WO2011106514A2

WO2011106514A2 - Cleaning apparatus and method for a material dryer

Info

Publication number: WO2011106514A2
Application number: PCT/US2011/026059
Authority: WO
Inventors: Richard Guillory; Kyle David; Jake Garber; Aaron Doman; Michael Lagasca; Dwayne Kennerson; Chad Ardoin; Dustin Prejean
Original assignee: M-I L.L.C.
Priority date: 2010-02-25
Filing date: 2011-02-24
Publication date: 2011-09-01
Also published as: EP2539658A2; BR112012021517B1; CA2789955A1; WO2011106514A3; EA024214B1; EA201290829A1; MX2012009848A; CA2789955C; BR112012021517A2; EP2539658A4

Abstract

A flushing system for a dryer includes a support ring, a tubing ring fixed to the support ring, wherein the tubing ring comprises an inner diameter and an outer diameter, a fluid source in fluid communication with the inner diameter of the tubing ring, and a plurality of openings disposed around a circumference of the tubing ring configured to expel fluid from the tubing ring. A method of flushing a solids outlet of a material dryer separating a mixture of solids and liquids into a solids phase and a liquid phase, collecting the solids phase in a discharge chamber section, providing a flow of fluid to an inner diameter of a tubing ring, expelling the fluid through a plurality of openings disposed in the tubing ring, and removing accumulated solids from a wall of the discharge chamber section of the material dryer.

Description

CLEANING APPARATUS AND METHOD FOR A MATERIAL DRYER

BACKGROUND OF INVENTION

Field of the Invention

[0001] Embodiments disclosed here generally relate to a material dryer configured to receive a mixture of solids and liquids and to separate the mixture into a solids phase and a liquid phase. In particular, embodiments disclosed herein generally relate to a material dryer configured to temporarily store the solids phase. More specifically, embodiments disclosed herein generally relate to a material dryer having a flushing system.

Background Art

[0002] Rotary drilling methods employing a drill bit and drill stems have long been used to drill wellbores in subterranean formations. Drilling fluids or muds are commonly circulated in the well during such drilling to cool and lubricate the drilling apparatus, lift drilling cuttings out of the wellbore, and counterbalance the subterranean formation pressure encountered. Recirculation of the drilling mud requires removal of drilling cuttings and other entrained solids from the drilling mud prior to reuse. Shaker separators are commonly used to remove bulk solids from the drilling fluid.

[0002] Bulk solids removed from the drilling fluid by shaker separators often include oil wet or water wet cuttings including hydrocarbons from the drilling fluid, the wellbore, or both. Such oily cuttings are typically not discharged directly into the environment due to environmental concerns relating to hydrocarbons, and because valuable additives that are often entrained in the cuttings can be recovered. A drying operation for drill cuttings may be implemented as a secondary operation to the shaker separator to remove residual drilling fluid from the cuttings.

[0003] Vertical, centrifugal separators are often used to dry the cuttings before discharge or collection. In general, vertical separators, or material dryers, include a housing containing a drive mechanism which is connected to both a flight assembly and a screen assembly. The separator further includes an inlet to receive the material to be separated. Material directed into the separator is captured by flight and screen assemblies, and separation occurs as the material travels downwardly. A liquid component and/or very small particles are forced outwardly by centrifugal force through a fine mesh screen into a space between the screen and the housing. The majority of the liquids are then drawn off and the solids are generally ejected from an outlet assembly having a circumferential outer wall located below the rotor drive assembly.

[0004] Due to the centrifugal force used to separate the liquid component from the solid component, the solid component tends to be flung outward in the direction of rotation of the flight and screen assemblies during discharge. This often causes an accumulation of solid material in the circumferential outer wall of the solid outlet assembly which must periodically be removed to prevent the solid outlet assembly from backing up into the area between the flight and screen assemblies. Cleaning the solids outlet assembly requires stopping the separator for an amount of time required to clean out the assembly.

[0005] To prevent the buildup of solid material, U.S. Patent Publication No.

2008/0120864 discloses a centrifugal separator having a plurality of pulse nozzles in fluid communication with an air source. The pulse nozzles may be actuated periodically, thereby discharging a burst of air to the solids outlet assembly. Additionally, the pulse nozzles may be positioned to provide an air burst in a radial direction toward the circumferential outer wall, or the pulse nozzles may be positioned to discharge air in an axial direction relative to the circumferential wall.

[0006] There exists a need for a cleaning apparatus for preventing solids build up in a solids outlet assembly of a material dryer.

SUMMARY OF INVENTION

[0007] In one aspect, the embodiments disclosed herein relate to a flushing system for a dryer, the flushing system including a support ring, a tubing ring fixed to the support ring, wherein the tubing ring comprises an inner diameter and an outer diameter, a fluid source in fluid communication with the inner diameter of the tubing ring, and a plurality of openings disposed around a circumference of the tubing ring configured to expel fluid from the tubing ring. [0008] In another aspect, the embodiments disclosed herein relate to a method of flushing a solids outlet of a material dryer, the method including introducing a mixture of solids and liquids into the material dryer, separating the mixture of solids and liquids into a solids phase and a liquid phase, and collecting the solids phase in a discharge chamber section, providing a flow of fluid to an inner diameter of a tubing ring, wherein the tubing ring is disposed within the discharge chamber section. In certain embodiments, the method further includes expelling the fluid through a plurality of openings disposed in the tubing ring, and removing accumulated solids from a wall of the discharge chamber section of the material dryer.

[0009] In yet another aspect, the embodiments disclosed herein relate to a material dryer assembly including an inlet configured to receive a mixture of solids and liquids into the material dryer, a centrifugal separator configured to separate the mixture of solids and liquids into a solids phase and a liquid phase, a solids discharge chamber configured to receive the separated solids phase, and a flushing system. In certain embodiments, the flushing system includes a tubing ring fixed to the support ring, wherein the tubing ring comprises an inner diameter and an outer diameter, a fluid source in fluid communication with the inner diameter of the tubing ring, and a plurality of openings disposed around a circumference of the tubing ring configured to expel fluid from the tubing ring.

[0010] Other aspects and advantages of the invention will be apparent from the following description and the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

[0011] FIG. 1 is a perspective view of a flushing system in accordance with embodiments disclosed herein.

[0012] FIG. 2 is a cross sectional view of a flushing system in accordance with embodiments disclosed herein.

[0013] FIG. 3 is a cross-sectional view of a material dryer in accordance with embodiments disclosed herein.

[0014] FIG. 4 is a perspective view of a flushing system in accordance with embodiments disclosed herein. DETAILED DESCRIPTION

[0015] In one aspect, embodiments disclosed herein relate to a material dryer configured to receive a mixture of solids and liquids and to separate the mixture into a solids phase and a liquid phase. In particular, embodiments disclosed herein generally relate to a material dryer configured to prevent material build up in a discharge chamber of the material dryer.

[0016] Referring initially to Figures 1 and 2, perspective and cross-sectional views, respectively, of a flushing system 100 in accordance with embodiments disclosed herein are shown. Flushing system 100 may include a support ring 102 made of a material configured to withstand water temperatures of between approximately 25 and approximately 120 degrees Fahrenheit. In certain embodiments, support ring 102 may be formed by rolling a flat bar of metal, such as, for example, steel or stainless steel, into a hoop having an outer diameter 104, and two ends of the flat bar may be welded or otherwise fastened together.

[0017] A tubing ring 106 having an inner diameter 108 slightly larger than or approximately equal to outer diameter 104 of support ring 102 may be mounted on an outer surface 1 10 of support ring 102. In certain embodiments, tubing ring 106 may be mounted to support ring 102 using welds, adhesives, or mechanical fixtures such as, for example, brackets. In an embodiment using brackets 1 12, a plurality of holes 114 may be drilled in support ring 102 having any desirable spacing therebetween, and holes 1 14 may then be tapped. Tubing ring 106 may be fixed to support ring 102 by aligning brackets 112 with holes 1 14 and attaching brackets 112 securely to support ring 102 by, for example, bolts, screws, rivets, or any other fastener known in the art.

[0018] Referring now to Figure 2, tubing ring 106 may include an inner diameter 116 and an outer diameter 1 18. Tubing ring 106 may be formed by rolling a section of plastic hose or metal tubing into a hoop, and two ends of the tubing section may be connected using, for example, threaded pipe fittings or welding. In certain embodiments, the threaded pipe fittings may be formed from a corrosion resistant material such as, for example, stainless steel. Referring briefly to Figure 1, in one embodiment, a union fitting 120 may be coupled to each end of the rolled tubing section of tubing ring 106, and a tee fitting 122 having three openings may be connected therebetween. A first opening of tee fitting 122 may be coupled to a first union fitting 120 and a second opening of tee fitting 122 may be coupled to a second union fitting 120.

[0019] A third opening on tee fitting 122 may be connected to a fluid supply line (not shown), and the fluid supply line may be configured to provide a flow of fluid to flushing system 100. In certain embodiments, water from a storage tank (not shown) may be provided to flushing system 100. Alternatively, for embodiments used in an offshore drilling environment, a salt water line (not shown) of an oil rig may provide a flow of salt water to flushing system 110. In embodiments using salt water fluid, it may be beneficial for components of flushing system 100 to be made from a non- corrosive material such as, for example, stainless steel, or may be coated with a non- corrosive material, such as, for example, zinc.

[0020] Referring now to Figure 3, a cross sectional view of a material dryer 300 in accordance with embodiments disclosed herein is shown. One example of a commercially available dryer is the Verti-G Dryer from M-I SWACO® L.L.C. (Houston, Texas). Material dryer 300 may include an inlet 302 configured to receive a mixture of solids and liquids, and may further include a separator assembly 304 to separate the mixture into a solids phase and a liquid phase. In certain embodiments, separator assembly 304 may include, for example, a flight and screen assembly (not shown), as discussed above. The separated solids phase may be collected in a solids discharge chamber 306 having an outer circumferential wall 308. Flushing system 100 may be disposed within material dryer 300 and may be mounted on a top surface 310 of solids discharge chamber 306. In certain embodiments, flushing system 100 may be fixed to top surface 310 using welds, adhesives, or mechanical fasteners. For example, support ring 102 may be welded to top surface 310 of solids discharge chamber 306. In alternate embodiments, tubing ring 106 may be directly attached to top surface 310 of solids discharge chamber 306 using, for example, brackets, welding, or adhesives. Top surface 310 of solids discharge chamber 306 may be disposed below a rotor (not shown) in separator assembly 304. A fluid supply line (not shown) may be connected to tubing ring 106 through an outer housing 312 of material dryer 300 such that the fluid supply line may be in fluid communication with inner diameter 116 of tubing ring 106. In select embodiments, a control valve (not shown) may be disposed in the fluid supply line such that the fluid flow rate may be controlled.

[0021] Referring now to Figure 4, a perspective view of flushing system 100 assembled within material dryer 300 is shown. During operation, fluid may be received into an inner diameter (not shown) of tubing ring 106 and may be expelled through a plurality of openings 402 disposed in tubing ring 106. Openings 402 may be disposed lengthwise around tubing ring 106 and, in certain embodiments, openings 402 may be disposed end to end with approximately 1 inch of separation therebetween. At least one of the openings 402 may include a straight or an arched slot cut into tubing ring 106 such that fluid may be expelled over the length of the slot, thereby expelling fluid in the form of a fluid wall. In select embodiments, opening 402 may have a length of approximately 5 inches and a width of approximately 1/16 inch. Those of ordinary skill in the art will appreciate that a variety of design variables such as, for example, shape, length, and width of opening 402, may be used to determine an amount of fluid expelled from tubing ring 106 and to create a desired expelled fluid profile, such as, for example, a spray, stream, or wall. Those of ordinary skill will further appreciate that the number of openings 402 in addition to flow rate of fluid through the system may also be factors in determining the amount of fluid injected into the solids discharge chamber.

[0022] Additionally, the pressure at which fluid exits openings 402 may be related to the flow rate of fluid through flushing system 100. In certain embodiments, it may be desirable to expel fluid from openings 402 at a high pressure such that the fluid may contact accumulated solids (not shown) that may be disposed on outer circumferential wall 308 at a high pressure, and may thereby remove the accumulated solids. Pressure at which fluid contacts the accumulated solids and or outer circumferential wall 308 may be determined by the design variables discussed above in addition to the flow rate of fluid through flushing system 100. In certain embodiments, fluid may be pumped using, for example, a diaphragm pump (not shown), through flushing system 100 at a flow rate between approximately 40 gallons per minute (gpm) and approximately 75 gpm. Those of ordinary skill in the art will appreciate that it may be desirable to scale the flushing system according to the size and capacity of the material dryer in which the flushing system will be installed. For example, a larger material dryer may require a larger flushing system having a higher fluid flow rate, while a smaller material dryer may require a smaller system having a lower fluid flow rate.

[0023] Trajectory of the fluid expelled from tubing ring 108 may be determined by the design variables discussed above, namely, shape, length, width, and number of openings 402, and flow rate of fluid to flushing system 100, in addition to the position of openings 402 on tubing ring 108. In certain embodiments, openings 402 may be disposed on a lower portion or an outer portion of tubing ring 108 that faces outer circumferential wall 308 such that fluid is expelled toward outer circumferential wall 308. Thus, the fluid may contact and runs off of outer circumferential wall 308. The initial contact of the fluid on outer circumferential wall 308 and/or on accumulated solids may remove accumulated solids from outer circumferential wall 308 of solids discharge chamber 306. The fluid run off over outer circumferential wall 308 may prevent further accumulation of solids thereon.

[0024] Fluid flow to flushing system 100 may be continuous or may be pumped in intervals. Flushing system 100 may be configured to perform a flushing operation at predetermined time intervals or may be configured to flush solids discharge chamber 306 after a certain volume of material has accumulated therein. In certain embodiments, flushing may be performed while the material dryer is operating, or alternatively, flushing may be performed between material dryer operations. Those of ordinary skill in the art will appreciate that flushing system 100 may be activated manually or may be automated to provide flushing at particular times.

[0025] Flushing system 100 may prevent solids accumulation on outer circumferential wall 308; however, a solid volume may continue to build up within solids discharge chamber 306 as material dryer 300 continues to operate. Once solids accumulate to a certain height or volume within solids discharge chamber 306, a cleaning operation may be performed to remove the accumulated solids leaving solids discharge chamber 306 substantially empty.

[0026] Advantageously, embodiments disclosed herein may provide for cleaning accumulated solids off of an outer circumferential wall disposed in a solids discharge chamber of a material dryer. Additionally, embodiments disclosed herein may prevent the accumulation of solids on the outer circumferential wall. A flushing system and method in accordance with embodiments disclosed herein may advantageously decrease the frequency at which the solids discharge chamber must be manually cleaned, and further, embodiments disclosed herein may decrease the amount of time and labor that each manual solids discharge chamber cleaning requires. Removing and/or preventing the accumulation of solids on the outer circumferential wall may keep accumulated solids from building up and damaging a rotor disposed in the material dryer.

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.

Claims

CLAIMS What is claimed:

1. A flushing system for a dryer, the flushing system comprising:

a support ring;

a tubing ring fixed to the support ring, wherein the tubing ring comprises an inner diameter and an outer diameter;

a fluid source in fluid communication with the inner diameter of the tubing ring; and a plurality of openings disposed around a circumference of the tubing ring configured to expel fluid from the tubing ring.

2. The system of claim 1, wherein the tubing ring is formed from a material selected from a group consisting of steel and stainless steel.

3. The system of claim 1, wherein the inner diameter of the tubing ring is approximately ½ inch.

4. The system of claim 1, wherein the tubing ring is coupled to the support ring using a plurality of brackets.

5. The system of claim 1, wherein the openings are configured to direct water out of the tubing ring in a downward direction.

6. The system of claim 1, wherein the openings are approximately 5 inches in length and approximately 1/16 inch in width.

7. The system of claim 1, wherein the openings are spaced lengthwise on the tubing ring approximately 1 inch apart.

8. The system of claim 1, wherein a fluid pumped through the tubing ring from the fluid source is one selected from the group consisting of water and salt water.

9. A method of flushing a solids outlet of a material dryer, the method comprising:

introducing a mixture of solids and liquids into the material dryer;

separating the mixture of solids and liquids into a solids phase and a liquid phase; collecting the solids phase in a discharge chamber section;

providing a flow of fluid to an inner diameter of a tubing ring, wherein the tubing ring is disposed within the discharge chamber section;

expelling the fluid through a plurality of openings disposed in the tubing ring; and removing accumulated solids from a wall of the discharge chamber section of the material dryer.

10. The method of claim 9, wherein the fluid is expelled toward the wall of the discharge chamber section of the material dryer.

11. The method of claim 9, wherein providing a flow of fluid to the inner diameter of the tubing ring further comprises pumping the fluid at a flow rate between approximately 40 gpm and 75 gpm.

12. The method of claim 9, wherein providing a flow of fluid to the inner diameter of the tubing ring further comprises pumping salt water to the tubing ring from a salt water line of an offshore rig.

13. The method of claim 9, wherein a diaphragm pump provides the flow of fluid to the inner diameter of the tubing ring from a fluid supply tank.

14. A material dryer assembly comprising:

an inlet configured to receive a mixture of solids and liquids into the material dryer; a centrifugal separator configured to separate the mixture of solids and liquids into a solids phase and a liquid phase;

a solids discharge chamber configured to receive the separated solids phase; and a flushing system comprising:

15. The material dryer assembly of claim 14, further comprising a support ring.

16. The material dryer assembly of claim 14, wherein the flushing system is coupled to a top surface of the solids discharge chamber.

17. The material dryer assembly of claim 16, wherein the flushing system is coupled to the dryer body using a weld.

18. The material dryer assembly of claim 14, wherein the tubing ring is formed from a material selected from the group consisting of steel and stainless steel.

19. The material dryer assembly of claim 14, wherein a salt water line of an offshore rig supplies fluid to the tubing ring.

20. The material dryer assembly of claim 19, wherein the salt water line provides salt water to the tubing ring at a flow rate between approximately 40 gpm and approximately 75 gpm.