WO2014065670A1

WO2014065670A1 - Shale shaker with a filter pack adapter

Info

Publication number: WO2014065670A1
Application number: PCT/NO2012/000061
Authority: WO
Inventors: Bjørn DAHL
Original assignee: Optipro As
Priority date: 2012-10-23
Filing date: 2012-10-23
Publication date: 2014-05-01

Abstract

A shale shaker comprising: - a base frame (1), - a vibration frame (2) in a flexible suspension (20) in said base frame (1) and driven by a motorized vibrator (23), - wherein said vibration frame (2) is provided with first holding devices (22) for at least one filter unit (3), - an inlet (4) for receiving drilling mud for filtration, - a first outlet (5) for filtered liquid and a second outlet (6) for separated particles, wherein said filter unit (3) comprises an adapter piece (32) comprising two or more holding devices (33, 33a, 33b,.. ) in separate elevation levels (34a, 34b,..) for filters (35a, 35b,..).

Description

SHALE SHAKER WITH A FILTER PACK ADAPTER

The invention relates to an improved shale shaker. More specifically the invention is a shale shaker with a filter pack box unit which replaces at least one filter deck in a shale shaker.

Background and prior art

A commonly known type of shale shakers comprises a shaker frame for a resilient suspension in a mainframe and driven by a motorized vibrator, wherein the shaker frame is provided with a first fastener for a filter unit for drilling mud, wherein the filter unit is situated in one single level. The shaker frame may comprise two filter units, the one on top of the other, and wherein the one on top is the coarsest and separates the coarsest particles. The shale shaker has an inlet for receiving drilling mud to be filtered. In general the drilling mud comes from a return line from a petroleum drilling process and comprises cuttings and other particles which are to be filtered out from the drilling mud. Shale shakers have an outlet for filtered fluid and an outlet for separated particles. The filtered fluid may be used with or without chemical adjustments in the further drilling process where it is lead down through a drill pipe to a drilling bit, and returns again to the surface with cuttings .

US-patent US5248043 describes that the filter unit is subdivided with cross directional support beams wherein sections with filter cloths are replaceable.

Problems related to prior art

Of several reasons it is desirable to replace the upper filter level at an existing shale shaker with one or more filter elevation levels to better utilize existing ineffective shale shakers, and thereby save replacement, or extensive rebuilding of shale shakers at drilling units such as drilling platforms at sea and drilling rigs on shore. Generally there is a desire for a more rapid flow-through of drilling mud through the shale shakers.

It is desriable to modify known shale shakers to comprise some additional filter elevation levels but only one or two filter elevation levels are available, and a rebuilding of a shale shaker to additional levels is time consuming and it is likely easier to replace shale shakers with only one or two elevation levels, than to rebuild them on site.

It is generally important to shorten the processing time for the drilling mud in general, and to reduce the operators' exposure to oil mist and oil vapor. Chemical pneumonia due to exposure from oil vapor at the shale shakers by operating those for maintaining the drilling mud is a health problem and should in general be reduced.

Short summary of the invention

The invention is a shale shaker, is defined in patent claim 1, and comprises the following features:

- a main frame (1) ,

- a motorized shaker frame (2) in a resilient suspension (20) in the main frame (1) and driven by a motorized vibrator (23)

- wherein the shaker frame (2) is provided with first fasteners (22) for a filter unit (3)

- an inlet (4) for receival of drilling mud to be filtered,

- a first outlet (5) for filtered fluid and

- a second outlet (6) for separated particles, wherein the filter unit (3) comprises an adapter piece (32)

comprising two or more fasteners (33, 33a, 33b, ..) in separate elevation levels (34a, 34b, ..) for filters (35a, 35b, ..). Further features by the invention are referred in the dependent patent claims.

Figure captions

The invention is illustrated in the attached drawing figures.

Fig. la shows in perspective view a shale shaker according to the invention with a main frame (1) and a shaker frame (2) with a filter unit (3) according to the invention, wherein the filter unit (3) comprises an adapter piece (32) with two or more second fasteners (33, 33a, 33b, ..) in separate elevation levels (34a, 34b, ..) arranged to receive or hold filters (35a, 35b, ..) .

Fig. lb shows in similar perspective a partial view equivalent to Fig. la, and a longitudinal vertical section through the shale shaker according to the invention with an inlet (4) for the drilling mud, the box shaped adapter piece (32) with three filters (35a, 35b, 35c) on top of an underlying first outlet (5) for filtered liquid and to the left a second outlet (6) for separated particles. There is a broken line for a particle path.

Fig.lc is a vertical sectional view corresponding to Fig. lb. The path for particles is also here indicated by a broken line. Filtered liquid ends up down in the outlet (5) for filtered liquid.

Fig. Id is a end view seen towards the particle outlet (6).

Fig.2a is a perspective view of the box-shaped adapter piece (32) according to the invention, here shown without filters, but with pneumatic packers in the horizontal slots (33a, 33b, 33c) . Fig.2b is a perspective view equivalent to Fig. 2a but with a vertical section equivalent to the vertical sectional view in

Fig. lb. Here the horizontal slots (33a, 33b, 33c) in the rear edge of the box-shaped adapter piece (32) are evident. The upper portion with the slot (33a) extends further back in the cartridge to pick up down flowing liquid from the inlet (4) . Filters may be sled into the horizontal gaps (33) . The pneumatic packers may lock the filters when they have completely entered into their place in the slots (33) .

Fig.2c is a vertical section view of a vertical section of the box- shaped adapter piece (32) in a way that the rear, inner portion of the box-shaped adapter piece (32) underneath the inlet 4 is not shown. Here we can see the pneumatic packers in the upper portion in the slots (33a, 33b, 33c) .

Fig.2d is a vertical section view of the box-shaped adapter piece (32) in a way that the rear, inner portion (31i) of the box-shaped adapter piece (32) underneath the inlet 4 is shown. Here one sees that in an embodiment the slots (33a, 33b, 33c) may run via the rear, innermost portion of the box-shaped adapter piece (32) in a way that continuous slots between the two long sides (31) and the inner wall portion (31i) of the box formed adapter piece (32) are formed. In an embodiment of the invention the inner wall portion (31i) in its upper part, with the upper slot (33a) , extends in the inward direction, so that it extends beneath the inlet (4) for drilling mud. The final design of the inner wall portion (31i) and the box- shaped adapter piece (32) should be adjusted to each model of existing shale shaker.

Fig. 2e is a vertical sectional longitudinal view of the box- shaped adapter piece (32) and corresponds to the section in Fig. 2b. Here we also see the pneumatic packers in their upper portions in the slots (33a, 33b, 33c) , both as an elevation view and a sectional view .

Fig.3a is a perspective view of the box-shaped adapter piece (32) according to the invention, here shown without pneumatic packers.

Fig. 3b is a partial perspective view with a vertical sectional view equivalent to the vertical sectional view in Fig. 2b, that is, without the pneumatic packers.

Fig.3c corresponds to the end elevation view in Fig. 2d, but here without the pneumatic packers.

Fig.3d is a vertical sectional view of a section in the same way as in Fig. 2c, but here without the pneumatic packers.

Fig.4a is a perspective view of the box-shaped adapter piece (32) according to the invention, here with filters (35a, 35b and 35c) inserted in each their horizontal slots (34a, 34b, 34c) . The filters are in an embodiment subdivided into horizontally consecutive sections and here only the inner filter section is shown. No specific structure of the filters are indicated, they may have a continuous cloth or be subdivided into different cloths.

Fig.4b is a perspective view of the box-shaped adapter piece (32) according to the invention and a vertical section view corresponding to the one in Fig.2b, here with the difference from Fig. 4a that there is one filter section at the farther end and in the upper horizontal slot (33a) , two shoved into the underlying, here the slot (33b) in the middle, and three shoved into the lover slot (33c) . All the slots should of course be filled up completely by filter sections. Flat outlet sills, not shown, is arranged to be shoved in towards the outer edge of the slots (34a, b, c) , here in the outlet (6) . Those are shown in Fig. 1.

Fig.5a is a perspective view and the vertical sectional view equivalent to the one in Fig. 4b, but wherein a so-called plug-in- filter frame is shoved into the upper horizontal slot (33a) and in the lower horizontal slot (33c) . Due to clarity considerations of the drawings it is not shown a plug- in filter frame in the

intermediate slot (33b) . Flat outlet sills are here shown shoved into the outer edge of the slots (33a, b, c) , here in the outlet (6) .

Advantages of the invention:

A first advantage by the invention is that one may place several levels of filters in a shale shaker where more levels are desired and where there is only one free level, generally the top level, to put in a filter. Then the shale shaker may achieve to filter out particles more efficiently, please see below.

A second advantage by the invention is that by replacing at least one level of filters with two or more filter levels arranged in several levels in top of each other, is that particles may be separated out more efficiently at the top of the filtering sequence, and where several particle sizes otherwise could have counteracted each others separation. The efficiency in a filter sequence for drilling mud with a certain particle size distribution (psd) will be improved substantially if the coarsest particles are taken out in successively decreasing size in the filtering process. In this way the filter efficiency of the filter unit (3) comprising a box-shaped cartridge with several levels of filters may be better than the single level with one filter unit in the prior art. A third advantage of the invention is that the filter unit (3) comprises a box-shaped cartridge according to the invention with several levels of filters could be placed in existing shale shakers with one or more filter elevation levels, and thus save replacements or extensive rebuilding of shale shakers at such as drilling platforms at sea and drilling rigs on shore.

A fourth advantage of the invention is that the modification of known shale shakers to comprise a cartridge with more filter elevation levels just takes very short time, as the cartridge may be pre adapted in advance to known fastening points in the existing machine, and rapidly be inserted. The cartridge may be industrially pre manufactured when one simply has the measured dimensions of the shale shaker it shall be inserted into and replace an existing, preferably upper filter level.

A fifth advantage is related to health. It is generally important to reduce the processing- and maintenance time for the drilling mud to reduce the exposure to oil mist and oil vapor to the personnel.

Chemical pneumonia due to long lasting exposure from oil vapor at the shale shakers by operating those for maintaining the drilling mud is a health problem and may be reduced by increasing the efficiency and reduce the exposure time the operators are exposed.

Embodiments of the invention

The invention is a shale shaker and comprises a main frame (1) which will reside on a deck or floor as an operating part of a drilling unit, for instance a drilling platform at sea or drilling rig on shore. The main frame holds a shaker frame (2) in a resilient suspension (20) in the main frame (1) . The shaker frame (2) is driven by a motorized vibrator (23) which may be electrical driven and is supplied by energy from a generator. The shaker frame (2) is generally provided with first fasteners (22) for a filter unit (3) . The first fasteners (22) for the filter unit (3) may be designed in different ways, and we will revert to this further down.

The shale shaker has an inlet (4) for receival of drilling mud to be filtered. This may also be designed in different ways. In general the drilling mud comes from a return line from a petroleum drilling process and comprises cuttings and other particles which have their origin in the drilling process and are to be filtered out from the drilling mud. The vibrations which arise by the motor operate an axle with eccentric weight in a way that the vibrations transmits via the shaker frame (2) to the filters. The direction of the vibrations and their polarizing results in that filtered-out particles moves towards the opposite end of the filter and runs over the edge at a particle outlet (6) .

The shale shaker has a first outlet (5) for filtered fluid and a second outlet (6) for separated particles. The filtered liquid contains particles which have not been separated out, generally particles which is finer than the finest filter of the filter unit, and may be used further in the drilling process. Possibly the filtered liquid has to be adjusted with regard to its chemical content or particle content before it is further used.

The new features of the shale shaker according to the invention is that the filter unit (3) comprises a box-shaped adapter piece (32) comprising two or more fasteners (33, 33a, 33b,..) in separate elevation levels (34a, 34b, ..) arranged for recieval of, and holding filters (35a,a35b, ..). Different embodiments of the invention are described below.

According to an embodiment of the invention the shale shaker (2) comprises sidewalls (21) and wherein said first fasteners (22) for said filter unit (3) is arranged along at least two opposite sidewalls (21) . In general the shaker frame (2) has one rear wall (26) and two sidewalls (21) and a bottom part (24) which leads the filtered drilling mud to an outlet (5) for the filtered drilling mud. The inlet (4) is arranged near the rear wall (26) and in an opposite end of the shaker frame (2) there is an opening to form the second outlet (6) for separated particles, i.e. a particle outlet (6) . This is shown in Fig. 1 and Fig. 5a.

The inlet

The inlet (4) may comprise a feeder box (41) arranged to receive drilling mud from a drilling mud supply pipe and lead and spread the drilling mud over an inlet-end at the upper filter in the shale shaker. The feeder box (41) is the applicant's own patent. The feeder box turns the flow of drilling mud in the direction towards the rear wall of its own frame in a way that the drilling mud is distributed entirely upstream on the upper filter. The particles of the drilling mud will anyway be transported by the vibration towards the particle outlet (6) . Thus the surface of the filter is utilized to a high degree.

The particle outlet

The particle outlet (6) is simply an open end of the filter in a way that the particles are transported over the edge and falls down into a collecting device. Flat outlet sills (39) are shown in Fig. 1 and in Fig. 5a shown shoved into the outer edge of the slots (33a, b, c) here in the outlet (6) .

An alternative to fasten the filter unit (3) in at least two of the sidewalls (21) is to fasten the filter unit (3) in the bottom of the shaker frame (2) .

The fastening of the filter unit (3) in the shaker frame

The box- shaped adapter piece (32) has in the shown embodiment in Fig. 2 a protruding lower cartridge frame (36) . This may be arranged with a downwards pointing flange (34) which shores up the lower cartridge frame (36) . The exact design of the lower cartridge frame (36) is of less importance as long as the lower cartridge frame (36) is arranged to be inserted into and is held releaseably in the original first fasteners (22) for the filter unit (3) . An advantage of the lower cartridge frame (36) is that it shores up the box-shaped adapter piece (32) . The same effect will apply for an angled slot (33a, 33b, 33c) .

Interlocking profiles

The first fastener (22) for the filter unit (3) is preferably in accordance with the embodiment of an existing shape of a shale shaker. Thus the existing material structure is utilized and one will save rebuilding time. This may in an embodiment comprise interlocking profiles (221) mounted at horizontally tensioning screws (222) through the side members (21) and wherein the

interlocking profiles (221) in the prior art are arranged to interlocking with corresponding interlocking profiles along the side edges of metallic filter cloths but wherein the single filter cloth according to prior art here is replaced for the invention by the lower cartridge frame (321) interlocking profile, for instance by a profile part of the downwards pointing flange (34) .

Slots with pneumatic packer

In an other embodiment of the invention the first fastener (22) , which should hold the protruding lower cartridge frame (36) , comprises a horizontal slot (201) in the shaker frame (2) arranged with a pneumatic packer (202) arranged to lock the cartridge frame (36) firmly in the slot. The lower cartridge frame (36) may

preferably constitute the filter units (3) box-shaped lower portion of the adapter piece (32) as shown in the enclosed drawings. With that, the filter unit (3) according to the invention extends only in the height above an existing upper level in an existing shale shaker, and the lower portion of the inlet (4) should be adjusted accordingly, as shown in Fig. lb and Fig.lc.

The second fastening devices for the filters

The filter unit (3) according to the invention comprises in general a box-shaped adapter piece (32) comprising two or more second fasteners (33, 33a, 33b, ..) in separate elevation levels (34a, 34b, ..) for filters (35a,a35b, ..).

The shale shakers adapter piece (32) must have locking arrangements to lock the filter in place. The filter in one elevation level (34a, 34b, ..) has in general a rectangular frame or several successive frame sections. In a first embodiment of the second fasteners (33) for the lower cartridge frame (321) these horizontal slots (33, 33a, 33b, 33c) comprise at least the sidewalls (31) of the adapter piece (32), see Fig. 2. In the indicated embodiment is pneumatic packer (38) arranged in the overlying surface in each slot. The pneumatic packer (38) is arranged to be pressurized by activating and opening of a pressure air supply valve (381) which receive pressurized air from a compressed air hose from a compressed air supply.

In an embodiment of the invention at leas one of the filters (35a, 35b, 35c) in the adapter piece (32) comprises a rectangular filter main frame arranged to be shoved into the horizontal slots (33a, 33b, ..). Each filter (35a, . .) which fills a level (43a,. .) is preferably subdivided into sections. In this way each filter becomes easy to handle manually in smaller sections. At the same time a section of the filter may be replaced separately in the case where wear or damage provides this. At the same time a section of the filter may be replaced separate in the case where a section of another cut point than the surrounding sections is desired. In an embodiment the adapter piece is made of metal profiles and metal plates.

The shale shaker according to an embodiment of the invention has the adapter piece (32) formed in mainly a fiber composite material.

This is an advantage because one reduces the weight of the adapter piece (32) so that the vibration mass is not increased to an unnecessary degree.

The shale shaker according to the invention may have the adapter piece (32) arranged in a way that it comprises at least two

horizontal slots (33a, 33b, ..) for insertion of at least two elevation levels (34a, 34b, ..) of filter frames.

Claims

A shale shaker comprising the following features:

- a main frame (1) ,

- a shaker frame (2) in a resilient suspension (20) in said main frame (1) and driven by a motorized vibrator (23)

- wherein said shaker frame (2) is provided with first fasteners (22) for at least one filter unit (3)

- an inlet (4) for receival of drilling mud to be filtered,

- a first outlet (5) for filtered fluid and a second outlet (6) for separated particles, characterized in that

- said filter unit (3) comprises an adapter piece (32) comprising two or more fasteners (33, 33a, 33b, ..) in separate elevation levels (34a, 34b, ..) for filters (35a, 35b, ..).

2. The shale shaker according to claim 1, wherein said adapter piece (32) is rectangular box-shaped and has two opposite aligned side walls (31) which comprises said two or more second fasteners (33a, 33b, .. ) .

3. The shale shaker according to claim 1 or 2, wherein said shaker frame (2) is mainly rectangular and comprises sidewalls (21) and wherein said first fasteners (22) for said filter unit (3) are arranged along at least two of said shaker frames (2) sidewalls

(21) .

4. The shale shaker according to claim 1, 2 or 3 wherein said first fastener (22) for said filter unit (3) comprises

interlocking profiles (221) mounted at horizontally tensioning screws (222) which extends through the side members (21) and wherein said interlocking profiles (221) are arranged to interlocking with corresponding interlocking profiles (331) at said lower cartridge frame (36) , preferably in a way that said interlocking profiles (331) are a part of a mainly vertical flange (331) at the lower cartridge frame (36) .

5. The shale shaker according to claim 1, 2 or 3 , wherein said first fastener (22) for said filter unit (3) comprises first horizontal slots (27) in at least in said shaker frames side members (21) and is arranged with pneumatic overlying packers to hold said lower cartridge frame (36) .

6. The shale shaker according to any of the preceding claims, wherein said filter units (3) second fasteners (33a, 33b, ..) are shaped as horizontal slots (33a, 33b, 33c.) in at least in said sidewalls (31) of said adapter piece (32) .

7. The shale shaker according to one of the preceding claims, with a pneumatic packer (38) at an overlaying surface in at least one of said horizontal slots (33a, 33b, ..) .

8. The shale shaker according to claim 7, wherein the pneumatic packer (38) is arranged to be pressurized by activating and opening of a pressure air supply valve (381) for locking said filter in place .

9. The shale shaker according to one of the preceding claims, wherein said filter comprises a rectangular filter main frame arranged to be pushed into said horizontal slots (33a, 33b, ..) and preferably subdivided into sections.

10. The shale shaker according to one of the preceding cl wherein said adapter piece (32) is formed in mainly a fiber composite material.

11. The shale shaker according to any of the preceding claims, wherein said adapter piece (32) comprises at least two horizontal slots (33a, 33b, ..) for insertion of at least two elevation levels (34a, 34b, ..) of filter frames.