OILFIELD CHEMICALS

TECHNICAL FIELD

The present disclosure relates generally to oilfield equipment and in particular to surface equipment for supporting fracturing operations.

BACKGROUND

Well site locations for oil and gas wells have become increasingly congested, particularly as enhanced recovery techniques have been developed. After drilling operations have finished and during well completion operations, a well site may generally include a wellhead, blowout preventers, hydraulic fracturing and proppant systems, pumps, generators, water storage, transfer and treatment equipment, and chemical and proppant storage containers. Other equipment associated with drilling, completing, and/or producing wellbore may also be provided at the well site location.

Modern enhanced recovery techniques may result in multiple wellheads at a single well site and/or wellbores with multiple lateral branches. Hydraulic fracturing operations utilized in enhanced oil and gas recovery, for example, may generally include raw materials for preparation of fracturing fluid, a blender system, a pump system, as well as transfer equipment. In the past, a fracturing operation for a single well might take three to ten days, after which, the fracturing equipment was removed. However, now with multiple wellhead per well site or multiple lateral branches extending from a primary wellbore being more common, fracturing equipment may remain at a single location for multiple weeks. Accordingly, there is a recognized need to reduce the footprint of fracturing equipment at a well site.

The traditional method for transporting and storing liquid or dry chemicals on location at a well site is by conventional tractor/trailer, flatbed trailer, or bobtail truck.

Prior to delivery to a well site, large quantities of required liquid chemicals are loaded into one or more tanker trailers. In some cases, large volumes of liquid chemical are supplied in International Standards Organization "ISO" specified tanks-— chemical tanks contained inside a 20 ft. by 8 ft. by 8.5 ft. frame with standardized mounting locations. ISO tanks are attached to a semi-trailer specifically designed to accept ISO frames. Smaller volumes of liquid chemicals are typically loaded in totes and carried on flatbed trailers. The tanker trailers and flatbed trailers are then transported to the well site, where they remain parked for the duration of the fracturing job or until the tanks are emptied.

The liquid chemicals are typically dispensed directly from the tanker trailers, ISO tanks, and totes during the fracturing job. In large-volume chemical operations, the chemical inventory is typically monitored manually by dipstick, but in some cases, an electronic fluid level device may be available. In small-volume liquid chemical operations, the chemical inventory is usually monitored by dipstick, or in some instances, by weigh scales.

In the case of dry chemicals, large volumes of dry chemicals are traditionally supplied in "big bags"— approximately 4 cubic foot bags with a bottom drawstring outlet. Big bags are typically transported from the supplier to the well site by a tractor-trailer. Small volumes of dry chemicals are commonly packaged in sacks or bags, for example 50 lb. bags. The bags are transported to the well site on flatbed trucks or tractor-trailers and stored there for the duration of the fracturing job or until the load is used up. Dry chemicals are susceptible to moisture and must be covered while stored in inclement weather.

To dispense, big bags are suspended by a crane over a screw feeder at ground level, and the dry chemical is gravity fed into the screw feeder hopper to be introduced into the fracturing blender system. Small bags are transferred manually from the truck or trailer to a metering feeder on a fracturing blender as required by the fluid system being mixed. In large or small volume dry chemical operations, the inventory is monitored by counting the bags of chemical used.

Accordingly, if a particular job calls for 3000 gallons each of five different liquid chemicals and a large quantity of dry chemical, there would be five tanker tractor-trailers and at least one van tractor-trailer parked on location for the duration of the fracturing operations, occupying at least six 8 ft. by 60 ft. footprints of pad space, or 2880 sq. ft. Similarly, in the case of smaller volume liquid or dry chemicals, a flatbed trailer with totes or small bags of chemicals occupies another 8 ft. by 60ft (320 sq. ft.) footprint of pad space. In addition to footprint requirements, there is a capital expense associated with tractor-trailers, flatbeds, and tandem axle trucks being tied up and idle for a substantial part if not the entire duration of a fracturing operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are described in detail hereinafter with reference to the accompanying figures, in which:

Figure 1 is an elevation view in partial cross section of a well site during completion operations that employs a hydraulic fracturing system, chemical storage units, and associated systems and equipment for supporting fracturing operations according to an embodiment;

Figure 2 is a perspective view of a chemical transportation, storage, and dispensation system according to one or more embodiments, showing a base designed to accommodate either "roll off" or "hook" portable container technologies adapted for carrying an intermodal shipping container on load cells;

Figure 3 is an elevation view of the chemical transportation, storage, and dispensation system of Figure 2, shown carrying a tank mounted within a shipping container frame; Figure 4 is an elevation view of the chemical transportation, storage, and dispensation system of Figure 2, shown carrying a van container for storage of small volume dry chemical bags;

Figure 5 is an elevation view of the chemical transportation, storage, and dispensation system of Figure 2, shown carrying a commercially available screw conveyor adapted with corner castings for dispensing large volumes of dry chemical; Figure 6 is an enlarged exploded perspective diagram of a quick disconnect connector system according to an embodiment for use with the system of Figures 2-5;

Figure 7 is an enlarged perspective view of the quick disconnect connector system of Figure 6, showing a mount and connector of the base of Figure 2 received into an oval hole of a corner casting of an intermodal shipping container and oriented in an unlocked position; Figure 8 is an enlarged perspective view of the quick disconnect connector system of Figure 7, shown in a locked position; and

Figure 9 is a flow chart of a portion of a method for completing a wellbore according to an embodiment, demonstrating use of the chemical transportation, storage, and dispensation system of Figures 1 -8.

DETAILED DESCRIPTION

The foregoing disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, spatially relative terms, such as "beneath," "below," "lower," "above," "upper," "uphole," "downhole," "upstream," "downstream," and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the apparatus in use or operation in addition to the orientation depicted in the figures. Figure 1 is an elevation view in partial cross-section of a well site 120 during well completion operations according to an embodiment. Well site 120 may include a well head 124, which may be fluidly connected to a hydraulic fracturing pumping system 126. According to an embodiment, well site 120 may include a chemical transportation, storage, and dispensation system 10, which may consist of one or more chemical handling apparatus 20, 30, for example. Figure 2 is a perspective view of a chemical handling apparatus according to one or more embodiments, and in particular of a chemical transportation, storage, and dispensation system 10. Figure 3 is an elevation view of chemical transportation, storage, and dispensation system 10, shown carrying a tank mounted within a shipping container frame. Figure 4 is an elevation view of chemical transportation, storage, and dispensation system 10, shown carrying a van container for storage of small volume dry chemical bags. Referring to Figures 2-4, chemical transportation, storage, and dispensation system 10 provides a common platform or base 12, with mounts 14 and connectors 16 for enabling an intermodal shipping tank container 20 (Figure 3) or van container 30 (Figure 4), for example, to be attached to the upper side 1 3 of platform 12. In an embodiment, each mount 14 and connector 16 interfaces with a structural receptacle 26 located at the bottom of containers 20, 30, typically at the corners.

In one or more embodiments, base 12, mounts 14, and connectors 16 are designed and arranged to carry standard 20 ft. ISO shipping containers, although base 12, mounts 14, and connectors 16 may equally be designed to carry shipping containers conforming with other standards and having other dimensions or mounting arrangements, as appropriate. In some embodiments, base 12 is no larger than 8 ft. by 60ft.

Base 12 is ideally designed to accommodate either the "roll off or "hooklift hoist" technologies, or both, which are associated with the refuse business and allow portable containers to be loaded and unloaded easily. A first end 17 of base 12 is carried by one or more rollers 18, which allow end 17 to be rolled on the ground as base 12 is loaded on or unloaded from a transport vehicle (not illustrated). "Roll-off technology employs a truck or trailer with a tiltable bed, and base 12 is winched on and off the tilted bed by connection to a pad eye 22 mounted to a second end of base 12. "Hooklift hoist" technology, on the other hand, employs a pivoting hydraulic hooklift hoist arm that engages an elevated hooklift hoist attachment 32 and lifts the container onto a rack that is attached to the truck or trailer frame. The underside 1 1 of base 12 may be reinforced with ribs or track (not illustrated) to allow smooth and straight rolling of the base 12 on the bed or rack of the transport vehicle.

According to one or more embodiments, a "roll off truck or trailer, or a "hooklift" truck or trailer is used only for the transportation of base 12 with its carried ISO tank 20 or van container 30. Base 12 is unloaded at the well site and occupies a fraction of the footprint required by the traditional storage of a tractor-trailer on site. For example, for the above requirement of five 3000 gallon liquid chemical tanks and one large quantity of dry chemical, there need only be six of 8 ft. by 20 ft. ISO containers on location, occupying approximately 1000 sq. ft. of pad compared to the original 2880 sq. ft.

After unloading base 12, the transport truck then leaves the well site location and is free to retrieve another ISO tank or container as appropriate. Thus, a single transport vehicle with "roll off or "hooklift" technology can support multiple ISO tanks or containers, reducing the invested capital by lowering the vehicle requirements to support the liquid and dry chemical operations by fifty percent or greater over prior art methods.

As shown in Figures 2 and 3, according to one or more embodiments, mounts 14 include or incorporate weigh scales 50 that allow the gross weight of tank container 20 to be determined. In particular, base 12 includes weight scales 50 between the ISO mounts and the surface 13 of base 12. Scales 50 allow the operator to monitor the inventory of chemicals and provide reduction-in- weight measurement of chemicals as they are used. Scales 50 may be mechanical, or electronic using load cells, strain gauges, or the like. Scales 50 may provide independent weight measurements, or they may provide separate quality control checks to correlate volumetric metering devices.

Figure 4 is an elevation view of an arrangement for storage of small volume dry chemicals, in which a standard 20ft ISO van container is attached to base 12, allowing for the weatherproof storage of the sacked dry chemicals for future use. Scales 50 may be used for inventory control in addition to or in lieu of counting dry chemical sacks. Figure 5 is an elevation view of an arrangement for handling of large volume chemicals. Base 12 carries an industry-standard screw conveyor 60 that is outfitted with an ISO frame or mounts 62 to transport, store, and meter large volume dry chemicals to a fracturing blender mixer (not illustrated) with minimal human and weather exposure. However, bulk material devices other than an auger may be used and carried atop base 12 as appropriate. In an embodiment, screw conveyor 60 includes a conveyor body 64 and an elongate auger assembly 66. Conveyor body 64 may include a chemical storage compartment 67 with an internal hopper 68 that feeds material into a lower end of auger assembly 66. Auger assembly 66 includes a tube 70 that houses and engages a rotatable auger screw 72. A motor 74 selectively rotates auger screw 72 within tube 70, thereby transferring the material that falls from hopper 68 into the lower end of auger assembly to the upper end of auger assembly 66, where the material is dispensed through a chute 76. An actuator 78 may be included to selectively control the tilt of auger assembly 66. Figure 6 is an exploded diagram in perspective view of a quick-disconnect connector system used with base 12, containers 20, 30, and screw conveyor 60 according to an embodiment. Figure 7 is a perspective view of the quick-disconnect connector system of Figure 6 in a connected but unlocked state. Figure 8 is a perspective view of the quick-disconnect connector system of Figure 6 in a connected and locked state. Referring to Figures 6-8, in one or more embodiments, the quick-disconnect connector system is an ISO twistlock connector. Receptacle 26 forms the female part of the connector system and is structurally fitted to the container frame itself, typically at the corners. Accordingly, receptacle 26 is commonly known as a corner casting. Receptacle 26 has no moving parts, and it has an oval aperture 27 formed in the bottom. Connectors 16 are fixed atop mounts 14 of base 12 (Figure 2). Each connector 16 has a fixed stand or pedestal 24. A tapered crown 25 is fixed atop stand 24 so that it may be rotated about an axis 29 through connector 16 that is normal to base 14, as indicated by arrow 28 on Figure 6. To carry a container atop base 12, crown 25 is oriented to align with the major axis of oval aperture 27, and the container is lowered so that connector 16 is received within oval aperture 27 as shown in Figure 7. Next, crown 25 is rotated 90 degrees, so that it will no longer pass through oval aperture 27, thereby locking the container to mount 14, as shown in Figure 8.

Figure 9 is a flow chart that details a portion of a method for completing a well according to an embodiment using chemical transportation, storage, and dispensation system 10 of Figures 1 -8. The portion of the method shown in Figure 9 is particularly useful when hydraulic fracturing operations are used.

At step 200, a shipping container, which may be an ISO tank 20 (Figure 3) or van container 30 (Figure 4), for example, is provided. At step 202, the shipping container is filled with a chemical. At step 204, a base 12 (Figure 2), equipped with a roller at one end and at least a winching pad eye or a hook lift hoist attachment at the other end, is provided. At step 206, the shipping container is mounted atop the base. Although step 202, holding a chemical within the shipping container, is illustrated as occurring before the shipping container is mounted to the base, in an embodiment the shipping container may be filled with the chemical after it has been mounted to the base. Next, at step 208, a transport vehicle is provided. The transport vehicle may have a tiltable bed and a winch or a rack and a hooklift hoist arm. At step 210, the base with shipping container is lifted on to the transport vehicle. In the case of the transport vehicle having a tiltable bed, the bed is first tilted, the winch is connected to the winching pad eye of the base, the base is winched atop said bed while the roller carries at least part of the weight of the base for at least part of the winching process, and finally the bed is lowered back to a level orientation. In the case of the transport vehicle having a hooklift hoist arm, the hooklift hoist arm is connected to the hooklift hoist attachment of the base and the base is hoisted atop the rack of the transport vehicle by said hooklift hoist arm while the roller carries at least part of the weight of the base for part of the hoisting process.

At step 212, the base with its mounted shipping container is moved by the transport vehicle to well site 120 (Figure 1). At step 214, the base and its shipping container are unloading from the transport vehicle by essentially reversing the loading process of step 210, and the base and its shipping container are placed on the ground at the well site. The above process of Figure 9 may then be repeated until all the required chemicals are located at the well site. There, the chemicals held by the shipping containers are readily available for fracturing operations without requiring the larger footprint or capital expense of multiple tractor- trailers.

In summary, a chemical handling apparatus, a well completion system, and a method for handling chemicals have been described. Embodiments of the chemical handling apparatus may generally have: A generally planar base; a roller rotatively coupled to a first end of the base; at least one a winching pad eye or a hooklift hoist attachment mounted to a second end of the base opposite the first end; and a plurality of mounts coupled to the base and arranged to securely carry a shipping container atop the base. Embodiments of the well completion system may generally have: A wellhead atop a wellbore; a fracturing system disposed adjacent to the wellhead and fluidly coupled to the wellbore via the wellhead; and at least one chemical handling apparatus disposed in proximity to the fracturing system, each of the at least one chemical handling apparatus including a generally planar base, a roller rotatively coupled to a first end of the base, at least a winching pad eye or a hooklift hoist attachment mounted to a second end of the base opposite the first end, a plurality of mounts coupled to the base, and a shipping container carried atop the base and fixed to the base by the plurality of mounts. Embodiments of the method for handling chemicals may generally include: Providing a shipping container; holding a chemical within the shipping container; providing a generally planar base, a roller rotatively coupled to a first end of the base, and at least a winching pad eye or a hooklift hoist attachment mounted to a second end of the base opposite the first end; and mounting a the shipping container atop the base.

Any of the foregoing embodiments may include any one of the following elements or characteristics, alone or in combination with each other: The shipping container is an intermodal container that conforms to International Standards Organization specifications; the plurality of mounts is dimensioned to accept the shipping container; a connector carried atop each of the plurality of mounts for securing the shipping container to the base; a twistlock connector carried atop each of the plurality of mounts and arranged to be received in a corner casting of the shipping container for securing the shipping container to the base; a scale coupled to the base and arranged for measuring a weight of the shipping container when carried atop the base; the scale includes at least one of the group consisting of a strain gauge and a load cell; the shipping container connected to the mounts; the shipping container is a 20 foot ISO tank container; the shipping container is a 20 foot ISO van container; a bulk material conveying device connected to the mounts; a first of the at least one chemical handling apparatus, wherein the first chemical handling apparatus is characterized by a 20 foot ISO van container; a second of the at least one chemical handling apparatus, wherein the first chemical handling apparatus is characterized by a 20 foot ISO tank container; a fracturing blender; a screw conveyer disposed in proximity to the fracturing blender so as to convey a quantity of a chemical into the fracturing blender, the screw conveyor being mounted atop a generally planar base, the base having a roller rotatively coupled to a first end of the base, at least one of the group consisting of a winching pad eye and a hooklift hoist attachment mounted to a second end of the base opposite the first end; providing a transport vehicle having a tiltable bed and a winch; tilting the bed of the transport vehicle; coupling the winch to the winching pad eye; winching the base carrying the shipping container atop the bed; providing a transport vehicle having a rack and a hooklift hoist arm; coupling the hooklift hoist arm to the hooklift hoist attachment; hoisting the base carrying the shipping container atop the rack by the hooklift hoist arm; providing a transport vehicle; lifting the base carrying the shipping container on to the vehicle, the roller carrying at least a part of the weight of the base and the shipping container while lifting; transporting the base and the shipping container to a well site; placing the base on the ground at the well site; placing the base in proximity to a fracturing system at the well site; removing a quantity of the chemical from the shipping container; introducing the quantity of the chemical into the fracturing system; conducting fracturing operations; providing a scale on the base; weighing the shipping container with the scale; determining an amount of the chemical dispensed from the shipping container using the scale; and determining an amount of the chemical present within the shipping container using the scale. The Abstract of the disclosure is solely for providing the United States Patent and Trademark Office and the public at large with a way by which to determine quickly from a cursory reading the nature and gist of technical disclosure, and it represents solely one or more embodiments.

While various embodiments have been illustrated in detail, the disclosure is not limited to the embodiments shown. Modifications and adaptations of the above embodiments may occur to those skilled in the art. Such modifications and adaptations are in the spirit and scope of the disclosure.