businesses in the extractive industries involved in the 16 disposal of drilling waste.

17 Reducing human error may lead to significant economic benefit. The 18 cost of non-compliance can range from about $5,000 CDN to more than $25,000 19 CDN per failure in follow up assessments, reclamation efforts and possible monetary fines. With about 20,000 qualifying wells drilled yearly in Alberta, Canada alone and, 21 as applicant understands it, at an projected rate of 12% of disposals being at high 22 risk, that is over 2000 potential case of non-compliance annually.

1 Further advantages include improvement to the health and safety of 2 drivers and protection of communities where waste fluid is sprayed. Driving safety is 3 improved due to the visual guidance provided in on display 108, which could greatly 4 aid night time driving. Furthermore, steering-assist unit 110 provides additional assurance against potentially unsafe excursions, overlaps and non-compliance 6 events.

7 As may be recalled, conventional methods involve physically marking 8 exclusion and/or inclusion zones with pylons and instructing operators to remain 9 outside of exclusion zones during the spraying operation. Preparation and subsequent operations under these conditions contributes to driver fatigue and 11 generally increases stress associated with operating the vehicle.

12 In contrast, embodiments disclosed herein reduce fatigue and stress 13 by allowing the operators of vehicle 102 to concentrate primarily on driving. The 14 spraying operation is automatically controlled by the system and the operator is relieved from tasks associated with starting and stopping spraying operations, 16 looking for pylons and other markers and the like. Moreover, steering-assist unit 110 17 may help avoid collisions and accidental incursions into excluded zones.

18 Although embodiments discussed above involve the use of land 19 vehicles, other embodiments of the present invention may be adapted for use in aircraft and other traversing vehicles. An aircraft quipped with a navigation system, 21 may carry a fluid filled container to spray a land surface at low altitudes. For example 22 embodiments of the present invention may be used to dispense pesticides, or 23 combat forest fires from helicopters. Embodiments of the present invention may also 1 have maritime applications. The fluid container may be carried by a vessel.
2 Examples of maritime application may include spraying oil dispersants into oceans 3 after accidental oil spills during transport or offshore exploration.
Further, 4 municipalities may use it for mapping bio-solids application to farmland, application of oil, calcium chloride, or other amendments to public roads and so forth, tracking 6 rates and mapping applied areas. Intensive livestock operations could also use the 7 product to map the application of manure and so forth which, in the case of the hog 8 industry, also use similar vacuum-type vehicles to convey and spray liquid manures.
9 Using embodiment herein result in fewer non-compliance events and any occasional events of non-compliance are recorded and documented for ease of 11 identification and remedy. This reduces the amount of effort related to investigations 12 of non-compliance.

Claims (71)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN
EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS
FOLLOWS:

1. A method for controlled spraying of a surface with fluid from a mobile container, the method comprising:

obtaining a plurality of spatial coordinates for the surface;

establishing boundary coordinates within the spatial coordinates defining one or more exclusion zones on the surface which are not to be sprayed;
providing an on-off spray nozzle having a fully open position for spraying fluid at a flow rate C in units of volume per time from the container, and a fully closed position to stop spraying;

determining a spray width W for the fluid when sprayed from the container;

traversing at least a portion of the surface with the container along a path and, for each current position of the container along the path:

obtaining position coordinates, determining a speed V for the rate of change of the current position, computing the areal spray rate as R = C/(WV), and automatically spraying the fluid from the container by opening the on-off spray nozzle from the fully closed position to the fully open position for spraying fluid width W and flow rate C if the following spray conditions are met, including the spray width W is outside the exclusion zones, and the areal spray rate R is less than a predetermined maximum spray rate RMAX.

2. The method of claim 1 wherein overlaps of the path are avoided, further comprising:

maintaining a record of previously sprayed positions that have already been automatically sprayed; and automatically spraying only if an additional spraying condition is met, including, the current position is not in the record as a previously sprayed position.

3. The method of claim 2 wherein while traversing the path and upon encountering any of the previously sprayed positions, further comprising spraying only if the current position is further than a predetermined minimum distance away from the nearest one of the encountered previously spayed positions.

4. The method of claim 1, further comprising:

determining a minimum speed V min associated with the predetermined maximum areal spray rate R MAX as V min = C/(WR MAX), and wherein performing the automatically spraying step only if V < V min.

5. The method of claim 3 or 4, wherein determining the flow rate C
comprises:

calibrating the spray nozzle by discharging a known volume F V1 of fluid from the container;
measuring the duration t1 required to discharge the volume F V1 of fluid; and computing the flow rate as C = F V1/t1.

6. The method of any one of claims 1 to 5, further comprising:
measuring pressure in the container; and automatically spraying only if an additional spraying condition is met, including, the measured pressure is above a predetermined minimum pressure.

7. The method of any one of claims 1 to 6, further comprising:
obtaining the slope of the surface at the current position; and automatically spraying only if an additional spraying condition is met, including, the slope is below a predetermined maximum slope.

8. The method of any one of claims 1 to 7 wherein:

the fluid is a waste fluid comprising solid particle debris; and the opening of the on-off spray nozzle from the fully closed position to the fully open position for spraying fluid at a flow rate C comprises, fully opening a valve for passing the waste fluid including the solid particle debris.

9. The method of any one of claims 1 to 8, further comprising pressurizing the container by maintaining an air pad therein for lessening variability in a hydrostatic head of the fluid in the container while spraying.

10. Apparatus for spraying controlled spraying of a surface to be sprayed with fluid from a mobile container, comprising:

a vehicle supporting and transporting the container;

a navigation unit for determining at least a current position of the vehicle;

a speed indicator for determining a speed V of the vehicle;

an on-off valve for a spray nozzle, the on-off valve having a fully open position for spraying fluid at a flow rate C in units of volume per time from the container at a pre-determined a spray width W for the flow rate C, and a fully closed position to stop spraying;

an actuator interconnected to the valve for alternately controlling the valve between the fully open position and fully closed positions; and a control unit having a processor in communication with the navigation unit and the actuator, the control unit having a memory for storing processor-executable instructions for:

determining spatial coordinates of the surface including boundary coordinates defining one or more exclusion zones on the surface which are not to be sprayed;

determining the current position and speed V of the vehicle;
determining whether the current position is outside the exclusion zones; and determining a minimum speed Vmin for the vehicle for spraying an areal spray rate R = C/(WV) less than a predetermined maximum spray rate RMAX; and automatically signalling the actuator to open the valve from the fully closed to the fully open position to deliver spray fluid only if the current position is outside the exclusion zone and the speed is greater than or equal to the minimum speed Vmin.

11. The apparatus of claim 10, further comprising a flow meter for determining the fluid flow rate C from the container, the flow meter being in communication with the control unit for determining the minimum speed Vmin.

12. The apparatus of claim 11, wherein the flow meter is an ultrasonic flow meter.

13. The apparatus of claim 10, 11 or 12, wherein the processor-executable instructions further comprises a processor-readable medium for identifying and storing sprayed positions in a record on the processor-readable medium and wherein the processor-executable instructions only automatically signal the actuator controllably deliver spray fluid if the current position is not in the record of sprayed positions.

14. The apparatus of claim 13, wherein the current position is not in the record of sprayed positions, the processor-executable instructions signal the actuator to open only if the current position is further than a predetermined minimum distance away from any of the sprayed positions in the record.

15. The apparatus of any one of claims 10 to 14, wherein the processor-executable instructions further comprise a processor-readable medium recording a real-time log of the areal spray rate R = C/(WV).

16. The apparatus of any one of claims 10 to 15, further comprising a steering-assist unit coupled to the vehicle and the control unit, wherein the processor-executable instructions further adapt the control unit to vary the speed of the vehicle to V' in response to a varied flow rate C' while still maintaining that V' >
C'/(WR MAX) to ensure that a new area spray rate R' = C'/(WV') remains below the predetermined maximum rate R MAX.

17. The apparatus of any one of claims 10 to 16, further comprising a pressure switch in the container providing pressure data inside the container, wherein the processor-executable instructions further adapt the control unit to signal the actuator to close the valve while the pressure data is below a predetermined minimum pressure.

18. The apparatus of any one of claims 10 to 17, further comprising a slope measurement unit in the vehicle providing slope at the target position, wherein the processor-executable instructions further adapt the control unit to signal the actuator to open the valve only if the slope is below a predetermined maximum slope.

19. The apparatus of any one of claims 10 to 18, wherein the actuator comprises one of a pneumatic actuator, a hydraulic actuator and an electric actuator.

20. The apparatus of any one of claims 10 to 18, wherein the actuator comprises a solenoid-piloted actuator.

21. The apparatus of any one of claims 10 to 18, wherein the actuator comprises a solenoid-piloted pneumatic actuator for opening and closing the valve, the solenoid-piloted actuator electrically coupled to the control unit for receiving the signalling from the control unit to alternately open the valve, and close the valve.

22. The apparatus of claim 21, wherein the actuator further comprises:

an air toggle switch having a first output connected to the valve to open the valve and a second output connected to the valve to close the valve; and a shuttle valve connected between the second output and the valve an connected between the solenoid-piloted pneumatic actuator and the valve; and wherein the solenoid-piloted pneumatic actuator receives the signalling from the control unit to alternately direct air to the air toggle switch for opening the valve, and direct air to the shuttle valve to close the valve.

23. A kit for retrofitting a vehicle for use in spraying fluid onto a surface, said vehicle having a container mounted thereon, the container having a valve to control fluid discharge, said kit comprising:

an on-off actuator assembly for the valve;
a navigation unit;

a control unit comprising: a processor in communication with memory, an a control unit comprising a processor in communication with the navigation unit, the actuator assembly; and memory storing processor-executable instructions adapting the control unit to:

obtain a plurality of coordinates of the surface including boundary coordinates defining exclusion zones which are not to be sprayed;
determine position coordinates for a spraying target position on the surface from the navigation unit;

determine whether the target position is outside the exclusion zones by comparing the position coordinates with the boundary coordinates;

obtain a spray width W, a flow rate C, and a predetermined maximum spray rate RMAX for fluid sprayed from the container, to determine a minimum speed Vmin = C/(WRMAX) for the vehicle; and automatically signal the actuator assembly to open the valve to the fully open position only if the target position is outside the exclusion zone and V > Vmin; and otherwise signal the actuator to close the valve; and a plurality of interconnects for connecting the actuator assembly to the valve; and for interconnecting the control unit to the actuator assembly and the navigation unit.

24. The kit of claim 23, wherein the actuator assembly comprises a solenoid-piloted pneumatic actuator for opening and closing the valve, the solenoid-piloted actuator electrically coupled to the control unit for receiving the signalling from the control unit to alternately open the valve, and close the valve.

25. The kit of claim 24, wherein the actuator assembly further comprises:

an air toggle switch having a first output connected to the valve to open the valve and a second output connected to the valve to close the valve; and a shuttle valve connected between the second output and the valve an connected between the solenoid-piloted pneumatic actuator and the valve; and wherein the solenoid-piloted pneumatic actuator receives the signalling from the control unit to alternately direct air to the air toggle switch for opening the valve, and direct air to the shuttle valve to close the valve.

26. The kit of any one of claims 23 to 25, further comprising a relief valve to maintain pressure in the container below a predetermined maximum pressure.

27. A control unit for controlling spraying of fluid from a container to a surface, said control unit comprising:

a processor;

an interface circuit coupled to the processor, providing interconnections to a navigation unit, and an actuator for an on-off valve controlling spraying from the container;

memory in communication with said processor, storing processor-executable instructions adapting said processor to:

obtain a plurality of coordinates of the surface including boundary coordinates defining exclusion zones which are not to be sprayed;
determine position coordinates for a spraying target position on the surface from the navigation unit;

determine whether the target position is outside the exclusion zones by comparing the position coordinates with the boundary coordinates;

obtain a spray width W, a flow rate C, and a predetermined maximum spray rate RMAX for fluid sprayed from the container when the valve is fully open, so as to determine a minimum speed Vmin =
C/(W RMAX) for the vehicle; and automatically signal the actuator to fully open the valve only if the target position is outside the exclusion zone and V > Vmin; and otherwise signal the actuator to fully close the valve.

28. A system for spraying fluid on a surface, comprising:

a database of maps representative of surfaces available for spraying;

a computing device interconnected to the database, the computing device having a processor and a processor readable medium storing a set of processor-executable instructions adapting the computing device to:

select a map from the database; and annotate the map from the database to form an annotated map having exclusion zones in the surface, not to be sprayed;

a vehicle comprising: a speed indicator proving the speed V of the vehicle; a navigation unit providing a current location of the vehicle; and a container with a discharge valve coupled to an actuator, mounted on the vehicle, the valve having a fully open position and a fully closed position;

a control unit having a second processor in communication with the navigation unit, the valve and memory storing a second set of processor-executable instructions adapting the control unit to:

obtain a plurality of coordinates of the surface from the annotated map including boundary coordinates for the exclusion zones;

determine position coordinates for a spraying target position on the surface from the navigation unit;

determine whether the target position is outside the exclusion zones by comparing the position coordinates with the boundary coordinates;

obtain a spray width W, a flow rate C, and a predetermined maximum spray rate RMAX for fluid sprayed from the container when the valve is in the fully open position, to determine a minimum speed Vmin = C/(W RMAX) for the vehicle; and automatically signal the actuator to open the valve to the fully open position only if the target position is outside the exclusion zone and V >
Vmin; and otherwise signal the actuator to close the valve to the fully closed position.

29. The system of claim 28, wherein the second set of processor-executable instructions further adapt the control unit to maintain a record of all sprayed positions, and signal the actuator to open the valve only if the target position is not in the record.

30. The system of claim 29, wherein the second set of processor-executable instructions further adapt the control unit to record spray rate data computed as R = C/(WV) for the each position sprayed.

31. The system of claim 28, 29 or 30, further comprising a second computing device adapted to receive wireless data; a wireless communication antenna interconnecting the control unit; the second set of processor-executable instructions further adapting the control unit to transmit the spray rate data recorded to the second computing device using the data communication antenna.

32. The system of claim 31, wherein the database of maps is stored on the computer device.

33. The system of claim 32, further comprising a third computing device, storing the database of maps.

34. A computer readable medium storing processor-executable instructions for loading into a memory of a control unit, for use in spraying a surface with fluid from a container mounted on a vehicle, the control unit having a processor in communication with a navigation unit, an actuator actuating a discharge valve in the container and the memory, the instructions adapting the control unit to:

obtain a plurality of coordinates of the surface including boundary coordinates for the exclusion zones;

determine position coordinates for a spraying target position on the surface, from the navigation unit;

determine whether the target position is outside the exclusion zones by comparing the position coordinates with the boundary coordinates;

obtain a spray width W, a flow rate C, and a predetermined maximum spray rate RMAX for fluid sprayed from the container when the discharge valve is in a fully open position, to determine a minimum speed Vmin = C/(WRMAX) for the vehicle; and automatically signal the actuator to open the discharge valve tol the fully open position only if the target position is outside the exclusion zone and V >
Vmin; and otherwise signal the actuator to close the valve a fully closed position.

35. A method for controlled spraying of a surface with fluid from a mobile container, the method comprising:

obtaining a plurality of spatial coordinates for the surface;

establishing boundary coordinates defining one or more exclusion zones on the surface which are not to be sprayed;

traversing at least a portion of the surface with the container along a path, the container having a spray nozzle for controllably delivering a spray width W
of fluid at an areal spray rate R (volume/area) to the surface along the path, and for each current position of the container along the path:
obtaining position coordinates, obtaining the slope of the surface at the current position, and determining the areal spray rate R; and automatically spraying the spray width W at a sprayed position along the path with the fluid from the container, if the following spray conditions are met, including the spray width is outside the exclusion zones, the slope is below a predetermined maximum slope, and the areal spray rate R is less than a predetermined maximum spray rate RMAX.

36. The method of claim 35 wherein overlaps of the path are avoided, further comprising:

maintaining a record of previously sprayed positions that have already been automatically sprayed; and automatically spraying only if an additional spraying condition is met, including, the current position is not in the record as a previously sprayed position.

37. The method of claim 36 wherein while traversing the path and upon encountering any of the previously sprayed positions, further comprising spraying only if the current position is further than a predetermined minimum distance away from the nearest one of the encountered previously spayed positions.

38. The method of claim 35 or 36, further comprising:

determining a minimum speed V min associated with the predetermined maximum areal spray rate R MAX as V min = C/(WR MAX), and wherein performing the automatically spraying step only if V < V min.cndot.

39. The method of any one of claim 35 to 38, wherein determining the flow rate C comprises:

calibrating the spray nozzle by discharging a known volume F v1 of fluid from the container;
measuring the duration t1 required to discharge the volume F v1 of fluid; and computing the flow rate as C = F v1/t1.

40. The method of any one of claims 35 to 339, further comprising:
measuring pressure in the container; and automatically spraying only if an additional spraying condition is met, including, the measured pressure is above a predetermined minimum pressure.

41. Apparatus for spraying controlled spraying of a surface to be sprayed with fluid from a mobile container, comprising:

a vehicle supporting and transporting the container;

a navigation unit for determining a current position of the vehicle;
a speed indicator for determining a speed of the vehicle;

a valve-operated spray nozzle mounted on the container for controllably delivering fluid to the spray nozzle;

an actuator interconnected to the valve;

an ultrasonic flow meter for determining a fluid flow rate C from the container; and a control unit having a processor in communication with the navigation unit and the actuator, the control unit having a memory for storing processor-executable instructions for:

determining spatial coordinates of the surface including boundary coordinates defining one or more exclusion zones on the surface which are not to be sprayed;

determining the current position and of the vehicle;

determining whether the current position is outside the exclusion zones; and determining a minimum speed Vmin for the vehicle for spraying an areal spray rate at the fluid flow rate C which is less than a predetermined maximum spray rate RMAX; and automatically signalling the actuator controllably deliver spray fluid only if the current position is outside the exclusion zone and the speed is greater than or equal to the minimum speed Vmin.

42. The apparatus of claim 41, wherein the processor-executable instructions further comprises a processor-readable medium for identifying and storing sprayed positions in a record on the processor-readable medium and wherein the processor-executable instructions only automatically signal the actuator controllably deliver spray fluid if the current position is not in the record of sprayed positions.

43. The apparatus of claim 41 or 42, wherein the current position is not in the record of previous sprayed positions, the processor-executable instructions signal the actuator to open only if the current position is further than a predetermined minimum distance away from any of the previous sprayed positions in the record.

44. The apparatus of claims 41, 42 or 43, wherein the processor-executable instructions further comprise a processor-readable medium recording a real-time log of the areal spray rate R = C/(WV).

45. The apparatus of any one of claims 41 to 44, further comprising a steering-assist unit coupled to the vehicle and the control unit, wherein the processor-executable instructions further adapt the control unit to vary the speed of the vehicle to V' in response to a varied flow rate C' while still maintaining that V' >
C'/(WR MAX) to ensure that a new area spray rate R' = C'/(WV') remains below the predetermined maximum rate R MAX.

46. The apparatus of any one of claims 41 to 45, further comprising a pressure switch in the container providing pressure data inside the container, wherein the processor-executable instructions further adapt the control unit to signal the actuator to close the valve while the pressure data is below a predetermined minimum pressure.

47. The apparatus of any one of claims 41 to 46, further comprising a slope measurement unit in the vehicle providing slope at the target position, wherein the processor-executable instructions further adapt the control unit to signal the actuator to open the valve only if the slope is below a predetermined maximum slope.

48. The apparatus of any one of claims 41 to 47, wherein the actuator comprises one of a pneumatic actuator, a hydraulic actuator and an electric actuator.

49. The apparatus of any one of claims 41 to 48, wherein the actuator comprises a solenoid-piloted actuator.

50. The apparatus of any one of claims 41 to 48, wherein the actuator comprises a solenoid-piloted pneumatic actuator for opening and closing the valve, the solenoid-piloted actuator electrically coupled to the control unit for receiving the signalling from the control unit to alternately open the valve, and close the valve.

51. The apparatus of claim 50, wherein the actuator further comprises:

an air toggle switch having a first output connected to the valve to open the valve and a second output connected to the valve to close the valve; and a shuttle valve connected between the second output and the valve an connected between the solenoid-piloted pneumatic actuator and the valve; and wherein the solenoid-piloted pneumatic actuator receives the signalling from the control unit to alternately direct air to the air toggle switch for opening the valve, and direct air to the shuttle valve to close the valve.

52. Apparatus for spraying controlled spraying of a surface to be sprayed with fluid from a mobile container, comprising:

a vehicle supporting and transporting the container;

a navigation unit for determining a current position of the vehicle;
a speed indicator for determining a speed of the vehicle;

a valve-operated spray nozzle mounted on the container for controllably delivering fluid to the spray nozzle;

a solenoid-piloted pneumatic actuator interconnected with the valve for opening and closing the valve; and a control unit having a processor in communication with the navigation unit and the solenoid-piloted actuator, the solenoid-piloted actuator further comprising an air toggle switch having a first output connected to the valve to open the valve and a second output connected to the valve to close the valve; and a shuttle valve connected between the second output and the valve and connected between the solenoid-piloted pneumatic actuator and the valve; and the control unit having a memory for storing processor-executable instructions for:

determining spatial coordinates of the surface including boundary coordinates defining one or more exclusion zones on the surface which are not to be sprayed;

determining the current position and of the vehicle;

determining whether the current position is outside the exclusion zones; and determining a minimum speed Vmin for the vehicle for spraying an areal spray rate less than a predetermined maximum spray rate RMAX; and automatically and electrically signalling the solenoid-piloted pneumatic actuator for alternately directing air to the air toggle switch for opening the valve, and directing air to the shuttle valve to close the valve for delivering spray fluid only if the current position is outside the exclusion zone and the speed is greater than or equal to the minimum speed Vmin.

53. The apparatus of claim 52, wherein the processor-executable instructions further comprises a processor-readable medium for identifying and storing sprayed positions in a record on the processor-readable medium and wherein the processor-executable instructions only automatically signal the actuator controllably deliver spray fluid if the current position is not in the record of sprayed positions.

54. The apparatus of claim 52 or 53, wherein the current position is not in the record of previous sprayed positions, the processor-executable instructions signal the actuator to open only if the current position is further than a predetermined minimum distance away from any of the previous sprayed positions in the record.

55. The apparatus of claims 52, 53 or 54, wherein the processor-executable instructions further comprise a processor-readable medium recording a real-time log of the areal spray rate R = C/(WV).

56. The apparatus of any one of claims 52 to 55, further comprising a steering-assist unit coupled to the vehicle and the control unit, wherein the processor-executable instructions further adapt the control unit to vary the speed of the vehicle to V' in response to a varied flow rate C' while still maintaining that V' >
C'/(WR MAX) to ensure that a new area spray rate R' = C'/(WV') remains below the predetermined maximum rate R MAX.

57. The apparatus of any one of claims 52 to 56, further comprising a pressure switch in the container providing pressure data inside the container, wherein the processor-executable instructions further adapt the control unit to signal the actuator to close the valve while the pressure data is below a predetermined minimum pressure.

58. The apparatus of any one of claims 52 to 57, further comprising a slope measurement unit in the vehicle providing slope at the target position, wherein the processor-executable instructions further adapt the control unit to signal the actuator to open the valve only if the slope is below a predetermined maximum slope.

59. The apparatus of any one of claims 52 to 58, wherein the actuator comprises one of a pneumatic actuator, a hydraulic actuator and an electric actuator.

60. The apparatus of any one of claims 52 to 59, wherein the actuator comprises a solenoid-piloted actuator.

61. The apparatus of any one of claims 52 to 59, wherein the actuator comprises a solenoid-piloted pneumatic actuator for opening and closing the valve, the solenoid-piloted actuator electrically coupled to the control unit for receiving the signalling from the control unit to alternately open the valve, and close the valve.

62. The apparatus of claim 61, wherein the actuator further comprises:

an air toggle switch having a first output connected to the valve to open the valve and a second output connected to the valve to close the valve; and a shuttle valve connected between the second output and the valve an connected between the solenoid-piloted pneumatic actuator and the valve; and wherein the solenoid-piloted pneumatic actuator receives the signalling from the control unit to alternately direct air to the air toggle switch for opening the valve, and direct air to the shuttle valve to close the valve.

63. A method to avoid overspraying of a surface with fluid from a mobile container, the method comprising:

providing an on-off spray nozzle having a fully open position for spraying a spray width W of fluid at a flow rate C in units of volume per time from the container, and a fully closed position to stop spraying;

traversing the surface with the container along a path at a speed V, for each current position of the container along the path, computing the areal spray rate as R = C/(WV); and automatically spraying the fluid by opening the on-off spray nozzle from the fully closed position to the fully open position when the areal spray rate R is less than a predetermined maximum spray rate RMAX.

64. The method of claim 63 wherein the surface includes one or more exclusion zones on the surface which are not to be sprayed, further comprising:

automatically spraying the fluid by opening the on-off spray nozzle from the fully closed position to the fully open position only when both the areal spray rate R is less than the predetermined maximum spray rate RMAX; and the spray width is outside the exclusion zones.

65. The method of claim 63 or 64, further comprising:

determining a minimum speed V min associated with the predetermined maximum areal spray rate R MAX as V min = C/(WR MAX), and wherein performing the automatically spraying step only if V < V min.

66. The method of claim 63, 64 or 65, wherein determining the flow rate C comprises:

calibrating the spray nozzle by discharging a known volume F v1 of fluid from the container;
measuring the duration t1 required to discharge the volume F v1 of fluid; and computing the flow rate as C = F v1/t1.

67. The method of any one of claims 63 to 66, further comprising:
measuring pressure in the container; and automatically spraying only if an additional spraying condition is met, including, the measured pressure is above a predetermined minimum pressure.

68. The method of any one of claims 63 to 67 wherein:
the fluid is a waste fluid comprising solid particle debris; and the opening of the on-off spray nozzle from the fully closed position to the fully open position for spraying fluid at a flow rate C comprises, fully opening a valve for passing the waste fluid including the solid particle debris.

69. The method of any one of claims 63 to 68, further comprising pressurizing the container by maintaining an air pad therein for lessening variability in a hydrostatic head of the fluid in the container while spraying.

70. The method of any one of claims 63 to 69 wherein overlaps of the path are avoided, further comprising:

maintaining a record of previously sprayed positions that have already been automatically sprayed; and automatically spraying only if an additional spraying condition is met, including, the current position is not in the record as a previously sprayed position.

71. The method of claim 70 wherein while traversing the path and upon encountering any of the previously sprayed positions, further comprising spraying only if the current position is further than a predetermined minimum distance away from the nearest one of the encountered previously spayed positions.