Sample collection system and parts thereof

Abstract

The invention relates to a sample collection system for collecting sub-samples from a material stream, the system including a valve arrangement and a static cone splitter, and wherein the valve arrangement is arranged to enable operation of the static cone splitter to collect a non-biased sample of the material stream fed to the static cone splitter under first and second operational conditions, the first operational condition requiring the material stream to be at substantially atmospheric pressure and flowing at a minimum functional flow rate, and the second operational condition requiring the material stream to be pressurised above atmospheric pressure and at a flow rate higher than the minimum functional flow rate. The invention also relates to a static cone splitter for use with the system, together with a cone member for use with the static cone splitter.

Claims

1. A sample collection system for collecting sub-samples from a material stream, said system including a valve arrangement and a static cone splitter, and wherein the valve arrangement is arranged to enable operation of the static cone splitter to collect a non-biased sample of the material stream fed to the static cone splitter under first and second operational conditions, the first operational condition occurring when the material stream is at substantially atmospheric pressure and flowing at a minimum functional flow rate, and the second operational condition occurring when the material stream is pressurized above atmospheric pressure and at a flow rate higher than the minimum functional flow rate, wherein the valve arrangement includes an air valve which, at the minimum functional flow rate of the material stream, remains open allowing air to enter the valve arrangement to allow the material stream to flow without restriction at substantially atmospheric pressure, and wherein at flow rates higher than the minimum functional flow rate the air valve is arranged to allow the evacuation of air from the system until the system is full of material stream at which point the air valve closes.

2. A sample collection system according to claim 1 wherein the valve arrangement is a passive component that operates automatically dependent on the flow rate of the material stream.

3. A sample collection system according to claim 1 further including a chamber, and wherein the material stream is arranged to flow into the chamber before entry into the static cone splitter.

4. A sample collection system according to claim 3 wherein the valve arrangement is connected to the chamber distal from the cone splitter.

5. A sample collection system according to claim 3 wherein the cone splitter is located substantially vertically below the chamber and is connected thereto by a substantially vertical chamber exit pipe.

6. A sample collection system according to claim 5 wherein the vertical chamber exit pipe connects to an inlet tube of the static cone splitter.

7. A sample collection system according to claim 6 wherein the inlet tube has a cross-sectional flow area sized such that the unrestricted flow by gravity of the material stream through the inlet tube is substantially equal to or less than the minimum functional flow rate of the system.

8. A sample collection system according to claim 1 configured to receive the material stream at a flow rate of greater than about 60 litres per minute.

9. A sample collection system according to claim 1 comprises an upper housing, a cone member and a lower housing, the cone member including a slant surface and at least two blades, said at least two blades defining at least in part a first and a second opening of equal flow area, the first opening being a sub-sample opening and the second opening being a waste opening, wherein the cone splitter is configured so that in use the material stream entering the upper housing is directed into contact with the slant surface and then a portion of the material stream after contacting the slant surface is directed through the sub-sample opening and is arranged to exit from the cone splitter via a sample outlet tube of the lower housing, the remaining material stream forming a waste stream which is directed through said waste opening, and the flow resistance of the portions of the material stream about the slant surface at entry into the openings is substantially equal.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 is a front view of a static cone splitter according to an embodiment of one aspect of the invention;

(3) FIG. 2 is an oblique cut-away view of the cone splitter shown in FIG. 1;

(4) FIG. 3 is a front cut-away view of the cone splitter shown in FIG. 1;

(5) FIG. 4 is a side cut-away view of the cone splitter shown in FIG. 1;

(6) FIG. 5 is an assembly view of the cone splitter shown in FIG. 1;

(7) FIG. 6 is an enlarged isometric view of the cone member of the cone splitter shown in FIG. 5;

(8) FIG. 7 is an enlarged plan view of the cone member shown in FIG. 6; and

(9) FIG. 8 illustrates a sample collection system according to an embodiment of another aspect of the invention.

DETAILED DESCRIPTION OF DRAWINGS

(10) As shown in the Figures, a static cone splitter 10 in accordance with an embodiment of the invention includes an upper housing 20, a cone member 30 and a lower housing 40. The upper housing 20, cone member 30 and lower housing 40 are assembled so that in use of the cone splitter 10 a material stream enters the cone splitter 10 via an inlet 22 of the upper housing 20. As illustrated, inlet 22 has a circular cross-sectional configuration, although other configurations are envisaged.

(11) The cone member 30 includes a slant surface established on a central cone shaped component 32 (hereafter referred to as cone 32), eight blades 34 and a flange 36. The eight blades 34 define, at least in part, eight different openings 38.

(12) In accordance with the illustrated embodiment of the invention, the material stream enters the cone splitter 10 and is then divided into six waste streams and two sub-sample streams. The six waste streams join together below the cone member 30 after passing through their respective opening and exit the cone splitter via outlet tube 42. Each sub-sample stream exits via a respective sample outlet tube 44, 46. As shown in FIG. 1, sample outlet tube 44 is located to the left of the outlet tube 42 and sample outlet tube 46 is located to the right of the outlet tube 42. The sample outlet tubes 44, 46 are located symmetrically about the outlet tube 42 so as to establish a symmetrical configuration.

(13) Sample outlet tube 44 has an upper opening 44a and a lower opening 44b. Sample outlet tube 46 has an upper opening 46a and a lower opening 46b. The shape of the upper opening 44a, 46a of each of the sample outlet tubes 44, 46 is best shown in FIG. 5.

(14) In use of the cone splitter 10, outlet tube 42 of the lower housing 40 may be connected to appropriate pipework to enable the waste stream to be appropriately dealt with. Alternatively, outlet tube 42 may dispense the waste stream to the ground, a container or other reservoir. Similarly, the first and second sample outlet tubes 44, 46 of the lower housing 40 may be connected to appropriate pipework to enable collection of the respective sub-sample stream. Alternatively, each sample outlet tube 44, 46 may dispense the sub-sample stream to a container or other sample collection arrangement.

(15) When the upper housing 20, cone member 30 and lower housing 40 are assembled together, the flange 36 of the cone member 30 is located between a flange 24 of the upper housing 20 and a flange 48 of the lower housing 40. Bolts (not shown) pass through respective aligned apertures 50 in the respective flanges 24, 36, 48 and are used to secure the assembled parts together.

(16) In use, the cone member 30 is orientated so that an apex or tip 32a of the cone 32 is located upwardly in the direction of the inlet tube 22. The apex or tip 32a may be pointed or rounded with a small radius (e.g. 1.5 mm radius). The longitudinal central axis of the cone 32 is also coincident with the longitudinal central axis of the inlet tube 22 of the upper housing 20.

(17) The cone 32 of the cone member 30 and the interior wall 20a of the upper housing 20 establish a chamber C above the blades 34. This chamber C is best illustrated in FIGS. 3 and 4 and has an annular shape. As illustrated, the interior wall 20a bounding the chamber C extends substantially parallel to the plane of the slant surface of the cone 32 at any point thereabout. This configuration ensures that any portion of the material stream is not inadvertently entrained within the chamber C.

(18) The cone 32 has a base diameter larger than the diameter of the inlet 22 of the upper housing 20 so that all of the material stream flowing into the interior of the cone splitter 10 via the inlet 22 will be directed onto and will come into contact with some portion of the slant surface of the cone 32.

(19) It is preferable to establish the cone angle of the cone 32 as high as possible to reduce back pressure within the chamber C of the cone splitter 10.

(20) As best shown in FIG. 7, the eight blades 34 extend radially of the longitudinal central axis of the cone 32. The blades 34 are equally spaced around the cone 32 and are angled so as to intersect the flow of the material stream substantially perpendicularly. This perpendicular intersection is shown in FIG. 3.

(21) After contacting a portion of the slant surface of the cone 32, the flow of the material stream is redirected and then passes through the openings 38 located between the adjacent blades 34 of the cone member 30. Accordingly, the blades 34 divide the material stream into eight equally sized parts or sub-streams and thus 12.5% of the material stream will pass through each of the openings 38.

(22) As shown, each opening 38 is bounded by the associated adjacent blades 34, a part 32b of the base of the cone 32, and a part 36a of the flange 36. The planar shape of the openings 38 as viewed from above is best illustrated in FIG. 7. As clearly shown, the shape and size of each opening is identical.

(23) It should be noted from FIG. 5, that the upper opening 44a, 46a of each of the first and second sample outlet tubes 44, 46 mimic the planar shape of the openings 38. Further, when the flange 36 of the cone member 30 is located on the flange 48 of the lower housing 40, the upper openings 44a, 46a of the sample outlet tubes 44, 46 are located so as to align with respective ones of the openings 38 of the cone member 30. These particular openings 38 are thus referred to hereafter as the sub-sample openings. Accordingly, during use of the illustrated cone splitter 10, any portion of the sample stream that passes through the sub-sample openings is diverted to the respective aligned sample outlet tubes 44, 46 for collection.

(24) It will be appreciated by a person skilled in that art that the arrangement disclosed ensures that the flow resistance of the portions of the material stream about the slant surface of the cone member 30 at entry to the openings 38 is arranged to be substantially equal. Accordingly, the flow characteristic of the material stream at entry through the openings 38 is substantially identical and thus an unbiased sample of the total material stream will flow for collection via the sub-sample openings into the sample outlet tubes 44, 46.

(25) In accordance with the illustrated embodiment, two sub-samples each representative of 12.5% of the total material stream can be simultaneously collected with the remaining 75% ultimately divested to the outlet tube 42. However, it will be appreciated that different configurations are possible. For example, only a single sample outlet tube may be provided and/or the number of blades of the cone member can be varied to correspondingly vary the percentage of the sub-sample flow actually collected by the or each of the sample outlet tubes of the cone splitter.

(26) FIG. 8 illustrates a sample collection system 100 in accordance with an embodiment of the invention. The sample collection system 100 includes pipework 105 through which a material stream is arranged to flow, a chamber 110 fitted with a course screen 115, a valve arrangement 120, a chamber exit pipe 125, and a static cone splitter 10. The static cone splitter 10 of this embodiment adopts the form described previously in connection with FIGS. 1 to 7.

(27) As illustrated in FIG. 8, the chamber 110 is connected via the chamber exit pipe 125 to the inlet tube 22 of the static cone splitter 10. The chamber 110 is located substantially vertically above the static cone splitter 10 and is of a larger diameter than the diameter of the exit pipe 125. Chamber 110 is arranged to collect the material stream prior to it flowing into the cone splitter 10.

(28) The chamber 110 includes the course screen 115 which is capable of screening out oversize material contained in the material stream that would otherwise block flow through the cone splitter 10. The screen 115 would be removable for cleaning. The use of other arrangements to screen out oversize material from the material stream is envisaged. Further, it is envisaged that such screening arrangements may be excluded.

(29) The chamber 110 has a base 102 which adopts a conical shape to prevent build-up of particulate material thereon. Other base configurations are envisaged.

(30) Valve arrangement 120 is located at the top 104 of the chamber 100 and distal from the cone splitter 10. The valve arrangement 120 is configured to enable the break of any vacuum established within the system 100 and to provide a discharge point for excess material stream in the event that the flow rate through the system 100 is too high to be handled by the chamber 110. In accordance with an embodiment of the invention the valve arrangement 120 includes an air valve.

(31) The sample collection system 100 is preferably arranged to receive the material stream at an operating flow rate greater than about 60 litres per minute and up to about 150 litres per minutes. The upper flow rate limit of the system according to the described embodiment of the invention is generally limited to a rate at which back pressure on the bore hole and the equipment is less than about 1 Bar.

(32) The relative diameters of the chamber 110 and exit pipe 125 and the location of the valve arrangement 120 at the top of the chamber 100 allows material stream to flow through the chamber 110 and into the cone splitter 10, with any vacuum broken and without excess air being drawn into the chamber 110. This is because the air flowing via the valve arrangement 120 is not in direct contact with the material stream.

(33) The length direction of the exit pipe 125 from the chamber 110 extends substantially vertically and directs the material stream into the inlet tube 22 of the static cone splitter 10. The exit pipe 125 is a short vertical pipe with a length of approximately 300 mm. This compares with a chamber 110 having a diameter of about 200 mm and a height of about 300 mm.

(34) During operation of the system 100, the material stream from a drilling operation is fed via pipework 105 into the chamber 110. The chamber 110 is located generally vertically above and centrally of the inlet 22 of the upper housing 20 of the cone splitter 10. Preferably, the material stream is supplied at a flow rate of greater than about 60 litres per minute. This ensures that there is always a substantially constant and uniform distribution of liquid and cuttings in the material stream when it enters the inlet 22 of the cone splitter 20.

(35) Embodiments of the invention are advantageous because they enable collection of a non-biased sample of a material stream. Further, the system does not include any moving parts and thus the system is less likely to break down. Further, the system requires no external power supply to operate. If the cone 32 of the static cone splitter 10 becomes damaged, the cone member 30 can be easily and quickly replaced and thus down time for the system is only minor.

(36) Embodiments of the invention are capable of collecting smaller sample sizes (i.e. a smaller percentage of the total material stream) and are not flow rate dependent. Further, embodiments of the invention enable reliable sampling of a material stream with greater than 90% liquid, such as that generated in coiled tubing drilling.

(37) The embodiments have been described by way of example only and modifications within the spirit and scope of the invention are envisaged.