Patent ID: 12215046

DETAILED DESCRIPTION

Described herein is a centralized wastewater treatment system for use with a plurality of oilfield well pads disposed within a predetermined distance about the centralized sewage treatment system, where the centralized wastewater treatment system includes both a primary treatment system and a secondary treatment system capable of accepting different types, quantities and qualities of wastewater from the man camps of different oilfield well pads. As used herein, wastewater includes stormwater, greywater and blackwater.

Referring toFIG.1, a centralized wastewater treatment system100is shown according to one or more embodiments. The centralized wastewater treatment system100includes a centralized treatment facility105at a first or central location106adapted to service a plurality of oilfield well pads110within a geographic area115, where each oilfield well pad110is at a separate secondary or remote location108spaced apart a distance D from the central location106. Each well pad110a-dof the plurality of well pads110may include oilfield equipment114a-dfor drilling and/or production operations, as well as a man camp120a-dwhere operators stationed at the well pad110a-dlive. The man camps120a-dinclude showers, toilets, sinks, kitchens, etc., which all produce wastewater (or “sewage”) for delivery to the centralized wastewater treatment system100as influent.

Wastewater from the man camps120a-dis stored in one or more septic tanks125a-dlocated on-site at the well pads110a-dat the remote locations108a-d. In one or more embodiments, the one or more septic tanks125a-dmay be enclosed receptacle or storage vessel that can be disposed above ground or in ground. In this regard, the one or more septic tanks125a-dmay be plastic. In one or more embodiments, each septic tank125may have a capacity of 200-500 gallons. Each septic tank125may include one or more sensors127to measure the volume of wastewater collected in the septic tank125, or otherwise, a condition of the wastewater flowing into the septic tank125. In one or more embodiments, each sensor127is coupled to a wireless transceiver128at the well pad110to transmit the measured volume, or condition, of the wastewater back to the centralized treatment facility105, which likewise may include a transceiver128to allow wireless communication therebetween.

As used herein, geographic area115may be an oilfield or oilfield lease having a plurality of wells116disposed therein. In this regard, the geographic area115may be a single oilfield or multiple oilfields. The geographic area115may be defined by a single oilfield lease or multiple oilfield leases. Likewise, as used herein, a well pad110has at least one well116and a man camp120disposed to support oilfield equipment114adjacent to or in the vicinity of the man camp120, where such oilfield equipment114may include drilling rigs, workover rigs, wellheads, production equipment, fracking equipment or the like. The man camp120in turn has at least one septic tank125.

The average man camp typically generates about 500-2,000 gallons of wastewater per day. During peak operation, however, each man camp120a-dcan generate up to 3,000-4,000 gallons of wastewater per day. A large percentage of this wastewater may be generated within a 3-4 hour window each day, such as, for example, at the end of the day or at the end of a shift when the operators use the showers and kitchen.

As discussed above, traditional mobile wastewater treatment systems servicing individual oilfield well pads often have difficulty balancing these high-flow periods because they typically do not employ full or complete primary treatment processes to balance the flow and water quality (i.e., solid settlement and equalization tanks).

In one or more embodiments of the centralized wastewater treatment system100, at determined times or capacities, as will be discussed in further detail below, the septic tanks125a-dare at least partially drained of wastewater and the wastewater is transferred to the centralized treatment facility105via a transport mechanism126. In one or more embodiments, transport mechanism126may be a wastewater transport vehicle126a, such as tank truck.

As will also be discussed in more detail below, the centralized treatment facility105is located at a central location106within the geographic area115, the central location106being geographically optimized within the geographic area115in order to service the plurality of well pads110as efficiently as possible. For example, in some embodiments, each of a plurality of well pads110a-dmay be a select distance Da-dfrom the centralized treatment facility105, where distance D ranges between a minimum distance Dminand a maximum distance Dmaxin order to optimize the overall operations of the centralized wastewater treatment system100. As described above, the plurality of oilfield well pads110within the geographic area115are each at a remote location108a-dso as to be spaced apart from, or remote from, the centralized treatment facility105, and additionally, may be spaced apart from each other as well.

As will be discussed, optimization can vary between the centralized wastewater treatment system100and each well pad110and may depend on the amount of wastewater generated by a particular well pad110, the terrain within a geographic area115between any given well pad110and the centralized treatment facility105, and the available transport mechanism126, among other things. Thus, each well pad110a-dmay be spaced apart from the centralized treatment facility105a distance Da, Db, Dcand Dd, where these individual distances may differ based on optimization. For example, well pad110amay produce a larger amount of wastewater than well pad110c, and thus, the distance Damay be selected to be shorter than the distance Dc. In another example, the terrain between well pad110band centralized treatment facility105may be more rugged and difficult to traverse than terrain between well pad110dand centralized treatment facility105, and thus, the distance Dbmay be selected to be shorter than the distance Dd. In some embodiments, distance D ranges between at least 0.5 miles and no greater than 50 miles for each of at least three well pads110. In some embodiments, distance D ranges between at least 3 miles and no greater than 20 miles for each of at least three well pads110. In some embodiments, distance D is at least 1 mile for each of at least three well pads110.

The centralized treatment facility105utilizes transportable components so as to be semi-permanent (as compared to inground tanks and permanent infrastructure), such that it can be removed or relocated at a future time. In this regard, it will be appreciated that as additional well pads110are developed within a geographic area115, it might be desirable to move centralized treatment facility105to maintain an optimized location with respect to all of the well pads110within the geographic area115. In other words, the addition of one or more new well pads110to the geographic area115changes the original optimization criteria utilized to select the original first location106for the centralized treatment facility105. Being transportable, the centralized treatment facility105may be moved to a new centralized location to accommodate the new well pads110. This is particularly desirable in the development of new oil fields where new well pads110may be deployed to better access underground hydrocarbons.

The centralized treatment facility105of the disclosure includes both a primary treatment system132and a secondary treatment system134. It will be appreciated that while prior art man camps may include all or a portion of the primary treatment system132, because of the low wastewater volumes at any given man camp, it is not economically feasible to include a secondary treatment system134because such a secondary treatment system134requires a minimum throughput of wastewater, particularly those secondary treatment systems that are membrane treatment systems utilizing a membrane for filtration, such as membrane bioreactor (MBR) systems and membrane aerated biofilm reactor (MABR) systems. Thus, in one or more embodiments, the secondary treatment system134is a membrane treatment system. In any event, primary treatment system134includes at least a solid settlement tank(s)135, an equalization tank(s)140, and a solids screen(s)145, while secondary treatment system134includes at least a membrane treatment system150, such as MBR or MABR, and an effluent storage tank(s)155.

In one or more embodiments of primary treatment system132, there may be one or more of each of the solid settlement tank135, the equalization tank140, and the solids screen145. In one or more embodiments of secondary treatment system134, there may be one or more of the membrane treatment systems150and/or the effluent storage tank155. The solid settlement tank135, the equalization tank140, and the solids screen145together perform a primary treatment process with respect to the influent received from the septic tanks125a-d. In one or more embodiments, the solid settlement tank135, the equalization tank140, and the solids screen145forming the primary treatment system132may be combined in a single tank or apparatus.

It will be appreciated that because the primary treatment system132described herein is disposed to receive and treat larger volumes of influent than would be produced at any one well pad, the components of the primary treatment system132, in particular, the solid settlement tank(s)135and equalization tank(s)140, can have a significantly greater capacity for receiving and handling influent when compared to primary treatment equipment of the prior art that might be disposed at an individual well pad. Thus, each septic tank125may be defined to have a total capacity for storing wastewater, such as, for example, 5000 gallons for an expected daily wastewater storage of 500-3000 gallons. In such embodiments, the capacity of the solid settlement tank(s)135and/or the equalization tank(s)140is greater than the combined total capacity of at least two or more of the septic tanks125. This larger capacity permits wastewater from a plurality of well pads110and septic tanks125to be combined and processed simultaneously which, in turn, results in improved treatment of the influent when compared to primary treatment equipment that might be disposed at an individual well pad.

In one or more embodiments, the total capacity of the solid settlement tank(s)135may be, for example, at least 20,000 gallons, which is greater than the total solid settlement tank capacity commonly found at individual well pads. Likewise, in one or more embodiments, the total capacity of the equalization tank(s)140may be, for example, at least 20,000 gallons, which is greater than the total equalization tank capacity commonly found at individual well pads. In this regard, the solid settlement tank(s)135and/or the equalization tank(s)140may include one or more sensors127to measure a condition of the liquid therein.

The effluent storage tank(s)155are in fluid communication with an effluent spray system160. In one or more embodiments, effluent spray system160may be an effluent sprinkler system160a, such as nozzles, water gun(s), jets, or apertured conduit, which may be positioned adjacent the centralized treatment facility105and dispose to spray effluent from the centralized treatment facility105on the ground about the centralized treatment facility105for purposes of dust control or irrigation of agricultural crops. In other embodiments, effluent spray system160may be one or more effluent spray vehicles160b, such as a tank truck, disposed to receive and transport a volume of effluent to another location for spraying on the ground, such as for purposes of dust control or irrigation.

In some embodiments, effluent spray vehicles160bmay return to the one or more of the well pads110a-dand spray the effluent from centralized treatment facility105on the ground around one or more well pads110to control dust. In other embodiments, effluent spray vehicles160bmay be utilized to spray roads (not shown) utilized to access the well pads110or within geographic area115. In this way, the effluent may be utilized back at the one or more remote locations108from which wastewater was originally obtained. It will be appreciated that the one or more wastewater transport vehicles126aused to collect wastewater as described herein are different from the one or more effluent spray vehicles160bas described herein so as not to contaminate the effluent produced by centralized treatment facility105. In one or more embodiments, the wastewater transport vehicles126amay be equipped with multiple separate tanks such that the same wastewater transport vehicles126acan transport both wastewater and effluent in the separate tanks.

Referring toFIG.2, with continued reference toFIG.1, a method200of operation of the centralized wastewater treatment system100is provided according to one or more embodiments. As discussed above, at determined times or capacities, wastewater from one or more of the septic tanks125a-dat each well pad110a-dis collected. The frequency with which wastewater from each individual septic tank125a-dis collected may vary depending on the demand for water at each well pad110a-dor the production of wastewater at each well pad110a-d. When a well pad110a-dis at peak operation, for example, the demand for water will increase and hence, the resulting volume of wastewater produced will increase.

In one or more embodiments, one or more well pads110a-dinclude at least one sensor, such as sensor127, to measure water usage, wastewater production, or a related characteristic or condition. A signal based on the measurements made by the sensor127may be transmitted to the centralized treatment facility105or another dispatch facility in order to prompt a wastewater transport vehicle126ato be sent to the well pad110to collect influent from a septic tank125. For example, the sensor127can measure the volume of wastewater collected in a septic tank125and once the septic tank volume has reached a predetermined amount, the aforementioned signal may be transmitted to initiate movement of the wastewater to the centralized treatment facility105by wastewater transport vehicles126a.

Thus, at step203of the method200, at least a portion of the wastewater from one or more well pads110a-dis removed from septic tanks125a-dand transported to the centralized treatment facility105, where the well pads110a-dare remote from the centralized treatment facility105, and may be individually spaced apart from one another. In one or more embodiments all or a portion of the wastewater collected in a given septic tank125may be removed from the septic tank125for transport. In one or more embodiments, step203may be accomplished by transporting the wastewater by a wastewater transport vehicle126a, such as tank truck. In one or more embodiments, a separate wastewater transport vehicle126amay be sent to each well pad110while in other embodiments, a single vehicle126amay collect wastewater from a plurality of well pads110for transport to the centralized treatment facility105.

Additionally, step203may include measuring a condition at one or more well pads110related to the wastewater at the one or more well pads110and generating a signal to prompt initiation of the removal and transport of at least a portion of the wastewater from the one or more well pads110. This may include prompting a wastewater transport vehicle126ato be sent to the well pad110for wastewater collection. Because the demand for and use of water at each of the well pads110a-dmay vary, the wastewater from the septic tanks125a-dat each of the well pads110a-dmay not be removed and transported to the centralized treatment facility105at the same time. For example, wastewater at well pad110amay be removed twice a day because of high volume of wastewater collected within septic tanks125a, while wastewater at well pad110bmay be removed only every other day because of the low volume of wastewater collected within septic tanks125b. In this regard, the hydrocarbon drilling and production activities at the two well pads110a,110bmay be at different stages of operation thereby resulting in the difference in wastewater production. For example, well pad110amay have active drilling operations which typically involves a large number of personnel who would in turn generate higher volumes of wastewater. In contrast, well pad110bmay be in primary production stage, which would typically require far fewer personnel on site, thereby generating much lower volumes of wastewater.

At step205of the method200, the wastewater from the well pads110a-dis received at the centralized treatment facility105as influent for processing. Because the demand for and use of water at each of the well pads110a-dmay vary, the influent from the various septic tanks125a-dat each of the well pads110a-dmay not be received at the centralized treatment facility105at the same time. In some circumstances, however, large volumes of influent may be received at the centralized treatment facility105all at once. Regardless of the frequency and volume of influent received at the centralized treatment facility105, the centralized treatment facility105is disposed to process the influent because of the presence of the primary treatment process, and more specifically because of the equalization tank140, as will be discussed in more detail below, that allows the flow and composition of the influent passing through the system to be controlled.

At step210, the influent is deposited into and received within the one or more solid settlement tank(s)135. The solid settlement tank135is adapted to segregate settleable and floatable solids. The denser solids and sludge will sink to the bottom of the solid settlement tank135, which can then be removed and stored in the solid storage tanks (not shown). The less dense and floatable solids, as well as other scum, will float to the top of the solid settlement tank135. This layer of floatable solids and scum can also be removed and stored in the solid storage tanks, or another storage tank (not shown) separate from the denser solids.

The use of the solid settlement tank135as described enables the centralized wastewater treatment system100to accept a greater variety of influent types and qualities as compared to traditional mobile wastewater treatments systems used at individual well pads. The solid settlement tank(s)135as described herein enable the centralized treatment facility105to accept influent with more diverse contaminants and solid matter. In one or more embodiments, for example, the centralized treatment facility105using the solid settlement tank135would be able to accept stormwater, greywater, and blackwater, whereas well pad primary treatment systems of the prior art typically would not be disposed to accept these different types of wastewater due to capacity limitations and treatment limitations. Moreover, in one or more embodiments, the solid settlement tank(s)135as described collectively have a larger capacity than any individual septic tanks125, thereby allowing the solid settlement tank(s)135to receive and begin treating wastewater from two or more well pads110simultaneously.

At step215, after the dense solids and floatable solids have been removed from the influent, the influent is transferred to the equalization tank140. The primary purpose of the equalization tank140is to serve as a buffer to balance the composition and/or flow velocity of the inflow of influent received from the well pads110a-dlocated in the geographic area115and serviced by the centralized treatment facility105. By balancing the inflow of influent received, the equalization tank140can deliver a flow of influent that is more consistent in composition, containing a substantially uniform composition and consistency of contaminants, to the secondary treatment equipment150. Moreover, in one or more embodiments, the equalization tank(s)140as described collectively have a larger capacity than any individual septic tanks125, thereby allowing the equalization tank(s)140to receive and treat wastewater from two or more well pads110simultaneously.

As discussed above, traditional mobile wastewater treatment systems servicing individual well pads do not typically use full primary treatment processes. In this regard, use of equalization tanks in the primary treatment process of prior art well pads is uncommon because of cost and capacity restrictions. As a result, an inconsistent flow of influent may be processed by prior art primary treatment processes at well pads to the extent such primary treatment processes are employed at all. Because biological treatment processes take time to stabilize, an inconsistent flow of influent can result in untreated/undertreated wastewater and an overall lower quality of treated wastewater, i.e., effluent.

In one or more embodiments, additional solids may be accumulated, consolidated, removed, and stored during processing in, and discharge from, the equalization tank140. In one or more embodiments, the equalization tank140may also digest organic matter via anaerobic treatment processes whereby anaerobic microorganisms digest organic contaminants in the absence of oxygen. In such embodiment(s), the equalization tank140would be sealed. In one or more embodiments, such anaerobic treatment processes may occur in tanks separate from the equalization tank140and may occur before or after step215(i.e., before or after the influent is received within the equalization tank140).

In one or more embodiments, the equalization tank(s)140may be an open-air tank and may be aerated using a mechanical mixing device or an aeration pump so that influent discharged from the equalization tank(s)140are more homogenous than the wastewater received in step205. The aeration of the equalization tank140promotes suspension of the contaminants in the influent and maintains a consistent distribution of the contaminants in the influent. The equalization tank140processes the influent and discharges primary effluent. The consistent distribution of contaminants in the flow of primary effluent to the secondary treatment equipment150promotes more efficient processing of the influent in the secondary treatment process and improves the quality of the resultant secondary effluent.

At step220, the flow of primary effluent discharged from the equalization tank140is passed through and filtered by the solids screen145before being received by the secondary treatment system134. The solids screen145removes additional solid contaminants from the primary effluent. In one or more embodiments, there are multiple solids screens145with progressively smaller through-holes. In one or more embodiments, the solids screen(s)145is located within the equalization tank140, while in other embodiments, the solids screen(s)145may be separate from the equalization tank(s)140. In one or more embodiments, the additional solid contaminants are removed and stored in solid storage tank(s) (not shown).

At step225, the primary effluent, which has been filtered, equalized, and discharged from the equalization tank140, is directed to the secondary treatment system134and, more particularly, to the secondary treatment equipment150. The secondary treatment equipment150includes tankage and aeration equipment designed to biologically treat the influent from the primary treatment system132. In one or more embodiments, the biological treatment includes oxidizing the primary effluent. The aeration equipment may include mechanical mixing equipment, aeration pumps and blowers, or other aeration equipment known in the art. The secondary treatment equipment150is adapted to digest soluble organic matter and suspended solids, filter finer solids, perform nitrification processes to remove ammonia from the primary effluent by converting it to nitrate, and, where required by regulation, perform denitrification processes to subsequently reduce the resultant nitrate to nitrogen gas. In one or more embodiments, the nitrification and denitrification processes may be performed simultaneously. After being processed by the secondary treatment equipment150, the primary effluent can be considered secondary effluent.

In one or more embodiments, the secondary treatment equipment150may perform aerobic treatment processes and/or biofiltration processes. In both processes, aerobic microorganisms are used to breakdown and digest organic contaminants in the primary effluent.

In one or more embodiments, the secondary treatment equipment150includes a membrane bioreactor (MBR) system, which includes a membrane filter. In one or more embodiments the secondary treatment equipment150includes a membrane aerated biofilm reactor (MABR) system. In one or more other embodiments, the secondary treatment equipment150utilizes other types of membranes or filters through which biologically treated water is passed. Multiple of these systems or other such systems known in the art can be used at the centralized treatment facility105to easily scale-up the centralized treatment facility105as needed in order to service additional well pads110. Notably, in the case of any type of filtration system as described with respect to step225, a minimum throughput of influent is required for operation of secondary treatment equipment150. Such throughput is typically 10,000-20,000 gallons/day. Given this throughput requirement, such systems would not be deployed at individual well pads since well pads typically only produced around 500-3,000 gallons/day of wastewater. For this reason, wastewater treated on site at typical well pads cannot achieve the same effluent quality level or level of purification as can be achieved by the centralized treatment facility105.

At step230, the secondary effluent is discharged from the secondary treatment equipment150and is stored in the effluent storage tank155. The effluent storage tank155can be stored onsite at the central location106or can be store offsite and remote from the centralized treatment facility105.

At step235, the secondary effluent is dispersed. The secondary effluent can be dispersed in a number of ways.

First, the secondary effluent may used in agricultural irrigation and/or dust control applications. It will be appreciated that because centralized treatment facility105is typically located in remote areas, there is no infrastructure, such as a network of pipes, pumps, reservoirs, for disposing of or removing the secondary effluent. Rather, as described above, the secondary effluent may be dispersed by spraying it on ground for dust control or agricultural irrigation within geographic area115. In this regard, the secondary effluent may be sprayed adjacent to or in the vicinity of centralized treatment facility105utilizing an effluent spray system160adisposed adjacent to or in the vicinity of the centralized treatment facility105, such as within 0.5 miles of the centralized treatment facility105. In other embodiments, the effluent may be loaded into one or more effluent spray vehicles160bdisposed to receive and transport a volume of effluent to another location for spraying on the ground.

The secondary effluent may also be returned or sold back to the individual well pads110a-dto be used for downhole operations and hydraulic fracturing. As discussed above, the secondary effluent is dispersed via one or more effluent spray vehicles160b, which are different from the wastewater transport vehicles126aso as to not contaminate the secondary effluent. Regardless of whether the secondary effluent is utilized for dust control, irrigation, or drilling or production operations, it will be appreciated that the secondary effluent may be sold for these purposes. Thus, from an economic standpoint, the operator of centralized wastewater treatment system100can receive compensation both for removal and treatment of the wastewater and also for delivery of the secondary effluent for the purposes described above, it being understood that it is common for well pad operators to purchase water for these purposes.

It will be appreciated that because the wastewater collected from well pads110as described herein has been treated with both a primary treatment system132and a secondary treatment system134, it is of a sufficient quality that it can be disposed of in this manner. Thus, the centralized treatment facility105permits wastewater from well pads110to be treated to a higher quality than may occur at prior art well pads, and thus the resulting effluent can be re-used for various operations associated with the well pads110.

Referring toFIG.3, with continued reference toFIGS.1and2, a method300of optimizing the centralized wastewater treatment system100, including the method200as shown and described with respect toFIG.2, is provided according to one or more embodiments.

At step305, a condition or quality of the wastewater produced at each of the one or more well pads110a-dlocated within the geographic area115is monitored. In one or more embodiments, the condition monitored can be the capacity of each septic tank125a-dof the plurality of well pads110a-dlocated within the geographic area115. In some embodiments, one or more sensors127may be operably connected to the septic tanks125a-dto monitor or measure the volume of wastewater in the septic tanks125a-d. In one or more embodiments, this data may be transmitted and stored at a control system located at the centralized treatment facility105. In some embodiments, this data may be transmitted wirelessly with a transceiver128.

At step310, a schedule for collecting at least a portion of the wastewater from two or more of the well pads110a-d, and for transporting the collected wastewater to the centralized treatment facility105, is determined. By monitoring the capacities of the septic tanks125a-dof the well pads110a-d, or some other quality or condition of the produced wastewater, and analyzing that data with respect to the processing capacity of the centralized treatment facility105, the schedule can be optimized to reduce energy consumption and promote efficient operation of the centralized treatment facility105. Determining which septic tanks125a-dneed to be emptied, or at least partially drained, and when may largely depend on the stage of operation of each well pad110a-din the drilling and production process.

At step315, the primary effluent discharged from the equalization tank140is monitored and analyzed. More particularly, the quality of the primary effluent, including the type, concentration, and consistency of the contaminants in the primary effluent, is analyzed in light of the processing capabilities of the secondary treatment equipment150.

At step320, a flow rate of the primary effluent from the equalization tank140to the secondary treatment equipment150is determined. As discussed above, biological treatment processes take time to stabilize. In addition, membrane filtration also requires a minimum amount of throughput in order to maintain desired pressures for operation. Depending on the quality of the primary effluent that is discharged from the equalization tank140, the amount of time required by the secondary treatment equipment150to treat and process the primary effluent may vary.

Using the analysis of the primary effluent discharged from the equalization tank140, the amount of time required to treat the primary effluent using the secondary treatment equipment150can be determined. Once the time required to treat the primary effluent using the secondary treatment equipment150is determined, an optimal flow rate of the primary effluent from the equalization tank140can be determined. The optimal flow rate of the primary effluent discharged from the equalization tank140promotes efficient processing of the primary effluent by exposing the primary effluent to the secondary treatment equipment150for the optimal amount of time required to yield the highest quality effluent possible.

At step325, the secondary effluent discharged from the secondary treatment equipment150to the effluent storage tank155is analyzed. The secondary effluent is analyzed to determine whether the concentration of contaminants remaining in the secondary effluent satisfies governmental permitting requirements and/or governmental quality requirements and allows for the secondary effluent to be subsequently dispersed via downhole fracking, irrigation, dust control, or other permissible means of dispersing the secondary effluent.

At step330, using the analysis of the secondary effluent discharged from the secondary treatment equipment150, the flow rate of the primary effluent discharged from the equalization tank140(i.e., the determination made at step320) is adjusted as needed to optimize the quality of the secondary effluent and improve the efficiency of the secondary treatment equipment150. For example, if the concentration of contaminants remaining in the secondary effluent after passing through the secondary treatment equipment150is too high and does not satisfy permitting requirements, the flow rate of the primary effluent coming from the equalization tank140can be decreased such that the primary effluent is exposed to the secondary treatment equipment150for a longer period of time.

If, in the alternative, the concentration of contaminants remaining in the secondary effluent is well below the required limit, the flow rate of primary effluent into the secondary treatment equipment150may be increased to improve efficiency and increase the rate at which the primary effluent is being treated by the secondary treatment equipment150.

At step335, using the analysis of the secondary effluent discharged from the secondary treatment equipment150, the schedule for collecting and transporting wastewater from each septic tank125a-dof the well pads110a-dto the centralized treatment facility105(i.e., the determination made at step310) is adjusted as needed to improve the efficiency of the centralized wastewater treatment system100and of the operation of the centralized treatment facility105.

In one or more embodiments, adjusting or updating the schedule for collecting and transporting wastewater from the septic tanks125a-dto the centralized treatment facility105may depend solely on the capacities of the septic tanks125a-dmonitored at step305. As water consumption at the man camps120a-dvaries (e.g., as oil production operations at the well pads110a-dramp-up or ramp-down) the schedule for collecting and transporting the wastewater from the septic tanks125a-dat the man caps120a-dmay need to be updated in order to accommodate the increased or decreased production of wastewater in an efficient manner.

In one or more embodiments, adjusting or updating the schedule for collecting and transporting the wastewater from the well pads110a-dto the centralized treatment facility105may depend upon, and may be adjusted simultaneously with, the adjustment of the flow rate at which the primary effluent is discharged from the equalization tank140(i.e., step330). If it is determined at step330that the secondary treatment equipment150is capable of processing the primary effluent at a greater flow rate and the flow rate is subsequently increased, then the schedule for collecting and transporting wastewater from the well pads110a-dmay be adjusted to increase the volume of wastewater received as influent, or the rate at which the wastewater is received, at the centralized treatment facility105. If it is determined at step330that the flow rate of the primary effluent from the equalization tank140should be reduced and the flow rate is subsequently reduced, then the schedule for collecting and transporting wastewater from the well pads110a-dmay be adjusted to decrease the volume of wastewater received as influent, or the rate at which the wastewater is received, at the centralized treatment facility105.

Referring toFIG.4, with continued reference toFIG.1, a method400of determining and optimizing the central location106of the centralized treatment facility105within the geographic area115is provided according to one or more embodiments.

At step405, the geographic area115to be serviced by the centralized treatment facility105is identified. As discussed above, because the wastewater produced at the plurality of well pads110is treated at the centralized treatment facility105, the centralized wastewater treatment system100, including the plurality of well pads110and the centralized treatment facility105, is more easily scalable than was possible with individual mobile wastewater treatment systems. As such, the boundaries of the geographic area115may change as the centralized wastewater treatment system100is scaled.

At step410, locations of the existing well pads110a-dare identified. The existing well pads110a-dare the well pads that have already been established, are located within the geographic area115, and are producing wastewater that will be treated by the centralized treatment facility105.

At step415, future locations for future well pads are identified. The future locations are dependent on available leases. In one or more embodiments, the future locations are within the geographic area115. In one or more embodiments, the future locations are outside the existing boundaries of the geographic area115, but as discussed above, the boundaries of the geographic area115can change as the operations of the centralized wastewater treatment system100are scaled. In other words, the locations of the well pads110a-dserviced, or that will be serviced, by the centralized treatment facility105define the bounds of the geographic area115.

At step420, potential locations for the centralized treatment facility105are identified. Like the future locations for the future well pads, the potential locations for the centralized treatment facility105depend upon land available to be leased and upon which the centralized treatment facility105can be built.

At step425, existing infrastructure connecting the existing well pads110a-dand the future locations for future well pads to the potential locations for the centralized treatment facility105is identified and analyzed. Alternatively, or in addition thereto, to optimize placement of the centralized treatment facility105, topography within geographic area115is analyzed to determine where future infrastructure is likely to be positioned based on existing and planned future well pads. In one or more embodiments, the infrastructure includes roadways that enable the wastewater to be trucked from the well pads110a-dto the centralized treatment facility105.

The infrastructure is analyzed with respect to the locations of the existing well pads110a-d, the future locations of the future well pads, and the potential locations for the centralized treatment facility105in order to determine, at step430, which potential location for the centralized treatment facility105is the most efficient. In one or more embodiments, this analysis may include: an analysis of traffic data and navigational routes with respect to the infrastructure connecting the existing and future well pad locations and the potential locations for the centralized treatment facility105; an analysis of the current or anticipated wastewater production of each individual well pad; and/or an analysis of the likelihood of future well pads being established at the future locations.

In one or more embodiments, the analysis of the traffic data and navigational routes may be prioritized, or given a greater weight, such that the determination, at step430, of the central location106optimizes the total distance or time required to navigate from the well pads110a-dto the centralized treatment facility105. In such embodiment(s), the centralized treatment facility105may be substantially centered within the geographic area115. In one or more embodiments, the wastewater production at each of the well pads110a-dmay be given greater weight in the analysis performed at step425such that the potential locations for the centralized treatment facility105are evaluated based on proximity to well pads that produce higher volumes of wastewater. In still other embodiments, greater weight may be given to the future locations for the future well pads when performing the analysis at step425such that the determination of the central location106of the centralized treatment facility105is optimized with respect to the anticipated expansion, or scaling-up, of oilfield operations and of the centralized wastewater treatment system100. The analysis performed at step425may take into account any one or more of the above-mentioned factors and may assign various weights to each factor depending on the requirements of the application.

Optimizing the central location106of the centralized treatment facility105within the geographic area115promotes improved energy efficiency of the centralized wastewater treatment system100by reducing the energy consumption required to transport the wastewater from the well pads110a-dto the centralized treatment facility105.

As disclosed herein, the centralized wastewater treatment system100is more efficient than traditional mobile wastewater treatment systems. The centralized wastewater treatment system100is more energy efficient because rather than operating an individual mobile wastewater treatment system at each well pad110a-d, the centralized treatment facility105can receive the wastewater produced at each of the well pads110a-dand treat all of the wastewater together using a single system.

The centralized wastewater treatment system100is also more cost effective for the same reasons. Rather than purchasing or renting a traditional mobile wastewater treatment system for every single well pad110a-d, only the centralized treatment facility105needs to be established in the centralized wastewater treatment system100. In addition, operating the centralized treatment facility105is more cost effective because only one permit is required, whereas previously a permit was required for each mobile wastewater treatment system in operation. As a result, the overall cost of treating the wastewater produced within the geographic area115is reduced for both owners and customers.

The centralized wastewater treatment system100is also more efficient because it is more versatile. Because the wastewater is consolidated and processed at the central location106, it is more economically feasible to introduce the primary treatment processes, including the solid settlement tank135, the equalization tank140, and the solids screen145, at the centralized treatment facility105. Because the centralized treatment facility105uses the primary treatment processes, a wider range of types and qualities of wastewater are able to be processed by the centralized wastewater treatment system100than was previously able to be processed using the individual mobile wastewater treatment systems.

The centralized wastewater treatment system100also yields higher quality effluent because of the use of the primary treatment processes at the centralized treatment facility105. The use of the primary treatment processes in combination with the secondary treatment processes improves the treatment of the influent and results in the secondary effluent having a lower concentration of contaminants. The use of the equalization tank140additionally contributes to the higher quality of effluent exported from the centralized treatment facility105because the equalization tank140enables the flow of primary effluent to be controlled and maintained at a constant rate, which enables the biological processes taking place in the secondary treatment equipment150to perform more efficiently and provide more consistent treatment of the primary effluent received.

The centralized wastewater treatment system100is also more efficient than traditional individual mobile wastewater treatment systems because the centralized wastewater treatment system100is more easily scalable. The centralized treatment facility105itself is more readily scalable because it is a standalone facility capable of treating the plurality of well pads110. As the number of well pads110serviced by the centralized treatment facility105increase, the capacity of the centralized treatment facility105can also be increased. The future well pads can be established in various spaced-apart locations within the geographic area115and remote from the centralized treatment facility105; however, the only modifications required to be made to the centralized wastewater treatment system100, if any, to accommodate the additional wastewater production would be at the centralized treatment facility105. Because modifications would only need to be made at the centralized treatment facility105, it is much easier to adjust for and accommodate increases in wastewater production from the well pads110. Also, because the well pads110will no longer need mobile wastewater treatment systems, the obstacles and costs deterring the establishment of new well pads, including acquiring new permits for sewage treatment, are reduced or eliminated. Thus, the centralized treatment facility105makes it easier to scale-up hydrocarbon recovery operations in the geographic area115by more readily installing new well pads and man camps within the geographic area115.

Finally, with respect toFIG.5, while centralized wastewater treatment system100has been described above in relation to man camps120and associated septic tanks125supporting the man camps120for oil and gas operations (seeFIG.1), it will be appreciated that centralized wastewater treatment system may also be used to support other types of remote, temporary structures having plumbing systems that are not connected to local water utilities.

InFIG.5, a centralized wastewater treatment system500is shown supporting at least three and in some cases, a plurality, of remote locations508a-d, each remote location508having temporary housing facilities520for construction activities, agricultural activities, industrial activities or the like, where each temporary housing facility320has one or more associated septic tanks525. In the illustrated embodiment, each temporary housing facility520is located at a remote site510, such as a farm, construction site, or industrial site. Thus, in one embodiment, during harvesting season, at least three and in some cases, a plurality, of farms510may each include temporary housing facilities520a-dfor workers, where each temporary housing facility520at each farm510may include sleeping structures and associated plumbing systems. The centralized wastewater treatment system500is positioned to provide wastewater treatment for each of a plurality of temporary housing facilities520a-dfor personnel supporting the agricultural activities, where each temporary housing facility520includes one or more sleeping structures along with plumbing systems requiring one or more septic tanks525.

In one or more other embodiments, at least three and in some cases, a plurality, of construction sites510may each include temporary housing facilities520a-dfor workers, where each temporary housing facility520at each construction site510may include sleeping structures and associated plumbing systems. The centralized wastewater treatment system500is positioned to provide wastewater treatment for each of the plurality of temporary housing facilities520a-dfor personnel supporting the construction activities, where each temporary housing facility520includes one or more sleeping structures along with plumbing systems requiring one or more septic tanks525.

In one or more other embodiments, at least three and in some cases, a plurality, of industrial sites510may each include temporary housing facilities520a-dfor workers, where each temporary housing facility520at each industrial site510may include sleeping structures and associated plumbing systems. The centralized wastewater treatment system500is positioned to provide wastewater treatment for each of the plurality of temporary housing facilities520a-dfor personnel supporting the industrial activities, where each temporary housing facility520includes one or more sleeping structures along with plumbing systems requiring one or more septic tanks525. In one or more embodiments, each remote site510may include agricultural fields514or industrial facilities514or construction514, as the case may be, that is the focus of the personnel occupying the temporary housing. In other embodiments, at least three and in some cases, a plurality, of remote sites510having temporary housing facilities520may be utilized for other purposes, such as housing military personnel or other groups of people in remote locations.

Although various embodiments have been shown and described, the disclosure is not limited to such embodiments and will be understood to include all modifications and variations as would be apparent to one skilled in the art. Therefore, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed; rather, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.