GB2539314A

GB2539314A - Test apparatus for evaluating solid particle movement during hydrocarbon production, and method therof

Info

Publication number: GB2539314A
Application number: GB1606383.6A
Authority: GB
Inventors: Thomas Maurice Patey Ian; Louise Collins Gemma
Original assignee: Corex UK Ltd
Current assignee: Corex UK Ltd
Priority date: 2015-04-13
Filing date: 2016-04-13
Publication date: 2016-12-14
Also published as: GB201506186D0; WO2016166528A1

Abstract

A test apparatus and a method for evaluating particle movement during hydrocarbon production includes a screen assembly 100 which has a sealed fluid passage between an input-end portion and an output-end portion. A fluid inlet port (104, fig 2) is fluidly coupleable to the input-end portion and provides fluid communication with a fluid source. A fluid outlet port (106, fig 2) is fluidly coupleable to the output-end portion and provides a fluid outlet from the sealed fluid passage. The screen assembly 100 includes at least one radiolucent screen member 112 adapted to allow in-situ imaging. Also disclosed is a screen assembly having plural interchangeable and operatively coupleable screen members, 112, 114, 116, 118 each adapted to provide a predetermined solids control characteristic to solids suspended in fluid passing through the assembly. The testing method includes the steps of: operatively coupling said test apparatus to a test tubing and commencing a predetermined sanding experiment; removing said test apparatus from said test tubing and imaging at least one zone of interest of said at least one radiolucent screen member in-situ utilizing a predetermined imaging method; and post-processing the resulting images to determine at least one material property of said at least one radiolucent screen member.

Description

TEST APPARATUS FOR EVALUATING SOLID PARTICLE MOVEMENT DURING HYDROCARBON PRODUCTION, AND METHOD THEROF The present invention relates generally to the field of oil and gas exploration and in particular to an apparatus and a method for evaluating wellbore stability and solid particle movement and/or migration during hydrocarbon recovery and more particularly to a substantially radiolucent, tomographically or otherwise radiation scannable/imageable test apparatus for evaluating wellbore stability and solid particle movement and/or migration during hydrocarbon recovery.

Introduction

Sediment movement in the field of hydrocarbon production is a big problem for hydrocarbon recovery, effecting the productivity and injectability of a well. There may be instability in the near wellbore area as a consequence of wellbore operations, or simply due to the natural weaknesses in the rock formations. Unstable formations can break down loose sediment during production and move into the near wellbore. Consequently, laboratory tests have long been used to explore and evaluate the stability of different rock types in the wellbore and the control options available, e.g. sand control. These procedures have been used as a means to select suitable hardware for inclusion in the completion of the wellbore. The hardware could be, for example, wire wrap or weave screens that have a predetermined aperture size and which in general act to permit flow of produced hydrocarbons into production tubing but prevent flow of such sediment (including sand) into the production tubing. Additional hardware may also be used (e.g. gravel pack, proppants or filter medium) in combination with screens.

Typical laboratory tests that are of interest in hydrocarbon recovery/production may be as follows: Shiny Testing Slurry injection testing represents sand production at the near wellbore. Testing involves flowing slurry of low and/or high density fluid with suspended sediment through the hardware under evaluation and this may allow the natural build up of a sediment pack against the hardware. Effluent samples are collected which are then available for laser particle size analysis and total suspended solids determination.

As a sediment pack builds up against a filter or screen hardware assembly, the sediment pack may replace (or more correctly, precede) the hardware assembly as the main filter and in this situation may account for most of the resistance to flow of the reservoir carrier phase(s) (i.e. the produced fluid from the reservoir). The resistance to the flow of the slurry may continue to increase as the pack continues to builds up.

Laboratory slurry simulations are designed to evaluate elutriated sediment within reservoir phase(s) under representative well velocities. Sediment which drops out of suspension maybe excluded as it will not travel in the representative flow phase(s) due to gravitational force being able to exceed those forces which would otherwise keep sediment buoyant. Only elutriated sediment travels to flow out of the reservoir into the production tubing through the hardware and/or is gradually filtered out to build up a sediment pack. The particle size distribution of the elutriated sediment (slurry) is usually different to that used to represent a prepack test (mentioned below). This elutriated sediment which is normally separated from the near wellbore constituents (bulk rock and/or operational fluid solid components or constituents) is determined by separate elutriation tests. Elutriation tests discover which sediment is only carried by the representative velocities during flow of the reservoir phase(s).

Prepack Testing Laboratory prepack simulations are designed to more closely mimic a sudden instability of the near wellbore area. Collapse of all the rock constituents from a catastrophic event will instantaneously get trapped against the selected hardware or be filtered out. Particle size distribution maybe all of the sediment from the near wellbore constituents.

The sediment is wetted with a small amount of low x-ray density fluid. This wetted sediment is then placed above the hardware (pre-packed) to produce a sediment pack. The prepack test is commenced by pumping low and/or high density fluid from a reservoir at representative flow rate(s) through the sediment pack and out of the perforated plate at the base of the tube assembly.

Prepack/ Slurry sequence Testing Laboratory prepack/slurry sequence testing simulations are designed to mimic sediment pack made up of the bulk rock trapped against the hardware followed by the flow of slurry (the elutriated sediment within reservoir carrier phase(s)) under representative well velocities.

Currently available test apparatus and/or evaluation methods (e.g. imaging) are usually very "rigid" standard test set-ups that are not adaptable to specific test requirements, as well as, difficult to evaluate in situ or in the post-processing phase, therefore, only allowing inferior accuracy from, for example, the post-processing data extraction, 3D visualisation and computed fluid dynamic modelling.

Accordingly, it is an object of the present invention to provide an improved test apparatus and method that allows improved visualisation and accuracy of images acquired from the test apparatus, as well as, adaptability to specific test scenarios.

Summary of the Invention

Various aspects of the invention seek to overcome one or more of the above

disadvantages of the prior art.

According to a first aspect of the present invention, there is provided a test apparatus for evaluating particle movement during hydrocarbon production, comprising: a screen assembly adapted to provide a sealed fluid passage between an input-end portion and an output-end portion; a fluid inlet port, fluidly coupleable to said input-end portion and adapted to provide fluid communication with a fluid source; a fluid outlet port, fluidly coupleable to said output-end portion and adapted to provide a fluid outlet from said sealed fluid passage, wherein said screen assembly further comprises at least one radiolucent screen member, adapted to allow in-situ imaging of a predetermined solids-control characteristic to solids suspended in a fluid moving from said fluid inlet port towards said fluid outlet port.

The use of a radiolucent material (e.g. Polyether Ether Ketone, i.e. PEEK) provides the advantage of greatly improved imaging results from, for example, 3D tomographic acquisition.

Advantageously, said radiolucent screen member comprises at least one radiolucent polymer sleeve. Preferably, said radiolucent polymer sleeve is made from Polyetherether-ketone (PEEK).

Advantageously, said at least one screen member comprises any one or any combination of a perforated plate, a metallic screen assemblage operatively secured by a radiolucent polymer sleeve, at least one filter medium operatively secured by a radiolucent polymer sleeve, and a radiolucent polymer sleeve.

Advantageously, said at least one filter medium is secured to said radiolucent polymer sleeve by a resin adapted to sealingly bond said at least one filter medium to an internal wall of said radiolucent polymer sleeve. Preferably, said resin is adapted to hold and bond said filter medium without invading the porous space of said at least one filter medium. Even more preferably, said resin is impermeable when in-situ. Advantageously, said at least one filter medium is a gravel pack.

Alternatively, said at least one filter medium is a premade sediment pack.

According to a second aspect of the present invention, there is provided a test apparatus for evaluating solid particle movement during hydrocarbon production, comprising: a screen assembly adapted to provide a sealed fluid passage between an input-end portion and an output-end portion; a fluid inlet port, fluidly coupleable to said input-end portion and adapted to provide fluid communication with a fluid source; a fluid outlet port, fluidly coupleable to said output-end portion and adapted to provide a fluid outlet from said sealed fluid passage, wherein said screen assembly further comprises a plurality of interchangeably and operatively coupleable screen members, each one adapted to provide a predetermined solids-control characteristic to solids suspended in a fluid moving from said fluid inlet port towards said fluid outlet port.

This provides the advantage of an adaptable test apparatus where interchangeable screen members (i.e. detachable test components such as filters or screens) allow measurements of specific parameters (e.g. permeability, porosity etc.) of individual screen members and/or a predetermined sequence combination of a plurality of different screen members. Furthermore, the present invention provides the advantage that different materials may be removed, e.g. to improve tomographic imaging by removing metallic components and therefore minimise potential artefacts. In particular, laboratory tests can be designed selecting criteria of significant interest to explore potential uncertainties for hardware performance evaluation. Also, the scope of laboratory tests can be tailored to investigate parameters of significant interest, which may be compressibility, temperature variation, pH fluctuations, formation variability, velocity changes and flowing phase alteration. These variables can be adjusted within different test scopes. These scopes may also incorporate sediment in suspension (referred to as slurry) which builds up against the hardware during throughput, sudden formation failure in the near wellbore during operations trapped against the hardware (referred to as prepack) and sudden formation failure followed by a subsequent throughput of slurry (referred to as prepack -slurry).

Advantageously, the plurality of interchangeably and operatively coupleable screen members may be selectively arrangeable in a predetermined sequence.

Advantageously, at least one first screen member of said plurality of screen members may comprise a perforated plate having a plurality of perforations of a predetermined size. Preferably, the shape and/or size of said plurality of perforations may be identical. Alternatively, the shape and/or size of said plurality of perforations may be variable. Advantageously, said at least one first screen member may be made from radiolucent material. The use of a radiolucent material (e.g. Polyether Ether Ketone, i.e. PEEK) provides the advantage of greatly improved imaging results from, for example, 3D tomographic acquisition.

Advantageously, at least one second screen member of said plurality of screen members may comprise a metallic screen assemblage operatively arranged in an internal passage of a first sleeve member. Preferably, said metallic screen assemblage may comprise at least one metal screen wrapped with a radiolucent material which more preferably may be a film or tape and most preferably is a polytetrafluoroethylene (PTFE) film or tape. Even more preferably, said first sleeve member may be made from a polymer. Even more preferably, said first sleeve member may be made from a radiolucent material and is preferably in the form of a tube or cylinder.

Advantageously, at least one third screen member of said plurality of screen members may comprise at least one filter medium operatively arranged in an internal passage of a second sleeve member. Preferably, said filter medium may be secured in said internal passage of said second sleeve member by a sealing material which may preferably comprise a resin adapted to sealingly bond said filter medium to an internal wall of said second sleeve member. Advantageously, said resin may be adapted to hold and bond said filter medium without invading the porous space of said filter medium. Preferably, said resin may be impermeable when in situ. Advantageously, said filter medium may be a gravel pack. Preferably, said second sleeve member may be made from a polymer. Even more preferably, said second sleeve member may be made from a radiolucent material.

Advantageously, at least one fourth screen member of said plurality of screen members may comprise a third sleeve member adapted to allow solids suspended in a flowing fluid to be deposited inside an internal passage of said third sleeve member during use. Preferably, said third sleeve member may be made from a Polymer. Even more preferably, said third sleeve member may be made from a radiolucent material.

Alternatively, said first and third sleeve member may be replaced by a fourth sleeve member adapted to operatively secure all of said plurality of interchangeably and operatively coupleable screen members in a predetermined sequence, so as to form a sealed fluid passage between said input-end portion and said output-end portion. Preferably, said fourth sleeve member may be made from a Polymer.

Advantageously, the test apparatus may further comprise a fifth sleeve member adapted to encase any combination or all of said plurality of interchangeably and operatively coupleable screen members and said fluid inlet port and said fluid outlet port. Preferably, said fifth sleeve member may be made from a Polymer.

Advantageously, at least one fifth screen member may comprise a premade sediment pack. Preferably, said premade sediment pack is encased in said resin and/or a sixth sleeve member. Even more preferably, said sixth sleeve member may be made from a Polymer. Even more preferably, said sixth sleeve member may be made from a radiolucent material.

Advantageously, said plurality of interchangeably and operatively coupleable screen members may be secured in place by a heat shrinkable sleeve.

Advantageously, said test apparatus may further comprise a casing adapted to receive, secure and sealingly encase said screen assembly, as well as, said fluid inlet port and said fluid outlet port when operatively coupled to said screen assembly. Preferably, said test apparatus may be further adapted to provide a predetermined temperature to said encased screen assembly. Advantageously, said test apparatus may comprise at least one removable heater element adapted to selectively control the temperature of said tube assembly.

Advantageously, said radiolucent material is Polyether-ether-ketone (PEEK). This provides the advantage of that the sleeve(s) provide a rigidity suitable to prevent potential collapse when an overburden pressure is applied.

According to a third aspect of the invention, there is provided a method for evaluating solid particle movement during hydrocarbon production, comprising the steps of: CO assembling a test apparatus comprising at least one radiolucent screen member; (ii) operatively coupling said test apparatus to a test tubing and commencing a predetermined sanding experiment; (iii) removing said test apparatus from said test tubing and imaging at least one zone of interest of said at least one radiolucent screen member in-situ utilizing a predetermined imaging method; (iv) post-processing the resulting images to determine at least one material property of said at least one radiolucent screen member.

Advantageously, said predetermined imaging method may be any one of radiography, magnetic resonance imaging and ultrasonography. Advantageously, said at least one material property may be any one of a permeability, a porosity, a density, a compaction and grain size distribution of said zone of interest.

In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments of the present invention will be shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention, and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results.

The following definitions will be followed in the specification. As used herein, the term "wellbore" refers to a wellbore or borehole being provided or drilled in a manner known to those skilled in the art. The wellbore may be 'open hole' or 'cased', being lined with a tubular string. Reference to up or down will be made for purposes of description with the terms "above", "up", "upward", "upper" or "upstream" meaning away from the bottom of the wellbore along the longitudinal axis of a work string toward the surface and "below", "down", "downward", "lower" or "downstream" meaning toward the bottom of the wellbore along the longitudinal axis of the work string and away from the surface and deeper into the well, whether the well being referred to is a conventional vertical well or a deviated well and therefore includes the typical situation where a rig is above a wellhead, and the well extends down from the wellhead into the formation, but also horizontal wells where the formation may not necessarily be below the wellhead. Similarly 'work string' refers to any tubular arrangement for conveying fluids and/or tools from a surface into a wellbore. In the present invention, production tubing is the preferred work string.

The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one embodiment can typically be combined alone or together with other features in different embodiments of the invention. Additionally, any feature disclosed in the specification can be combined alone or collectively with other features in the specification to form an invention.

Various embodiments and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary embodiments and aspects and implementations. The invention is also capable of other and different embodiments and aspects, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention.

Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including", "comprising", "having", "containing" or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of", "consisting", "selected from the group of consisting of", "including" or "is" preceding the recitation of the composition, element or group of elements and vice versa. In this disclosure, the words "typically" or "optionally" are to be understood as being intended to indicate optional or non-essential features of the invention which are present in certain examples but which can be omitted in others without departing from the scope of the invention.

All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein including (without limitations) components of the apparatus are understood to include plural forms thereof and vice versa.

Brief Description of the Drawings

Preferred embodiments of the present invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which: Figure 1 shows a first embodiment of a screen assembly of the test apparatus of the present invention having four screen members (i.e. screens, filters and a void PEEK tube for sediment to accumulate); here the slurry or clear fluid passes through the fluid passage; the screen members are fixated by suitable heat-shrink tubing (dotted line); Figure 2 shows an exploded view of a typical example of the test apparatus of the present invention, where the screen assembly of Figure 1, including a rubber sleeve, covering the screen members, and inlet-and outlet ports are assembled into a casing (the inlet port also acting as the casing lid); during the test, fluid is entered through the inlet port (casing lid) and exited through the outlet port protruding through an aperture of the casing; Figure 3 shows a sectional view of the screen assembly of Figure 1, comprising a perforated PEEK plate, a metallic screen assemblage, a filter medium and a PEEK tube, sequentially arrange to form a first test setup; depending on the test requirements any one or more of the screen members may be removed or replaced, or additional screen member(s) may be added; Figure 4 shows a sectional view of a second embodiment of a screen assembly of the test apparatus of the present invention, comprising a rubber sleeve adapted to sealingly encase a metal screen assemblage, a filter medium (PEEK tube encased and resin-set gravel filter), a pre-made sediment pack, a perforated PEEK plate and a PEEK tube, as well as, a perforated PEEK plate coupled to the outlet port of the screen assembly; here the PEEK tubes encased by the rubber tube are used to provide rigidity to prevent potential collapse during overburden pressure; Figure 5 shows a sectional view of the screen assembly of Figure 4, but without the filter medium (PEEK tube encased and resin-set gravel filter); Figure 6 shows a sectional view of a third embodiment of a screen assembly of the test apparatus of the present invention, where resin is used to create a seal around the periphery of the pre-made sediment pack against the inner wall of a PEEK tubing; the encased PEEK tube and perforated plate is used to prevent grain loss; the enlarged area shows how the resin (black) creates a seal around the periphery without substantially invading into the sediment pack; Figure 7 shows an example embodiment of the screen assembly, comprising radiolucent materials through which 3D acquisition equipment will have to scan; Figure 8 shows example embodiments of two different screen assemblies, depicting the zone of interests (dotted rectangles) which are imaged individually to optimise the resolution and contrast of the resulting image; Figure 9 shows an example diagram illustrating the aperture space selected for segmentation (white dotted rectangles); the segmented binary images of the aperture space can be used to determine blockages within the screen assemblage; Figure 10 shows (a) a depiction of a CT scan for a gravel pack before testing and (b) after testing; the before and after imaging allows the change in distribution, that has been incurred as a result of the test, to be plotted (i.e. by subtracting the image (a) from image (b)); the change in distribution could be due to sediment invasion and/or gravel pack redistribution; Figure 11 shows (a) a depiction of a CT scan for a filter medium before testing and (b) after testing; the image (b) shows a possible test outcome, where sediment pack builds up against the filter medium, sediment infiltrates in the pore space of the filter medium, and the filter medium is compacted; the before and after test imaging allows for measuring the reduction of filter volume, filter length, reduction in porosity and reduction in permeability; Figure 12 shows how sub-sections may be selected for segmentation, where (a) shows a CT scan image of the sediment pack, and (b) illustrating a binary representation of physical properties (i.e. grain size, porosity) of the sediment pack at a selected area; Figure 13 shows an illustration of a 3D binary skeleton of a selected area of a sediment pack, where the black areas represent the sediment pack skeleton (grains) and the white represents the pore space open to flow; 3D models are used to extract porosity, permeability and grain size distribution information utilising a post-processing 3D visualisation software, and Figure 14 shows examples of potential applications that 3D imaging can produce, (A) a depiction of a CT scan image for the screen assembly, (B) visualisation of the changes in the nature of the sediment pack which has built up in the face of the filter, (C) spatial distribution of the introduced material within the filter medium and (D) aperture blockages within the metal screen assemblage.

Detailed description of the preferred embodiment(s) 1. Tube assemblies and test set-up Example of First embodiment Referring now to Figures 1 and 2, a first embodiment of the present invention comprises, inter alia, a screen assembly 100, a sealable casing 102, a mountable inlet port 104 (also forming the lid of the casing 102), a mountable outlet port 106 (assembleable with said casing 102), and an encasing polymer sleeve 108 (e.g. a rubber sleeve 108). The screen assembly 100, which is the scan-able component of the test set-up of the present invention, may also be referred to as a tube assembly 100.

As shown in Figure 1, the first embodiment of the tube assembly 100 comprises four separate interchangeable components 112, 114, 116, 118 that are held together to form one continuous cylinder using at least one heat shrink tubing 110 (dotted line).

Preferably (but not restricted to), PolyEther Ether Ketone (PEEK) tubing material is predominantly utilised for the tube assembly 100. However, it will be understood by the person skilled in the art, that any other suitable (i.e. radiolucent or low density material, such as, carbon fibre) material may be used. A first screen member 112 may comprise a perforated PEEK plate 112a, a second screen member 114 may comprise a rubber sleeve 114a (see Figure 3) encasing a screen hardware 114b (e.g. a metallic screen/filter assemblage 114b), a third screen member 116 may comprise a PEEK tube 116a containing a filter medium and/or gravel pack 116b (see Figure 3) that is surrounded by resin 116c binding the filter medium 116b to the outer PEEK tube 116a and a fourth screen member 118 may comprise a hollow PEEK tube 118a, suitable to allow solids 118b (i.e. sand particles) to be deposited inside the fluid passage 118c of the PEEK tube 118 to form a sediment pack 118b. Dimensions shown in the Figures are not to scale and may vary in accordance with testing requirements.

In the first embodiment of the present invention, the filter medium and/or gravel pack 116b is placed into the tube 116a (made of low density/radiolucent material such as PEEK) and a predetermined resin mix 116c, such as for example fast setting Urethane Plastic Isocyanate, is prepared and poured between the filter 116b and tube 116a and left to set. The resin mix 116c may be any suitable mix that enables a thin layer to hold and bond the filter medium 116b in place within the tubing 116a without invading the porous spaces of the filter medium 116b.

Example of a test set-up for the first embodiment Figure 2 illustrates a test set-up for the first embodiment of a tube assembly 100 of the present invention, however, it is understood by the person skilled in the art, the test set-up may be equally applied to any other embodiment of the present invention.

Typically (but not restricted to) a 1 inch (2.54 cm) diameter screen/shroud 114b and screen support assemblage 114d are wrapped with PTFE tape 114e and inserted into a short rubber sleeve 114a with an internal diameter of 1 inch (2.54 cm) to form the second screen member 114. The second screen member 114 is then attached to the third screen member 116, containing the resin 116c bound filter medium/gravel pack 116b, which is then attached to the fourth screen member 118. The second, third and fourth screen members 114, 116, 118 together with the first screen member 112 (0.e. the perforated plate 112a) that is placed against the end of the second screen member 114) then have the heat shrink tubing 110 applied to their combined outer surface by a heat shrink process to form the tube assembly 100. The tube assembly 100 is then inserted into the encasing rubber sleeve 108, which in this example has an internal diameter of 1.5 inch (ca. 3.8 cm). The encasing rubber sleeve 108 then joins the first screen member 112 to the outlet port 106 and the fourth screen member 118 is joined to the inlet port 104 (which is also the lid of the casing 102). The assembled components 106, 108, 110, 112, 114, 116, 118 are placed inside the casing 102 with the inlet port 104 sealing the entire test set up. An overburden pressure (e.g. 1000psi, ca. 69 bar) is then applied to the tube assembly 100. After the test (see "test procedure") and during the imaging (e.g. x-ray tomography) of the tube assembly 100, the encasing rubber sleeve 108 is removed.

Test procedure A test is commenced by pumping (with a typical flow rate of 50m1/min) slurry or clear phase(s), depending on the scope from the reservoir (inlet port 104) through the tube assembly 100 (i.e. from the fourth screen member 118 to the first screen member 112) out through the outlet port 106 of the test apparatus. As a consequence of pumping slurry through the tube assembly 100, sediment may be deposited at the interface of the filter medium/gravel pack 116b and/or screen(s) 114, 112. The sediment pack will begin to form on the top filter medium/gravel pack 116b and/or screen(s) 114, 112, and effluent is collected in 100m1 bottles.

Typically (but not restricted to) for slurry testing, a 1.5 litre throughput of slurry is swapped to sediment free phase(s) for around 0.5 litre. Typically (but not restricted to) for prepack testing (not shown in Figures, but placed in the fluid passage of the fourth screen member 118), sediment free phase(s) is flowed for around 2 litre of throughput.

Example of second embodiment -premade sediment pack When using a tube assembly 100 as described in the first embodiment, the PEEK tube 118a of the fourth screen member 118 does not provide any compressibility when an overburden pressure is applied during testing, potentially causing the slurry or clear phase(s) to bypass around the periphery of the sediment pack (i.e. where the sediment pack meets the side wall of the PEEK tube 118a), because it may be the path of least resistance.

Alternative embodiments of the tube assembly 100 of the present invention may be used to overcome the potential problem. In one alternative embodiment, the sediment pack may be allowed to be compressed (using an overburden pressure) during a test.

Figure 4 shows an example of a second embodiment of a tube assembly 200, where a 1 inch (ca. 2.54 cm) diameter screen/shroud 204b and screen support assemblage 204d is wrapped with PTFE tape 204e (i.e. to form a second screen member 204) and which 204 is inserted into the base of a rubber sleeve 202 with an internal diameter of 1 inch (ca. 2.54 cm). Hardware 206d (i.e. a filter or gravel pack 206d) is bound by an outer layer of resin 206c (to prevent bypass) and is located inside a PEEK tube 206b (for strength) that is 1 inch (ca. 2.54 cm) in diameter to form a third screen member 206 and which 206 is then placed above the second screen member 204. Indeed, the tube assembly 200 is assembled with the first screen member 214 (in the form of a perforated PEEK plate 214a) placed at the bottom and the subsequent screen members 204, 206 being placed on top, i.e. vertically upwards.

A pre-made sediment pack 208 (which may be obtained from the outcome of a test using the tube assembly 100 of the first embodiment) is then placed above the third screen member 206 and inside the rubber sleeve 202. A perforated PEEK plate 210 and subsequent PEEK tube 212 of 1 inch (ca. 2.54 cm) in diameter is then placed on top of the premade sediment pack 208. The PEEK tube 212 then provides a void space for sediment to accumulate during throughput of slurry. Another perforated PEEK plate 214 (which forms the first screen member 214a) is securely attached to the end (i.e. second screen member 204) of the assembly 200 utilising heat shrink tubing 216 (dotted line). The assembly 200 will be incorporated into the test set-up as discussed for the first embodiment (see Figure 2) utilising the casing 102 and inlet-/outlet ports 104 shown in Figure 2.

Figure 5 shows a variation 200a of the second embodiment of the tube assembly 200, where the hardware 206d and the rest of the third screen member 206 has simply been removed or omitted from the tube assembly 200 of the second embodiment but the rest of the tube assembly 200 remains as described above.

Referring now to Figure 6, a third embodiment of a tube assembly 300 in accordance with the present invention is shown. The tube assembly 300 removes the compressibility of the sediment pack (i.e. as used in the tube assembly 200) during testing (whilst preventing potential bypass of fluid), but has the additional advantage of obtaining a more representative sediment pack. In order to prepare the tube assembly 300 of the third embodiment, plunge plugging (i.e. soft sediment plugging) a representative sediment pack created during a previous test (e.g. using the tube assembly 100 of the first embodiment) may be utilised. Here, the sediment pack plug 302 obtained will be undersized deliberately to allow space for encasing the pack 302 in resin 304 and PEEK tubing 306. Before the sediment pack 302 is fixed inside the PEEK tube 306 using resin 304, the sediment pack 302 is submerged into liquid nitrogen (typically but not restricted to a 10 minute exposure). The liquid nitrogen immersion fixes all phase(s) in-situ within the plunge plugged sediment pack 302, therefore providing a solid cylinder form. The immersion process also prevents (instantaneously) the liquid constituents of the sediment pack 302 from expanding, allowing the solid sediment pack 302 to be enclosed inside the PEEK tube 306 using resin 304 to bond the outside edges of the sediment pack 302 and the internal edges of the PEEK tubing 306 (see Figure 6 and enlarged area thereof). The hardware components 308, 310, 312 (e.g. perforated plate screen 312a, metallic screen assemblage 310a, gravel pack/filter medium 308a) of the tube assembly 300 are fixed to the face of the sediment pack assembly 302, 304, 306, wherein a perforated PEEK plate 314 is inserted into the PEEK tube 306 between the sediment pack 302/resin 304 and a subsequent PEEK tube 316 at the opposite end from the hardware components 308, 310, 312, so as to prevent grain loss after the pack 302 has thawed.

It is understood by the person skilled in the art that the interchangeability of the plurality of screen members of the tube assembly(s) described in the detailed example of the description of the present invention allows for any variation of sequences of the plurality of screen members without departing from the scope of the present invention.

2. Post processing and 3D image analysis of the tube assembly(s) The post processing procedures and imaging analysis described below utilises a further embodiment 400 of a tube assembly 400 but may alternatively be utilised with any one of the described embodiments of the tube assembly 100, 200, 300 (or any suitable variation) of the present invention.

Imaging a tube assembly The experimental test set up utilises a test or tube assembly 400 which comprises a PEEK tube 401 which holds a sediment pack 402, a porous filter or gravel pack 404 bound in place with a hard resin 406 (bonding it to the inside of a PEEK tube 408). A screen assemblage 410 is mounted to the outer end of the porous filter or gravel pack 404 and is held in place with a heat shrink layer 416 which straddles the adjoining outer surfaces of the PEEK tube 408 and a further rubber tubing 412 (although other resilient materials could also be used) and the outer circumference of a screen/shroud 114b.

After a sanding experiment has been performed (e.g. slurry or prepack), the resulting sample may be scanned with the whole assemblage of the tube assembly 400 in situ. This provides the advantage that the interfaces between different materials are not disturbed. The low density (radiolucent) properties of the PEEK tubing material 401, 408, 412 in combination with a minimised wall thickness allows for improved imaging potential when using X-rays. XRM scans (X-ray microscopy) of the PEEK tube(s) 401, 408, 412 and metal screens 114b, 410 can be done in a number of separate stages for improved image resolution.

Imaging procedure Referring now to Figure 8, on the left hand side is shown a test assembly 400 identical to that as shown in Figure 7 and on the right hand side is shown a yet further embodiment of a test assembly 450 (which is similar to the test assembly 400 but doesn't include the section comprising the porous filter/gravel pack 404 bound in place with a resin 406).

For the test assembly 400, imaging zones 500, 502, 504 (areas encased by broken lines) are selected for scanning, where each zone 500, 502, 504 is based on material, screens, porous filter and sediment.

For the test assembly 450, imaging zones 500 and 504 (areas encased by broken lines) are selected for scanning, where each zone 500 and 504 is based on material, screens, porous filter and sediment.

For either test assembly 400, 450, depending on the length of each material, it may be required to scan a material in sections. A situation when this may be required is the sediment pack 402 being more than a 1 cm thick. The area in and around the screen 410 is the first zone of interest to be scanned (zone 504). The scan would incorporate the screens 114b, 410 and the interface of the adjacent material. The screens 114b, 410 are then removed before any more scans (e.g. of zones 502 (for the test assembly 400 only) and 500) are made (the reason for this removal is that the metallic properties of the screens 410 will cause interference artefacts propagating into the adjacent material, which could be the porous filter 404).

Additional scans of each material will be performed, ensuring the interfaces between materials are captured.

The materials used in the tube assembly 100, 200, 300, 400, 450 etc. can also be maintained at an elevated temperature (when required) for transport from the casing 102 to the 3D imaging facility. Heated pads (not shown) for example can be attached to the outside of the tube assembly 100, 200, 300, 400, 450 which can then be wrapped in a material that has adequate insulation properties, therefore retaining the heat around the test subject e.g. tube assembly 100, 200, 300, 400, 450. The equipment and tools assembly 100, 200, 300, 400, 450 used to maintain the tube at temperature are then removed prior to imaging.

Post processing and outputs The 3D tomographic scans are post processed using suitable 3D imaging software. Using the difference in greyscale tomographic data (grey scale changes based on material density and atomic number) the analyst is able to separate the individual components of the screen, filter and sediment. Because the material properties of screen (high x-ray density), sediment (medium x-ray density) and filter (low x-ray density) are significantly different from one another the tomographic data is adequate for performing a successful segmentation of each material.

For example, permeability measurements are made using the segmented 3D skeletons from the imaged scan-able tube assembly 100, 200, 300, 400, 450 using a permeability solver. These computer based permeability computations allow for pressure ports to be eliminated from the experimental test set up. Pressure ports in these types of laboratory tests have been used to measure pressure for permeability calculations e.g. the screen sediment pack interface. However, pressure ports are known to block with sediment during fluid throughput. These blockages may cause inaccuracies and therefore uncertainty on the hardware performance evaluation. The present invention aims to eradicate this problem from the test altogether with added value of being able to measure any interface, material or sub-region.

Investigation work-flow summary:

1. Segment the screen and material (sediment grains) blocking apertures of the screen. Determine the porosity of the apertures (open = >90% porosity, partially occluded = 90-10% porosity, fully occluded = <10% porosity).

Compute the permeability of the screen filter interface. 3D images of the sediment material distribution within the apertures can be made along with 3D permeability simulations.

2. The porosity and permeability will be investigated across the interface of the screen and filter material.

3. Segment the material trapped in the pores, filter or gravel. Determine the porosity of the filter or gravel with and without the introduced material. These measures can be used to identify the reduction in porosity due to sediment throughput 3D images of the sediment material distribution within the filter or gravel can be made. The permeability can be measured with and without the sediment material present within the filter or gravel. These data measurements can be used to produce permeability alterations before and after testing. 3D images of the permeability simulations through the filter or gravel material can be made. Compaction measurements (size reduction, porosity reduction and permeability reduction) can be calculated for the filter medium.

4. The porosity and permeability will be investigated across the interface of the filter and sediment pack material.

5. Segment the sediment pack. Determine the porosity and permeability of the sediment pack at several intervals moving away from the filter interface or screen (if no filter is used). Changes in these parameters could be plotted with distance from the filter or screen interface. 3D images of the sediment pack material distribution and permeability can be made. Grain size distribution could also be investigated at several places moving away from the interface.

Referring now to Figures 9 to 14, the first area of interest 504 is the screen 410 and its interface with the screen 114 and its other interface with the filter 404. The screen 410 could potentially be occluded with sediment material. The material in areas 600 blocking the apertures of the screen 410 can be separated from the surrounding components (see Figure 9) by segmentation. These isolated areas 600 can be measured; obtaining porosity and permeability measurements. These measures can then be used to determine to what degree the apertures of the screens 410 had been blocked.

The known approach used to quantify the blockage of the screen hardware 410 is to remove the screen 410 from the interface in order to conduct a point count using a light microscope or any other suitable method. However, this approach is not representative, as any disruption during separation of the screen 410 from test body (filter media, sediment pack, gravel pack or proppants) will cause changes to both sides of the boundary, misrepresenting the simulation end point. Measures should be made of the undisturbed, connected body that is within and/or filtered against the hardware (i.e. screens, filters etc.). The present invention, which allows in-situ 3D imaging, addresses this problem.

The second area of interest 502 is the filter 404 and the interface with the sediment pack 402. The filter 404 could potentially include sediment material trapped within the pores of the filter 404. Segmentation of the two materials will allow for porosity and permeability measures of the filter 404 (with and without the sediment grains present).

This provides an alteration before (without sediment) and after (with sediment) the test. The sediment material can be viewed spatially within the filter 404 and conclusions can be made on distribution, i.e. evenly distributed, channelized distribution or isolated blockages. Percentage quantities of filter 404, sediment and pore space may also be quantified.

In cases where the second area of interest 502 is a gravel pack, a different work-flow may potentially need to be considered to plot the distribution of introduced material. For example, the introduced material (e.g. primarily quartz based sediment) may be of a similar x-ray density (radio-translucency) to that of the gravel pack, thus, making it difficult to segment the two material phases (gravel and sediment) successfully. A workflow which may overcome this problem is to image (tomographic scans) the gravel pack before throughput, and then after throughput (see Figure 10). Post processing of the two tomographic scans (before and after throughput) enables the unchanged components of the gravel pack caused by throughput to be removed from the 3D skeleton, depicting only what has changed (this process is referred to as change mapping). Changes, such as gravel pack movement / redistribution and/or slurry sediment trapped within the gravel pack, can be viewed spatially. The change can be quantified as a percentage of the bulk sample. The same work-flow can be applied if the filter medium 404 is expected to change (become compacted/reduce in size) during high throughput pressures (see Figure 11). Porosity and permeability reductions may be measured in addition to the reduction in bulk volume of the filter medium 404 (after compaction).

The third area of interest 500 is the sediment pack 402, which propagates away from the filter or gravel interface 404. Areas of the sediment pack 402 are investigated, for example, at the interface, 5 mm away from interface, 10 mm away and 15 mm away (see Figure 12). Segmentation of the sediment pack 402 to form a binary image, sediment grains and pores, enables porosity and permeability measures (see Figure 13). The grain size distribution at selected areas of the sediment pack 402 can be investigated using any suitable post-processing software, providing information on the sediment pack distribution.

The diagram illustrated in Figure 14 shows some of the potential applications that 3D imaging can produce.

(A) A depiction of a CT scan image for the tube assembly.

(B) Visualisation of the changes in the nature of the sediment pack which has built up on the face of the filter (in this example).

(C) Spatial distribution of the introduced material within the filter medium (in this

example).

(D) Aperture blockages within the screen assemblage.

It will be appreciated by persons skilled in the art that the above embodiment has been described by way of example only and not in any!imitative sense and that various alterations and modifications are possible without departing from the scope of the invention as defined by the appended claims.

Claims

CLAIMS1. A test apparatus for evaluating particle movement during hydrocarbon production, comprising: a screen assembly adapted to provide a sealed fluid passage between an input-end portion and an output-end portion; a fluid inlet port, fluidly coupleable to said input-end portion and adapted to provide fluid communication with a fluid source; a fluid outlet port, fluidly coupleable to said output-end portion and adapted to provide a fluid outlet from said sealed fluid passage, wherein said screen assembly further comprises at least one radiolucent screen member, adapted to allow in-situ imaging of a predetermined solids-control characteristic to solids suspended in a fluid moving from said fluid inlet port towards said fluid outlet port.
2. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 1, wherein said at least one radiolucent screen member comprises at least one radiolucent polymer sleeve.
3. A test apparatus for evaluating particle movement during hydrocarbon production according to either of claims 1 or 2, wherein said at least one radiolucent screen member comprises any one or any combination of:-a perforated plate, a metallic screen assemblage operatively secured by a radiolucent polymer sleeve, at least one filter medium operatively secured by a radiolucent polymer sleeve, and a radiolucent polymer sleeve.
4. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 3, wherein said at least one filter medium is secured to said radiolucent polymer sleeve by a resin adapted to sealingly bond said at least one filter medium to an internal wall of said radiolucent polymer sleeve.
5. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 4, wherein said resin is adapted to hold and bond said filter medium without invading the porous space of said at least one filter medium.
6. A test apparatus for evaluating particle movement during hydrocarbon production according to either of claims 4 or 5, wherein said resin is impermeable when in-situ.
7. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 3 to 6, wherein said at least one filter medium is one of a gravel pack and a premade sediment pack.
8. A test apparatus for evaluating particle movement during hydrocarbon production according to any preceding claim, wherein said screen assembly further comprises a plurality of interchangeably and operatively coupleable screen members.
9. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 8, wherein each interchangeably and operatively coupleable screen member is adapted to provide a predetermined solids-control characteristic to solids suspended in a fluid moving from said fluid inlet port towards said fluid outlet port.
10. A test apparatus for evaluating solid particle movement during hydrocarbon production, comprising: a screen assembly adapted to provide a sealed fluid passage between an input-end portion and an output-end portion; a fluid inlet port, fluidly coupleable to said input-end portion and adapted to provide fluid communication with a fluid source; a fluid outlet port, fluidly coupleable to said output-end portion and adapted to provide a fluid outlet from said sealed fluid passage, wherein said screen assembly further comprises a plurality of interchangeably and operatively coupleable screen members, each one adapted to provide a predetermined solids-control characteristic to solids suspended in a fluid moving from said fluid inlet port towards said fluid outlet port.
11. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 11, wherein the plurality of interchangeably and operatively coupleable screen members may be selectively arrangeable in a predetermined sequence.
12. A test apparatus for evaluating particle movement during hydrocarbon production according to either of claims 10 or 11, wherein at least one first screen member of said plurality of screen members comprises a perforated plate having a plurality of perforations of a predetermined size.
13. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 12, wherein at least one second screen member of said plurality of screen members comprises a metallic screen assemblage operatively arranged in an internal passage of a first sleeve member.
14. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 13, wherein said metallic screen assemblage comprises at least one metal screen wrapped with a radiolucent material.
15. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 14, wherein said metallic screen assemblage comprises at least one metal screen wrapped with a radiolucent film or tape material.
16. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 15, wherein said first sleeve member is formed from a radiolucent material in the form of a tube or cylinder.
17. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 16, wherein at least one third screen member of said plurality of screen members comprises at least one filter medium operatively arranged in an internal passage of a second sleeve member.
18. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 17, wherein said filter medium is secured in said internal passage of said second sleeve member by a sealing material.
19. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 18, wherein said sealing material comprises a resin adapted to sealingly bond said filter medium to an internal wall of said second sleeve member.
20. A test apparatus for evaluating particle movement during hydrocarbon production according to claim 19, wherein said resin is adapted to hold and bond said filter medium without invading the porous space of said filter medium.
21. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 16, wherein said plurality of interchangeably and operatively coupleable screen members are secured in place by a heat shrinkable sleeve.
22. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 21, further comprising a casing adapted to receive, secure and sealingly encase said screen assembly, as well as, said fluid inlet port and said fluid outlet port when operatively coupled to said screen assembly.
23. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 22, wherein said test apparatus is adapted to provide a predetermined temperature to said encased screen assembly.
24. A test apparatus for evaluating particle movement during hydrocarbon production according to any one of claims 10 to 23, wherein said test apparatus comprises at least one removable heater element adapted to selectively control the temperature of said tube assembly.
25. A method for evaluating solid particle movement during hydrocarbon production, comprising the steps of (0 assembling a test apparatus comprising at least one radiolucent screen member; (ii) operatively coupling said test apparatus to a test tubing and commencing a predetermined sanding experiment; (iii) removing said test apparatus from said test tubing and imaging at least one zone of interest of said at least one radiolucent screen member in-situ utilizing a predetermined imaging method; (iv) post-processing the resulting images to determine at least one material property of said at least one radiolucent screen member.
26. A method for evaluating solid particle movement during hydrocarbon production according to claim 25, wherein said predetermined imaging method is any one of radiography, magnetic resonance imaging and ultrasonography.
27. A method for evaluating solid particle movement during hydrocarbon production according to claim 25, wherein said at least one material property is any one of a permeability, a porosity, a density, a compaction and grain size distribution of said zone of interest.
28. A test apparatus for evaluating particle movement during hydrocarbon production substantially as hereinbefore described with reference to the accompanying drawings.
29. A method for evaluating solid particle movement during hydrocarbon production substantially as hereinbefore described with reference to the accompanying drawings.