Water-storage ponds and methods for treating water

Abstract

A pond comprising (i) an embankment having a generally circular outer dimension; (ii) a generally circular pond bottom within the embankment; (iii) a drain sump that is located at or near the center of the generally circular pond bottom, where the drain sump includes a drain outlet that allows fluid to be removed from the pond; and (iv) one or more fluid injection ports within the embankment.

Description

WATER-STORAGE PONDS AND METHODS FOR TREATING WATER FIELD OF THE INVENTION

[0001] Embodiments of the present invention are directed toward water-storage ponds and associated systems, and the use of these ponds for storing water and / or treating large volumes of water. BACKGROUND OF THE INVENTION

[0002] Large volumes of water are often used in oil and gas production. The availability of water is often a limiting factor, especially in remote regions. While water reuse, such as water obtained from oil and gas production or other industrial or power generation processes, is an option, the ability to store large volumes of water is problematic since water can turn septic during storage. In other words, when large volumes of water are stored, such as in large frac ponds, bacteria within the water can rapidly reproduce and turn the water septic, which frustrates its further use. This skilled person understands that bacterial growth is a function of time, and it is desirable to extend the storage time of the water before it turns septic. Additionally, other characteristics of the water are important to its usefulness in oil and gas production. These characteristics include, but are not limited to, hydrogen sulfide content, the level of suspended solids, the presence of oil and grease, and the turbidity of the water. SUMMARY OF THE INVENTION

[0003] One or more embodiments of the present invention provide a pond comprising (i) an embankment having a generally circular outer dimension; (ii) a generally circular pond bottom within the embankment; (iii) a drain sump that is located at or near the center of the generally circular pond bottom, where the drain sump includes a drain outlet that allows fluid to be removed from the pond; and one or more fluid injection ports within the embankment.

[0004] Other embodiments of the present invention provide a pond array comprising (i) a first pond including an embankment with a generally circular dimension, a generally circular pond bottom within the embankment, a drain sump that is located at or near thecenter of the generally circular pond bottom, where the drain sump includes a drain outlet that allows fluid to be removed from the pond; and (ii) a second pond including an embankment with a generally circular dimension, a generally circular pond bottom within the embankment, and a drain sump that is located at or near the center of the generally circular pond bottom, where the drain sump includes a drain outlet that allows fluid to be removed from the pond, where a portion of the embankment of the first pond forms a portion of the embankment of the second pond.

[0005] Yet other embodiments of the present invention provide a pond system comprising (i) a pond including an embankment having a generally circular dimension; a generally circular pond bottom within the generally circular embankment; a drain sump that is located at or near the center of the generally circular pond bottom; an injection port within the embankment; (ii) a water transfer subsystem; and (iii) conduit that provides fluid communication between the water transfer subsystem and the drain sump and between the water transfer subsystem and the injection port.

[0006] Still other embodiments of the present invention provide a method of storing water, the method comprising (i) providing a pond including an embankment having a generally circular dimension; a generally circular pond bottom within the generally circular embankment; a drain that is located at or near the center of the generally circular pond bottom; and an injection port within the embankment; (ii) injecting water into the pond via the injection port to thereby provide a volume of water within the pond, where said injecting causes the volume of water to circulate within the pond; and (iii) draining a portion of the volume of water from the drain.

[0007] Yet other embodiments of the present invention provide a method of treating water, the method comprising (i) providing a pond including an embankment having a circular dimension; a circular pond bottom within the circular embankment; a drain that is located at or near the center of the circular pond bottom; and an injection port within the embankment; (i) injecting water into the pond via the injection port to thereby provide a volume of water within the pond, where said injecting causes the volume of water to circulate within the pond; (iii) draining a portion of the volume of water from the drain; and (iv) treating the portion of the volume of water from the drain.

[0008] Still yet other embodiments of the present invention provide a method of providing water to an oilfield, the method comprising (i) collecting water from one or more sources of water; (ii) introducing the water to a pond, where the pond has an embankment having a circular dimension and drain centrally located to the circular dimension; (iii) circulating the water within the pond; (iv) removing at least a portion of the water from the drain; and (v) routing at least a portion of the water removed from the drain to an oilfield. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Fig. 1 is a perspective view of a water-storage pond system according to embodiments of the present invention.

[0010] Fig. 2 is a perspective view of a water-storage pond assembly according to embodiments of the present invention.

[0011] Fig. 3 is a top plan view of a water-storage pond system according to embodiments of the present invention.

[0012] Fig. 4 is a top plan view of water-storage pond system showing a conduit network according to embodiments of the present invention.

[0013] Fig.5 is a cross-sectional view of a portion of a water-storage pond according to embodiments of the present invention.

[0014] Fig. 6 is a cross-sectional view of a portion of a water-storage pond showing a radial trench according to embodiments of the present invention.

[0015] Fig. 7 is a cross-sectional view of a primary undermount drain assembly according to embodiments of the present invention.

[0016] Fig. 8 is a cross-sectional view of a secondary undermount drain assembly according to embodiments of the present invention.

[0017] Fig. 9 is a cross-sectional view of a portion of a primary and secondary containment assembly according to embodiments of the present invention. DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

[0018] Embodiments of the invention are based, at least in part, on the discovery of water-storage ponds, as well as systems that include water-storage ponds, that are adaptedto store and treat large volumes of water. In one or more embodiments, the water-storage ponds and systems are adapted to inhibit bacterial growth by circulating the water within the ponds. In one or more embodiments, the ponds have a substantially circular perimeter and include water inlets adapted to promote water circulation within the water-storage ponds. The water-storage ponds also include a centrally located drain. In one or more embodiments, the drain and water inlets are in fluid communication with a fluid loop that allows for rolling of the water within the ponds; i.e. water can be displaced from the bottom of the pond and reintroduced into the pond at a higher elevation within the volume of the pond. The loop can also be in fluid communication with a water treatment process, and therefore the system allows for the circulation, rolling, and treatment of the water. Where the system includes two or more ponds, the ponds can be placed in fluid communication with each other and / or an intervening water treatment system. The ponds and / or systems of embodiments of the present invention therefore provide, among other benefits, the ability to store large volumes of water that can be used in downstream operations such as oil field operations. FRAC POND

[0019] An exemplary water-storage pond, which may also be referred to as frac pond, storage pond, or simply a pond, can be described with reference to Figs. 1-6. It will be appreciated that Figs. 1-4 show a plurality of ponds, but reference can be made to these figures to describe aspects of the individual ponds. In one or more embodiments, each of the ponds within a plurality of ponds have the same or similar features and / or elements.

[0020] As generally shown, pond 101 has a generally circular perimeter with a generally bowl-shaped and / or frustoconical overall dimension. With reference to Figs.5 and 6, pond 101 includes a dry-side slope 111, a crest 112, a wet-side slope 121, and a bottom 151. The skilled person will appreciate that dry-side slope 111, crest 112, wet-side slope 121, and bottom 151, are generally constructed by manipulating the earth (e.g. excavating) to form the structure, which is generally a circular embankment that can retain water. Pond 101 may also include a sump 141, a drain 171, and a drain pipe 301. As shown, crest 112 generally forms the outer circumference of pond 101, and sump 141, drain 171, and drain pipe 301 are generally centrally located relative to crest 112. In one or more embodiments,sump 141 defines the lowest point of pond 101. Pond 101 also includes protective membrane 119, which may also be referred to as geomembrane 119, which will be described in greater detail below.

[0021] In one or more embodiments, the overall capacity of a frac pond according to the present invention can vary by selecting an overall diameter, height, and embankment design. In one or more embodiments, the capacity of a frac pond according to the present invention may be expressed by the number of barrels of fluid (bbl) that can be stored in the frac pond. In one or more embodiments, a frac pond according to the present invention (i.e. a single pond) may have a capacity of greater than 100,000 bbl, in other embodiments greater than 200,000 bbl, in other embodiments greater than 300,000 bbl, in other embodiments greater than 400,000, in other embodiments greater than 500,000, in other embodiments greater than 600,000 bbl, and in other embodiments greater than 700,000 bbl.

[0022] In one or more embodiments, a height of crest 112, relative to sump 141, is greater than 5 ft, in other embodiments greater than 10 ft, in other embodiments greater than 15 ft, and in other embodiments greater than 20 ft. In these or other embodiments, the height of crest 112, relative to sump 141 is less than 50 ft, in other embodiments less than 40 ft, in other embodiments less than 30 ft, and in other embodiments less than 25 ft.

[0023] Wet-side slope 121 has a slope that generally runs from crest 112 to an inner circumferential location 129 where wet-side slope 121 meets bottom 151. In one or more embodiments, the wet-side slope has a slope that is designed in accordance with Non- Commercial Fluid Recycling (NCFR) pit requirements. As the skilled person appreciates, these requirements include maximums related to the ability of a person to walk out of a pit. In one or more embodiments, the slopes of wet-side slope 121 may be less than 3.5:1, in other embodiments less than 3.3:1, in other embodiments less than 3:1, and in other embodiments less than 2.7:1.

[0024] In one or more embodiments, bottom 151 includes a slope that runs from the location where bottom 151 meets wet-side slope to the location where bottom 151 meets sump 141. The slope of bottom 151 facilitates flow of water towards sump 141. In one or more embodiments, the slope of bottom 151 is less than the slope of wet-side slope 121.

[0025] In one or more embodiments, and with reference to Figs.2 and 6, frac pond 101 includes a plurality of sediment trenches 161, which may also be referred to as trenches 161, that generally extend radially from sump 141 to inner circumferential portion 129. Trenches 161 are adapted to allow solids and other contaminants to settle or otherwise be trapped in the trenches during circulation of water within the pond. Further, without wishing to be bound by theory, it is believed that the presence of the sediment trenches prevents a vortex from forming during a rolling operation because the plurality of sediment trenches operates as baffles. It is also believed that sediment trenches 161 advantageously prevent or reduce solids and other contaminants from entering undermount drain 171 when water is removed from frac pond 101, as will be described in greater detail below.

[0026] As noted above, pond 101 includes sump 141, which has a depth lower than bottom 151. In one or more embodiments, the depth of trenches 161 and sump 141 may be equivalent or generally equivalent at the location where trench 161 and sump 141 meet. In other embodiments, the depth of sump 141 is greater than the depth of trench 161 at the location where trench 161 meets sump 141.

[0027] In one or more embodiments, the ponds of the present invention also include one or more water injection ports, which may also be referred to as inlet ports, that allow water to be injected or otherwise released into the pond. With reference to Figs. 4 and 6, pond 101 includes water injection ports 211, 221, and 231. Each of these ports are in fluid communication, respectively, with conduits 311, 321, and 331. In one or more embodiments, injection ports 211, 221, and 231 may simply include an open conduit that penetrates through geomembrane 119 at locations within wet-side slope 121. Each of the ports may be oriented, relative to the pond, and / or adapted to induce circulation of the water within and being introduced into the pond. For example, the injections ports may be disposed at an angle relative to the wall of the pond. Although not shown, injection ports 211, 221, and 231 and / or conduits 311, 321, and 331 are appropriately sealed to geomembrane 119 to prevent water from leaving pond 101 when the water level is above the injection ports. As also shown in Figs. 5 and 6, each of the respective water injection ports 211, 221, and 231 are located at different height along wet-side slope 121 relative to sump 141. Relative to the circumference of pond 101, injection ports 211, 221, and 231 may be relatively aligned fromtop to bottom as shown in Figs. 5 and 6; i.e. they may generally be located along a line extending from crest 112 to inner circumferential portion 129. In other embodiments, injection ports 211, 221, and 231 can be located at different locations, relative to each other, along the circumference of pond 121. It will be appreciated that while Figs. 5 and 6 show pond 101 as including three injection ports, pond 101 may include one injection port or a plurality of injection ports including a number greater than three injection ports.

[0028] As discussed above, pond 101 includes geomembrane 119. In one or more embodiments, the geomembrane includes a dual membrane system. While the specifics of the geomembranes and / or geomembrane assembly will be described in greater detail below, it will be appreciated that the geomembranes be held in place for proper use. For example, it may be useful to prevent wind uplift forces from damaging or otherwise affecting the geomembrane when the ponds do not contain sufficient fluid to otherwise resist these forces. This may be accomplished by using ballasting. For example, one or more ballasts, such as ballast bags (e.g. US flood bags), that are strategically placed within the ponds. These ballast bags may be filled with fluid or other material of a sufficiently greater density than the fluids to be handled, treated, and stored within the ponds of the present invention (e.g. the fluids have a density greater than brine water). With reference to Figs. 5 and 6, ballast 131 is position at or near the inner circumferential portion 129 of pond 101 and may circumscribe the entirety of inner circumferential portion 129. Although not shown, bottom 151 of pond 101 may be adapted to receive ballast 131. For example, a trench or other form of saddle may be excavated into or near the inner circumferential portion. The skilled person understands that this can be accomplished by, for example, keyholing the wet-side slopes to receive the ballast bags. The upper portion of the geomembrane, which is the end at or near the crest (e.g. crest 112) can be keyed into the embankment. As generally shown in Figs.5 and 6, a portion of crest 112 can be removed, the membrane positioned into the cleared area, and then earth or other material (such as slag), can be placed on top of a portion of the membrane to key in the membrane and prevent it from deleteriously moving. Likewise, although not shown, it may be useful to provide a membrane or other similar-type barrier on the dry-side slope to prevent erosion thereof.POND ASSEMBLY

[0029] In one or more embodiments, the present invention provides a pond assembly, which may also be referred to as a pond network or pond array. A pond assembly includes two or more ponds that share one or more structural features. In these or other embodiments, a pond assembly includes two or more ponds that are in fluid communication with each other through one or more conduits.

[0030] For example, Fig.1 shows a pond assembly 10 including four ponds 101, 102, 103, and 104. As will be described in greater detail below, these four ponds form an assembly because they are fluid communication with each other. Within this assembly, there are two sub-assemblies 11, 12, which may also be referred to as first dual pond 11 and second dual pond 12. First dual pond 11 includes pond 101 and pond 102, which share a common crest at location 107. Second dual pond 12 includes pond 103 and pond 104, which share a common crest at location 108. Stated differently, pond 101 and pond 102 are located relative to each other such that respective locations on their outer circumference are proximate to or adjacent to each other and they therefore advantageously share a structural feature (e.g. portions of their respective embankments are shared). It will be appreciated that this feature advantageously provides a reduction in the amount of construction required due to the shared structural feature.

[0031] As described above, pond 101 includes dry-side slope 111, crest 112, wet-side slope 121, and bottom 151. Similarly, and with reference to Fig.3, pond 102 includes dry- side slope 111', crest 112', wet-side slope 122, and bottom 152. Frac pond 102 also includes sump 142, a drain (not shown), and a drainpipe (not shown). In other words, it will be appreciated that pond 101 and pond 102 may generally be constructed in a similar or corresponding manner and therefore any aspects or elements of pond 101 will, according to one or more embodiments, be present within pond 102. Similarly, in one or more embodiments, the ponds of dual pond 12 may likewise be constructed in a similar manner and include similar or corresponding aspects or elements to pond 101. For example, pond 103 and pond 104 of second dual pond 12, each respectively include dry-side slopes 113, 113', crests 114, 114', wet-side slopes 123, 124, and bottoms 153, 154. Ponds 103, 104 also include, respectively, sumps 143, 144, drains (not shown), and drainpipes (not shown). Eachpond also includes geomembranes, not shown, at least partially held in place by ballasts 131, 132, 133, 134, respectively, positioned with respective inner circumferential locations. Further, each pond also includes a plurality of sediment trenches 161, 162, 163, 164, respectively. FRAC POND SYSTEM

[0032] In one or more embodiments, a frac pond system, which may also be referred to as a pond system or water system, includes one or more frac ponds as described above (e.g. a pond assembly) and a fluid transfer subsystem, which may work in conjunction with a pump or plurality of pumps. The system may also include a water treatment subsystem. It will be appreciated that the pond or ponds, the fluid transfer subsystem, and the water treatment subsystem may advantageously be in fluid communication with each other.

[0033] In one or more embodiments, the fluid transfer subsystem, which may also be referred to as a transfer network or transfer unit, is adapted to transfer fluids from the drain of one pond to the injection port(s) of the same pond, or transfer fluid from a drain of a first pond to the injection port(s) of second pond. In one or more embodiments, the fluid transfer system is also adapted to transfer fluid from the drain of a pond to a downstream use, or from an upstream source to the injection port(s) of a pond or ponds.

[0034] In one or more embodiments, the fluid transfer subsystem includes one or more conduits that are fluid communication with the inlets into the ponds (i.e. injection ports), the outlets out of the ponds (i.e. drain), as well as conduits that communicate with sources and / or destinations outside of the system. In one or more embodiments, the fluid transfer subsystem is in fluid communication with one or more pumps that facilitate fluid flow through the transfer network. In these or other embodiments, the fluid transfer subsystem is in fluid communication with one or more manifolds and / or switches to facilitate transfer of the fluids between the ponds. It will be appreciated that by co-locating the conduits associated with the inlets into the ponds, the outlets out of the ponds, as well as conduits that communicate with sources outside of the system provide enhanced simplicity in configuring the systems of the present invention. For example, the transfer subsystem can serve as a central switching zone where fluids can be redirected.

[0035] In one or more embodiments, the fluid transfer subsystem is included within a water management hub, which may also be referred to as a central hub or central zone. Where the system includes a single pond, the fluid transfer subsystem can be located adjacent to the pond. In those embodiments that include a plurality of ponds, the water management hub may be centrally located relative to the plurality of ponds of the pond assembly. It will be appreciated that positioning the water management hub in this manner will facilitate construction and management of the system. For example, this may facilitate construction and management of the system where all conduits, including the undermount drainpipes and inlet pipes, are buried in trenches excavated during construction of plurality of ponds. In one or more embodiments, the water management hub, may be located below the level of the drain or drains of the pond or pond array. In this way, the network of conduits, which will be described in greater detail below, are easily visible. Also, any pumps located at the water management hub will be below the level of the drainpipes and will therefore maintain a net positive suction head (i.e. they will maintain proper priming).

[0036] In one or more embodiments, the water management hub includes a water treatment subsystem. The water treatment subsystem is in fluid communication with the fluid transfer subsystem. A variety of water treatment devices or units can be included within the water treatment subsystem. The skilled person can readily select desirable units based upon the desired treatments, which may include, but are not limited to, dissolved air flotation (DAF), oxidation processes (air treatment, chlorination, ozonation, and potassium permanganate treatment) , phase separation processes, chemical treatment processes (e.g. mineral addition such as calcium, magnesium, and iron), H2S removal processes, use of air pressure vessels, and biological treatment (e.g. sulfate-reducing bacteria (SRB)).

[0037] An exemplary pond system including a water management hub can be described with reference to Fig. 4, which shows pond system 100 including first dual pond 11 and second dual pond 12, which as noted above form an array. The dual ponds are in fluid communication with each other (and the respective ponds within the dual arrangement) via a network of conduits, which will be described in greater detail below, that are routed through a water management hub 300, which may also be referred to as central zone 300.More specifically, the network of conduits is routed through a fluid transfer subsystem 310 that is located within a water management hub 300 (also referred to as a central zone 300).

[0038] With respect to the network of conduits, the network includes system-inlet conduit 320 and system-outlet conduit 330, which are in fluid communication with fluid transfer subsystem 310. System-inlet conduit 320 may be in fluid communication with an upstream source of water including, but not limited to, a pre-treatment process, a production stream separator, or a water-storage device. Examples of pre-treatment processes may include comingling water, dissolved air flotation (DAF), oxidation processes, phase separation processes, chemical treatment processes (e.g. mineral addition such as calcium, magnesium, and iron), H2S removal processes, use of air pressure vessels, and biological treatment (e.g. sulfate-reducing bacteria (SRB)). System-outlet conduit 330 may be in fluid communication with downstream uses for the water including, but not limited to, use within oil fields, sub-surface storage, and disposal. It will also be appreciated that while this specific embodiment is shown in Fig.4, other arrangements are possible including direct feed into any of the respective ponds from an outside source, as well as a direct outlet to an external destination from one or more of the ponds.

[0039] According to the embodiments shown in Fig.4, since system-inlet conduit 320 and system-outlet conduit 330 are in fluid communication the fluid transfer subsystem 310, the direction of the fluids can be manipulated (e.g. directed to or from one more of ponds 101, 102, 103, 104). The skilled person can readily select appropriate conduit and associated fittings to accomplish the desired transfer of fluids between conduits within central zone 310. Exemplary fittings include splitters, switching devices, and valves that can allow for a variety of manipulations to the direction of the various stream include, but not limited to, the recirculation of water out of and back into the same pond, removal to a different pond, transfer to a different treatment process, or transfer to recycling and storage.

[0040] As indicated above, pond system 100 may include a pump, including a plurality of pumps, which may also be referred to as pumping devices, to facilitate transfer into and out of the system (i.e. via conduits 320, 330) and / or to and from the various ponds; e.g. from a drain of a pond to one or more injection ports of a pond or ponds (i.e. transfer within a pond or between ponds). Pumps that are useful for the transfer of types of water managedby the present invention are known to those skilled in the art and can be employed in the practice of this invention. In one or more embodiments, the pumps (not shown) may be located within central zone 300. In other embodiments, the pumps are located outside of central zone 300. In one or more embodiments, water management hub 300 is below the level of the pond sump, or in other embodiments below the pond drain, and the pumps are located within water management hub 300, which advantageously provides for a net positive suction head on the pump. In other embodiments, vertical turbine pumps are employed, which allows water management hub to be above the surface of the drains and / or sump.

[0041] As indicated above, water management hub may include a water treatment subsystem, which may also be referred to as a water treatment unit (not shown). In one or more embodiments, the water treatment unit may be positioned within a loop between the drain of one or more ponds and the injection ports of one or more ponds. For example, the treatment unit may be positioned so that fluid drained through the drain of a pond may be treated at the treatment unit before being reintroduced to the same pond via the injection port of the pond. Likewise, the treatment unit may be positioned so that fluid drained through the drain of a first pond may be treated at the treatment unit before being reintroduced to a second pond via injection port of the second pond.

[0042] Returning to the network of conduits, and with reference again to Fig. 4, first pond 101 includes undermount drain pipe 301, which may also be referred to as outlet conduit 301, which is in fluid communication with sump 141 (shown in Fig.3) via drain 171 (shown in Figs. 5 and 6). Outlet conduit 301 is in fluid communication with fluid transfer subsystem 301. Pond 101 also includes a plurality of inlet conduits that are in fluid communication with corresponding inlet ports at one end and fluid transfer subsystem 310 at the other end. For example, pond 101 of Fig.4 includes first inlet conduit 311, second inlet conduit 321, and third inlet conduit 331. It will be appreciated that each conduit (e.g.311, 321, and 331) are in fluid communication with respective inlet ports positioned with pond 101 where water can be discharged into the pond as described with reference to Figs.5 and 6. As also shown, conduits 311, 321, and 331 are in fluid communication with fluid transfersubsystem 310, which may advantageously be in fluid communication with other conduit of the network.

[0043] In a similar fashion, second pond 102 includes undermount drainpipe 302, which may also be referred to as outlet conduit 301, first inlet pipe 312, second inlet pipe 322, and third inlet pipe 332. Third pond 103 includes undermount drain pipe 303, first inlet pipe 313, second inlet pipe 323, and third inlet pipe 333. Fourth pond 104 includes undermount drain pipe 304, first inlet pipe 314, second inlet pipe 324, and third inlet pipe 334. These inlet and outlet conduits may be configured and / or designed to accomplish the same goals provided for with respect to the conduits of pond 101. For example, the outlet conduit connects the sumps of the respective ponds to the fluid transfer unit, and the inlet conduits connect the fluid transfer unit to respective ports for discharging water into the respective ponds.

[0044] In one or more embodiments, the diameters of the inlet conduit and the outlet conduit are 24 inches or greater. In one or more embodiments, the inlet pipes and the undermount drain pipes may comprise pipe materials conventional in oil and gas operations. In these or other embodiments, the inlet pipes and the undermount drain pipes may comprise high-density polyethylene (HDPE).

[0045] In one or more embodiments, the inlet pipes (e.g. inlet pipes 311, 321, and 331) have their associated outlets (i.e. the injection ports through which water discharged into the ponds) positioned in wet-side slope 121. As indicated above, this requires that the conduit and / or injection port penetrate through the geomembrane, which then requires that an appropriate seal is made between the injection port (and / or associated conduit) and the geomembrane. For example, the seal can be formed by employing one or more boots. In one or more embodiments, the conduit is adapted to compensate for forces that may otherwise disrupt the seal between the conduit and the geomembrane. For example, the conduit can be fashioned to include one or more bends, such as Z-bends, to alleviate vibration forces. Also, the conduit can be positioned on pillow blocks that absorb vibrational forces.

[0046] Additionally, the injection ports are positioned in the wet-side slope (e.g. wet- side slope 121) according to the desired operating conditions of the pond (e.g. pond 101). For example, where a frac pond includes three injection ports, each port may be positionedat a different height relative to the sump within the wet-side wall. For example, a first injection port may be positioned at a lower point on the wet-side slope, a second injection port may be positioned above the first injection port relative the sump, and the third injection port may be positioned above the second injection port relative to the sump. Each injection port may also be positioned at different angles relative to the surface of wet-side slope 121. The angle, height on wet-side slope, and positioning around the circumference of a given pond allow for the overall circulation characteristics of the ponds to be tuned to achieve effective circulation rates. Further, by locating the injection ports at differing heights, the filling operation can be manipulated such that flow of production water from the inlet ports does not damage the geomembrane liner since high flow rates are possible through those inlets that are below the water level within the pond.

[0047] With respect to the undermount drain, it will be appreciated that since the drain is located at the bottom of a given frac pond, the pressure head is created by water present in the pond, which advantageously creates a net positive suction head that can allow the water to be transferred to downstream pumping devices. In one or more embodiments, pumping equipment therefore does not need to be co-located with the pond or used to draw water from the pond. Additionally, since the force associated with the head of pressure can transfer water to downstream pumping devices, the need for priming pumping equipment can be eliminated or otherwise facilitated. Additionally, one or more undermount drain may be included in the drain sump of frac ponds according to the present invention. DRAIN ASSEMBLY

[0048] As noted above the ponds according to embodiments of the invention include a drain. The drain may be included within a drain assembly, which may also be referred to a drain system. The systems of the present invention may also include a lead detection and remediation system, which will be described in greater detail below. That said, the leak detection and remediation system includes a drain. Therefore, the drain that is employed to drain the pond during normal operations will be referred to as the primary drain, and the associated system may be referred to as the primary drain assembly or system. The drain and drain assembly associated with the leak detection and remediation system may be referred to as the secondary drain or secondary drain assembly or system.

[0049] An exemplary drain assembly can be described with reference to Figs.7 and 8. As specifically shown in Fig.7, primary drain 171 includes an inlet body 901 that is in fluid communication with outlet body 902. Bodies 901, 902 are generally tubulars with opening for the flow of fluids. The opening of inlet body 901 may include a filtering device 903, such a mesh top, as shown, that is adapted to prevent large solid objects from entering into drain 171.

[0050] Disposed between inlet body 901 and outlet body 902 is a drain trap 905 and a geomembrane-attachment assembly 920. As shown, outlet body 902 may be integrated with trap 905. Inlet body 901 and drain trap 905 may include integrated flanges (not shown) through which fasteners (e.g. bolts) may be used to secure inlet body 901 to drain trap 905 with geomembrane-attachment assembly 920 disposed there between. As shown, the integrated flange is internal to the outer diameter of outlet body 902 and drain trap 905.

[0051] As also shown in Fig.9, geomembrane-attachment assembly 920 includes four free-floating flanges 910, 912, 914, and 916. For example, these free-floating flanges may include metal rings adapted to receive fasteners, such as bolts, that are employed to secure inlet body 901 to drain trap 905 to thereby secure them in place relative to the other components of assembly 920. The free-floating flanges are positioned relative to the two geomembranes 931 and 932. As will be appreciated, geomembrane 931 is the upper of two membranes that is in contact with fluid within a pond. Geomembrane 932 is the lower of two membranes and serves as a backup or secondary membrane in the event the upper membrane, or a seal within the upper membrane, fails. It will also be appreciated that membranes 931, 932 include an opening that is configured to allow fluid to pass through drain 171 when the geomembrane is attached to geomembrane-attachment assembly 920. It will also be appreciated that the opening within the geomembranes will be configured to allow geomembranes to be secured to assembly 920 in a watertight fashion where fluids cannot leak or otherwise penetrate through the attachment. With reference again to Fig.7, flange 910 is disposed above membrane 931, and flange 912 is disposed below membrane 931. Flange 914 is disposed above membrane 932, and flange 916 is disposed below membrane 932. As generally shown, gaskets are placed between each layer of assembly 920. For example, gaskets are disposed between body 901 and flange 910, between flange 910and membrane 931, between membrane 931 and flange 912, between flange 912 and flange 914, between flange 914 and membrane 932, between membrane 932 and flange 916, and between flange 916 and trap 905. Additionally, in one or more embodiments, a sealant can be placed in between each contact point (e.g. between each flange and each gasket). During assembly, bolts and other mechanical fastenings, along with the sealants, are used to compress each component together to create the leak-free seal. In these and other embodiments, sealants are applied in between every layer of gasket, steel ring, and geomembrane liner. The steel rings sandwich the gaskets and geomembrane liners between flanges of the undermount drain assembly.

[0052] With reference to Fig. 9, a secondary undermount drain assembly 1000 is shown. This drain assembly may be similarly constructed to primary undermount drain assembly 171. It will be appreciated that the secondary undermount drain 1000 may be a redundant drain, located beneath primary geomembrane liner 931, and therefore it need only be sealed to secondary geomembrane liner 932. Accordingly, the combination of steel rings 910 and gaskets 920 are used to form a leak-free connection to secondary geomembrane liner 932. As shown, this includes, from top to bottom, steel ring 910, an optional gasket attached to secondary geomembrane liner 932, steel ring 910, and an optional gasket. As with primary undermount drain assembly 171, during assembly, bolts and other mechanical fastenings, along with sealants and gaskets, are used to compress each component together to create the leak-free seal. GEOMEMBRANES

[0053] As indicated above, the ponds of the present invention include a geomembrane; i.e. a geomembrane lines at least a portion of the pond in a manner suitable to retain fluid within the pond and prevent or inhibit the transfer of fluid from within the pond to the ground below the pond (i.e. below the geomembrane). Practice of the present invention is not limited by the selection of any particular geomembrane. The skilled person will be able to readily select an appropriate geomembrane for use in the present invention. Exemplary geomembranes include rubber or thermoplastic membrane system. Useful plastic membranes include HDPE membranes.

[0054] The skilled person understands that multiple membrane panels are typically required to line the ponds of this invention. These various membrane panels can be seamed to adjacent panels in order to create a leak-free, continuous barrier. The plurality of membrane panels may be referred to as a membrane system. Further, rub sheets may be added to the surface of geomembrane liners employed for use in the present invention. Rub sheets improve the ability for operators to move around on the surface of the liner.

[0055] As discussed above, the geomembrane liners used in the present invention may be anchored using ballast and / or by burying (keying) the edges in excavated earth. LEAK DETECTION AND REMEDIATION SUBSYSTEM

[0056] In one or more embodiments, the ponds of the present invention include a leak detection system. In these or other embodiments, the ponds include a remediation system that is adapted to remove fluid that leaks through the primary geomembrane and is captured in a secondary sump. In one or more embodiments, the leak detection sub-system and the remediation sub-system share one or more features.

[0057] An exemplary leak detection and remediation system can be described with reference to Fig.9, which shows drain sump 141, upper geomembrane liner 931, which may be referred to as primary geomembrane 931, and lower geomembrane 932, which may be referred to as secondary geomembrane line 932, both of which are disposed within sump 141 on ground 930. Consistent with the foregoing description, it will be appreciated that membranes 931, 932 extend across the entirety of the pond in which the sump is located.

[0058] Primary drain assembly 900, which may be referred to as first or upper drain assembly 900, and secondary drain assembly 1000, which may be referred to as second or lower drain assembly 1000, are located in sump 141. Primary drain assembly 900 is in fluid communication with conduit 902, and secondary drain assembly 1000 is in fluid communication with conduit 1002. As generally shown, and as understood with reference to Figs. 7 and 8, primary and secondary geomembranes 931 and 932 are sealed against primary drain assembly 900. Secondary geomembrane 932 is sealed against secondary drain assembly 1000. As a result, secondary drain assembly 1000 is located underneath primary geomembrane 931.

[0059] In one or more embodiments, a geonet 933 is positioned between primary geomembrane 931 and secondary geomembrane 932. As the skilled person appreciates, a geonet is adapted to facilitate flow of liquid trapped between first and second membranes 931, 932 to sump 141. Examples of useful geonets, which may also be referred to as geo- composites, include those sold under the name HydraNetTMfrom Layfield Group.

[0060] In one or more embodiments, conduit (not shown) having a smaller diameter than conduit 1002 may be disposed within conduit 1002 to provide fluid communication between secondary drain assembly 1000 and an accessible point downstream of drain 1000. This configuration is adapted to allow for monitoring of fluids within drain assembly 1000, which as the skilled person understands would be indicative of leaks within primary membrane 931.

[0061] In one or more embodiments, secondary drain assembly 1000 can be configured in a similar fashion to primary drain assembly 900 (or 171 with reference to Fig.7), except that geomembrane-attachment assembly 908 is adapted for attachment to a single membrane (i.e. membrane 932). An exemplary configuration can be described with reference to Fig.8. METHODS OF OPERATION

[0062] The ponds systems described above can be operated in a variety of ways to store and treat large volumes of water. As a result, the methods of the present invention provide for, among other things, reclaiming, reusing, and recycling water.

[0063] To begin with, the fluids introduced to the pond system, and optionally the fluid exiting the pond system (e.g. after treatment and / or storage) are water-based fluids. For purposes of this specification, water-based fluids, which may be referred to simply as water or fluids unless otherwise specified, include water with dissolved and / or suspended solids, and therefore can also be referred to as brine or frac water. In one or more embodiments, the water-based fluids, for example upon introduction to the systems of this invention, can have a total solids content (i.e. both suspended and dissolved solids) of greater than 100,000, in other embodiments greater than 200,000, and in other embodiments greater than 230,000 parts per million.

[0064] The water-based fluids introduced to the systems of this invention can be obtained from a variety of sources including, but not limited to, oil field operations (e.g. produced water), water disposal facilities, and power generation facilities.

[0065] In one or more embodiments, prior to being introduced to the system of this invention, the water may be pre-treated. For example, the water can be physically treated by, for example, filtration, clarification, settling, or cyclone treatment. In addition to, or in the alternative, the water can be chemically treated. For example, the water can be chlorinated, oxygenated, or acidified. Other chemical pre-treatments may include hydrogen sulfide control, the addition of biocides, antifoamers / defoamers and demulsifiers, surfactants, and water clarifiers.

[0066] In one or more embodiments, the water introduced to the systems of the present invention can be analyzed prior to being introduced to the systems. In addition to, or in the alternative, the water can be analyzed upon exit from the systems of this invention. In addition to, or in the alternative, water can be analyzed within the ponds and / or it can be analyzed when transferred from drain to injection port (e.g. within the transfer unit).

[0067] As indicated above, the systems of the present invention include a water transfer subsystem (also referred to as a transfer unit). Accordingly, in one or more embodiments, water introduced to the system is first introduced to a transfer subsystem. The water transfer subsystem may include or work in conjunction with one or more pumping devices that can pump the water to one or more ponds. In one or more embodiments, the water transfer subsystem may transfer water to a treatment subsystem (e.g. chemically or physically treating fluids). Alternatively, chemicals may be added to fluids within the transfer unit via an injection quill. In addition to, or in lieu of, the transfer unit may be in fluid communication with treatment devices. In one or more embodiments, water treated within the transfer subsystem or at a treatment unit in communication with the transfer subsystem can advantageously be treated in a more controlled or precise manner than bulk treatment within the ponds.

[0068] According to aspects of the invention, either through a transfer unit or via separate pumping systems, fluid is introduced to one or more ponds. As described above, the fluid is injected into one or more ponds through one or more injection ports. In one or moreembodiments, the nature of the injection (e.g. the orientation of the inlet pipe) and the manner of delivering the fluid to the inlet pipe (i.e. the pressure and flow rate), induces a circulatory current within the pond (also referred to as spinning the pond). In one or more embodiments, substantially all of the fluid within the pond is constantly moving with substantially no dead zones (i.e. areas of reduced or no circulatory flow) during the spinning operation.

[0069] According to embodiments of the present invention, injecting fluid into one or more ponds includes an initial filling stage where the water level within the pond is below one or more of the injection ports. During this filling stage, it may be advantageous to give consideration to the location of the injection port through which the fluid is injected into the pond relative to the flow rate and the pressure of the injected fluid since the geomembranes and / or the conduit network associated with the injection ports and / or the seal between the injection ports and the membrane may be damaged by the fluid or mechanical forces caused by fluid flow as it is injected into the pond. Once the depth of the fluid within the pond reaches the depth of the inlet, flow rates may be increased since the risk of damage is decreased by the presence of water at the injection port.

[0070] Once the pond is at a sufficient depth of fluid, additional fluid may be injected through one or more injection ports at a flow rate (i.e. velocity) sufficient to induce a circulatory flow, which may also be referred to as circulatory current, within the pond. Without wishing to be bound by theory, it is believed that while a circular flow is occurring, suspended solids are subjected to centrifugal force and are thus moved outward from the middle of the pond. This advantageously reduces the amount of solids that settle near the drain of the pond. As used herein, circulatory flow refers to flow around the middle of the pond and / or around the sump. The circulatory flow may also be characterized by an edge velocity of the fluid, which is the circular velocity of the fluid at a point on the outer circumference of the pond. The determination of a sufficient edge velocity for forcing solids away from the drain is based at least in part on the dimensions of the frac pond. For example, as the length of the radius increases, the velocity at the edge of the radius must increase to maintain the same overall revolutions per unit time. Accordingly, a sufficient edge velocity may be defined as the velocity measured at the outer edge of the frac pond wherein solids are observed to settle away from the drain sump.

[0071] While circular flow is induced by water injected from injection ports below the surface of the fluid within the pond, the surface of the fluid may be free from deleterious surface agitation. As discussed above, the pond may include sediment trenches or other features such as baffles, which also may reduce the likelihood of surface agitation. In one or more embodiments, circular flow is maintained at a velocity sufficiently high enough to induce and maintain spinning, but low enough to inhibit deleterious surface agitation.

[0072] The circular flow may be maintained by continuing to inject fluid via the one or more injection ports. At the same time, fluid may be simultaneously removed from the pond via the drain. By manipulating the volume of water added to and removed from the pond, an equilibrium depth may be achieved. In one or more embodiments, as spinning takes place within the pond, the depth of the fluid is generally maintained at this equilibrium depth so that water continues to circulate within the pond without over-topping the crest.

[0073] Various storage and treatment methods can be described with reference to Fig. 4. In one or more embodiments, fluid is injected, for example, from transfer unit 310, into pond 101 via respective injection ports to create a circular flow. At the same time, fluid is drained from pond 101 at rate to optionally create a substantially constant volume of fluid within pond 101. The fluid drained from pond 101 via drain 171 (Fig.5) is routed to transfer unit 310 and pumped back into pond 101 via the injection ports. It will be appreciated that by operating the system in this manner, the fluid within the pond it rolled (i.e. turned over) by transferring the fluid at or near the bottom (i.e. from the sump) to a location higher within the pond. This technique may be referred to as rolling the pond. In one or more embodiments, the fluid within the pond simultaneously undergoes spinning and rolling.

[0074] In other embodiments, the pond is rolled as described above, except when the water is returned to transfer unit 310, the water is treated (e.g. chemically or physically) and then returned to pond 101 via injection ports 211, 221, and 231.

[0075] In other embodiments, the spinning and rolling operation can take place between multiple ponds. For example, and with reference again to Fig.4, fluid, which can be received from an outside source via conduit 320 is transferred, by way of transfer unit 310 and conduits 311, 321, and 331, to pond 101 where spinning takes place, as described above. In one or more embodiments, during spinning, fluid is drained through drain 171 and routedback to fluid transfer subsystem 310 via conduit 301. From transfer unit 310, the fluid is transferred to a second pond (e.g. pond 102), where it is circulated, as described above. For example, fluid is transferred from transfer unit 310 to pond 102 via conduits 312, 322, 332, and spinning takes place. Water is drained from a drain (not shown) within the second pond and routed back to the transfer subsystem via conduit 302 where it can be routed back to the second pond or to one of the other ponds within the array such as the third pond. It will be appreciated that a single transfer unit can be employed or multiple transfer units can be employed to accomplish the method.

[0076] In other embodiments, first and second ponds 101, 102 are rolled as described above, except when the water is returned to transfer unit 310 from first pond 101, the water is treated (e.g. chemically or physically) and then routed to second pond 102.

[0077] In yet other embodiments, water is first introduced to pond 102, and where spinning takes place (as described above). Water is removed via the centrally-located drain and transferred, via one or more transfer units, to pond 101. In between transfer from pond 102 to pond 101, the water may be treated. Within pond 101, spinning is continued, and water is drained from pond 101 via then centrally-located drain. Water from pond 101 can then be transferred to pond 103 or pond 104 depending on the conditions of the water and the desired characteristics of the water that is ultimately send to downstream uses. In one or more embodiments, water can be recirculated back into pond 101. In other words, rather than transfer water to ponds 103 or 104, the water can be returned to pond 101 for a rolling operation. Likewise, water can be recirculated between the transfer unit 310 and ponds 103 and / or 104 to perform a spinning and rolling operation within these ponds. It will be appreciated that water treatment can take place at any stage where the water is routed to transfer station 310.

[0078] Also, in one or more embodiments, treatment can occur within one or more of the ponds. For example, chemicals can be added to one or more of the ponds. It will also be appreciated that the stirring and rolling operation, either within a single pond, or between multiple ponds, provides adequate movement of the water, optional oxidation of the water, and minimization of dead zones, to thereby provide a method for storing large volumes of water with extended life prior to turning septic.

[0079] In one or more embodiments, fluid is injected into a pond at a rate of greater than 50, in other embodiments greater than 60, in other embodiments greater than 70, in other embodiments greater than 80, in other embodiments greater than 90, in other embodiments greater than 100, in other embodiments greater than 110, and in other embodiments greater than 120 bbl per minute. In these or other embodiments, fluid is removed from the pond at a rate of greater than 50, in other embodiments greater than 60, in other embodiments greater than 70, in other embodiments greater than 80, in other embodiments greater than 90, in other embodiments greater than 100, in other embodiments greater than 110, and in other embodiments greater than 120 bbl per minute.

[0080] In one or more embodiments, the overall water capacity being stored and / or handled in a pond system of the present invention is greater than 100,000 barrels (bbl), in other embodiments greater than 200,000 bbl, in other embodiments greater than 300,000 bbl, in other embodiments greater than 400,000 bbl, in other embodiments greater than 500,000 bbl, in other embodiments greater than 600,000 bbl, in other embodiments greater than 700,000 bbl, in other embodiments greater than 800,000 bbl, and in other embodiments greater than 1 million bbl. It will be appreciated that these amounts can include the amount of water stored and handled within a single pond for a one-pond system (e.g. one pond having a capacity of over 1 million barrels), or by multiple ponds in a system that includes a plurality of ponds (e.g. four ponds each with a capacity of 500,000 bbl).

[0081] In one or more embodiments, the processes of one or more embodiments of the present invention provide for the reduction in total solids of the source fluid. In one or more embodiments, by treating and / or storing (e.g. rolling and spinning) water within the systems of the present invention, the dissolved solids content is reduced by at least 50,000, in other embodiments by at least 75,000, in other embodiments by at least 100,000, in other embodiments by at least 125,000, in other embodiments by at least 150,000, in other embodiments by at least 175,000, and in other embodiments by at least 200,000 ppm.

[0082] In one or more embodiments, solids that have settled to the bottom of a pond may be removed. According to embodiments of the invention, water is at least partially drained from the pond (e.g. water can remain in the sump) to thereby expose sediment that can, for example, be trapped in the radially-disposed trenches (e.g. trenches 161). In one ormore embodiments, the sediment can be washed from these trenches. Washing away settled solids may include spraying water to form a slurry of water and settled solids that may be removed from the frac pond via the drain. Once drained, the slurry may be removed via the drain conduit and, for example, collected at or near the transfer subsystem (e.g. at or near the management hub) for removal from the system. For example, it may be sent to further processing and disposal.

[0083] In addition to rolling or spinning fluids in a frac pond, other processes may be employed to improve the storage, treatment, and handling of the fluid. This may include prevention of hydrogen sulfide (H2S) formation. Other exemplary processes may include employing the use of one or more floating skimmers and booms at the surface of the fluid within a pond, as well as the use of aerators, such as a bubbler or venturi aerator, located at the bottom of the frac pond. LEAK DETECTION AND REMEDIATION METHODS

[0084] Systems of the present invention, such as described with reference to Fig. 9, provide for leak detection and remediation methods. For example, and with reference to Fig. 9, nature and volume of liquid within secondary drain assembly 1000 can be monitored. This may take place, for example, by removing samples of fluid that accumulate within drain assembly 1000. It will be appreciated that the design of the system allows for fluids that penetrate through membrane system 931 to migrate to drain assembly 1000. Testing and analysis may indicate the source of the leak depending on the composition of the analyzed fluids. For example, the fluid within drain assembly 1000 may be ground water that has entered through a leak in secondary geomembrane 932. Alternatively, the nature of the water may indicate a leak in primary geomembrane 931 (e.g. based upon chloride content). Furthermore, in the event of a leak in one of the geomembranes, secondary drain assembly 1000, and the associated conduit system (e.g. conduit 1002, can be used to remove fluids from secondary drain assembly 1000. INDUSTRIAL APPLICABILITY

[0085] It should be appreciated that the systems and methods of the invention provide the ability to store large volumes of water. This water can be collected from a variety of sources and accumulated at the systems of the present invention. By operation of thesystems, the useful life of the water (i.e. before the water turns septic) can be advantageously extended. As a result, large volumes of water can be stored and remain ready for use in downstream operations, such as oil field operations, where large volumes of water are required.

[0086] It should also be appreciated that the systems and methods of the invention provide the ability to treat large volumes of water. This is advantageous for several reasons. For example, the ability to treat large volumes of water provides the ability to receive water from a variety of sources and tailor the water for desired downstream uses.

[0087] In one or more embodiments, the ponds and pond systems of the present invention are used in conjunction with oilfield operations. For example, water can be received, at least partially, from oilfield operations. This oilfield water can include frac water, as well as production water. The water can be pre-treated prior to being received by the water pond system of the present invention. In these or other embodiments, the ponds and pond systems provide water to oilfield operations. For example, the water can be provided as frac water. Accordingly, the present invention provides the ability to maintain, treat, and store large volumes of water that are readily available for large volume uses such as oilfield uses.

[0088] Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. This invention is not to be duly limited to the illustrative embodiments set forth herein.

Claims

CLAIMS What is claimed is:

1. A pond comprising: (i) an embankment having a generally circular outer dimension; (ii) a generally circular pond bottom within the embankment; (iii) a drain sump that is located at or near the center of the generally circular pond bottom, where the drain sump includes a drain outlet that allows fluid to be removed from the pond; and (iv) one or more fluid injection ports within the embankment.

2. The pond of claim 1, further comprising one or more sediment trenches in the generally circular pond bottom.

3. The pond of any of the preceding claims, wherein the one or more sediment trenches extend radially from the drain sump.

4. The pond of any of the preceding claims, wherein the one or more fluid injection ports are arranged such that fluid injected into the pond through the one or more injection ports induces a generally circular flow around the center of the generally circular pond bottom.

5. The pond of any of the preceding claims, where the drain outlet is in fluid communication with said one or more fluid injection ports.

6. The pond of any of the preceding claims, where said pond has a capacity of greater than 100,000 barrels of fluid.

7. The pond of any of the preceding claims, where the pond further includes a geomembrane layer adapted to retain fluid within the pond.

8. The pond of any of the preceding claims, where the first pond is in fluid communication with the second pond.

9. A pond array comprising: (i) a first pond including an embankment with a generally circular dimension, a generally circular pond bottom within the embankment, a drain sump that is located at or near the center of the generally circular pond bottom where the drain sump includes a drain outlet that allows fluid to be removed from the pond; and (ii) a second pond including an embankment with a generally circular dimension, a generally circular pond bottom within the embankment, a drain sump that is located at or near the center of the generally circular pond bottom where the drain sump includes a drain outlet that allows fluid to be removed from the pond, where a portion of the embankment of the first pond forms a portion of the embankment of the second pond.

10. The array of any of the preceding claims, where the first and second ponds form a first pond pair, and where the array further includes a second pair adjacent to the first pair.

11. A pond system comprising: (i) a pond including an embankment having a generally circular dimension, a generally circular pond bottom within the circular embankment, a drain sump that is located at or near the center of the circular pond bottom, an injection port within the embankment; (ii) a water transfer subsystem; and (iii) conduit that provides fluid communication between the water transfer subsystem and the drain sump and between the water transfer subsystem and the injection port.

12. The pond system of any of the preceding claims, where the water transfer subsystem includes a pump in fluid communication with the drain sump and the injection port.

13. The pond system of any of the preceding claims, where the water transfer subsystem is in fluid communication with a water treatment device.

14. The pond system of any of the preceding claims, further comprising a second a pond including an embankment having a generally circular dimension; a generally circular pond bottom within the generally circular embankment; a drain sump that is located at or near the center of the circular pond bottom; an injection port within the embankment, and a conduit that provides fluid communication between the water transfer subsystem and the drain sump of the second pond and between the water transfer subsystem and the injection port of the second pond.

15. A method of storing water, the method comprising: (i) providing a pond including an embankment having a generally circular dimension; a generally circular pond bottom within the generally circular embankment; a drain that is located at or near the center of the generally circular pond bottom; and an injection port within the embankment; (ii) injecting water into the pond via the injection port to thereby provide a volume of water within the pond, where said injecting causes the volume of water to circulate within the pond; and (iii) draining a portion of the volume of water from the drain.

16. The method of any of the preceding claims, further including reintroducing the portion of the volume of water from the drain back into the pond via the injection port.

17. The method of any of the preceding claims, further comprising the step of providing a second pond including an embankment having a generally circular dimension; agenerally circular pond bottom within the generally circular embankment; a drain that is located at or near the center of the generally circular pond bottom; and an injection port within the embankment, and further including introducing the portion of the volume of water from the drain into the second pond via the injection port.

18. The method of any of the preceding claims, further including treating the portion of the volume of water from the drain.

19. The method of any of the preceding claims, where said treating including physically treating the water.

20. The method of any of the preceding claims where said treating includes chemically treating the water.

21. A method of treating water, the method comprising: (i) providing a pond including an embankment having a generally circular dimension; a generally circular pond bottom within the generally circular embankment; a drain that is located at or near the center of the generally circular pond bottom; and an injection port within the embankment; (ii) injecting water into the pond via the injection port to thereby provide a volume of water within the pond, where said injecting causes the volume of water to circulate within the pond; (iii) draining a portion of the volume of water from the drain; and (iv) treating the portion of the volume of water from the drain.

22. A method of providing water to an oilfield, the method comprising: (i) collecting water from one or more sources of water; (ii) introducing the water to a pond, where the pond has an embankment having a generally circular dimension and drain centrally located to the generally circular dimension;(iii) circulating the water within the pond; (iv) removing at least a portion of the water from the drain; and (v) routing at least a portion of the water removed from the drain to an oilfield.

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