Patent Application
20140166592
1. Field of the Invention
Embodiments disclosed herein generally relate to a shaker for separating solids from fluid. In particular, embodiments disclosed herein relate to a shaker having at least two decks, in which the shaker may be used to allow processing of drilling fluid both in series and in parallel.
2. Background Art
Oilfield drilling fluid, often called “mud,” serves multiple purposes in the industry. Among its many functions, the drilling mud acts as a lubricant to cool rotary drill bits and facilitate faster cutting rates. Typically, the mud is mixed at the surface and pumped downhole at high pressure to the drill bit through a bore of the drillstring. Once the mud reaches the drill bit, it exits through various nozzles and ports where it lubricates and cools the drill bit. After exiting through the nozzles, the “spent” fluid returns to the surface through an annulus formed between the drillstring and the drilled wellbore.
Furthermore, drilling mud provides a column of hydrostatic pressure, or head, to prevent “blow out” of the well being drilled. This hydrostatic pressure offsets formation pressures thereby preventing fluids from blowing out if pressurized deposits in the formation are breeched. Two factors contributing to the hydrostatic pressure of the drilling mud column are the height (or depth) of the column (i.e., the vertical distance from the surface to the bottom of the wellbore) itself and the density (or its inverse, specific gravity) of the fluid used. Depending on the type and construction of the formation to be drilled, various weighting and lubrication agents are mixed into the drilling mud to obtain the right mixture. Typically, drilling mud weight is reported in “pounds,” short for pounds per gallon. Generally, increasing the amount of weighting agent solute dissolved in the mud base will create a heavier drilling mud. Drilling mud that is too light may not protect the formation from blow outs, and drilling mud that is too heavy may over invade the formation. Therefore, much time and consideration is spent to ensure the mud mixture is optimal. Because the mud evaluation and mixture process is time consuming and expensive, drillers and service companies prefer to reclaim the returned drilling mud and recycle it for continued use.
Another significant purpose of the drilling mud is to carry the cuttings away from the drill bit at the bottom of the borehole to the surface. As a drill bit pulverizes or scrapes the rock formation at the bottom of the borehole, small pieces of solid material are left behind. The drilling fluid exiting the nozzles at the bit acts to stir-up and carry the solid particles of rock and formation to the surface within the annulus between the drillstring and the borehole. Therefore, the fluid exiting the borehole from the annulus is a slurry of formation cuttings in drilling mud. Before the mud can be recycled and re-pumped down through nozzles of the drill bit, the cutting particulates are removed.
Apparatuses in use today to remove cuttings and other solid particulates from drilling fluid are commonly referred to in the industry as shale shakers or vibratory separators. A shaker is a vibrating sieve-like table or screening deck upon which returning solids laden drilling fluid is deposited, and through which drilling fluid, that has been separated from much of the solids, emerges from the shaker. Typically, the shaker is an angled table with a generally perforated filter screen bottom, also known as a “deck.” Returning drilling fluid is deposited at a feed end of the shaker. As the drilling fluid travels along the length of the vibrating table, the fluid falls through the perforations to a reservoir below leaving solid particulate material behind. The vibrating action of the shaker table conveys solid particles left behind until they fall off the discharge end of the shaker table. The deck may be at an angle relative to ground. In some shakers, the angle of inclination of the deck results in the movement of particulates in a generally upward direction, while others are inclined such that the movement of particulates is in a generally downward direction, and still other shakers are not inclined or angled relative to the ground. Regardless, table inclination and/or design variations of existing shakers should not be considered a limitation of the present disclosure.
The amount of vibration and the angle of inclination of the shaker decks may be adjustable to accommodate various drilling fluid flow rates and particulate percentages in the drilling fluid. After the fluid passes through the perforated bottom of the deck of the shaker, it can either return to service in the borehole immediately, be stored for measurement and evaluation, or pass through other equipment (e.g., a drying shaker, centrifuge, or a smaller sized shale shaker) to further remove smaller cuttings.
A typical shaker with a screening deck includes of an elongated, box-like, rigid bed, and a screen attached to, and extending across, the bed. The bed is vibrated as the material to be separated is introduced to the screen. The vibrations, often in conjunction with gravity, move the relatively large size material along the screen and off the end of the bed. The bed is typically vibrated by pneumatic, hydraulic, or rotary vibrators, in a conventional manner. In certain shakers, multiple stages of screening may be used to refine the solids laden fluid to a desired purity. In order to reduce space requirements, multiple screening decks may be disposed in a single shaker.
Referring to
In a shaker having a series configuration, effluent from the top screen deck 102 is directed to the middle screen deck 104 by a first flowback pan (not shown) disposed below the top screen deck 102. Solids larger than the mesh of the middle screen deck 104 do not pass through the middle screen deck 104 and are discarded from the shaker 100, while effluent from the middle screen deck 104 is directed to the bottom screen deck 106. Effluent from the bottom screen deck 106 may be collected in a sump (not shown), while solids too large to pass through the bottom screen deck 106 are removed from the shaker 100 and are discarded. Thus, in series operation, fluid is processed by the top screen deck 102, the middle screen deck 104, and the bottom screen deck 106 in order. A multi-deck shaker configured to process fluid in series may remove more solids from the fluid being processed and may be used in selective screening applications where specific solids are recovered for re-use.
Another shaker having a parallel fluid processing configuration may be used instead of the series configuration, described above. In a parallel configuration, effluent from the top screen deck 102 is divided into two streams by a first flowback pan (not shown). One of the streams is directed to the middle screen deck 104, while the other stream is directed to the bottom screen deck 106. Effluent passing through the middle screen deck 104 and the bottom screen deck 106 may then be collected in a sump (not shown) for re-use. A multi-deck shaker configured to process fluid in parallel may have a higher fluid capacity for a given mesh size of the screen decks 102, 104, and 106, and thus, may process more fluid in a given time than a shaker configured to process fluid in series.
Accordingly, there exists a need for a multi-deck shaker that may be operated in series or in parallel. Furthermore, there exists a need for a multi-deck shaker that may be selectively switched from series mode to parallel mode, or from parallel mode to series mode.
In one aspect, embodiments disclosed herein relate to a shaker to separate solids from a fluid. The shaker includes a first screening deck having a first channel and a second channel, and a second screening deck. Fluid received by the first channel and separated through the first screening deck is directed to the second screening deck, and fluid received by the second channel and separated through the first screening deck is directed to a sump of the shaker.
In another aspect, embodiments disclosed herein relate to a method to separate solids from drilling fluid. The method includes receiving drilling fluid onto a first channel of a first screening deck, the first screening deck having the first channel and a second channel, separating solids from drilling fluid in the first channel of the first screening deck, directing drilling fluid from the first channel of the first screening deck onto a second screening deck, and separating solids from drilling fluid in the second screening deck. Drilling fluid received by the second channel and separated through the first screening deck is directed to a sump of the shaker.
In yet another aspect, embodiments disclosed herein relate to a method to separate solids from drilling fluid. The method includes operating a shaker in a series configuration to process drilling fluid, including receiving drilling fluid in a first channel of a first screening deck of the shaker, the first screening deck having the first channel and a second channel, separating solids from drilling fluid in the first channel of the first screening deck, directing drilling fluid from the first channel of the first screening deck onto a second screening deck of the shaker, separating solids from drilling fluid in the second screening deck, and directing drilling fluid from the second screening deck to a sump of the shaker. The method further includes operating the shaker in a parallel configuration to process drilling fluid, including receiving drilling fluid in the second channel of the first screening deck of the shaker, separating solids from drilling fluid in the second channel of the first screening deck, directing drilling fluid from the second channel of the first screening deck to the sump of the shaker, receiving drilling fluid in the second screening deck of the shaker, separating solids from drilling fluid in the second screening deck, and directing drilling fluid from the second screening deck to the sump of the shaker. The method yet further includes adjusting between operating the shaker in the series configuration and in the parallel configuration to process drilling fluid.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
In one aspect, embodiments disclosed herein relate to apparatuses and methods to separate solids from a drilling fluid. In particular, embodiments of the present disclosure provide for a shaker, such as a multi-deck shaker, having a first screening deck and a second screening deck, in which the screening decks may be operated in a series configuration and/or a parallel configuration when separating solids from the drilling fluid. As such, embodiments disclosed herein may relate to apparatuses and methods to increase the efficiency of a shaker, such as by providing drilling fluid to multiple decks of a shaker, as desired.
Referring now to
As shown, the first screening deck 211 and/or the second screening deck 221 may have one or more channels 213. For example, the first screening deck 211 may include a first channel 213A, a second channel 213B, and a third channel 213C. Further, the second screening deck 221 may include a first channel 223A and a second channel 223B. However, screening decks 211 and 221 may include one or more channels, depending on the requirements of the screening operation. For example, the first screening deck 211 may include two or more channels 213, and the second screening deck 221 may include one or more channels 223. As such, it should be understood that the second screening deck 221 includes at least one channel, which in some embodiments may be the only channel, to receive and direct drilling fluid.
Further, the shaker 201 may include a feeder 203 coupled thereto, such as having the feeder 203 coupled to a feed end of the shaker 201. The feeder 203 may be used to receive and direct drilling fluid to the first screening deck 211 of the shaker 201. Particularly, the feeder 203 may be used to control and selectively direct drilling fluid to the first screening deck 211 of the shaker 201, such as by selectively directing drilling fluid to the first channel 213A, the second channel 213B, and/or the third channel 213C of the first screening deck 211.
As such, the feeder 203 may have one or more inlets and/or one or more outlets, such as corresponding to the number of channels used within the first screening deck 211, to receive and direct drilling fluid to the one or more channels 213A-C of the first screening deck 211, as desired. In one or more embodiments, the feeder may include one or more gates, valves, and/or any other mechanisms that may be used to facilitate receiving and/or directing drilling fluid to the shaker. Further, in one or more embodiments, the feeder may include one or more stationary screens included therewith, such as by having one or more screens disposed within the feeder to facilitate separating solids from the drilling fluid before having the drilling fluid directed to a screening deck of the shaker. Furthermore, as shown, one or more motors 209 may be coupled and/or attached to the shaker 201 to provide vibratory motion while separating solids from drilling fluid with the shaker 201.
A screening mesh may be provided on each of the screening decks of the shaker, and, more particularly, may be provided on each of the channels of the screening decks of the shaker. The screening mesh may be used to filter out and separate solids of various sizes from drilling fluid according to the size of the respective screening mesh. As such, in
For example, the screening decks may use or incorporate screening mesh of different sizes, such as by having a coarser screening mesh on the first screening deck 211 and a finer screening mesh on the second screening deck 221, such that the second screening deck 221 may be capable of filtering out and separating solids having a smaller size as compared to that of the first screening deck 211. Furthermore, the channels of the screening decks may use or incorporate screening mesh of different sizes, such as by having a coarser screening mesh on the first channel 213A of the first screening deck 211 and a finer screening mesh on the second channel 213B and/or the third channel 213C of the first screening deck 211. As such, the second channel 213B and/or the third channel 213C may be able to filter out and separate solids having a smaller size as compared to that of the first channel 213A.
Referring still to
A shaker in accordance with one or more embodiments of the present disclosure may also include one or more flowback pans. For example, as shown in
In accordance with embodiments disclosed herein, a shaker 201 may include one or more flowback pans 231 therewith, or may not include any flowback pans 231. Further, a flowback pan 231 may be separated into multiple separate flowback pans 231. For example, rather than having a flowback pan 231 positioned beneath and between the first screening deck 211 and the second screening deck 221, multiple flowback pans 231 may be positioned beneath the different channels 213A-213C of the first screening deck 211. As such, different shapes, sizes, structures, arrangements, and configurations may be used for a flowback pan 231 without departing from the scope of the present disclosure.
As discussed above, a shaker 201 in accordance with the present disclosure may be used in a series configuration and/or a parallel configuration when separating solids from the drilling fluid. Accordingly, with respect to
Further, drilling fluid may pass and flow through the screening mesh of the first channel 213A. As such, in an embodiment in which the flowback pan 231 is included within the shaker 201, the drilling fluid may then be received by the flowback pan 231 such as to direct the drilling fluid to the second screening deck 221. Particularly, the flowback pan 231 may be used to direct drilling fluid to the first channel 223A and/or the second channel 223B of the second screening deck 221, such as to the feed ends 225A and 225B of the first channel 223A and the second channel 223B, respectively. However, in an embodiment in which a flowback pan is not included within the shaker 201, the drilling fluid may flow through the screening mesh to be directed and fall directly onto the first channel 223A and/or the second channel 223B of the second screening deck 221. In one or more embodiments, a flowback pan 231 may be used to prevent unnecessary wearing of one or more screening decks of the shaker.
As drilling fluid is directed to the first channel 223A and/or second channel 223B of the second screening deck 221, the channels 223A and 223B may be used to separate solids from the drilling fluid received therein. Particularly, solids from the drilling fluid having a larger size than that of the screening mesh of the first channel 223A and/or the second channel 223B may be discharged off from the discharge ends 227A and/or 227B of the channels 223A and/or 223B of the second screening deck 221. Further, the drilling fluid may pass and flow through the screening mesh of the channels 223A and/or 223B, in which the drilling fluid may then be directed to the sump 241 of the shaker 201. As discussed above, the block diagram in
Continuing, in a parallel flow configuration, drilling fluid may still be directed to the first channel 213A of the first screening deck 211, as discussed above with respect to
Further, the drilling fluid may pass and flow through the screening mesh of the channels 213B and/or 213C, in which the drilling fluid may then be directed to the sump 241 of the shaker 201. For example, as discussed above, the flowback pan 231 (if desired), or another separate flowback pan, may be used to direct the drilling fluid from the channels 213B and/or 213C of the first screening deck 211 to the sump 241 of the shaker 201. However, in one or more embodiments, a flowback pan may not be used, in which other means, such as the sides or the rear of the shaker 201 may be used to direct the drilling fluid to the sump 241 of the shaker 201.
As discussed above, the block diagram in
In accordance with one or more embodiments of the present disclosure, one or more of the screening decks, and one or more of the channels of the screening decks, may be disposed at different deck angles with respect to each other. For example, one or more of the channels 213A-213C of the first screening deck 211 and one or more of the channels 223A and 223B of the second screening deck 221 may be disposed at and movable between different deck angles with respect to each other, if desired.
In one embodiment, the first screening deck 211 may be disposed at a different deck angle than that of the second screening deck 221. In another embodiment, the first channel 213A of the first screening deck 211 may be disposed at about zero degrees, whereas the second channel 213B and/or the third channel 213C of the first screening deck 211 may be disposed at an incline of about four degrees, as shown in
Referring now to
Further, as shown in
As shown in
With respect to
Further, as shown in
As mentioned above, the shaker is not limited to an arrangement of only two screening decks. As such, the shaker may include more than two screening decks, and the arrangement of the screening decks may vary with respect to each other. For example, rather than having the first screening deck arranged above the second screening deck, the screening decks may be arranged side-by-side configuration, or in other configurations. For example, in one embodiment, the shaker may include multiple deck separators, such as the MD-3 Shale Shaker, commercially available from M-I, L.L.C., a Schlumberger Company, in Houston, Tex. Accordingly, the number, arrangement, and configuration of screening decks used with the shaker should not be considered a limitation of the present disclosure.
Advantageously, one or more embodiments disclosed herein may provide a more efficient shaker. In particular, embodiments disclosed herein may provide for a shaker that may seamlessly be able to change flow configurations. For example, the shaker may not need to be powered off to reconfigure the flow of the shaker. Rather, drilling fluid may be redirected through the shaker, as desired, by changing the flow through the feeder and the configuration of one or more of the flowback pans included within the shaker. Further, embodiments disclosed herein may provide for a shaker that may be able to have multiple deck angles, such as multiple deck angles for different channels and/or different screening decks. For example, in one embodiment, one or more channels of the first screening deck may be disposed at and/or movable between different deck angles with respect to one or more channels of the first screening deck and/or the second screening deck, if desired. Furthermore, embodiments disclosed herein may provide for a shaker with an increased effective screening area. For example, as shown in
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2012/038096 | 5/16/2012 | WO | 00 | 2/12/2014 |
| Number | Date | Country | |
|---|---|---|---|
| 61486683 | May 2011 | US |
