1. Field of the Invention
The present invention is directed to the handling, storage and disposal of earthen drill cuttings circulated out of an oil and gas well being drilled.
2. Description of Related Art
Drill cuttings are typically wet with drilling fluid and lose only a portion of the fluids on the rig shakers, leaving wet cuttings to address in an appropriate manner, consistent with economic constraints and environmental considerations, especially in an offshore environment. Drying processes include several well known techniques for drying the cuttings, which is often desirable, especially if any overboard disposal is intended.
Various transportation devices exist for moving the cuttings to various destinations, for further treatment and/or disposal, including, without implied limitation, gravity-drawn movement along troughs, augers (screw conveyors), vacuum systems, where the cuttings are pulled through conduits by creating a downstream pressure drop, and dense phase conveyance systems, where the cuttings are forced through conduits to another destination in response to positive pressure upstream. There are a few options available for the required bulk storage and transport, with some using a pneumatic ISO tank with conical bottoms and some using slider tanks with mechanical discharge systems.
In the offshore environment, particularly, it is often the case that the cuttings must be transported to onshore disposal facilities by boats, barges or other floating vessels. It is common for boat schedules, delays, bad weather and the like, to require the rig operator to store cuttings until the cuttings can be transported to storage on the boat. “Rig buffer storage,” as used herein, includes all cases such as this where it is desirable to store large quantities of cuttings on the rigs while waiting for the opportunity to transport the same to the boat. At any point when the on-rig storage is full, the rig must cease drilling while waiting for a location to transport the cuttings generated by any continued drilling. This is often referred to as “NPT,” an acronym for non-productive time, and is extremely expensive.
As to rig based storage, cuttings boxes on the rig can be used for this purpose, but their use requires extensive use of a crane and is a generally time consuming process. Other techniques and devices in the current art are available, as discussed in part below. The above-referenced dense phase conveyance system (herein “DPCS”) has been implemented in various ways to move the cuttings, especially moving the cuttings down long hoses from rig based storage to boat storage, e.g. a fill station bank on the boat. It has also been used for receiving cuttings at the rig shaker and transporting the cuttings for treatment, e.g. to a desorption unit or to the rig based storage. A frequent problem faced by rig operators arises when cuttings are being generated and delivered to the DPCS at a rate faster than the DPCS can handle. This also causes NPT and is very expensive. No prior art is known which specifically provides “surge storage,” as a means to accommodate a DPCS, such that rapidly accumulating cuttings can be stored until the DPCS can catch up. Conversely, it is also common for a low rate of cuttings accumulation to fall below the minimum cuttings supply requirements for operation of the DPCS. In this regard, surge storage is needed to allow the slow accumulation of cuttings until enough has accumulated to justify utilizing the DPCS, or until the rig begins a higher rate of cuttings generation. Such surge storage does not need to handle the large cuttings volumes that rig based storage requires.
The general problem of high cuttings generation rates requiring surge protection has been identified by McIntyre (U.S. Pat. No. 6,530,438; “McIntyre”) although McIntyre does not contemplate use of his solution with a DPCS, and his approach is not optimized to eliminate the arching, ratholing, segregation, and/or degradation known to be associated with bulk storage of materials. For example, McIntyre feeds cuttings from the rig shaker to what appears, from the limited information provided, to be a funnel flow hopper (
Burnett, et al. (U.S. Pat. No. 7,493,969; “Burnett”) at FIGS. 1-5, discloses a schematically depicted hopper receiving cuttings from the rig shakers. The hopper has a double cone bottom with each cone having steep sides, suggesting a mass flow hopper. However, the cones have long lengths, so available space is not maximized and each cone is more subject to arching. At a later point in the Burnett system (FIGS. 13A-13D), Burnett also discloses a straight-sided, flat bottom cuttings tank that generally provides more space efficient storage. This Burnett tank includes various flow assisters that slide back and forth in linear fashion to move cuttings, from both directions, toward a diametrically oriented slot in the flat bottom, the slot being aligned with and above a screw conveyor. As cuttings fill the tank the entire flat bottom and slot are covered. There is no provision for controlling the amount of cuttings moved to the slot, nor any provision for isolating the screw conveyor during off periods. Burnett also discloses rig buffer storage at a downstream point in its system (FIG. 11), which has a steep-sided, cone bottom hopper. An agitator screw (97) is intended to address the arching that is common to steep-sided cones. Available space is not maximized when using a hopper with steep-sided cones.
Eide (U.S. Published Patent Application 2007/0183853; “Eide”) discloses a mass flow hopper for drill cuttings in which it is intended that drill cuttings enter a hopper with a lower truncated cone portion. The entering cuttings fall and strike a cone that extends upwardly to a distance that appears to enter the cylindrical portion of the tank above the truncated cone portion. The upward facing cone has six guide arms extending down the cone sides and across a short floor, with two of the arms continuing up the inside surface of the truncated cone. A discharge port is in the floor leading to a screw conveyor which is fully exposed to the cuttings in the hopper above. A gate valve (19) opens the discharge port variably and is intended to control the discharge rate. No control is available to regulate movement from the upward facing cone to the floor, resulting in the rapid vertical accumulation of cuttings between the upward facing cone and the hopper cone interior surface. After a period of time with the gate valve shut, the short portions of the arm adjacent the floor must overcome the full weight of the cuttings above. Furthermore, the significant size of the upward facing cone causes a reduction in space near the flat bottom. As a result a larger compactive force is present during times when the discharge port is closed, the larger compactive force significantly increasing the possibility of caking. The Eide device makes no provision for regulating or controlling the placement of cuttings above the discharge port, in that cuttings are free to fall onto the short floor portion as they enter the hopper and strike the upward facing cone.
No current products provide a reliable and flexible capability for metering the discharge of cuttings from a hopper or other storage vessel. This shortcoming prevents the operator from optimizing the use of the discharge cuttings for subsequent blending operations, particularly blending operations associated with various drying processes.
While the foregoing processes and treatments may function generally with respect to the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described. The options available are limited to volume they can hold due to pressure on mechanical equipment, very slow and poor discharge rates, and, in some cases, the need to dilute the stored cuttings with base oil to ensure it will flow. What is needed is a mass flow cuttings storage system and related techniques that will overcome the shortfalls in the products currently available in the market place, which will reduce NPT on the rig and/or service vessels as well as the costs associated with the additional base oil required and the increase in waste volume caused by the same. Systems and techniques are needed that maximize available space, provide optimized surge storage to optimize the use of downstream DPCS (and other transportation devices), provide optimized rig based storage and discharge, minimize or eliminate the occurrence of ratholing, bridging, degradation, segregation, and dehydration within the hopper, control the flow of cuttings from the hopper to the discharge port from the hopper, and provide metered discharge from the hopper storage, particularly when one hopper is discharging wet cuttings and a second hopper is discharging dry cuttings, and it is otherwise desirable to blend the wet and dry cuttings after such metered discharge.
The present invention overcomes the shortcomings of the prior art by providing systems and techniques for the handling of drill cuttings such that surge storage, rig buffer storage and wet and dry cuttings blending, which includes temporary storage of drill cuttings in a manner that optimizes storage capacity and the efficient and regulated movement of stored cuttings to a discharge port out of the hopper. Systems and techniques are provided that maximize available space, provide optimized surge storage to optimize the use of downstream DPCS (and other transportation devices), provide optimized rig based storage and discharge, minimize or eliminate the occurrence of ratholing, bridging, degradation, segregation, and dehydration within the hopper, control and regulate the flow of cuttings from the hopper to the discharge port from the hopper, and provide metered discharge from the hopper storage, particularly when one hopper is discharging wet cuttings and a second hopper is discharging dry cuttings, and it is otherwise desirable to blend the wet and dry cuttings after such metered discharge.
For use in a subterranean drilling operation of the type where earthen cuttings are produced, we have provided a method for the temporary storage of the cuttings, the method comprising: receiving the cuttings into a tank, the tank being positioned above a feeder, the feeder having an outer wall and an inner wall, a substantially flat floor having a first floor portion extending outwardly, a powered rotation member extending through the first floor portion, central sweep members, peripheral sweep members, a weir, an and a substantially flat second floor portion positioned about the first floor portion and extending to the outer wall, the second floor portion having a discharge port, the tank being configured such that cuttings received within the tank substantially cover the first floor portion, the accumulated cuttings forming a primary column above the first floor portion; sweeping the first floor portion with the central sweep members, the central sweep members being affixed to the powered rotation member, the powered rotation member positioning the sweep members proximate the first floor portion, the rotation of the central sweep members displacing cuttings toward and beyond the perimeter of the first floor portion onto the second floor portion; regulating the amount of cuttings being displaced from the first floor portion onto the second floor portion by alternatively lowering and raising the weir, the weir and the inner wall cooperating such that the lowered weir and the inner wall restrain sufficient cuttings above the first floor portion for formation of the primary column; sweeping the second floor portion with the peripheral sweep members, the peripheral sweep members being rotated by the powered rotation member and positioned proximate the second floor portion such that the peripheral sweep members displace cuttings along the second floor portion; discharging cuttings through the discharge port as the cuttings are displaced along the second floor portion; and receiving the discharged cuttings into a transportation device for transport away from the feeder, the receipt of cuttings being alternately terminated and started.
In exemplary embodiments of my invention, at least a portion of the discharged cuttings received into the transportation device are wet, and my method further comprises: receiving the transported wet cuttings in a first additional temporary storage in accordance with the above-described storage; metering the wet cuttings discharged from the first additional temporary storage; routing the metered wet cuttings to a drying process wherein the wet cuttings are at least partially dried; routing at least part of the at least partially dried cuttings for second additional temporary storage in accordance with the above-described storage; optionally, routing at least part of the at least partially dried cuttings from the drying process to storage on a floating vessel; metering the at least partially dry cuttings discharged from the second additional temporary storage; blending wet cuttings discharged from the additional temporary storage with the at least partially dried cuttings discharged from the second additional temporary storage; optionally, discharging the at least partially dried cuttings for overboard disposal; and routing the blend to the drying process.
In exemplary embodiments of my invention, at least a portion of the discharged cuttings received into the transportation device are wet, and my method further comprises: receiving the transported wet cuttings in a first additional temporary storage in accordance with the above-described storage; receiving the transported cuttings on a floating vessel; transporting the wet cuttings from the floating vessel using a transportation device for second additional second temporary storage in accordance with the above-described storage; metering the discharged wet cuttings from the first additional temporary storage; routing the metered wet cuttings to a drying process wherein the wet cuttings are at least partially dried; routing at least part of the at least partially dried cuttings for second additional temporary storage in accordance with the above-described storage; optionally, routing at least part of the at least partially dried cuttings from the drying process to onshore disposal; metering the discharged at least partially dry cuttings from the second additional temporary storage; blending wet cuttings discharged from the additional temporary storage with the at least partially dried cuttings discharged from the second additional temporary storage; optionally, discharging the at least partially dried cuttings for onshore disposal; and routing the blend to the drying process.
For use in a subterranean drilling operation of the type where earthen cuttings are produced, we have provided a method for the temporary storage of the cuttings, the method comprising: receiving the cuttings into a tank, the tank being positioned above a feeder, the feeder having an outer wall and an inner wall, a substantially flat floor having a first floor portion extending outwardly, a powered rotation member extending through the first floor portion, central sweep members, peripheral sweep members, a weir, an and a substantially flat second floor portion positioned about the first floor portion and extending to the outer wall, the second floor portion having a discharge port, the tank being configured such that cuttings received within the tank substantially cover the first floor portion; sweeping the first floor portion with the central sweep members, the central sweep members being affixed to the powered rotation member, the powered rotation member positioning the sweep members proximate the first floor portion, the rotation of the central sweep members displacing cuttings toward and beyond the perimeter of the first floor portion onto the second floor portion; regulating the amount of cuttings being displaced from the first floor portion onto the second floor portion by alternatively lowering and raising the weir, the weir and the inner wall cooperating such that the lowered weir and the inner wall restrain substantially all the cuttings above the first floor portion; sweeping the second floor portion with the peripheral sweep members, the peripheral sweep members being rotated by the powered rotation member and positioned proximate the second floor portion such that the peripheral sweep members displace cuttings along the second floor portion; discharging cuttings through the discharge port as the cuttings are displaced along the second floor portion; and receiving the discharged cuttings into a transportation device for transport away from the feeder, the receipt of cuttings being alternately terminated and started.
For use in a subterranean drilling operation of the type where earthen cuttings are produced, we have provided a system for the temporary storage of the cuttings, the system comprising: a transportation device for moving cuttings; a tank for receiving the cuttings moved by the transportation; a feeder beneath the tank, the feeder having an outer wall and an inner wall, a substantially flat floor having a first floor portion extending outwardly, a powered rotation member extending through the first floor portion, central sweep members, peripheral sweep members, a weir, an and a substantially flat second floor portion positioned about the first floor portion and extending to the outer wall, the second floor portion having a discharge port, the tank being configured such that cuttings received within the tank substantially cover the first floor portion, the accumulated cuttings forming a primary column above the first floor portion; the feeder being further configured such that the central sweep members sweep the first floor portion, the central sweep members being affixed to the powered rotation member, the powered rotation member positioning the sweep members proximate the first floor portion, the rotation of the central sweep members displacing cuttings toward and beyond the perimeter of the first floor portion onto the second floor portion; the weir being further configured for regulating the amount of cuttings being displaced from the first floor portion onto the second floor portion by alternatively being moved between lower and higher positions, the weir and the inner wall cooperating such that the lowered weir and the inner wall restrain sufficient cuttings above the first floor portion for formation of the primary column; the feeder being further configured such that the peripheral sweep members sweep the second floor portion, the peripheral sweep members being rotated by the powered rotation member and positioned proximate the second floor portion such that the peripheral sweep members displace cuttings along the second floor portion; the feeder being further configured such that cuttings are discharged through the discharge port as the cuttings are displaced along the second floor portion; and a second transportation device for receiving the discharged cuttings for transport away from the feeder, the receipt of cuttings being alternately terminated and started.
For use in a subterranean drilling operation of the type where earthen cuttings are produced, we have provided a method for the temporary storage of the cuttings, the method comprising: receiving the cuttings into a tank, the tank being positioned above a feeder, the feeder having an outer wall and an inner wall, a substantially flat floor having a first floor portion extending outwardly, a powered rotation member extending through the first floor portion, central sweep members, peripheral sweep members, a weir, an and a substantially flat second floor portion positioned about the first floor portion and extending to the outer wall, the second floor portion having a discharge port, the tank being configured such that cuttings received within the tank substantially cover the first floor portion, the accumulated cuttings forming a primary column above the first floor portion; sweeping the first floor portion with the central sweep members, the central sweep members being affixed to the powered rotation member, the powered rotation member positioning the sweep members proximate the first floor portion, the rotation of the central sweep members displacing cuttings toward and beyond the perimeter of the first floor portion onto the second floor portion; regulating the amount of cuttings being displaced from the first floor portion onto the second floor portion by adjusting the rotational speed of the central sweep members, the weir and the inner wall cooperating such that the lowered weir and the inner wall restrain sufficient cuttings above the first floor portion for formation of the primary column; sweeping the second floor portion with the peripheral sweep members, the peripheral sweep members being rotated by the powered rotation member and positioned proximate the second floor portion such that the peripheral sweep members displace cuttings along the second floor portion; discharging cuttings through the discharge port as the cuttings are displaced along the second floor portion; and receiving the discharged cuttings into a transportation device for transport away from the feeder, the receipt of cuttings being alternately terminated and started.
The foregoing features and advantages of my invention will be apparent from the following more particular descriptions of exemplary embodiments of the invention as illustrated, in some exemplary embodiments, in the accompanying drawings.
The following discussion describes exemplary embodiments of the invention in detail. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well.
Turning now to
Turning now to
In such exemplary embodiments, as cuttings leave the first floor portion 156 the cuttings pass under the inner wall 154, the vertical clearance beneath the inner wall being varied according to the position of the adjustment ring/weir 160, which is manually adjustable and set using a hand operated wheel 124. This allows the regulation of the amount of cuttings displaced from the first floor portion onto the second floor portion. When the weir 160 is in a lowered position, the weir and the inner wall 154 cooperate to restrain substantially all the cuttings in a position above the first floor portion, referred to herein, in some instances, as a “primary column.” The amount of cuttings displaced from the first floor portion onto the second floor portion is also regulated by adjusting the rotational speed of the central sweep members 170a-d.
The phrase “substantially all,” in this regard, addresses the large majority of the cuttings. For example, in some exemplary embodiments of the type depicted in
Furthermore, in some exemplary embodiments of the type illustrated in
Some exemplary embodiments utilizing the unit 100 illustrated in
Turning now to
In some exemplary embodiments of the present invention, and as shown in
Turning now to
Turning again to
Turning again to the exemplary embodiments illustrated in
In some exemplary embodiments, prospective materials include carbon steel or stainless steel for the tanks 110,210, carbon steel for the frames 112,212, carbon steel, stainless steel, or fiberglass for the inlets 114, carbon steel or stainless steel for the mass flow feeder floor portions 156,162, carbon steel, hard steel, hard faced carbon steel, or hard steel tungsten carbide for the rotation member 190, carbon steel for gear reduction equipment 122 linking the motor 192 and the rotation member 190, carbon steel or stainless steel for the discharge conduit 166, carbon steel, hard steel, hard faced carbon steel, or hard steel tungsten carbide for the central sweep members 170a-d, carbon steel, hard steel, hard faced carbon steel, hard faced carbon steel, or hard steel tungsten carbide for the peripheral sweep members 180a-f, carbon steel or stainless steel for the mass flow feeder outer casing that forms the outer wall 152, carbon steel or stainless steel carbon steel or stainless steel for the mass flow feeder inner wall 154, carbon steel or stainless steel for the mass flow feeder weir 160. Prospectively, seals constructed from buna nitrile will be used to ensure minimal liquid leakage near the rotation member. Prospectively, the auger 188 will be conventional and will be sized to accommodate 60 cubic meters per hour.
Yoshikawa (U.S. Pat. No. 6,860,410; “Yoshikawa”) discloses a circle feeder for powders and grains. A related company manufactures circle feeders that, prospectively, are adaptable for use in the methods and systems described herein.
All patents and published patent applications referenced herein are incorporated herein by reference for all purposes.
With respect to the above description then, it is to be realized that the optimum apparatus and methods for a particular drilling operation will include dimensional adjustments and accommodative structure which will occur to those skilled in the art upon review of the present disclosure.
All equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention.
The descriptions and explanations of terms in this specification are for purposes of illustration only and are not to be construed in a limiting sense.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/US10/50315 | 9/25/2010 | WO | 00 | 3/27/2012 |
Number | Date | Country | |
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61246494 | Sep 2009 | US |