Automated multi-silo aggregate management

Methods of managing aggregate inventory. The methods include utilizing a dynamic protocol for an oilfield operation with aggregate from chambers of a multi-silo system wherein each chamber accommodates a single aggregate type throughout operations. However, the chambers also have a dynamic classification as either active, idle or reserved depending on the stage of operations. Once more, even though each silo may accommodate multiple chambers, unique techniques may be utilized to obtain real-time inventory information for each chamber via weight measurement of entire silos.

BACKGROUND

Exploring, drilling and completing hydrocarbon and other wells are generally complicated, time consuming and ultimately very expensive endeavors. As a result, over the years, well architecture has become more sophisticated where appropriate in order to help enhance access to underground hydrocarbon reserves. For example, as opposed to wells of limited depth, it is not uncommon to find hydrocarbon wells exceeding 30,000 feet in depth. Furthermore, today's hydrocarbon wells often include deviated or horizontal sections aimed at targeting particular underground reserves. Indeed, at targeted formation locations, it is quite common for a host of lateral legs and fractures to stem from the main wellbore of the well toward a hydrocarbon reservoir in the formation.

The above described fractures may be formed by a fracturing operation, often referred to as a stimulation operation. The stimulation or fracturing operation, involves pumping of a fracturing fluid at high pressure into the well in order to form the fractures and stimulate production of the hydrocarbons. The fractures may then serve as channels through the formation through which hydrocarbons may reach the wellbore. The indicated fracturing fluid generally includes a solid particulate or aggregate referred to as proppant, often sand. The proppant may act to enhance the formation of fractures during the fracturing operation and may also remain primarily within fractures upon their formation. In fact, the fractures may remain open in part due to their propping open by the proppant.

The above described proppant for the fracturing operation may be supplied from a proppant delivery unit located at the oilfield near the well. This unit is generally very large due to the amount of proppant that may be required for any given fracturing operation. For example, where the proppant is a conventional dry sand, a fully loaded unit may exceed half a million pounds in weight. Once more, as wells become deeper and of ever increasing complex architecture, efforts to provide even larger ready supplies of proppant at the oilfield are increasingly common. That is, more downhole fracturing locations may be involved, thus requiring a greater available supply of proppant.

From an equipment standpoint, greater on-site or near-site supplies of proppant may include the use of mobile silos or even larger stationary silos that are used to gravity feed a blender therebelow. Thus, a proppant slurry may be formed and utilized in short order to support various fracturing operations. As a practical manner, however, this means that potentially several million pounds of proppant may require transport and storage at a given location.

A variety of challenges are presented where management of such massive amounts of proppant or any aggregate is sought. For example, as a silo is filled or emptied for sake of ongoing operations, it is quite difficult to measure with precision the exact amount of proppant being added or consumed. That is, as a given operation calls for the addition or consumption of a particular type of proppant from a silo, it is likely to be in the neighborhood of tens of thousands of pounds. This may involve an operator manually feeding a line to a silo for a period and estimating an amount added (or consumed). That is, at present, there is no practical manner to precisely monitor the increasing or decreasing volume of proppant in a given silo in an automated manner during operations.

Furthermore, if proppant becomes unexpectedly depleted leaving the mixer empty, the entire operation may require shutting down. As a result, operations often proceed with substantially more proppant available than is actually required for the operation. That is, as opposed to shutting down operations at a substantial cost of time and frustration for the well developer, expenses are more commonly shifted to an inefficient operational aspect of delivering and storing much more proppant than is actually required.

Additionally, to ensure that there is a surplus of proppant, operators rely on manual record keeping and visual inspection of proppant levels within a silo. Such visual inspections also mean that an operator is being more regularly exposed to a dust and particulate that is swirling about or being kicked up during this period of loading or consumption.

Manual tracking and monitoring of the loading and consumption process also presents other challenges such as avoiding proppant contamination, when one proppant is loaded into the wrong silo, or even the possibility of overloading a silo. Ultimately, operators are currently left with proppant management systems that may be generally inaccurate and may result in an inefficient overabundance of proppant on site due to a lack of practical automation for such large scale system.

SUMMARY

A method of automated aggregate management at an oilfield via a mobile multi-silo system with each silo having multiple chambers. The method includes establishing a dynamic protocol for an operation at the oilfield that utilizes at least one aggregate. At the outset of operations each chamber may be assigned a static designation to accommodate a given aggregate type throughout the operation. Operations may be run with at least one aggregate from the system filled according to the static designation and the dynamic protocol. Additionally, each chamber of the system may be classified as one of idle and available for loading, active for loading or unloading, and reserved to prohibit loading or unloading wherein the particular classification is dependent upon the dynamic protocol during the running of the operation. Further, chambers may be refilled in accordance with the protocol in light of the dynamic classification so as to provide for running of the operation in a substantially continuous manner.

DETAILED DESCRIPTION

In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the embodiments described may be practiced without these particular details. Further, numerous variations or modifications may be employed which remain contemplated by the embodiments as specifically described.

Embodiments are described with reference to certain embodiments of oilfield operations. Specifically, stimulation operations involving fracturing with aggregate in the form of proppant is described. However, other types of more automated aggregate management at an oilfield may benefit from management techniques detailed herein. For example, cementing and other applications that utilize a potentially large quantity of blended aggregates and other constituents may benefit from such management techniques. Indeed, so long as a management technique is employed that involves a dynamic protocol drawing from static designations of silo chambers holding a material such as aggregate that is carried out in light of dynamic chamber classifications of idle, active and reserved, appreciable benefit may be realized.

Referring now toFIG. 1, a perspective overview depiction of an oilfield100is shown where an embodiment of an automated multi-silo aggregate management system105is located. The system105includes a mobile multi-silo assembly125with four separate silos175,176,177,178supported by an underlying frame120. As described further below, each silo175-178includes multiple chambers. For example, the silo175includes chambers241and242as shown inFIG. 2Aand elsewhere. Furthermore, each such chamber is capable of holding tens of thousands of pounds of aggregate. Specifically, in the embodiments detailed further below, different types of proppant may be stored on a chamber by chamber basis in this fashion.

In an embodiment where the aggregate is proppant for stimulation operations as alluded to above, the proppant may be mixed along with other constituents at a mobile mixer140below the assembly125according to a predetermined protocol. The slurry that is formed from the mixture may then be delivered to a well180as part of a wellbore operation such as a fracturing application. For example, in the embodiment shown, the well180includes an upper casing185and traverses several thousand feet below a wellhead160, across various formation layers190eventually reaching a perforated production region197. Thus, a high pressure fracturing application may take place directed at delivering proppant to the region197so as to encourage opening and supporting hydrocarbon flow therefrom. A host of additional surface equipment, not apparent inFIG. 1, such as positive displacement pumps, a manifold, piping and other tools may be positioned at the oilfield surface100to support the application. The application itself may be directed by an operator at a control unit110with appropriate processing capacity. Similarly, a management unit101with sufficient processing capacity may be employed by another operator to direct the loading, monitoring and unloading of individual chambers of the silos175-178as needed in support of the application. However, in other embodiments, the features of the management unit101may be found at the more remote control unit101. Regardless, in an effort to maintain a substantially continuous supply of slurry for the fracturing application, an operator may employ a user interface and controls through the management unit101to direct ongoing filling aggregate into the silos175-178and consumption therefrom.

As shown inFIG. 1, a conveyor117and bucket elevator175may be utilized to obtain aggregate from proppant delivery trucks150,155or “sand haulers” for routing to augers130,135for filling of the silos175-178. However, in other embodiments, pneumatic equipment for filling of the silos175-178may be utilized. Regardless, in the embodiment shown, chutes137from the augers130,135may determine which specific chamber241-248a particular aggregate or proppant type is delivered to (e.g. seeFIG. 2A). Further, as suggested above, this type of loading as well as aggregate consumption from the silos175-178may be directed by an operator at a management unit101to support substantially uninterrupted fracturing. That is, as detailed below, a substantially continuous supply of aggregate, and therefore slurry, may be made available in an efficient, just-in-time, manner to support the application or operation.

As shown inFIG. 1, the management unit101is adjacent the silo assembly125. Thus, an operator having direct access and visibility of the aggregate supply also has more direct control over filling and consumption of aggregate through the unit101. In addition to directing the filling and consumption of aggregate, the management unit101may also record a substantial amount of historical data in terms of ongoing operations. Indeed, days or months' worth of data, including from prior applications at the well180may be of value and stored at the unit101. That is, as any given load of aggregate is brought to the assembly125or consumed, its delivery and/or consumption may be tracked at the unit101.

At the outset, tracking may initially include scanning or manually entering data regarding the aggregate to be supplied to the assembly125. However, as detailed below, the method of ensuring the amount of the load and subsequent consumption may be monitored with a more sophisticated level of data acquisition and tracking. Further, depending on entry of the new load information, the unit101may help to determine, based on a protocol or pre-set rules at a processor thereof, what particular chamber of what particular silo175-178, the aggregate/proppant should be delivered to in the first place.

Referring now toFIG. 2A, with added reference toFIG. 1, a front view of an embodiment of a user interface screen is shown with a display200. The screen may be utilized by an operator at a remote location such as at the control unit110or, if desired closer to the silo assembly125, at the management unit101where the operator has more direct access thereto. Regardless, the screen includes the display200for initially setting up automated aggregate management of the system105ofFIG. 1. For example, each of the eight different chambers241-248may be assigned a pre-determined type of proppant225to be stored therein to the exclusion of all others. Of course, depending on the protocol of the application, and overall proppant needs, more than one chamber241-248may be assigned the same proppant type225. That said, once assigned a given proppant type225, a chamber241-248will be excluded from accommodating other types throughout operations. In addition to preventing contamination, this also serves as a valuable inventory tool as proppant is loaded, stored and consumed over the course of operations.

Continuing with reference toFIG. 2A, the chambers241-248are shown oriented relative one another in groups representing different silos175-178. That is, as shown inFIG. 1there are four different silos175-178, each accommodating two different chambers241-248so as to provide a total of eight different possible proppant assignments. Additionally, as indicated above, these unchanging or “static” assignments are input by a user depending on the protocol for the application to be run. However, with particular reference toFIG. 2B, in another embodiment, a predetermined automated aggregate management setup may be employed. That is, rather than an operator manually making the noted assignments at the screen, a display201may be presented that allows an operator to select one of a variety of different files275with pre-stored chamber assignment information. Thus, human error may be minimized by ensuring that so long as the proper file with proper pre-stored information is selected for the application, the appropriate proppant assignments will be provided for management on a chamber by chamber basis.

In addition to chamber assignments for aggregate/proppant, the initial setup for ongoing operations may also account for chamber weights. Of course, in the embodiments shown, multiple chambers241-248are incorporated into single silos175-178. So, for example, the weight of chambers241and242are the combined weight of the corresponding silo175. Therefore, with added reference toFIGS. 4B and 5, available weight information from load cells510,520,530,540or other suitable weight determining mechanism, pertaining to the weight of the empty silo175may be substantially zeroed out or discounted from subsequently detected weight as the chambers241and/or242are filled or emptied. Further, a requirement that only one chamber241or242of the silo175be “active” for filling or emptying at any given point in time, allows for ongoing weight detections from the load cells510-540to be a reliable indicator of the actual inventory of proppant in each chamber241,242.

With brief added reference toFIG. 4A, once the proppant assignments are entered, the rules of the protocol will call for the actual loading of materials into the chambers241-248. As a practical matter, with added reference toFIG. 1, this will result in the operator directing different specifically called for trucks150,155to appropriate locations at the assembly125for unloading. This may take place over and over until the chambers241-248are filled according to the rules of the protocol for the application to be run during oilfield operations. The initial loading and set up as described may help avoid contamination, enhance inventory tracking, avoid overflow and even enhance safety by providing operators with step by step safety instructions during loading. Additionally, the display200,201may provide diagnostics and troubleshooting as needed. Further, as detailed below, the protocol itself may be forward “thinking” and allow for the reserving of particular chambers241-248based on anticipated future operational needs and not just the current needs of the near-term application.

Referring now toFIG. 3A, once the assembly125ofFIG. 1is set up, an application may proceed as an operator witnesses a monitoring display301. For example, the display301as shown inFIG. 3Aallows an operator to view consumption and depletion of proppant on a chamber241-248by chamber241-248basis. That it, each graphic representation of each chamber241-248notes an exclusive proppant type225for that chamber241-248as well as an approximate proppant level therein. As noted above, these levels are available due to the real-time weight information that is available as well as level sensors where provided. With reference to such a display301, the operator may have information readily available as to all proppant in terms of amounts received, consumed, unused, etc. This information may be utilized in determining ongoing needs in light of the overall application or various stages thereof as well as the rate of consumption taking place in real-time, even from a chamber by chamber standpoint. In the embodiment ofFIG. 3A, the display301also presents dynamic real-time numeric inventory information300to the operator. Thus again, an operator monitoring the display301is likely to have an idea of upcoming supply needs of the system125ofFIG. 1.

With reference now toFIG. 3B, a front view of an embodiment of a user interface screen is shown where the display310serves as an aid to the operator in evaluating chamber reloading options. That is, in light of depleting inventories, new proppant may be required. However, reloading thereof may depend on initial chamber assignments as to proppant type as well as the stored protocol being carried out by a processor of the control110and/or management101unit of the system105ofFIG. 1.

Continuing with reference toFIG. 3B, the display presents the chambers241-248in a manner highlighting available capacity301therein. As detailed above, this may be determined by the ongoing monitoring of weight information provided to the processor of the control110or management101unit. Thus, depending on upcoming aggregate/proppant needs, the operator may select one of the chambers243,245,247with available capacity for re-loading.

For example, with added reference toFIG. 1, consider a scenario where chamber247is assigned a proppant type that is not of a near term need in operations but chambers243and244are both assigned for holding the same type of proppant that is of near term need. The operator may then consult the protocol to determine whether chamber243with an available capacity of 130,000 lbs. or chamber245, with an available capacity of 75,000 lbs. is most appropriate for selecting. Certainly, if the near term need for the proppant type at issue is near or above 75,000 lbs. the operator would select chamber243for reloading.

Continuing with the above-proposed example and added reference toFIG. 1, it is of course, possible that the near term need of the given proppant type might exceed 130,000 lbs., in which case, both chambers243,245would be selected for sequential re-filling. In this situation, one chamber243of a silo176would be activated for filling while the other244remained inactive. By the same token, at this point in time needs for this proppant type would be met by the noted chamber245of another silo177. Once the initial chamber243is filled, the chamber243may now move to an active state for consumption while the other chamber245is temporarily moved to an inactive state and a chute137or diverter repositioned thereover. This chamber245may then be moved to an active state for filling. In this way, the mobile mixer140below the system125is not noticeably interrupted nor the operations in general. Instead, applications may proceed uninterrupted in a substantially continuous fashion.

Referring now toFIG. 4A, a front view of an embodiment of a user interface screen is shown with a display400that may be presented to an operator at the refilling site near the physical system125ofFIG. 1. So, for example, in one embodiment, the display301ofFIG. 3Bmay be presented to an operator at either unit110,101ofFIG. 1. However, the display400ofFIG. 4Amay be presented to an operator at the management unit101in the vicinity of the actual refilling. Thus, the display presents the operator with step by step direction and aid in terms of where to position trucks150,155, safety measures, checks and other practical issues which may emerge over the course of actual unloading/filling of chambers (e.g.243).

The display400ofFIG. 4Amay present a variety of practical alerts and guides to the operator apart from the general protocol. For example, warning of overfill conditions or alternatively, unanticipated depletion may occur based on level sensor indicators. Additionally, the display400may have built in temporary delays in terms of sequencing between one chamber being filled or emptied and another. This way, operations may proceed with assurance of proper weight and inventory tracking so as to avoid overloading or premature depletion of a chamber. This display400may also provide some guidance and flexibility in terms of loading options. For example, the display400may guide the operator through options of elevator versus pneumatic filling, the use of a skirted receiving belt for dust reduction, inclined versus horizontal transloading, and a variety of other unloading options. Once more, one type of rig-up guidance may be provided in light of other guidance. This may include a recognition, for example, that the elevator175is unavailable for loading a chamber because it is already in use for another chamber and thus, guide the operator to proceed with another unloading at another chamber (of another silo) via pneumatic means.

Referring now toFIG. 4B, another display screen401is presented to an operator which allows direct control over emptying of the aggregate/proppant during operations. That is, again in contrast to the monitoring display301ofFIG. 3A, this display screen401may be of particular benefit to an operator right at the site of the system125site where the potential for practical intervention and manual involvement may be more likely. Again, the display401notes the particular proppant types225assigned to each chamber241-248. Indeed, in the specific example depicted, the same proppant type, “2040 Sand” is allocated to different chambers242,244,245. However, it is evident that one of these chambers244is of a far lower level than the others242,245and yet, slated for unloading therefrom according to the protocol being carried out. Thus, as is also evident, the display presents a confirmation warning450to the operator to allow for the opportunity to abort475the unloading from that particular chamber244. If this abort intervention is selected by the operator, subsequent protocol options may be presented to allow for selecting of unloading from another chamber242,245. Of course, the operator may also select unload480where depletion of the chamber245is not of significant concern.

As alluded to above, the determination of whether to unload480may not only be a matter of whether or not sufficient proppant is available in the chamber243. That is, protocols may call for one or more chambers to remain “reserved” for later activation, whether for filling or unloading, depending on the anticipated needs of ongoing operations. Thus, while an operator may not be concerned about immediate depletion of the chamber243, there may be a need to hold a sufficient amount of proppant from this chamber in reserve based on the protocol. For example, the controlling processor of a unit101,110may predetermine that at a later time alternate proppant sources may be unavailable (e.g.242,245) due to adjacent chambers243,246being activated at such time. In this scenario, the operator may be required to abort475and draw from alternate sources242,245so as to hold the noted chamber245in reserve for the indicated later time. In this sense, the protocol of this embodiment is “forward looking”, thereby enhancing resource allocation and the ability for substantially continuous operations. By the same token, a variety of detected safety and other issues may require aborting of unloading from any or all chambers. Thus, the ability of the operator to abort475through the display401may be beneficial for a variety of additional reasons.

Referring now toFIG. 5, is a schematic top view of a multi-silo arrangement of the system125ofFIG. 1is shown. In this view, the silos175-178and chambers241-248are apparent over the frame120at the left depiction of the system125. However, at the right depiction of the system125, spaces500,575between the individual silos175-178are apparent. Thus, with particular reference to the silo175it is also apparent that a particular set of load cells510-540is shared for the entire silo175. That is, the load cells510-540are not made available on a chamber by chamber basis. This means that two chambers241,242share the same set of load cells for sake of estimating inventory therein at any given point in time.

In spite of this setup, as detailed hereinabove, only one chamber241or242may be active for loading or unloading at any given point in time. Thus, the processor acquiring information from the cells510-540may still allocate and track inventory on a chamber by chamber basis (i.e. even in absence of chamber by chamber load cells or other dedicated weight measurement tools). Specifically, the total weight of a given silo175is the empty weight known at the initial set up of operations plus the aggregate loaded thereinto. Therefore, as the weight changes due to loading or unloading, aggregate/proppant inventory may be tracked through the load cells510-540because only one chamber241or242may be affected at any given point in time. Indeed, this method of inventory tracking may be utilized where more than two chambers241,242are allocated to a given silo175. That is, so long as only one chamber is active, this technique for tracking inventory may be utilized.

Referring now toFIG. 6, a flow-chart is shown summarizing embodiments of employing automated multi-silo aggregate management techniques at an oilfield. As detailed above, a dynamic protocol for a given application such as stimulation or fracturing operations may be set up or selected and stored at a processor of a control or management unit as indicated at615. The protocol may rely upon a dedicated assignment of a variety of chambers to accommodate a particular aggregate or proppant type to the exclusion of all others (see635). Further, multiple chambers may share the same silo. Nevertheless, operations may proceed as noted at655with aggregate being consumed while the inventory thereof is reliably monitored due to a unique manner of accounting for silo weight in light of silo chamber classifications. Namely, only one chamber of a given silo may be active at any given point in time.

As alluded to above, the operations may proceed with each chamber being dynamically classified in terms of a state of active for filling or consuming, idle, or reserved for later use as indicated at675. Depending on the protocol being carried out and stages thereof, a chamber's state may dynamically change, for example from active in terms of consuming to idle until reactivated for filling. Indeed, as indicated at695, chambers may be refilled based on consumption and monitored aggregate level depending on the stages of the protocol remaining for the operation.

Embodiments described above allow for efficient inventory tracking of proppant or other aggregate at an oilfield during ongoing operations in an automated fashion. Indeed, techniques detailed herein largely eliminate manual accounting techniques for monitoring inventory of aggregate. Once more, the techniques allow for the substantially continuous use of proppant during operations without necessarily requiring an overabundance of proppant on site. Ultimately, a safer and more reliably efficient mode of aggregate management is provided through the automated operator friendly techniques detailed herein.

The preceding description has been presented with reference to presently preferred embodiments. Persons skilled in the art and technology to which these embodiments pertain will appreciate that alterations and changes in the described structures and methods of operation may be practiced without meaningfully departing from the principle, and scope of these embodiments. Furthermore, the foregoing description should not be read as pertaining only to the precise structures described and shown in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.