Apparatus and Method for Separating Liquid from a Material Comprising a Solid Fraction and a Liquid Fraction

Abstract

An apparatus and a method is for separating liquid from a material comprising a solid fraction and a liquid fraction. The apparatus has a conveyor belt for bringing the material from a receiving portion to a discharge portion. At least a portion of the conveyor belt is provided with at least one sorption means for absorbing and/or adsorbing liquid from the material while the material is carried between the receiving portion and the discharge portion.

Claims

1. An apparatus for separating liquid from a material comprising a solid fraction and a liquid fraction, the apparatus comprising: a conveyor belt for bringing the material from a receiving portion to a discharge portion, wherein at least a portion of the conveyor belt is provided with at least one sorption means for at least one of absorbing and adsorbing liquid from the material while the material is carried between the receiving portion and the discharge portion.

2. The apparatus in accordance with claim 1, wherein the discharge portion of the apparatus comprises a solids discharge means for discharging the solid fraction of the material from the apparatus and a liquid discharge means for discharging the liquid fraction of the material from the apparatus, and wherein the solids discharging means is arranged closer to the receiving portion than the liquid discharge means, so that the solid fraction is discharged before the liquid fraction is discharged.

3. The apparatus according to claim 1, wherein the at least one sorption means is an inlay arranged on the conveyor belt, the inlay extending along at least a portion of the conveyor belt.

4. The apparatus according to claim 1, wherein the conveyor belt is a flexible conveyor belt arranged to be moved around at least two turning rollers.

5. The apparatus according to claim 4, wherein the conveyor belt is endless.

6. The apparatus according to claim 4, further comprising guiding means adapted to lift side portions of the conveyor belt upwards from the receiving portion and towards the discharge portion, so that the conveyor belt is a pouch-like conveyor belt and the material is carried from the receiving portion towards the solids discharge portion the pouch-like conveyor belt.

7. The apparatus according to claim 4, wherein the solids discharge means is a roller of the at least two turning rollers which receives the conveyor belt carrying the solid fraction and the liquid fraction of the material, the solid fraction being discharged by redirecting the conveyor belt via the roller.

8. The apparatus according to claim 1, further comprising a liquid discharge means for discharging the liquid fraction of the material from the apparatus, wherein the liquid discharge means is a squeezing device adapted to compress the sorption means, so that an amount of the liquid absorbed by the sorption means is removed from the sorption means.

9. The apparatus according to claim 1, further comprising a liquid discharge means for discharging the liquid fraction of the material from the apparatus, wherein the liquid discharge means comprises a gas jetting means or a gas suction means.

10. The apparatus according to claim 8, further comprising a liquid discharge means for discharging the liquid fraction of the material from the apparatus, wherein the liquid discharge means is arranged at a portion of the conveyor belt wherein the sorption means faces towards a base of the apparatus.

11. The apparatus according to claim 8, wherein the conveyor belt is arranged to be moved around at least two turning rollers, and wherein one of the at least two turning rollers forms part of the liquid discharge means.

12. The apparatus according to claim 1, wherein the apparatus further comprises an agitation means for agitating the material while being carried between the receiving portion and the solids discharge means.

13. The apparatus according to claim 1, wherein the sorption means comprises at least two sorption means having different sorption characteristics.

14. The apparatus according to claim 13, wherein the at least two sorption means are arranged in parallel.

15. The apparatus according to claim 13, wherein the liquid removed from each of the at least two sorption means is communicated into separate collection means.

16. The apparatus according to claim 3, wherein the inlay is detachably connected to the carrier.

17. The apparatus according to claim 1, further comprising a sensor means for monitoring thea condition of the sorption means.

18. (canceled)

19. A method for separating liquid from a material comprising a solid fraction and a liquid fraction via an apparatus comprising a conveyor belt for bringing the material from a receiving portion to a discharge portion, the method comprising: supplying the material to the conveyor belt, wherein the conveyor belt comprises a sorption means for at least one of absorbing and adsorbing liquid; bringing the material towards a solid fraction discharge means; discharging the solid fraction; and then bringing the conveyor belt comprising the sorption means to a liquid discharge means, and discharging at least a portion of the liquid absorbed and/or adsorbed from the material.

20. The method in accordance with claim 19, wherein the conveyor belt is endless.

21. The method in accordance with claim 18, wherein the material is drilling fluid.

22. The method in accordance with claim 19, wherein the material is drilling fluid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In the following is described examples of preferred embodiments illustrated in the ac- companying drawings, wherein:

[0057] FIG. 1 shows a principal sketch of the apparatus in accordance with the present invention shown in perspective, wherein the apparatus comprises and endless conveyor belt;

[0058] FIG. 2a shows a side view of the apparatus in FIG. 1;

[0059] FIG. 2b shows in larger scale detail B in FIG. 2a;

[0060] FIGS. 3a and 3b show in larger scale a detail of a portion of two embodiments of the discharge means of the apparatus in FIG. 1;

[0061] FIGS. 4a and 4b show a portion of the an apparatus provided with an agitation means; and

[0062] FIG. 5 shows an alternative embodiment of the apparatus in FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

[0063] In what follows, positional indications such as for example above, below, right and left, refer to the position shown in the figures.

[0064] Same or corresponding elements are indicated by same reference numerals in the different figures.

[0065] A person skilled in the art will understand that the figures are principle drawings only and that relative proportions between individual elements may be distorted.

[0066] In the figures, reference number 1 shows an apparatus in accordance with the present invention. The apparatus 1 comprises a conveyor belt or carrier 3 for bringing a material M from a receiving portion 5 to a discharge portion 7.

[0067] The carrier 3 is provided with a compressible or squeezable sorption means 9 adapted to absorb and/or adsorb liquid from the material M while being carried between the receiving portion 5 and the discharge portion 7.

[0068] In FIG. 1 material M is supplied to a receiving portion 5 of the apparatus 1 by means of two sieving devices S, here illustrated as MudCube disclosed for example in Norwegian patent NO 323519 B1. It should be noted that the sieving device may alternatively be a Shale shaker as will be known to a person skilled in the art. The sieving devices S are in communication with a well bore (not shown).

[0069] A person skilled in the art will appreciate that a sieving device S (two shown) of the MudCube type, separates a substantial portion of the fluid (liquid and gas) from the solid particles of the drilling mud. However, the solid particles or material M discharged from the sieving devices S and into the receiving portion 5 of the apparatus 1 will still contain some liquid, typically 10-20% by weight. Material discharged from a traditional shale shaker may typically have a liquid content of about 50-80% by weight. However, a person skilled in the art will appreciate that the liquid content of a material discharged from a sieving apparatus may vary considerably due to the formation being drilled, any clogging of the sieving element, etc.

[0070] One purpose of the apparatus 1 in accordance with the present invention is to further separate liquid from the material M. This is achieved by providing at least a portion of the carrier 3 with at least one sorption means 9 adapted to absorb and/or adsorb liquid from the material while the material M is carried by means of the carrier 3 from the receiving portion 5 to the discharge portion 7. In the embodiment shown, the carrier 3 is a conveyor belt 3.

[0071] In FIG. 1, the conveyor belt 3 is of a type known per se, for example a commercially available rubber type belt. The conveyor belt 3 is provided with an inlay 9 of absorbent and/or adsorbent material. The inlay 9 comprises in the embodiment shown, two inlays arranged in parallel in a longitudinal direction of the conveyor belt 3. The two inlays 9 may have the same absorption/adsorption characteristics, or different absorption/adsorption characteristics as mentioned above.

[0072] The inlay 9 is detachably connected to the conveyor belt 3 by means of for example a Velcro or other suitable connecting means. This allows for replacement of the inlay 9 without replacing the conveyor belt 3.

[0073] At the receiving portion 5, the conveyor belt 3 has a U- or V-like shape in order to form an open pouch capable of holding the material M received from the sieving apparatuses S. At the discharge portion 7, the conveyor belt 3 with its inlays 9, is folded out to form a flat belt suitable for being partly rotated around a turning roller 11 as shown.

[0074] At the turning roller 11, the conveyor belt 3 with its inlays 9 are redirected and turned upside-down to allow discharging of the material M into for example a container (not shown) or other suitable receiving or transportation means. Thus, in this embodiment the turning roller 11 is a solid discharge means of the apparatus 1.

[0075] A secondary turning roller 11 is arranged after the turning roller 11 (as seen in the moving direction of the carrier 3). The purpose of the secondary roller 11 is to reorient the carrier or conveyor belt 3 into a position suitable for again receiving the material M from the sieving devices S.

[0076] In a prototype of the apparatus 1, an inlay 9 of polypropylene material showed very good results both with regards to absorbing liquid from the material M, and a subsequent removal or draining of the liquid from the inlay 9 by means of compression or squeezing of the carrier 3 and the inlay 9. The liquid content of the material M was reduced by about 17% by weight from the receiving portion 5 to the discharge portion 7.

[0077] The compression is provided by means of compression roller 13 biased towards a lower portion of the turning roller 11 as best can be seen in FIGS. 3a and 3b which shows the discharge portion 7 of the apparatus 1 in larger scale. The turning roller 11 rotates in a direction as indicated by arrow R in FIG. 3a and FIG. 3b. The rotation R is provided by means of a suitable driving means (not shown) or by means of frictional forces transferred from the carrier 3 if the carrier 3 is driven by driving means arranged at some other suitable location. The compression roller 13 is rotated in an opposite direction R.sub.o, either by means of a driving means (not shown) or by means of frictional forces transferred form the carrier 3 and inlays 9.

[0078] At the turning roller 11, the material M (see FIG. 1) carried by the carrier 3 and inlays 9 falls off and is collected by a receptacle such as for example a container (not shown). The carrier 3 and inlays 9 are then compressed between the turning roller 11 and compression roller 13, whereby a substantial amount of liquid absorbed by the inlays 9 (and in some embodiments also the carrier 3 itself) is freed and collected by means of a receptacle 15 arranged under the rollers 11, 13 as shown. Thus, in this embodiment the turning roller 11 together with the compression roller 13 provide a liquid discharge means of the apparatus 1.

[0079] Seen isolated, and in the moving direction of the carrier 3 and inlays 9, the turning roller 11 forming the solids discharge means is arranged closer to the receiving portion 5 of the apparatus 1 than the turning roller 11 and the compression turning roller 13 which together form the liquid discharge means.

[0080] It should be noted that the receptacle 15 shown is typically a receiving means arranged for communicating the liquid into larger container(s) or conduits in communication with such container(s).

[0081] In a configuration where the two inlays 9 have different absorbing/adsorbing characteristics as discussed above, it is advantageous if the different liquids are kept substantially separate after the liquids have being freed from the inlays 9. This is achieved by means of dividing the receptacle 15 into two separate sub-receptacles 15, 15 as shown in for example FIGS. 3a and 3b.

[0082] In FIG. 3b, the discharge means shown in FIG. 3a is further provided with a suction means 14. The suction means 14 is provided with suction nozzle 14 brought up towards the inlay 9 and carrier 3. The suction nozzle 14 is provided with a conduit 14 being in fluid communication with an underpressure generating device (not shown) known per se for example from NO 323519 B1. Upon activating the underpressure generating device, fluid will be evacuated from the suction means 14 and liquid will be sucked from the inlays 9 and carrier 3.

[0083] Although FIG. 3b shows a combination of a compression means 11, 13 and a suction means 14, it should be appreciated that the suction means 14 may be a standalone liquid discharge means, i.e. without the compression means.

[0084] In an alternative embodiment (not shown) the suction means 14 may comprise two or more separate suctions means configured for separately sucking each of the inlays 9. This allows for keeping liquid absorbed/adsorbed by inlays (9) having different sorption characteristics.

[0085] It should be appreciated that a supporting structure runs along the entire length of the carrier 3 apart from at the discharge portion 7 where the carrier is supported by turning rollers 11, 11. Further, the supporting structure disclosed in detail in the publication WO 2013/143551 A1 is a suitable supporting structure 20 for the present invention.

[0086] The sorption means, either being the carrier 3 itself, an inlay 9 or a combination thereof, may deteriorate after some time of operation.

[0087] In order to monitor the condition of the sorption means 3, 9, the apparatus 1 may be provided with a sensor means.

[0088] FIGS. 2a and 2b show a sensor means in the form of a weight 17 connecting the carrier 3 to a supporting structure 20 supporting the carrier 3. In the embodiment shown, a lower portion of the weight 17 is provided by a roller 19 being in engagement with a V-belt arrangement 19 formed in a portion of the carrier 3. The roller/V-belt arrangement is based on the same principle as disclosed in WO 2013/143551 A1.

[0089] By measuring the weight of an empty carrier 3 at certain intervals, for example once for each travelling round of the carrier 3, and compare the results with for example a predetermined value, a signal may be given to an operator when the weight deviates from the predetermined value. The carrier 3 is empty between the discharge portion 7 and the receiving portion 5 of the apparatus 1.

[0090] FIGS. 4a and 4b show an agitation means 25 suitable for stirring the material M while being carried between the receiving portion 5 and the discharge portion 7 of the apparatus 1. The agitation means 25 may for example be arranged about halfway between the receiving portion 5 and the discharge portion 7.

[0091] In the embodiment shown, the agitation means 25 comprises two turning rollers, a first roller 27 and a second roller 27. When the material passes the first turning roller 27, the material M will fall or, depending on the speed of the carrier 3 and type of material, be slung off the carrier 3. However, the second turning roller 27 redirects the carrier 3 such that the carrier 3 will again catch the material M being discharged by means of the first turning roller 27. Thus, an agitation means 25 forming part of the apparatus 1 shown in FIG. 1 as suggested above, will provide a stirring motion of the material M while being moved from the receiving portion 5 to the discharge portion of the apparatus 1 shown in FIG. 1. The first and second turning rollers 27, 27 will be additional to the turning rollers 11, 13 shown in for example FIG. 1.

[0092] Alternatively or additionally to the agitation means 25 shown in FIGS. 4a and 4b, agitation may also be provided by means of a scraper or plough device (not shown) being in contact with the material M while being transported from the receiving portion 5 to the discharge portion 7. Such a scraper or plough may typically extend from the support structure S into a partly open pouch similar to the open pouch at the receiving portion 5 shown in FIG. 1.

[0093] FIG. 5 shown an alternative apparatus 1 in accordance with the present invention. A main difference from the apparatus 1 shown in FIG. 1, is that the carrier or conveyor belt 3 is not endless. Other parts of the apparatus 1 shown in FIG. 5 are similar to the apparatus shown and described with regards to FIG. 1 and will thus not be repeated.

[0094] The apparatus 1 in FIG. 5 is provided with a carrier 3 that is connected to a winding drum 30, 30 at each of its two end portions. In operation, the carrier 3 is reciprocating (indicated by double arrow D) by winding it onto one of the winding drums 30, 30 while at the same time un-winding the carrier 3 from the other of the winding drums 30, 30. The reciprocating frequency, i.e. how often change of direction has to take place, depends inter alia on the capacity of the carrying capacity of the drums 30, 30, length and speed of the carrier 3. In the embodiment shown, the apparatus 1 is provided with two discharge portions 7, one at each winding drum 30, 30.

[0095] In FIG. 5, the carrier 3 is shown moving from left to right, i.e. un-winding from the left winding drum 30 onto the right winding drum 30.

[0096] Although not shown, the carrier 3 in FIG. 5 is connected to a support structure of the same type as partly shown and described concerning FIG. 1.

[0097] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb comprise and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article a or an preceding an element does not exclude the presence of a plurality of such elements.

[0098] The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.