CA2433475A1 - Drilling fluid treatment tank - Google Patents
Drilling fluid treatment tank Download PDFInfo
- Publication number
- CA2433475A1 CA2433475A1 CA 2433475 CA2433475A CA2433475A1 CA 2433475 A1 CA2433475 A1 CA 2433475A1 CA 2433475 CA2433475 CA 2433475 CA 2433475 A CA2433475 A CA 2433475A CA 2433475 A1 CA2433475 A1 CA 2433475A1
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- CA
- Canada
- Prior art keywords
- tank
- fluid
- drilling fluid
- weir
- drilling
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 126
- 238000005553 drilling Methods 0.000 title claims abstract description 104
- 238000011282 treatment Methods 0.000 title claims abstract description 32
- 239000007788 liquid Substances 0.000 claims abstract description 63
- 239000007787 solid Substances 0.000 claims abstract description 31
- 229920000642 polymer Polymers 0.000 claims abstract description 28
- 238000006243 chemical reaction Methods 0.000 claims abstract description 7
- 239000000654 additive Substances 0.000 claims description 22
- 230000000996 additive effect Effects 0.000 claims description 14
- 238000000034 method Methods 0.000 claims description 13
- 238000000926 separation method Methods 0.000 claims description 12
- 238000002347 injection Methods 0.000 claims description 11
- 239000007924 injection Substances 0.000 claims description 11
- 239000000463 material Substances 0.000 claims description 7
- 238000004891 communication Methods 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 13
- UHZZMRAGKVHANO-UHFFFAOYSA-M chlormequat chloride Chemical compound [Cl-].C[N+](C)(C)CCCl UHZZMRAGKVHANO-UHFFFAOYSA-M 0.000 abstract description 3
- 238000003860 storage Methods 0.000 abstract description 3
- 239000013049 sediment Substances 0.000 description 7
- 239000000203 mixture Substances 0.000 description 5
- 239000008394 flocculating agent Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- KJPRLNWUNMBNBZ-UHFFFAOYSA-N cinnamic aldehyde Natural products O=CC=CC1=CC=CC=C1 KJPRLNWUNMBNBZ-UHFFFAOYSA-N 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- UDCDOJQOXWCCSD-UHFFFAOYSA-N N,N-dimethyl-N'-p-tolylsulfamide Chemical compound CN(C)S(=O)(=O)NC1=CC=C(C)C=C1 UDCDOJQOXWCCSD-UHFFFAOYSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000006073 displacement reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000000887 hydrating effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
- E21B21/06—Arrangements for treating drilling fluids outside the borehole
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Treatment Of Sludge (AREA)
Abstract
A drilling fluid treatment tank has been invented that can be used for both water-based drilling fluid and for polymer-based drilling fluid. As such, the tank can be employed to manage the fluid from spudding to rig release, when the borehole is complete. The tank may include walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage positioned adjacent an upper edge of each weir permitting liquid to flow from compartment to compartment and a means for providing conversion between use for solids settling, use for stripping drilling mud and use for polymer-based drilling mud pre-mixing. The tank may be substantially self-contained including, for example, fluid handling tanks, pre-mix tanks and polymer storage tanks, and possibly also pumps, pump controls and fluid circulation lines.
Description
Drilling Fluid Treatment Tank Field of the Invention The present invention is directed to a drilling fluid tank and in particular to a tank for the treatment of drilling fluid.
Background of the Invention Drilling fluid, which is also termed mud, is circulated through a wellbore during drilling to lubricate the drill bit and to carry drilled cuttings to surface.
A selection of drilling fluid is made depending on various parameters including the nature of the formation being drilled through, the depth of the borehole and the speed under which the drilling is being progressed. In North America, it is possible to use a less expensive water-based drilling fluid initially, during spudding, before moving to a polymer based mud as the hole depth is increased.
Environmental concerns, as well as cost, have urged operators to move to closed loop systems, wherein the drilling fluid is recycled during use, rather than discarding it. In so doing, the drilling fluid must be treated in various ways. First, the drilling fluid must be treated to remove the drilled cuttings it contains when returning to surface. Polymer-based drilling fluids must, in addition to solids settling, be treated initially to mix the polymers into the carrying fluid.
During polymer drilling it often becomes necessary to have supply of drilling fluid available.
Traditionally, a tank has been used for the settling or stripping of water-based drilling muds. The tank permits a settling area for solids separation from the fluid. During this process other components must be brought in such as polymer injection units, pumps and lines. Once the drilling is moved to a polymer based fluid, the settling tank is removed and replaced with one or more tanks for mixing and handling the polymer-based fluids. This results in considerable equipment, space and transport requirements.
C:\lVrPoribHDMSLegat\CALDWELLR\15590~ 2.L~OC
Summary of the Invention A drilling fluid treatment tank has been invented that can be used for both water-based drilling fluid and for polymer-based drilling fluid. As such, the tank can be employed to manage the fluid from spudding to rig release, when the borehole is complete. The tank is substantially self-contained including, for example, fluid handling tanks, pre-mix tanks and polymer storage tanks, and possibly also pumps, pump controls and fluid circulation lines.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank system comprising; a tank including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage positioned adjacent an upper edge of each weir permitting liquid to flow from compartment to compartment, the tank including means for providing conversion between use for solids settling, use for stripping drilling mud and use for polymer-based drilling mud pre-mixing.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank system comprising; a tank including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage in each weir permitting liquid to flow from compartment to compartment; and a fluid mixing system positioned to act in at least some of the compartments.
In such an embodiment, the fluid mixing system can include a fluid circulation system for evacuating the fluid from the tank and reintroducing the fluid to the tank substantially without further treatment thereof. The fluid circulation system can include lines and a pump. The fines can be, for example, a slotted suction tube extending along a bottom of the tank in communication with an outlet line in the tank. The mixing system can alternately or in addition, include jet guns mounted in at least some of the compartments.
C:\MrPortbl\DMSLcgaIICALDWELLR\tSS9090 2.DOC
In one embodiment, the tank includes a mixer for mixing additives into any contained fluid in the tank. The mixer can be mounted in a fluid circulation line to introduce the additives to fluid circulating through the line. The fluid circulation line can include a feed line for evacuating fluid from the tank and a discharge line for reintroducing the additive-containing fluid to the tank after it has passed through the mixer.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank system comprising a skid, a tank mounted on the skid and including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage in each weir permitting liquid to flow from compartment to compartment; and an additive premixer selected from an inline mixer andlor a polymer injection tank, a fluid circulation pump and/or an additive injection pump mounted on the skid.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank comprising a tank including side walls, a first end wall and a second end wall for containing liquid-based drilling fluid, a tank separation wall positioned within the tank between the end walls to separation the tank into a first section and a second section, the tank separation wall restricting liquid flow therepast between the first section and the second section except through a closable opening in the wall; at least one weir spaced between the first end wall and the tank separation wall, dividing the first section into a plurality of compartments; and a liquid passage in the weir permitting liquid to flow from compartment to compartment.
In such an embodiment, the tank system can include a first material conveyor in the first section and a second material conveyor in the second section. The tank system can also include a fluid circulation system for moving fluid between the first section and the second section. The fluid circulation system can include lines and a pump. The fluid circulation system can, in addition or alternately, C:WrPortbl\DMSLegal\CALDW ELLR11559090_2.DOC
includes lines for evacuating fluid from one of the sections and reintroducing the fluid to that section.
In accordance with another aspect of the invention, there is provided a method for treating drilling fluid comprising: providing a tank system capable of solids settling and of mixing drilling mud, using the tank system to treat a drilling fluid by solids removal therefrom and using the tank to mix an additive into a liquid to form a polymer-based drilling fluid.
Detailed Description of the Drawings Figure 1 is an end perspective view of a tank system according to the present invention.
Figure 2 is a top perspective view of the tank system of Figure 1, with a side wall cut away to facilitate illustration of the inner tank components.
Figure 3 is an enlarged top perspective view of the pump and polymer mix areas useful in a tank system according to the present invention.
Figure 4 is a sectional view along line IV-IV of Figure 2, showing a flow path generated by operation of a jetting gun.
Figure 5 is a schematic flow diagram of a method of using the system of the present invention.
Figure 6 is a schematic flow diagram of another method of using the system of the present invention.
Figure 7 is a schematic flow diagram of another method of using the system of the present invention.
Figure 8 is a top perspective view of another tank system according to the present invention.
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Figure 9 is an enlarged perspective view of a portion of the tank system of Figure 8.
Detailed Description of the Invention Tanks according to the present invention are useful for drilling fluid treatment from drilling start up to drilling completion. The tanks can handle water-based and polymer-based drilling fluids and can handle batch treatments and closed loop systems.
One embodiment of a tank system 10 according to the present invention is shown in Figures 1 to 3. The system is built for drilling fluid management. It can be used for dewatering of drilling mud, for solids removal and stripping (also known as dewatering) for clear water drilling and for mixing polymer-based fluids for later well drilling operations. As such, the system can be used throughout the entire drilling operation, with simple conversion, when needed, to handle the various types or processing requirements of drilling mud.
The system is elongate having a first end and a second end and includes a skid-type base 12, on which the other components are mounted. The second end has positioned thereon a mechanical section 14 containing controls and pumps 16, 18 and an arrangement of mixers 20 and mix tanks 22.
A tank 24 capable of containing liquid extends from the first end to the mechanical room. The tank can be sized, as desired. The tank has sidewalls 24a and end walls 24b, 24c. The end walls are positioned one 24b at the first end of the system and the other 24c adjacent the mechanical room and mix tanks at the second end. The tank sidewalls extend between the end walls and converge at the their lower ends such that the tank narrows towards its bottom end.
There is a plurality of vertically oriented weirs 26a, 26b connected between the sidewalls. The weirs are spaced apart along the length of the tank such that a plurality of compartments 28, 28a, 28b are set up, which are separated by the C:\NrPortbl\DMSLcga I\CALD W ELLR\1559090_2.DOC
CA 02433475 2003-06-26 ' weirs. In the illustrated embodiment, the tank is-separated into 10 compartments by 9 weirs. However, other numbers of weirs can be provided, as desired. The weirs each contain an opening 30 adjacent their upper ends to permit flow communication of a liquid through the weirs. The positions of the openings on the weirs alternate from a position adjacent one and then the other sidewalls in series. One of the centrally positioned weirs 26b includes a gate 32 oriented to permit opening 30 therein to be closed and sealed against liquid flow therethrough, if desired. The gate can be connected in various ways for closing the opening. For example, the gate can be pivotally connected to the weir or slidably positioned. The gate can include a sealing member 34 such as an elastomeric ring that assists in the sealing action of the gate over the opening.
The weirs 26a each extend down adjacent the bottom end of the tank but are spaced therefrom to form a lower opening 36 permitting liquid flow under the weirs. Weir 26b, supporting gate 32, is sealingly disposed between the side walls and the bottom of the tank such that no flow is permitted therepast except through opening 30, when the gate is open. ' As such, weir 26b creates a tank separation wall that can separate the tank into two sections. In particular, the weir with gate 32 can provide convertability to the tank system to permit tank 24 to operate, when gate 32 is open, as one liquid containing area or to operate, when gate 32 is closed, as two separate smaller volume tanks with no or only controlled communication therebetween. Due to the ability of weir 26b to be used to separate the tank into two large compartments, it is preferably positioned centrally, although this is not essential.
The compartment adjacent the first end 28a, which will be termed herein the first compartment, includes an air union 38 in its upper end or sidewalls. The air union can accept connection or passage through of liquid supply tubes (not shown) to provide a flow of liquid, such as drilling mud, to the first compartment.
An arrangement of slotted suction tubes 40a, 40b, 40c extend beneath the weirs in the bottom of the tank. There are three slotted suction tubes in the illustrated C:VYrPortbl\DMSLegal\CALDWELLR\1559090_2.DOC
embodiment. However, any arrangement can be used to act as material conveyors in the bottom of the tank. A first slotted suction tube 40a is open to the first three compartments including compartment 28a, a second slotted suction tube.40b is open to the fourth compartment and the fifth compartment, which is adjacent weir 26b, and a third slotted suction tube 40c is open to the five compartments, including compartment 28b, closest to the second end of the system and on the opposite side of weir 26b from suction tubes 40a, 40b. The first and second suction tubes each extend out of the tank through first end 24b and have outlet ends 42a, 42b to which suction devices (not shown), such as pumps, can be connected. The suction tubes are used for removing settled solids, for fluid circulation and for complete emptying of the tank.
Other means are also provided for liquid evacuation from the tank. In particular, in the illustrated embodiment, the feed side of pump 16 has connected thereto a valve-controlled port 43 opening into compartment 28b and a valve-controlled line 44 opening into the compartment adjacent solid weir 26b toward end 24b.
Liquids drawn through pump 16 are discharged through fine 39 for recirculation or for returning to the rig, as will be discussed herein after. Alternately, a submersible pump (not shown) could be positioned in any of the compartments to draw liquid therefrom. A hoist 45 is provided to facilitate handling of heavy equipment such as, for example, a submersible pump.
An injection gun 46 is provided in each campartment to jet fluid into the compartment for mixing. The injection guns, in the illustrated embodiment, are formed with a perforated elongate end 46a joined in configuration to a pipe 46b extending down into the compartment. Injection guns 46 can be used to facilitate material conveyance and, in such an embodiment, are positioned with end 46a close above the slotted suction tubes. The elongate end extends with its long axis substantially parallel to the long axis of the slotted suction tube above which it is positioned. Straps and/or brackets 47 can be used to maintain the selected positioning of the injection guns. Of course, other configurations can be used.
However, with reference to Figure 4, this configuration permits a flow path 41 to C:WrPortbl\DMSLegal\CALDWELLR\1559090_2.DOC
be. set up in the tank that facilitates solids evacuation with the slotted suction tubes, for example 40b. In particular, jet ports 46c open substantially along the sides of the elongate end 46a such that fluid jetting out therefrom is directed substantially laterally and against the angled side walls, where the flow is diverted upwardly by the side walls and then down past the end 46a as driven by the low pressure region generated by operation of the suction tubes. This flow path permits settling of the solids leaving a clearer water upper layer, while the settled solids remain entrained in liquid and, thereby fluid, to facilitate their evacuation.
A supply pipe 48 is in fluid flow communication with the guns 46 and flow control to each gun is provided via a valve 49. Thus, flow can be shut off or reduced to certain guns by closing their valves while flow to other guns is selected by opening their valves. Pipe 48 receives fluid via line 39 from pump 16 discharge.
In the illustrated embodiment, pump 16 is arranged such that fluid can be drawn though third suction tube 40c, port 43 or line 44 for supplying pipe 48 and guns 46. However, other arrangements can be used for fluid supply to pipe 48, as desired.
Pipe 48 can also be used to convey large flows of liquid to the rig and/or to recirculate or move large flows through the tank. In particular, pipe 48 includes valued-connectors 48a for connection of return lines to the rig or to other drilling mud/liquid facilities or disposal sites. Pipe 48 also has secured thereto in fluid communication therewith a first outlet pipe 50 opening to ~ compartment between end 24b and solid weir 26b and a second outlet pipe 52 opening to a compartment between end 24c and solid weir 26b. Valves 54, 56 are provided on first outlet pipe 50 and second outlet pipe 52, respectively, to control flow therethrough. Pipe 48 with outlet pipes 50, 52, used independently or together, can be used to rapidly fill selected sides of the tank about weir 26b or the entire tank, when gate 30 is open on the solid weir.
CaNrPortbl\DMSLegatICALDwELLR\1559090 2.DOC
Mixer 20 is mounted on the skid to provide for mixing of drilling mud additives such as those for adjusting the solids-carrying properties of the mud, for example, bentonite or viscosity adjusting polymers. Mixer 20 in the illustrated embodiment, includes an inline mixer and a hopper. In the illustrated embodiment, mixer feed liquid comes from line 39 via a line 54 to the inline mixer. A valve is provided to control flow through pipe 48 to the inline mixer. In this way, liquid from the system can be used to produce the additive-containing liquid. Discharge of additive-containing liquid from the mixer is conveyed through pipe 56 to the tank and is bifurcated to permit flow, as controlled by valves 58, into a compartment between end 24b and solid weir 26b and/or into a compartment between end 24b and solid weir 26b.
A tank 22 with a driven mixer 60 disposed therein is also provided for the preparation additive-containing liquid such as flocculants. Tank 22 can include a steam,line for heat input. Liquid from the system or otherwise can be added to the tank for hydrating the additive. The tank is sized to hold a reserve of hydrated flocculent, for a period of operation. Once prepared, the hydrated flocculent is withdrawn by pumps 18. Sufficient pumps can be provided to have a pump dedicated to the supply of each process step where the additive is required to be injected. For example, in the illustrated embodiment, three pumps are provided so that flocculent can be injected independently to the tank input and one or possibly two centrifuges.
Pumps 18 can be positive displacement pumps, or any other pumps that can withstand the operational and flow requirements of the additive supply. Pump can be a centrifugal pump, or any other pump that can withstand the operational and flow requirements of rig supply/tank recirculation. The operation of the pumps and other components can be controlled through an electrical control panel or other control systems, as desired.
C:WrPortblIDMSLega1\CALDWELLR\1559090-2.DOC
Mechanical section also includes a heater 70 fior heating the mechanical room in which the pumps and controls are located, to reduce the risk of freeze up and downtime.
Walkways 72 are provided about 24 tank to facilitate operation fior example to permit access to the valves on pipe 48 and to permit observation of the liquids within the compartments.
The system can be powered by rig power or any other power source, with the required modifications.
As noted, the system can be used in a method for solids separation from drilling mud, for dewatering drilling mud and/or for pre-mixing of borehole additives.
With reference to Figure 5, when used for solids removal in a closed loop operation, the system is set up near the drill rig 73 to receive drilling mud, which is at this stage usually water-based. For use in solids separation, piping 74 is connected to the air union to convey drilling mud from the rig to compartment 28a. Depending on the rig circulation rate, pump 16 is readied to evacuate water through port 43 or a submersible pump assembly is positioned in one of the compartments, for example, that compartment 28b closest to the second end, and a line 75 is installed to feed the rig from pump 16 and pipe 48 or from the submersible pump. Unless the solids content and mud circulation rate are such that quick settling can be achieved, gate 32 is opened to permit flow from compartment 28a to compartment 28b. The system is used with a centrifuge 76 and, therefore, one is positioned nearby and lines 77 are connected between the outlets 42a, 42b and the centrifuge. A centrifuge liquid outlet 78 extends to the rig or to empty into tank 24. Flocculants are hydrated in tank 22 and lines 79a, 79b are connected between pumps 16 and piping 74 connected to the air union and to the centrifuge lines 77.
Drilling mud, from the rig, with the injected flocculants are then introduced to the first compartment 28a. The drilling mud begins to fill the tank, with the major portion of the flow from compartment to compartment being through openings 30.
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Once the tank is filled, the drilling mud is withdrawn from the last compartment and pumped to the rig. This causes the drilling mud to slowly move from the first compartment to the last compartment by a flow through the openings. Because of the positioning of the openings, the flow along the tank follows a sinuous path.
The slow movement of the drilling mud permits settling of sediments toward the bottom of the tank, such that the liquid in the last compartment 28b is generally free of sediments.
To ensure that the sediments remain fluid, mud, withdrawn from the later compartments through suction tube 40c and/or port 43 can be jetted through the one or more injection guns 46, as controlled by valves 49, to create turbulence in the lower portions of their compartments (see Figure 4) adjacent the first end 24b. The need to jet will depend on the accumulation of sediments in the compartment, as determined by circulation rate, rate of penetration, hole size and flocculent effectiveness.
Suction means are operated to draw the settled sediments into the first and second suction tubes 40a, 40b and to move it to the centrifuge. In one embodiment, suction tube 40a is evacuated more regularly than tube 40b, since generally more sediments accumulate in .the earlier compartments. The collected sediments are treated in the centrifuge to remove the solids from the liquids. The solids are collected and the liquids are returned to the tank or sent to the rig.
In this way, the tank system is operated, with the use of a centrifuge, a suction means and additional lines to remove solids from the drilling mud to provide clear mud, for reuse in a drilling operation, directly from compartment 28b, and possibly also directly from a centrifuge attached to tireat the settled solids.
Once the closed loop water-based drilling is complete, the tank can be readied for the next drilling mud procedure or can be cleaned out.
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The tank system 10 can also be used for stripping drilling mud, which is a batch method of solids removal as shown schematically in Figure 6. 1n this system, the full tank can be used or the gate 32 on weir 26b can be closed to reduce the volume to correspond to the batch size.
The tank system is set up in a manner similar to that described above with respect to a closed loop settling system and an amount of drilling mud with flocculants is introduced to the tank. The drilling mud is then permitted to settle, with the solids being removed through the suction tubes 40a, 40b until acceptable clear water is achieved. Liquid for jetting through guns 46 can be withdrawn through line 44. The clear water is removed via line 44 through pump 16, line 39, pipe 48 and valued-connectors 48a.
If only one section of the tank is being used for stripping, the other side can be used for stripping another batch of drilling mud, for storage of cleaned mud from the first section or for other mud procedures such as for the premix of polymer-based muds.
Once the need for stripping drilling mud is complete, the tank can be readied for the next drilling mud procedure or can be cleaned out.
Premix of polymer based mud can also be achieved using the tank system 10 of the present invention. In particular, with reference to Figure 7, when used for the preparation of a polymer-based mud, the system is set up near the drill rig 73, pump 16 is readied to evacuate water from the tank for recirculation and passage through mixer 20 and a line 75 is installed to connector 48a to feed the rig, when the mud is ready. Gate 32 is often closed to reduce the volume of the tank.
The selected section of the tank is then filled with a liquid. As the tank is filled, liquid is withdrawn, sent through mixer 20, where additives are introduced through the mixer hopper, and returned to the tank through pipe 56, for example, into the end including compartment 28b, by opening valve 58a and closing valve 58b.
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To ensure that the polymer becomes, and remains, mixed, the fluid can continue to be run through the mixer lines for circulation or the fluid can be withdrawn from .
the later compartments through suction tube 40c and/or port 43 can be jetted through the one or more injection guns 46 to create turbulence in their compartments. !f desired, considerable turbulence can be generated in a compartment by opening the gun"s valve 49 to greater levels.
In this way, the tank system is operated to premix drilling mud and to maintain the drilling mud in a mixed condition until it is desired to provide the mud, through pump 16 and line 75, to the rig.
Once the drilling mud pre-mix operation is complete, the tank can be readied for the next drilling mud procedure or can be cleaned out.
Cleaning is facilitated by use of guns 46 and suction tubes 40a, 40b, 40c, such that very little manual work is required to clean out the tank.
Referring to the remaining Figures, another embodiment of a tank system 10a according to the present invention is shown. This tank system is similar to the system of Figure 1, except with a few differences.
In particular, the first and second slotted suction tubes (40a, 40b of Figure 1 ) have been replaced with a plurality of smaller, divided, slotted suction tubes. In the illustrated embodiment, there is one slotted suction tube 40d opening into both the first compartment 28a and its next adjacent compartment and one slotted suction tube 40e, 40f, 40g in each of the next three compartments.
Slotted tube 40d has an output port 42c passing through the first end wall and an output tube 42d extending out through the sidewall 24a. Slotted suction tubes 40e, 40f, 40g each have an output tube 42e - 42g, respectively, extending out through the sidewall 24a. The materials in the first two compartments can be pumped out of the tank by either applying suction at output port 42c or by applying suction at output tube 42d extending through the sidewall. Output tubes 42e - 42g include connectors at their ends for connection to a source of suction C:WrPorlblU~MSLcgal\CALDWliLLR\15590 2.DOC
so that the compartment into which they extend can be cleaned out. This permits conveyance of solids out of selected compartments only, together or compartment by compartment. Thus, the heaviest mulls can be treated selectively offering the most effective use of treatment apparatus, such as centrifuges.
A liquid spillway 80 extends along the length of the flank above the weirs 26a, 26b and has a plurality of closeable openings 82 through which liquid can flow into selected compartments. The spillway is configured to permit liquids returning from the centrifuge to be introduced, via the spillway, to selected compartments along the tank, depending on the clarity of the liquid.
System 10a also includes lower floodgates 86 operable to seal enlarged openings at the bottom ends thereof 36. Handles 88 extend to permit operation of the floodgates, when desired to permit a greater flow through the bottom portion of the tank.
In addition to polymer mix tank 22, a second polymer mix tank 23 is provided.
So that greater volumes of additives can be prepared and, if desired, two batches can be readied so that a constant controlled solution can be available.
C:INrPort611DMSLegaIICALDWELLR\155 2.DOC
Background of the Invention Drilling fluid, which is also termed mud, is circulated through a wellbore during drilling to lubricate the drill bit and to carry drilled cuttings to surface.
A selection of drilling fluid is made depending on various parameters including the nature of the formation being drilled through, the depth of the borehole and the speed under which the drilling is being progressed. In North America, it is possible to use a less expensive water-based drilling fluid initially, during spudding, before moving to a polymer based mud as the hole depth is increased.
Environmental concerns, as well as cost, have urged operators to move to closed loop systems, wherein the drilling fluid is recycled during use, rather than discarding it. In so doing, the drilling fluid must be treated in various ways. First, the drilling fluid must be treated to remove the drilled cuttings it contains when returning to surface. Polymer-based drilling fluids must, in addition to solids settling, be treated initially to mix the polymers into the carrying fluid.
During polymer drilling it often becomes necessary to have supply of drilling fluid available.
Traditionally, a tank has been used for the settling or stripping of water-based drilling muds. The tank permits a settling area for solids separation from the fluid. During this process other components must be brought in such as polymer injection units, pumps and lines. Once the drilling is moved to a polymer based fluid, the settling tank is removed and replaced with one or more tanks for mixing and handling the polymer-based fluids. This results in considerable equipment, space and transport requirements.
C:\lVrPoribHDMSLegat\CALDWELLR\15590~ 2.L~OC
Summary of the Invention A drilling fluid treatment tank has been invented that can be used for both water-based drilling fluid and for polymer-based drilling fluid. As such, the tank can be employed to manage the fluid from spudding to rig release, when the borehole is complete. The tank is substantially self-contained including, for example, fluid handling tanks, pre-mix tanks and polymer storage tanks, and possibly also pumps, pump controls and fluid circulation lines.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank system comprising; a tank including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage positioned adjacent an upper edge of each weir permitting liquid to flow from compartment to compartment, the tank including means for providing conversion between use for solids settling, use for stripping drilling mud and use for polymer-based drilling mud pre-mixing.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank system comprising; a tank including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage in each weir permitting liquid to flow from compartment to compartment; and a fluid mixing system positioned to act in at least some of the compartments.
In such an embodiment, the fluid mixing system can include a fluid circulation system for evacuating the fluid from the tank and reintroducing the fluid to the tank substantially without further treatment thereof. The fluid circulation system can include lines and a pump. The fines can be, for example, a slotted suction tube extending along a bottom of the tank in communication with an outlet line in the tank. The mixing system can alternately or in addition, include jet guns mounted in at least some of the compartments.
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In one embodiment, the tank includes a mixer for mixing additives into any contained fluid in the tank. The mixer can be mounted in a fluid circulation line to introduce the additives to fluid circulating through the line. The fluid circulation line can include a feed line for evacuating fluid from the tank and a discharge line for reintroducing the additive-containing fluid to the tank after it has passed through the mixer.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank system comprising a skid, a tank mounted on the skid and including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage in each weir permitting liquid to flow from compartment to compartment; and an additive premixer selected from an inline mixer andlor a polymer injection tank, a fluid circulation pump and/or an additive injection pump mounted on the skid.
In accordance with a broad aspect of the present invention, there is provided a drilling fluid treatment tank comprising a tank including side walls, a first end wall and a second end wall for containing liquid-based drilling fluid, a tank separation wall positioned within the tank between the end walls to separation the tank into a first section and a second section, the tank separation wall restricting liquid flow therepast between the first section and the second section except through a closable opening in the wall; at least one weir spaced between the first end wall and the tank separation wall, dividing the first section into a plurality of compartments; and a liquid passage in the weir permitting liquid to flow from compartment to compartment.
In such an embodiment, the tank system can include a first material conveyor in the first section and a second material conveyor in the second section. The tank system can also include a fluid circulation system for moving fluid between the first section and the second section. The fluid circulation system can include lines and a pump. The fluid circulation system can, in addition or alternately, C:WrPortbl\DMSLegal\CALDW ELLR11559090_2.DOC
includes lines for evacuating fluid from one of the sections and reintroducing the fluid to that section.
In accordance with another aspect of the invention, there is provided a method for treating drilling fluid comprising: providing a tank system capable of solids settling and of mixing drilling mud, using the tank system to treat a drilling fluid by solids removal therefrom and using the tank to mix an additive into a liquid to form a polymer-based drilling fluid.
Detailed Description of the Drawings Figure 1 is an end perspective view of a tank system according to the present invention.
Figure 2 is a top perspective view of the tank system of Figure 1, with a side wall cut away to facilitate illustration of the inner tank components.
Figure 3 is an enlarged top perspective view of the pump and polymer mix areas useful in a tank system according to the present invention.
Figure 4 is a sectional view along line IV-IV of Figure 2, showing a flow path generated by operation of a jetting gun.
Figure 5 is a schematic flow diagram of a method of using the system of the present invention.
Figure 6 is a schematic flow diagram of another method of using the system of the present invention.
Figure 7 is a schematic flow diagram of another method of using the system of the present invention.
Figure 8 is a top perspective view of another tank system according to the present invention.
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Figure 9 is an enlarged perspective view of a portion of the tank system of Figure 8.
Detailed Description of the Invention Tanks according to the present invention are useful for drilling fluid treatment from drilling start up to drilling completion. The tanks can handle water-based and polymer-based drilling fluids and can handle batch treatments and closed loop systems.
One embodiment of a tank system 10 according to the present invention is shown in Figures 1 to 3. The system is built for drilling fluid management. It can be used for dewatering of drilling mud, for solids removal and stripping (also known as dewatering) for clear water drilling and for mixing polymer-based fluids for later well drilling operations. As such, the system can be used throughout the entire drilling operation, with simple conversion, when needed, to handle the various types or processing requirements of drilling mud.
The system is elongate having a first end and a second end and includes a skid-type base 12, on which the other components are mounted. The second end has positioned thereon a mechanical section 14 containing controls and pumps 16, 18 and an arrangement of mixers 20 and mix tanks 22.
A tank 24 capable of containing liquid extends from the first end to the mechanical room. The tank can be sized, as desired. The tank has sidewalls 24a and end walls 24b, 24c. The end walls are positioned one 24b at the first end of the system and the other 24c adjacent the mechanical room and mix tanks at the second end. The tank sidewalls extend between the end walls and converge at the their lower ends such that the tank narrows towards its bottom end.
There is a plurality of vertically oriented weirs 26a, 26b connected between the sidewalls. The weirs are spaced apart along the length of the tank such that a plurality of compartments 28, 28a, 28b are set up, which are separated by the C:\NrPortbl\DMSLcga I\CALD W ELLR\1559090_2.DOC
CA 02433475 2003-06-26 ' weirs. In the illustrated embodiment, the tank is-separated into 10 compartments by 9 weirs. However, other numbers of weirs can be provided, as desired. The weirs each contain an opening 30 adjacent their upper ends to permit flow communication of a liquid through the weirs. The positions of the openings on the weirs alternate from a position adjacent one and then the other sidewalls in series. One of the centrally positioned weirs 26b includes a gate 32 oriented to permit opening 30 therein to be closed and sealed against liquid flow therethrough, if desired. The gate can be connected in various ways for closing the opening. For example, the gate can be pivotally connected to the weir or slidably positioned. The gate can include a sealing member 34 such as an elastomeric ring that assists in the sealing action of the gate over the opening.
The weirs 26a each extend down adjacent the bottom end of the tank but are spaced therefrom to form a lower opening 36 permitting liquid flow under the weirs. Weir 26b, supporting gate 32, is sealingly disposed between the side walls and the bottom of the tank such that no flow is permitted therepast except through opening 30, when the gate is open. ' As such, weir 26b creates a tank separation wall that can separate the tank into two sections. In particular, the weir with gate 32 can provide convertability to the tank system to permit tank 24 to operate, when gate 32 is open, as one liquid containing area or to operate, when gate 32 is closed, as two separate smaller volume tanks with no or only controlled communication therebetween. Due to the ability of weir 26b to be used to separate the tank into two large compartments, it is preferably positioned centrally, although this is not essential.
The compartment adjacent the first end 28a, which will be termed herein the first compartment, includes an air union 38 in its upper end or sidewalls. The air union can accept connection or passage through of liquid supply tubes (not shown) to provide a flow of liquid, such as drilling mud, to the first compartment.
An arrangement of slotted suction tubes 40a, 40b, 40c extend beneath the weirs in the bottom of the tank. There are three slotted suction tubes in the illustrated C:VYrPortbl\DMSLegal\CALDWELLR\1559090_2.DOC
embodiment. However, any arrangement can be used to act as material conveyors in the bottom of the tank. A first slotted suction tube 40a is open to the first three compartments including compartment 28a, a second slotted suction tube.40b is open to the fourth compartment and the fifth compartment, which is adjacent weir 26b, and a third slotted suction tube 40c is open to the five compartments, including compartment 28b, closest to the second end of the system and on the opposite side of weir 26b from suction tubes 40a, 40b. The first and second suction tubes each extend out of the tank through first end 24b and have outlet ends 42a, 42b to which suction devices (not shown), such as pumps, can be connected. The suction tubes are used for removing settled solids, for fluid circulation and for complete emptying of the tank.
Other means are also provided for liquid evacuation from the tank. In particular, in the illustrated embodiment, the feed side of pump 16 has connected thereto a valve-controlled port 43 opening into compartment 28b and a valve-controlled line 44 opening into the compartment adjacent solid weir 26b toward end 24b.
Liquids drawn through pump 16 are discharged through fine 39 for recirculation or for returning to the rig, as will be discussed herein after. Alternately, a submersible pump (not shown) could be positioned in any of the compartments to draw liquid therefrom. A hoist 45 is provided to facilitate handling of heavy equipment such as, for example, a submersible pump.
An injection gun 46 is provided in each campartment to jet fluid into the compartment for mixing. The injection guns, in the illustrated embodiment, are formed with a perforated elongate end 46a joined in configuration to a pipe 46b extending down into the compartment. Injection guns 46 can be used to facilitate material conveyance and, in such an embodiment, are positioned with end 46a close above the slotted suction tubes. The elongate end extends with its long axis substantially parallel to the long axis of the slotted suction tube above which it is positioned. Straps and/or brackets 47 can be used to maintain the selected positioning of the injection guns. Of course, other configurations can be used.
However, with reference to Figure 4, this configuration permits a flow path 41 to C:WrPortbl\DMSLegal\CALDWELLR\1559090_2.DOC
be. set up in the tank that facilitates solids evacuation with the slotted suction tubes, for example 40b. In particular, jet ports 46c open substantially along the sides of the elongate end 46a such that fluid jetting out therefrom is directed substantially laterally and against the angled side walls, where the flow is diverted upwardly by the side walls and then down past the end 46a as driven by the low pressure region generated by operation of the suction tubes. This flow path permits settling of the solids leaving a clearer water upper layer, while the settled solids remain entrained in liquid and, thereby fluid, to facilitate their evacuation.
A supply pipe 48 is in fluid flow communication with the guns 46 and flow control to each gun is provided via a valve 49. Thus, flow can be shut off or reduced to certain guns by closing their valves while flow to other guns is selected by opening their valves. Pipe 48 receives fluid via line 39 from pump 16 discharge.
In the illustrated embodiment, pump 16 is arranged such that fluid can be drawn though third suction tube 40c, port 43 or line 44 for supplying pipe 48 and guns 46. However, other arrangements can be used for fluid supply to pipe 48, as desired.
Pipe 48 can also be used to convey large flows of liquid to the rig and/or to recirculate or move large flows through the tank. In particular, pipe 48 includes valued-connectors 48a for connection of return lines to the rig or to other drilling mud/liquid facilities or disposal sites. Pipe 48 also has secured thereto in fluid communication therewith a first outlet pipe 50 opening to ~ compartment between end 24b and solid weir 26b and a second outlet pipe 52 opening to a compartment between end 24c and solid weir 26b. Valves 54, 56 are provided on first outlet pipe 50 and second outlet pipe 52, respectively, to control flow therethrough. Pipe 48 with outlet pipes 50, 52, used independently or together, can be used to rapidly fill selected sides of the tank about weir 26b or the entire tank, when gate 30 is open on the solid weir.
CaNrPortbl\DMSLegatICALDwELLR\1559090 2.DOC
Mixer 20 is mounted on the skid to provide for mixing of drilling mud additives such as those for adjusting the solids-carrying properties of the mud, for example, bentonite or viscosity adjusting polymers. Mixer 20 in the illustrated embodiment, includes an inline mixer and a hopper. In the illustrated embodiment, mixer feed liquid comes from line 39 via a line 54 to the inline mixer. A valve is provided to control flow through pipe 48 to the inline mixer. In this way, liquid from the system can be used to produce the additive-containing liquid. Discharge of additive-containing liquid from the mixer is conveyed through pipe 56 to the tank and is bifurcated to permit flow, as controlled by valves 58, into a compartment between end 24b and solid weir 26b and/or into a compartment between end 24b and solid weir 26b.
A tank 22 with a driven mixer 60 disposed therein is also provided for the preparation additive-containing liquid such as flocculants. Tank 22 can include a steam,line for heat input. Liquid from the system or otherwise can be added to the tank for hydrating the additive. The tank is sized to hold a reserve of hydrated flocculent, for a period of operation. Once prepared, the hydrated flocculent is withdrawn by pumps 18. Sufficient pumps can be provided to have a pump dedicated to the supply of each process step where the additive is required to be injected. For example, in the illustrated embodiment, three pumps are provided so that flocculent can be injected independently to the tank input and one or possibly two centrifuges.
Pumps 18 can be positive displacement pumps, or any other pumps that can withstand the operational and flow requirements of the additive supply. Pump can be a centrifugal pump, or any other pump that can withstand the operational and flow requirements of rig supply/tank recirculation. The operation of the pumps and other components can be controlled through an electrical control panel or other control systems, as desired.
C:WrPortblIDMSLega1\CALDWELLR\1559090-2.DOC
Mechanical section also includes a heater 70 fior heating the mechanical room in which the pumps and controls are located, to reduce the risk of freeze up and downtime.
Walkways 72 are provided about 24 tank to facilitate operation fior example to permit access to the valves on pipe 48 and to permit observation of the liquids within the compartments.
The system can be powered by rig power or any other power source, with the required modifications.
As noted, the system can be used in a method for solids separation from drilling mud, for dewatering drilling mud and/or for pre-mixing of borehole additives.
With reference to Figure 5, when used for solids removal in a closed loop operation, the system is set up near the drill rig 73 to receive drilling mud, which is at this stage usually water-based. For use in solids separation, piping 74 is connected to the air union to convey drilling mud from the rig to compartment 28a. Depending on the rig circulation rate, pump 16 is readied to evacuate water through port 43 or a submersible pump assembly is positioned in one of the compartments, for example, that compartment 28b closest to the second end, and a line 75 is installed to feed the rig from pump 16 and pipe 48 or from the submersible pump. Unless the solids content and mud circulation rate are such that quick settling can be achieved, gate 32 is opened to permit flow from compartment 28a to compartment 28b. The system is used with a centrifuge 76 and, therefore, one is positioned nearby and lines 77 are connected between the outlets 42a, 42b and the centrifuge. A centrifuge liquid outlet 78 extends to the rig or to empty into tank 24. Flocculants are hydrated in tank 22 and lines 79a, 79b are connected between pumps 16 and piping 74 connected to the air union and to the centrifuge lines 77.
Drilling mud, from the rig, with the injected flocculants are then introduced to the first compartment 28a. The drilling mud begins to fill the tank, with the major portion of the flow from compartment to compartment being through openings 30.
C:NlrPortbl~DMSLegaI~CALDWELLR11559090_2.DOC
Once the tank is filled, the drilling mud is withdrawn from the last compartment and pumped to the rig. This causes the drilling mud to slowly move from the first compartment to the last compartment by a flow through the openings. Because of the positioning of the openings, the flow along the tank follows a sinuous path.
The slow movement of the drilling mud permits settling of sediments toward the bottom of the tank, such that the liquid in the last compartment 28b is generally free of sediments.
To ensure that the sediments remain fluid, mud, withdrawn from the later compartments through suction tube 40c and/or port 43 can be jetted through the one or more injection guns 46, as controlled by valves 49, to create turbulence in the lower portions of their compartments (see Figure 4) adjacent the first end 24b. The need to jet will depend on the accumulation of sediments in the compartment, as determined by circulation rate, rate of penetration, hole size and flocculent effectiveness.
Suction means are operated to draw the settled sediments into the first and second suction tubes 40a, 40b and to move it to the centrifuge. In one embodiment, suction tube 40a is evacuated more regularly than tube 40b, since generally more sediments accumulate in .the earlier compartments. The collected sediments are treated in the centrifuge to remove the solids from the liquids. The solids are collected and the liquids are returned to the tank or sent to the rig.
In this way, the tank system is operated, with the use of a centrifuge, a suction means and additional lines to remove solids from the drilling mud to provide clear mud, for reuse in a drilling operation, directly from compartment 28b, and possibly also directly from a centrifuge attached to tireat the settled solids.
Once the closed loop water-based drilling is complete, the tank can be readied for the next drilling mud procedure or can be cleaned out.
C: W rPortbl\DMST.egal\CALD W 61.T.RU 559090_2.DOC
The tank system 10 can also be used for stripping drilling mud, which is a batch method of solids removal as shown schematically in Figure 6. 1n this system, the full tank can be used or the gate 32 on weir 26b can be closed to reduce the volume to correspond to the batch size.
The tank system is set up in a manner similar to that described above with respect to a closed loop settling system and an amount of drilling mud with flocculants is introduced to the tank. The drilling mud is then permitted to settle, with the solids being removed through the suction tubes 40a, 40b until acceptable clear water is achieved. Liquid for jetting through guns 46 can be withdrawn through line 44. The clear water is removed via line 44 through pump 16, line 39, pipe 48 and valued-connectors 48a.
If only one section of the tank is being used for stripping, the other side can be used for stripping another batch of drilling mud, for storage of cleaned mud from the first section or for other mud procedures such as for the premix of polymer-based muds.
Once the need for stripping drilling mud is complete, the tank can be readied for the next drilling mud procedure or can be cleaned out.
Premix of polymer based mud can also be achieved using the tank system 10 of the present invention. In particular, with reference to Figure 7, when used for the preparation of a polymer-based mud, the system is set up near the drill rig 73, pump 16 is readied to evacuate water from the tank for recirculation and passage through mixer 20 and a line 75 is installed to connector 48a to feed the rig, when the mud is ready. Gate 32 is often closed to reduce the volume of the tank.
The selected section of the tank is then filled with a liquid. As the tank is filled, liquid is withdrawn, sent through mixer 20, where additives are introduced through the mixer hopper, and returned to the tank through pipe 56, for example, into the end including compartment 28b, by opening valve 58a and closing valve 58b.
C:\IHrPortbl\DMSLcgal\CALDWELLR115590~ 2.DOC
To ensure that the polymer becomes, and remains, mixed, the fluid can continue to be run through the mixer lines for circulation or the fluid can be withdrawn from .
the later compartments through suction tube 40c and/or port 43 can be jetted through the one or more injection guns 46 to create turbulence in their compartments. !f desired, considerable turbulence can be generated in a compartment by opening the gun"s valve 49 to greater levels.
In this way, the tank system is operated to premix drilling mud and to maintain the drilling mud in a mixed condition until it is desired to provide the mud, through pump 16 and line 75, to the rig.
Once the drilling mud pre-mix operation is complete, the tank can be readied for the next drilling mud procedure or can be cleaned out.
Cleaning is facilitated by use of guns 46 and suction tubes 40a, 40b, 40c, such that very little manual work is required to clean out the tank.
Referring to the remaining Figures, another embodiment of a tank system 10a according to the present invention is shown. This tank system is similar to the system of Figure 1, except with a few differences.
In particular, the first and second slotted suction tubes (40a, 40b of Figure 1 ) have been replaced with a plurality of smaller, divided, slotted suction tubes. In the illustrated embodiment, there is one slotted suction tube 40d opening into both the first compartment 28a and its next adjacent compartment and one slotted suction tube 40e, 40f, 40g in each of the next three compartments.
Slotted tube 40d has an output port 42c passing through the first end wall and an output tube 42d extending out through the sidewall 24a. Slotted suction tubes 40e, 40f, 40g each have an output tube 42e - 42g, respectively, extending out through the sidewall 24a. The materials in the first two compartments can be pumped out of the tank by either applying suction at output port 42c or by applying suction at output tube 42d extending through the sidewall. Output tubes 42e - 42g include connectors at their ends for connection to a source of suction C:WrPorlblU~MSLcgal\CALDWliLLR\15590 2.DOC
so that the compartment into which they extend can be cleaned out. This permits conveyance of solids out of selected compartments only, together or compartment by compartment. Thus, the heaviest mulls can be treated selectively offering the most effective use of treatment apparatus, such as centrifuges.
A liquid spillway 80 extends along the length of the flank above the weirs 26a, 26b and has a plurality of closeable openings 82 through which liquid can flow into selected compartments. The spillway is configured to permit liquids returning from the centrifuge to be introduced, via the spillway, to selected compartments along the tank, depending on the clarity of the liquid.
System 10a also includes lower floodgates 86 operable to seal enlarged openings at the bottom ends thereof 36. Handles 88 extend to permit operation of the floodgates, when desired to permit a greater flow through the bottom portion of the tank.
In addition to polymer mix tank 22, a second polymer mix tank 23 is provided.
So that greater volumes of additives can be prepared and, if desired, two batches can be readied so that a constant controlled solution can be available.
C:INrPort611DMSLegaIICALDWELLR\155 2.DOC
Claims (19)
1. A drilling fluid treatment tank system comprising; a tank including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage positioned adjacent an upper edge of each weir permitting liquid to flow from compartment to compartment, the tank including means for providing conversion between use for solids settling, use for stripping drilling mud and use for polymer-based drilling mud pre-mixing.
2. The drilling fluid treatment tank system of claim 1 wherein the weirs include a first weir adjacent one end of the tank, a second weir adjacent a second end of the tank and a third weir positioned between the first weir and the second weir and wherein the means for providing conversion includes a closeable gate on the third weir to control flow through the liquid passage thereon.
3. The drilling fluid treatment tank system of claim 1 wherein the weirs include a first weir adjacent one end of the tank, a second weir adjacent a second end of the tank and a third weir positioned between the first weir and the second weir, the third weir operating to define a first section and a second section in the tank and wherein the means for providing conversion includes a first fluid introduction system and a first fluid evacuation system for the first end of the tank and a second fluid introduction system for the second end of the tank and the first fluid introduction system is operable to introduce fluid to the first end of the tank without also introducing fluid to the second end of the tank.
4. The drilling fluid treatment tank system of claim 1 wherein the means for providing conversion includes an inline mixer and a mixing tank.
5. A drilling fluid treatment tank system comprising; a tank including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage in each weir permitting liquid to flow from compartment to compartment; and a fluid mixing system positioned to act in at least some of the compartments.
6. The drilling fluid treatment tank system of claim 5 wherein the fluid mixing system includes a fluid circulation system for evacuating the fluid from the tank and reintroducing the fluid to the tank substantially without further treatment thereof.
7. The drilling fluid treatment tank system of claim 6 wherein the fluid circulation system includes lines and a pump.
8. The drilling fluid treatment tank system of claim 7 wherein the lines include a slotted suction tube extending along a bottom of the tank in communication with an outlet line in the tank.
9. The drilling fluid treatment tank system of claim 5 wherein the fluid mixing system includes jet guns mounted in at least some of the compartments.
10. The drilling fluid treatment tank system of claim 5 further comprising a mixer for mixing additives into any contained fluid in the tank.
11. The drilling fluid treatment tank system of claim 10 wherein the mixer is mounted in a fluid circulation line to introduce the additives to fluid circulating through the line.
12. The drilling fluid treatment tank system of claim 11 wherein the fluid circulation line includes a feed line for evacuating fluid from the tank and a discharge line for reintroducing the additive-containing fluid to the tank after it has passed through the mixer.
13. A drilling fluid treatment tank system comprising: a skid, a tank mounted on the skid and including walls for containing liquid drilling fluid, weirs spaced along the tank dividing the tank into a plurality of compartments and a liquid passage in each weir permitting liquid to flow from compartment to compartment; and an additive premixer selected from an inline mixer and/or a polymer injection tank, a fluid circulation pump and/or an additive injection pump mounted on the skid.
14. A drilling fluid treatment tank comprising a tank including side walls, a first end wall and a second end wall for containing liquid-based drilling fluid, a tank separation wall positioned within the tank between the end walls to separation the tank into a first section and a second section, the tank separation wall restricting liquid flow therepast between the first section and the second section except through a closable opening in the wall; at least one weir spaced between the first end wall and the tank separation wall, dividing the first section into a plurality of compartments; and a liquid passage in the weir permitting liquid to flow from compartment to compartment.
15. The drilling fluid treatment tank system of claim 14 further comprising a first material conveyor in the first section and a second material conveyor in the second section.
16. The drilling fluid treatment tank system of claim 14 further comprising a fluid circulation system for moving fluid between the first section and the second section.
17. The drilling fluid treatment tank system of claim 16 wherein the fluid circulation system includes lines and a pump.
18. The drilling fluid treatment tank system of claim 17 wherein fluid circulation system includes lines for evacuating fluid from one of the sections and reintroducing the fluid to that section.
19. A method for treating drilling fluid comprising: providing a tank system capable of solids settling and of mixing drilling mud, using the tank system to treat a drilling fluid by solids removal therefrom and using the tank to mix an additive into a liquid to form a polymer-based drilling fluid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2433475 CA2433475A1 (en) | 2003-06-26 | 2003-06-26 | Drilling fluid treatment tank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2433475 CA2433475A1 (en) | 2003-06-26 | 2003-06-26 | Drilling fluid treatment tank |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2433475A1 true CA2433475A1 (en) | 2004-12-26 |
Family
ID=33569448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2433475 Abandoned CA2433475A1 (en) | 2003-06-26 | 2003-06-26 | Drilling fluid treatment tank |
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| Country | Link |
|---|---|
| CA (1) | CA2433475A1 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7527726B2 (en) | 2006-01-25 | 2009-05-05 | Q'max Solutions Inc. | Fluid treatment apparatus |
| CN113389200A (en) * | 2021-05-08 | 2021-09-14 | 深圳市工勘岩土集团有限公司 | Pile hole sediment gas lift reverse circulation equipment |
-
2003
- 2003-06-26 CA CA 2433475 patent/CA2433475A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7527726B2 (en) | 2006-01-25 | 2009-05-05 | Q'max Solutions Inc. | Fluid treatment apparatus |
| CN113389200A (en) * | 2021-05-08 | 2021-09-14 | 深圳市工勘岩土集团有限公司 | Pile hole sediment gas lift reverse circulation equipment |
| CN113389200B (en) * | 2021-05-08 | 2022-11-18 | 深圳市工勘基础工程有限公司 | Pile hole sediment gas lift reverse circulation equipment |
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