DK2403662T3 - USING a cleaning FOR CLEANING AND FLUIDTRANSPORTANORDNING cleaning fluid - Google Patents

Description

DESCRIPTION

[0001] The present invention relates to the use of a clean-up fluid for cleaning fluid-carrying apparatus. In one particular embodiment, the invention offers a clean-up fluid.

[0002] Fluid-carrying apparatus, such as fluid transport pipes, storage tanks or containers, are widely known to be used in a number of industrial applications. In road constructions, materials may have to be transported from a storage location to a road location where a road surface may need to be built up. In the oil and gas industry, apparatus in the form of pipelines are used to move hydrocarbon products between locations often large distances apart. In addition, recovered oil and gas is typically transported via a sequence of pipe selections as they are pumped from the well, onto the well installation, and into pipeline for export to a refinery. Further, recovered hydrocarbons may be treated at a well installation or a refinery where the product may also be run though different kinds of tanks, for example, separation tanks to separate out different gases, or heavy and light oils.

[0003] In the production of oil and gas therefore, a hydrocarbon product will typically be passed through numerous pipe systems.

[0004] Over time, unwanted residues, waxes and dirt may build up inside the fluid-carrying apparatus. Solids which may be carried along with the fluid may fall out and be deposited inside the apparatus, and some substances may even become adhered to the inner surfaces of such apparatus.

[0005] These unwanted particles and residues may contaminate a product passing through a pipeline, and after a long-term build up may adversely affect the performance of a pipeline system. It is therefore desirable to periodically remove these particles and residues to clean out the system. It can also be desirable to treat a cleaned system with a coating to protect and resist build up of such residues.

[0006] From time to time therefore, the interiors of such pipeline systems need to be cleaned to remove both residues adhered to inner surfaces of the pipeline system, to collect up loose deposits which have settled out from the fluid, and to be treated with protective coatings.

[0007] There are a number of difficulties that arise with a view to cleaning such systems. For example, one problem is how to access the interior surfaces of the fluid-carrying apparatus. A further difficulty is how to perform the cleaning and/or treatment effectively.

[0008] At present, pipeline cleaning and treatment is often carried out using Pipeline Inspection Gauges (pigs), which are pumped through a pipeline. The pigs may be fitted with brushes or scrapers which extend to engage with interior surfaces of the pipeline to remove material. Material removed from the pipeline walls or deposited in the pipeline is pushed along the pipeline ahead of pig and removed at an access point further along the pipeline. Other elements may be used to coat a pipeline wall.

[0009] The pig technique has significant drawbacks. One difficulty is that the pig is designed with a specific diameter to engage a pipe section with a corresponding diameter. Thus, any one pig may not be suitable for cleaning or treatment where a pipeline diameter changes along its length, or where the pipeline transfers into other kinds of fluid carrying apparatus such as tanks in other parts of the system. Pigs are therefore susceptible to becoming stuck in a pipeline. This can be a particular problem where any debris is present in the pipeline.

[0010] In addition, due to pig elements having limited dimensions, the cleaning and/or treatment elements may not be effective at accessing and cleaning pits, dimples or creases which typically may be formed in inner surfaces of the pipeline.

[0011] Furthermore, pigs themselves typically need to be maintained and removed from the pipeline after use. To achieve this, a pig launching and receiving assembly may be provided which connects to the pipeline, and allows manual access to prepare, launch, replace or retrieve pigs. Such launching and retrieving operations can be inconvenient, time consuming and thus costly.

[0012] Another specific cleaning method involves a gel which is pumped through a pipeline. Flowever, this technique is problematic because gels are highly viscous, such that particles or dirt removed from sides of a pipeline collects on an outer surface of the gel such that as the gel is moved along the collected dirt is further smeared against the interior pipe surfaces. Thus, after use of a gel, a second cleaning operation is often required to remove residues caused by use of the gel itself. In addition, the viscous nature of gels can give rise to blockages, particularly where material is pushed ahead of the gel and at restrictions in the pipeline system. Yet further, gels are expensive, and prohibitively so, if required to clean long-distance pipelines.

[0013] Yet further, removal of material build-ups in a pipe or tube system, for example, parafin wax build-up in an oil pipeline, is known to be carried out by passing specific solvents through the pipe to dissolve the material. However, this technique suffers in that solvent is often unevenly imparted to the pipe surface and it can be difficult to fully recover the solvent. Moreover, high volumes of solvent are often needed which can be costly.

[0014] Difficulties may also be encountered in connection with fluid-bearing pumps where solid particles, such as sand, are suspended in the fluid and settle out due to gravity, and can cause the pump to seize and stop functioning particularly when the pump is switched off. Solid particles that are settled out in this way may cause the pump to seize and stop running, and repair costs are typically high because pumps of this nature would typically need to be stripped down into component parts and replaced which is a time consuming process. In addition, dependent industrial processes may need to be halted while the pump is out of operation.

[0015] WOOO/29711 PALMER describes a method for removal of undesired fluids from a wellbore. More specifically, it describes a method for cleanout of subterranean wells such as hydrocarbon wells by the utilization of specific translocating fibers and/or platelets.

[0016] DE10142917 SCHOTT GLAS describes a suspension for polishing surfaces which includes polishing elements and an additional constituent in the form of fibers.

[0017] US5704991 MARCUS describes a washing method and composition. More specifically, it describes a process for cleaning vehicles, especially cars, with an alkaline washing composition, preferably comprising one or more surfactants, where the washing composition is combined with an aqueous solution of a cellulose derivative forming a semi-stable composition which congeals and absorbs/adsorbs the dirt particles removing them from the surface when the composition is rinsed off.

[0018] US4605329 DUFFY describes the hydraulic transportation of objects. More specifically, it describes a method and apparatus for hydraulically transporting objects, using a supporting material such as a quantity of flexible fibres mixed into a liquid.

[0019] DE19855255 KAERCHER GMBH & CO ALFRED describes a detergent. More specifically, it describes a cleaning agent which facilitates the contactless removal of graying from surfaces to be cleaned, the cleaning agent contains cellulose in a fibrous form.

[0020] W09519326 ALVAREZ describes a composition based on micronized sepiolite, and the preparation, process and application to the cleaning and restoration of buildings and monuments.

[0021] EP0767010 RYOBI describes a system and method for cleaning a liquid passage by negative pressure.

[0022] US6419019 PALMER describes a method to remove particulate matter from a wellbore using translocating fibers and/or platelets. More specifically, it describes utilization of specified fibers to aid in transport of the particulate matter.

[0023] EP0867495 DAVIS describes a method for removing debris from a well-bore. More specifically, it describes a method for cleaning debris from a well-bore and includes the steps of injecting hydrophilic fibers selected from the group consisting of polyolefins, polyesters and nylons, suspended or dispersed in a water based or oil based liquid into a well-bore.

[0024] US3852200 MEYER describes a drilling liquid containing microcrystalline cellulose. More specifically, it describes a drilling liquid for use in abrasive jet drilling.

[0025] US4629575 WEIBEL describes well drilling and production fluids employing parenchymal cell cellulose. More specifically, it describes circulating and non-circulating well-drilling fluids.

[0026] According to a first aspect of the invention, there is provided a clean-up fluid for cleaning fluid-carrying apparatus, as claimed in claim 15 and dependent claims.

[0027] Such clean-up fluid may comprise abrasive particles and fibre particles in admixture in the liquid.

[0028] Therefore, the clean-up fluid can be applied to pick up and carry additional particles in the volume of liquid, such as contaminants, residues, sediments or other solids which may be present and/or deposited inside pipes, containers, settling tanks or other fluid-carrying apparatus. In this way, the clean-up fluid can clean away the additional particles.

The fibre particles and/or any such additional particles picked up by the fluid, may be suspended in the volume.

[0029] The fibre particles and/or any such additional particles picked up by the fluid, may be suspended in the volume.

[0030] The clean-up fluid may take the form of a slurry for being pumped through a pipeline, tubing, tank, container or other fluid-carrying apparatus to interact with interior surfaces of such fluid-carrying apparatus.

[0031] The clean-up fluid may comprise: 0.5-10% w/wfibre particles; and 90-99.5% w/w liquid.

[0032] Preferably, the liquid comprises water. The liquid may comprise a saline liquid, such as salt water. The liquid may comprise an oil base, to take the form of an oil-based liquid.

[0033] The clean-up fluid may include a treatment agent for treating a surface of the fluid-carrying apparatus. The treatment agent may comprise a corrosion inhibitor or lubricant. The treatment agent may be adapted to apply a protective coating to the surface.

[0034] The clean-up fluid may include a solvent for treating a surface of the fluid-carrying apparatus.

[0035] In one embodiment, the clean-up fluid may be adapted to abrade an inner surface of a fluid-carrying apparatus. More specifically, the clean-up fluid may comprise abrasive particles. The abrasive particles may be adapted to abrasively remove said residues lining a pipeline wall, e.g. through a scraping action.

[0036] The abrasive particles may be dispersed and/or suspended in the volume of the liquid. In this embodiment, the fibre particles dispersed in the volume of the liquid may provide support to allow the abrasive particles to be suspended in the volume. Thus, in use, the clean-up fluid can scrape off, agitate, and remove solid residues by the presence of abrasive particles, whilst the fibres dispersed in the volume allow particles that have been removed to be picked up and carried along the volume.

[0037] The clean-up fluid may comprise: 0.5-10% w/w/fibre particles; 0.5-10% w/w abrasive particles; and 80-99% w/w/ liquid.

[0038] The abrasive particles may comprise grit, sand, clays, quartz, diamond, and/or tungsten carbide particles. The abrasive particles may comprise particles of different dimensions, shapes, and/or sizes for facilitating cleaning of dimples or pits formed in a wall of a fluid-carrying apparatus and which may be of different scales.

[0039] The clean-up fluid is further adapted to permit the additional particles to be mixed into the volume in use. For example, the clean-up fluid may be adapted to act as a low viscosity fluid for facilitating mixing of additional particles into the volume. Thus, as the additional particles, such as solid residues, are removed and/or collected, the additional particles are readily mixed into the volume such that the clean-up fluid acquires a new constituency including the additional particles. In this way, the contaminant particles can effectively incorporated in the volume to be carried/transported with the clean-up fluid, e.g., upon being pumped through fluid-carrying apparatus.

[0040] In a specific embodiment, the clean-up fluid may take the form of a papier-måché mixture, wherein the liquid volume comprises water and the fibre particles comprise paper and/or newsprint-derived fibre particles in admixture.

[0041] The fluid-carrying apparatus may include pumps, tanks, containers, tubes, pipes or the like.

[0042] According to a second aspect of the invention there is provided a method of use of a clean-up fluid according to the first aspect of the invention in the cleaning of fluid-carrying apparatus, as claimed in claim 1 and dependent claims.

[0043] The method may comprise the step of adding abrasive particles to the admixture.

[0044] The fluid-carrying apparatus may include a pump, tank, tubing or the like.

[0045] The method may comprise the step of admixing constituents to form a low viscosity clean-up fluid. In this way, additional particles, such as contaminants, of the fluid-carrying apparatus are effectively admixed and can be carried with the volume of the clean-up fluid.

[0046] The method may comprise the step of pumping the clean-up fluid at pressure to force the clean-up fluid through the fluidcarrying apparatus for picking up additional particles such as residues or solid fallouts. The method may comprise the step of pumping the clean-up fluid into contact with interior surfaces of the fluid-carrying apparatus to scrape residue from the surfaces and/or collect and carry loosened residues.

[0047] The clean-up fluid may be a clean-up fluid according to the first aspect of the invention.

[0048] In one embodiment, there is provided a treatment fluid comprising liquid and sufficient particles in admixture therewith for treating a fluid carrying apparatus, wherein particles of fibre are dispersed in a volume of the liquid in an amount that does not exceed the particle-carrying capacity of that volume of liquid.

[0049] The fluid may comprise a treatment agent for applying a protective coating to a surface of a fluid-carrying apparatus. The treatment agent may include a corrosion inhibitor.

[0050] The liquid and particles in admixture may initiate a cleaning action within fluid-carrying apparatus. The fluid-carrying apparatus may include a pump.

[0051] Other features of this further aspect of the invention may be defined with reference to any one or more of the features and corresponding method steps as appropriate of the first to second aspects of the invention.

[0052] There will now be described, by way of example only, embodiments of the invention with reference to the following drawings, of which:

Figure 1 is a cross-sectional representation of a pipeline with a clean-up fluid being pumped though to remove loose solid particles from the pipeline according to an embodiment of the invention.

Figure 2 is a cross-sectional representation of a pipeline with a clean-up fluid being pumped though to remove solid residues formed inner walls of the pipeline according to a further embodiment; and

Figure 3 is a close up representation of different size sand particles of the clean-up fluid of Figure 2.

[0053] With reference firstly to Figure 1, a fluid-carrying pipeline 10 is generally depicted. A clean-up fluid 12 introduced to the pipeline 10 is shown in Figure 1 in use whilst being delivered at pressure though the pipeline 10 in the direction of arrow 11 to remove loose solid particles 18 and clean the pipeline 10.

[0054] In this example, the clean-up fluid 12 comprises water 14 (constituting a "liquid") and newspaper particles 16 (constituting "fibre particles") in admixture.

[0055] The newspaper particles 16 are dispersed in the water 14, and are present generally throughout its volume. In this case, the clean-up fluid is prepared from 1 % w/w of newspaper particles, and 99% w/w of water. The newspaper particles appear as "suspended" in the volume. The resulting distribution of newspaper particles allows loose solid particles 18 (constituting "additional particles"), which are lifted into the volume as the clean-up fluid is moved though the pipeline, to be suspended or carried along with the clean-up fluid, in the volume.

[0056] The clean-up fluid 12 acts as a thick soup or "slurry" in the pipeline 10. Flowever, its overall viscosity is low, and sufficiently so that the loose particles 18 are picked up, drawn and mixed into the volume of the fluid 12 as it is moved along the pipeline 10. Thus, the clean-up fluid 12 changes its composition and acquires further constituent particles as it progresses through the pipeline; the further particles 18 themselves and the newspaper particles 16 being in admixture in the water 14. The newspaper particles assist to carry or suspend the loose particles from the pipeline in the clean-up fluid.

[0057] In Figure 2, a pipeline 100 is shown generally with a clean-up fluid being pumped through in a similar manner to that described with reference to Figure 1. In this example however, the clean-up fluid 112 is prepared in its initial constituency to comprise newspaper particles and additionally abrasive particles 122 in admixture in the volume of water 114. More specifically, the clean up fluid 112 is formed from a first volume comprising 99% w/w water 114 admixed with 1% w/w of newspaper particles 124 (identical to the clean-up fluid 12 described above), and a second volume of sand particles 122 (constituting the "abrasive particles") which is equal to the first volume.

[0058] The newspaper particles 116 assist to carry or suspend the sand particles 122 from the pipeline in the volume of water, and the clean-up fluid 112 as a whole acts as a slurry and functions in use in a similar manner as described in the Figure 1 example.

[0059] In addition, the clean-up fluid 112 in this example functions in use to scrape off unwanted residue or scale 126 coated or encrusted on an inner wall 120 of the pipeline 100. As the clean-up fluid 112 is pumped at pressure through the pipeline, the sand particles 122 scrape and abrade against the residue to remove it from the pipeline wall.

[0060] The scale or residue material that is removed from the pipeline wall is also mixed into the volume of water and carried through the pipeline in the volume along with the fluid. The solid loose particles acquired in the volume, along with the sand particles, and newspaper particles are again present in admixture in the volume of water.

[0061] With further reference to Figure 3, the sand particles 122 are shown in further detail. The particles have different sizes so that the composition can effectively clean the pits and dimples 130 formed in internal walls of the pipeline 120. This figure demonstrates that large sand particles 128 are not suitable for cleaning although they have a strong abrasive action themselves. Smaller abrasive particles 129 however can access smaller pits and dimples 130 to clean these more effectively.

[0062] The clean-up fluid as described in the present examples are prepared manually by measuring out appropriate amounts of the fibre particles, water and abrasive particles if required, locating these constituents together in a receptacle, and mixing these constituents by manual shaking or stirring. Of course, it will be appreciated that a mechanical arrangement could be used to automate these tasks and prepare sufficient quantities of the clean up fluid. The ingredients do not need to be added in any particular order.

[0063] In other embodiments, it will be understood that instead of water, an oil-based liquid is used. Further, it will be understood that other kinds of fibres or abrasive particles could be used in place of those described in the specific examples. In particular, it will be understood that although the examples describe the use of the cleanup fluid in connection with pipelines, it could equally be applied to clean other fluid- carrying apparatus, such as tanks, pumps, containers, or other apparatus.

[0064] In another example, the liquid and fibre particle admixture of Figure 1 includes a corrosion inhibitor in the liquid. The corrosion inhibitor has a "sticky" constituency allowing it to separate out from the fluid and adhere naturally to a surface of the pipeline when it comes into contact with the pipeline surface. Thus, as the fluid is pushed along the pipeline at a certain pressure such that the fluid makes contact with the sides a coating of protective corrosion inhibitor is applied evenly over the surface.

[0065] It will be appreciated that the corrosion inhibitor would typically be introduced to the fluid toward the end of a cleaning process, particularly after abrasives used to remove unwanted residues have been introduced and applied to the fluid. Thus, it will be appreciated more generally that the constituents of the fluids described herein may be introduced at different times as and when required for achieving particular cleaning or treatment effects.

[0066] In another example variant not of the invention as presently claimed, a liquid and fibre particle admixture constituting the fluid 12, as referred to above with reference to Figure 1, is used as a transport medium for carrying road aggregates from one location to another. In this example, a storage tank containing aggregate materials is provided at a roadside location, and the admixture is delivered to the tank and mixes with the aggregate materials so that the materials are carried in the volume of the liquid. The fluid including the aggregate is then pumped, to move the aggregates typically more readily than previously possible, from the tank to the road where the aggregate material can be evened out to form a road bed.

[0067] The present invention provides a number of advantages. The clean-up fluid having fibre particles and water in admixture provides a slurry-like admixture capable of picking up and carrying loose solids along the pipeline to remove them and clean the pipeline. In addition, providing the clean-up fluid with abrasive particles which are carried in a volume of the fluid and dispersed in the volume, allows scale built up on the inside surfaces of the pipeline to be scraped off, and also to be carried away in the volume to remove it from the pipeline.

[0068] Further, the unwanted particles and residues are readily mixed into and are dispersed in the volume of the fluid due to its low viscosity (as facilitated by the use of water), thus the clean-up fluid is an effective transport medium for particles and efficient at moving dirt away from the side surfaces of the pipeline, and away from the front of the flow. In turn, this helps to clean the pipeline in a single pumping process, potentially using a single batch of clean-up fluid, and to avoid blockages. In addition, components of the clean-up fluid are readily available and the technique is therefore cost effective, such that long-distance pipelines can be cleaned.

[0069] In examples where the fluid carrying apparatus includes a pump, the clean-up fluid described above is particularly effective at carrying with it solid particles so that they are prevented from settling out in the pump, thereby avoiding pump seizure.

[0070] In other examples, the clean-up fluid includes a solvent which helps to remove solids from the pipe surface. The solids which are removed are suspended in the fluid due to the presence of the fibre particles, and the fluid thereby forms a "solvent" slurry. This slurry is advantageous in that it ensures a relatively even application of the solvent to the pipe surface, decreases the amount and volume of the expensive solvent used, eases recovery of the solvent compared with prior art traditional solvent techniques.

[0071] Yet further, the ability of the clean-up fluid to support abrasive particles of various different sizes, along with its general flowability as described above, allows pits, creases, corners, dimples and areas around other irregularities in the fluid-carrying apparatus, to be effectively accessed, cleaned, and treated.

[0072] Various improvements and modifications may be made within the scope of the invention herein described. In particular, it will be appreciated that in other embodiments the water-to-fibre particle (e.g., newspaper particle) ratios indicated could differ from the specific example ratios referred to herein. For example, the clean up fluid may contain 5% w/w newspaper particles and 95% water. In other cases, the clean up fluid may contain 50% w/w of newspaper particles. The fibre-water composition used for a particular application will typically be dependent on the weight, size and suspendability of fibres selected, and the viscosity of fluid required.

REFERENCES CITED IN THE DESCRIPTION

This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

Patent documents cited in the description • WQ0029711A [90151 • DE1Q142917 [001S] • US5704991A FPQ171 • US48Q5329A [0018] • DEf 9655255 Γ00191 • WQ9519326A [80201 • EP0767010A [0021] . US6419019S Γ00221 • EP0867495A [0023] • US3852200A [0024] • US4829575A [002S1

Claims (16)

Use of a cleaning fluid (12, 112) for cleaning a fluid transport device (10) into which, out of which or through which fluid can flow, said cleaning fluid (12, 112) comprises: a volume of liquid (14 , 114) and fiber particles (16, 124) comprising paper fibers or paper and / or newsprint-derived fiber particles, said cleaning fluid (12, 112) having a low viscosity and comprising fiber particles distributed in the liquid volume (14, 114) in an amount not exceeding this liquid particle capacity of the liquid and having sufficient fiber particles (16, 124) distributed in the volume to provide a cleaning process in use, which cleaning process comprises collecting and carrying additional particles (18, 118) with the cleaning fluid in the volume while the cleaning fluid (12, 112) flows through the fluid conveying device (10). Use of a cleaning fluid (12, 112) according to claim 1, wherein the cleaning fluid (12) is in the form of a slurry for pumping through a fluid conveying device (10) to interact with the inner surfaces of such a fluid conveying device. Use of a cleaning fluid (12, 112) according to claim 1 or 2, wherein the cleaning fluid (12) changes composition and acquires the supplementary particles (18, 118) as supplemental constituent particles as it flows through the fluid transport device (10). Use of a cleaning fluid (12, 112) according to any one of the preceding claims, wherein the cleaning fluid comprises: 0.5-10% w / w fiber particles (16, 124) and 90-99.5% w / w liquid (14, 114) optionally, wherein the cleaning fluid (12, 112) comprises: 5% w / w fiber particles (16, 124); and 95% w / w fluid (14, 114), optionally wherein the cleaning fluid (12, 112) comprises: 1% w / w fiber particles (16, 124); and 99% w / w fluid (14, 114). Use of a cleaning fluid (12, 112) according to any one of the preceding claims, wherein the liquid comprises water or saline or the liquid (14, 114) comprises an oil-based liquid. Use of a cleaning fluid (12, 112) according to any one of the preceding claims, wherein the liquid (14, 114) comprises water or saline and the cleaning fluid is in the form of a papaché mixture. Use of a cleaning fluid (12, 112) according to any one of the preceding claims, wherein the cleaning fluid (12, 112) includes a treating agent for treating a surface of the fluid transport device, or the cleaning fluid (12, 112) includes a treating agent for application as protective coating on the fluid transport device. Use of a cleaning fluid according to claim 7, wherein the treating agent comprises a corrosion inhibitor or lubricant, and / or wherein the treating agent comprises a solvent for treating the interior surfaces of the fluid conveying device. Use of a cleaning fluid (112) according to any one of the preceding claims, wherein the cleaning fluid (112) comprises abrasive particles (122) and fiber particles (124) mixed in the liquid (114) and wherein the abrasive particles (122) is dispersed and / or suspended in the volume of the liquid (114) with the fiber particles (124) dispersed in the volume of the liquid (114), thereby providing a carrier to allow the abrasive particles to be suspended in the volume. Use of a cleaning fluid according to claim 9, wherein the cleaning fluid comprises: 0.5-10% w / w fiber particles (124); 0.5-10% w / w abrasive particles (122) and 80-99% w / w liquid. Use of cleaning fluid (112) according to claims 9 to 10, wherein the abrasive particles (122, 128, 129) comprise abrasive, sand, clay, quartz, diamond and / or tungsten carbide particles and / or wherein the abrasive particles ( 122, 128, 129) comprise particles of different dimensions, shapes and / or sizes to facilitate the cleaning of recesses or depressions (130) formed in the wall of a fluid conveying device (10) and which may be of different sizes. Use of a cleaning fluid (12, 112) according to any one of the preceding claims, which comprises pumping the cleaning fluid by pressure to force the cleaning fluid through the fluid conveying device (10). Use of a cleaning fluid (12, 112) according to any one of the preceding claims, comprising: - adding a cleaning fluid comprising first components at a first time, - adding additional component (s) at different times to cleaning fluid. Use of a cleaning fluid (12, 112) according to claim 13, wherein the cleaning fluid comprises abrasive particles as a first component and wherein a corrosion inhibitor is added as an additional component towards the end of the cleaning process. Cleaning fluid (12, 112) for flowing through a fluid transport device (10) in the use according to any one of claims 1 to 16, comprising cleaning fluid: - a volume of liquid (14, 114) and fiber particles (16, 124) comprising paper fibers, or paper and / or newsprint-derived fiber particles - said low-viscosity cleaning fluid (12, 112) comprising fiber particles (16, 124) distributed in the volume of liquid (14, 114) in an amount not exceeding the particle carrying capacity of this liquid volume having sufficient fiber particles distributed in the liquid volume to provide a cleaning process in use; said cleaning process comprising collecting and carrying additional particles (18, 118) with said cleaning fluid in volume while said cleaning fluid flows through a fluid conveying device. The cleaning fluid of claim 15, which comprises any of the properties of the fluid of claims 2 to 14.