Real time particle leakage detection and control

Abstract

Method and apparatus for detecting particles in a fluid are described herein. Such methods and apparatus can be used for bulk separation of solids and liquids in a hydrocarbon prospecting setting. In such cases, a solid liquid separation apparatus includes a shaker filtration device; a circulation conduit to circulate a fluid product of the shaker filtration device; a filtration medium disposed in the circulation conduit; and a pressure sensor adjacent to the filtration medium. The pressure sensor is used to monitor pressure adjacent to the filtration medium. An abnormal pressure reading, or plurality of readings, is used to indicate an event of particle leakage needing attention.

Description

Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.REAL TIME PARTICLE LEAKAGE DETECTION AND CONTROLCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority benefit of United States Provisional Patent Application Serial No. 63 / 737,068 filed December 20, 2024, which is entirely incorporated herein by reference.FIELD

[0002] This patent application relates to apparatus and methods for bulk solid / liquid separation in hydrocarbon prospecting operations. Specifically, methods and apparatus herein relate to detecting particle leaks in solid liquid bulk separation apparatus and processes.BACKGROUND

[0003] Shaker screens are used to separate solids from drilling fluids used when drilling wells. The drilling fluids perform a number of useful functions during well drilling, among them being removal of drill cuttings from the well. Drilling fluids bearing drill cuttings are processed using shaker screens to remove the cuttings so the drilling fluid can be reused.

[0004] Shaker screens wear out due to exposure to drill cuttings. In particular, screens can develop holes that reduce the separation efficiency of the screens. Currently, such holes must be discovered through manual inspection, often well after the leak has developed. Other processes can also benefit from automated detection of particles in fluids. There is a need for improved methods of detecting particle leakage in shaker screens, and generally of detecting particles in fluids.SUMMARY

[0005] Embodiments described herein provide a solid liquid separation apparatus that includes a fluid source; a circulation conduit to circulate a fluid of the fluid source and to return the fluid to the fluid source; a filtration medium disposed in the circulation conduit; and a pressure sensor coupled to the circulation conduit.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.

[0006] Other embodiments described herein provide an apparatus for detecting particles in a fluid that includes a flow conduit; a filtration medium disposed in the flow conduit; a pump coupled to the flow conduit to receive flow from the filtration medium; and a pressure sensor disposed in the flow conduit between the pump and the filtration medium.

[0007] Other embodiments described herein provide a method of operating a solid liquid separation apparatus that includes flowing a fluid product of a shaker filtration device through a filtration medium matched to a specification of the shaker filtration device; detecting a pressure of the fluid product; comparing the detected pressure to a standard; and performing maintenance on the shaker filtration device based on the comparisonBRIEF DESCRIPTION OF THE DRAWINGS

[0008] Fig. 1 is a flow diagram illustrating a solid liquid separation apparatus that includes a particle leak detection system according to one embodiment.

[0009] Fig. 2 is a flow diagram illustrating a solid liquid separation apparatus that includes a particle leak detection system according to another embodiment.

[0010] Fig. 3 and Fig. 4 are graphs showing data from a particle detection system.

[0011] Fig. 5 is a schematic process diagram of a particle detection and analysis apparatus according to one embodiment.

[0012] Fig. 6 is a graph showing pressure readings from another particle detection system.DETAILED DESCRIPTION

[0013] Apparatus and methods are described herein for detecting particles in a flowing fluid. The methods herein operate on a fluid source, which may be a liquid product of a shaker filtration device, to detect particles in the fluid obtained from the fluid source. In the case of a shaker filtration device, a particle leak in the shaker filtration device can be detected so the leak can be expeditiously corrected. The fluid is flowed through a filtration medium that is selected based on a characteristic of the fluid source or the particles that might be present in the fluid source. In the case of aPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. shaker filtration device, the filtration medium can be selected based on a specification of the shaker filtration device such as the size of particles to be filtered by the shaker filtration device. As the fluid is flowed through the filtration medium, a pressure of the fluid is monitored at a location adjacent to the filtration medium, which can be upstream, downstream, or within the filtration medium. The pressure readings are compared to criteria to determine whether any pressure reading, alone or combined with other pressure readings, is abnormal. An abnormal pressure reading, or collection thereof, is interpreted as a particle accumulation event at the filtration medium. In the case of a shaker filtration device, such particle accumulation can indicate leakage through the shaker filtration device. Based on identifying the particle accumulation event, appropriate action can be taken. For example, a shaker filtration device can be maintained or remediated based on detecting of particle leakage. In other cases, other remediation of the fluid source can be performed. In some cases, the methods and apparatus described herein can be used during such a remediation to detect an end point at which particle content of the fluid is low enough to discontinue the remediation.

[0014] Fig. 1 is a schematic process diagram of a solid liquid separation apparatus 100 according to one embodiment. The apparatus 100 uses a shaker filtration device 102 to separate solids from liquid, which emerges as a liquid product. The shaker filtration device 102 is configured to filter solids according to size. The shaker filtration device has a specification, which is generally a particle size or based on a particle size, with solids smaller than the specified size passing through with the liquid product and solids at or larger than the specified size being diverted by the shaker filtration device 102.

[0015] The shaker filtration device 102 is a fluid source for the apparatus 100. The liquid product of the shaker filtration device 102 is flowed into a flow conduit 104, in this case a circulation conduit, for sampling. A pressure sensor 106 is coupled to the flow conduit 104 to monitor a pressure of the fluid within the flow conduit 104. A main portion 110 of the flow conduit 104 has a filtration medium 108 disposed therein such that the liquid product flowing in the main portion 110 passes through the filtration medium 108 and is circulated back to the shaker filtration device 102. A pump 120Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. maintains flow of the liquid product within the flow conduit 104. Here, the pump 120 is located in the return portion of the flow conduit 104 between the filtration medium 108 and the shaker filtration device 102. Readings of the pressure sensor 106 can be monitored by a controller 122 (or other digital system) to detect any abnormal readings.

[0016] In this case, the filtration medium 108 is located in the main portion 110 with the pressure sensor 106 between the filtration medium 108 and the pump suction 120. That is, in this case the filtration medium 108 and the pressure sensor 106 are both located in the flow path on the suction side of the pump 120. In this configuration, the pressure sensor 106 is located at the pump 120, on the suction side thereof, and may be located immediately adjacent to the pump 120. The pump 120, pressure sensor 106, and filtration medium 108 can be arranged in any flow configuration. For example, the pressure sensor 106 and / or the filtration medium 108 can be located on the discharge side of the pump 120, or the pump 120 can be located between the filtration medium 108 and the pressure sensor 106, with either the filtration medium 108 or the pressure sensor 106 located on the suction side of the pump 120. In some situations, locating the filtration medium 108 on the suction side of the pump 120 can make the filtration medium 108 more sensitive in detecting leakage of particles. The pressure sensor 106 may also be more sensitive to pressure changes that can indicate particles being caught by the filtration medium 108 if the pressure sensor 106 is located in a lower pressure part of the flow conduit 104. In any configuration, however, particles collecting in the filtration medium 108 will impact fluid flow, and any impediment to fluid flow in the flow conduit 104 will cause a change in pressure that a suitable pressure sensor 106 can detect.

[0017] The filtration medium may be any suitable type, and can be selected based on a specification of the shaker filtration device so that the filtration medium can capture particles the shaker filtration device is designed to separate. In many instances, the filtration medium may be, or may include, a 400 pm mesh strainer. Any type of filtration medium can be used where the filtration medium is designed to capture particles at a limit that is near a limit of the shaker filtration device. The filtration medium may have a particle size limit that is somewhat larger than a particlePatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. size limit of the shaker filtration device in some cases to avoid over-sensitivity to incipient particle leaks, if desired.

[0018] To facilitate sampling, a bypass 114 can be used to bypass the filtration medium 108. The bypass 114 is coupled to the flow conduit 104 from a sample portion 105 of the flow conduit 104, between the shaker filtration device 102 and the filtration medium 108, to a return portion 111 of the flow conduit 104, between the pump 120 and the filtration medium 108. The main portion 110, which flows fluid in parallel configuration with the bypass 114, can include a first filter isolation valve 116 and a second filter isolation valve 118. The valves 116 and 118 can be located on either side of the filtration medium 108 in the main portion 110, so the filtration medium 108 is between the valves 116 and 118. The valves 116 and 118 can be used to isolate fluid flow from the filtration medium 108 when the liquid product is not being sampled. That is, the first filter isolation valve 116 can be located between the filtration medium 108 and the pump 120, and the second filter isolation valve 118 can be located between the filtration medium 108 and the shaker filtration device 102.

[0019] The bypass 114 can include a bypass valve 112, which can be a manually operated valve or a remotely operated valve, and which is opened and closed to start and stop flow in the bypass 114. A backflush inlet conduit 124 is coupled to the main portion 110 downstream of the filtration medium 108, between the filtration medium 108 and the pump 120, and in this case is between the filtration medium 108 and the first filter isolation valve 116 (which is located downstream of the filtration medium 108). The backflush inlet conduit 124 can be used to provide a backflush fluid to the filtration medium 108 to remove any solids trapped by the filtration medium 108. A backflush outlet conduit 126 is coupled to the main portion 110 upstream of the filtration medium 108 between the filtration medium 108 and the second valve 118 (located upstream of the filtration medium 108). In this case, the backflush inlet conduit 124 is coupled to the flow conduit 104 between the first filter isolation valve 116 and the filtration medium 108, but the backflush inlet conduit 124 can also be coupled to the flow conduit 104 between the first filter isolation valve 116 and the pump 120. Likewise, whereas the backflush outlet conduit 126 is shown here coupled to the flow conduit 104 between the second filter isolation valve 118 and the filtrationPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. medium 108, the backflush outlet conduit 126 can be coupled to the flow conduit 104 between the second filter isolation valve 118 and the shaker filtration device 102.

[0020] The backflush inlet conduit 124 has a backflush inlet valve 128, which may be a manually operated valve or a remotely operated valve. The backflush outlet conduit 126 has a backflush outlet valve 130, which may also be a manually operated valve or a remotely operated valve. Trapped solids may be cleared from the filtration medium 108 by closing the first filter isolation valve 116 and the second filter isolation valve 118, in no particular order. The backflush inlet valve 128 and the backflush outlet valve 130 can then be opened to allow a backflush fluid to flow through the filtration medium 108 in a reverse direction of the normal flow direction to dislodge any solids trapped in the filtration medium. Alternately, backflush fluid can be flowed through the backflush inlet conduit into the main portion 110 and into the shaker filtration device 102 to remove the solids. The backflush inlet conduit 124, backflush outlet conduit 126, backflush inlet valve 128, and backflush outlet valve 130 define a backflush system 140 that can be operated to remove accumulated particles from the filtration medium 108. Appropriate flow controls can be included to facilitate convenient operation of the backflush system 140.

[0021] A change in pressure detected by the pressure sensor 106 can indicate a particle accumulation event of particles collecting on the filtration medium 108. The change in pressure can be sudden if a large collection of particles is captured by the filtration medium 108 in a short time. If the accumulation of particles is gradual, however, the pressure sensor 106 may show a trend upward ordownward depending on the location of the pressure sensor 106. In the case of a shaker filtration device 102, the pressure sensor 106 can detect a leak of particles through the screen of the shaker filtration device 102.

[0022] The controller 122 can be provided with criteria to compare to readings of the pressure sensor 106 to determine whether an end point has been reached or an event, such as a particle leak, is detected. For example, in one case such an event or end point may be indicated when pressure readings of the pressure sensor 106 pass a threshold, either high or low. In another case, a change in pressure, within aPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. specified time, that is greater than a threshold may indicate an event or end point. More complicated criteria can be provided, as well, and more than one criterion can be used to determine an occurrence. The controller 122 can be configured to take automatic action when pressure readings of the pressure sensor 106 indicate that a particle leak has likely occurred.

[0023] In general, the detection systems herein can be configured to specifically detect particles in a fluid source such as the shaker filtration device 102. Thus, the filtration medium 108 can be selected based on a specification of a filtration device such as the shaker filtration device 102 so that particles having a size below the specification of the shaker filtration device 102 pass through the filtration medium 108 while particles having a size above the specification of the shaker filtration device 102 are captured by the filtration medium 108. In general, the filtration medium 108 can be selected based on a characteristic of the fluid source, which may be a specification of equipment or characteristics of particles that may be found in the fluid source or may be unwanted in a process utilizing fluid from the fluid source. For example, any leakage of unwanted particles through the shaker filtration device 102, which indicates failure or partial failure of the shaker filtration device 102, results in a buildup of particles at the filtration medium 108, reduction of flow through the filtration medium 108, and increase in pressure drop across the filtration medium 108. The increase in pressure drop can be detected by detecting pressure of the fluid circulating through the filtration medium 108 upstream of the filtration medium 108, downstream of the filtration medium 108, or both.

[0024] It should be noted that monitoring pressure in the flow conduit 104 can be performed in short periods of time by sampling the flow through the flow conduit 104. For example, flow can be sampled for 60 seconds or 60 minutes, or any suitable duration, which may be predetermined, to determine whether an accumulation of particles is present. Successive samples can be compared and statistical methods can be used to judge the likelihood that particle accumulation is detected. Historical data can be archived and used to compare with new readings. For example, failure frequency analysis can be performed to predict when a particle leak might develop.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.Artificial intelligence and machine learning techniques can also be applied to enhance understanding of the signals and prediction of physical realities based on the signals.

[0025] Fig. 2 is a schematic process diagram of a bulk solid-liquid separation apparatus 200 according to one embodiment. Like the apparatus 100, the apparatus 200 uses shaker filtration devices as a fluid source. In this case, the apparatus 200 has two shaker filtration devices, a first shaker filtration device 202A and a second shaker filtration device 202B. This version illustrates that the techniques described herein can be used in systems having a plurality of fluid sources like shaker filtration devices. In such a system, each shaker filtration device can be the same as all the others, for example designed to separate particles of the same size for all the shaker filtration devices. In other cases, the plurality of shaker filtration devices can be designed to separate particles of different sizes.

[0026] The two shaker filtration devices 202A and 202B, of the apparatus 200, are fluidly coupled to a particle detection system 250 that has a plurality of filtration media 208. In this case, the particle detection system 250 has a first filtration medium 208A and a second filtration medium 208B. The first and second filtration media 208A and 208B are fluidly coupled in a circulation 204 in parallel. The circulation 204 is fluidly coupled to each of the first and second shaker filtration devices 202A and 202B. An outlet 252 of each shaker filtration device 202 provides a fluid product of each device 202 to the circulation 204. Source isolation valves 254 can isolate one or both of the shaker filtration devices 202 from the circulation 204, so the circulation 204 can be used to sample one or both of the first and the second shaker filtration device 202A and 202B sequentially or concurrently on the source side. A source conduit 256 flows the fluid product of the shaker filtration devices 202 to the particle detection system 250 for sampling. The pressure sensor 106 is, in this case, coupled to the source conduit 256. A return conduit, 258 returns the fluid product from the particle detection system 250 to inlets 260 of each of the shaker filtration devices 202A and 202B. Return isolation valves 255 can also be used to isolate one or both of the shaker filtration devices 202 from the circulation 204 sequentially or concurrently on the return side.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.

[0027] Fluidly connecting the source conduit 256 with the return conduit 258 are three fluid paths. A first filter path 262A includes the first filtration medium 208A. Fluid product from the two shaker filtration devices 202A and 202B can flow through the source conduit 256, and through the first filter path 262A to be exposed to the first filtration medium 208A, to the return conduit 258. The first filter isolation valve 116 and the second filter isolation valve 118 can be included in the first filter path 262A to isolate the first filtration medium 208A for backflushing or other operations. A second filter path 262B includes the second filtration medium 208B. Fluid product from the two shaker filtration devices 202A and 202B can flow through the source conduit 256, and through the second filter path 262B to be exposed to the second filtration medium 208B, to the return conduit 258. The first filter isolation valve 116 and the second filter isolation valve 118 can be included in the second filter path 262B to isolate the second filtration medium 208B for backflushing or other operations. The first filter path 262A and the second filter path 262B together define a main portion 210 of the particle detection system 250. Using the valves 116 and 118 in each of the first and second filter paths 262A and 262B, the fluid product of the shaker filtration devices 202A and 202B can be directed sequentially to the first filtration medium 208A and the second filtration medium 208B, or to both concurrently.

[0028] The backflush system 140 is included in the apparatus 200. The backflush inlet and outlet conduits 124 and 126 are coupled to the main portion 210 of the system 250, in this case, at locations that can provide backflush fluid to flow through the first filter path 262A, the second filter path 262B, or both. The backflush inlet and outlet conduits 124 and 126 can be fluidly coupled to the first filter path 262A by opening the valves 128 and 130 and the valves 116 and 118 of the first filter path 262A. At the same time, the backflush inlet and outlet conduits 124 and 126 can be fluidly coupled to the second filter path 262B, or isolated from the second filter path 262B, by using the valves 116 and 118 of the second filter path 262B. Likewise, the backflush inlet and outlet conduits 124 and 126 can be fluidly coupled to the second filter path 262B by opening the valves 116 and 118 of the second filter path 262B, and the first filter path 262A can be isolated from the backflush inlet and outlet conduits 124 and 126, or fluid coupled thereto concurrently, by operation of the valvesPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.116 and 118 of the first filter path 262A. In this case, to prevent flowing backflush fluid into the shaker filtration devices 202A and 202B, the source and return isolation valves 254 and 255 can be closed during backflush operations, allowing selective backflushing of the first filtration medium 208A and the second filtration medium 208B on demand.

[0029] The particle detection system 250 also has the bypass 114 connecting the source conduit 256 with the return conduit 258. The bypass valve 112 can be opened and closed to provide fluid flow between the source conduit 256 and the return conduit 258 that does not flow through either filtration medium 208A or 208B. Optionally, intermediate valves 264 can be positioned in the source and return conduits 256 and 258 between connection points of the filter paths 262 and the bypass 114 to isolate the main portion 210 of the system 250 from the source and return conduits 256 and 258. Such valves can be used to allow fluid flow through the bypass 114 during backflush operations.

[0030] The particle detection system 250 can be used to sample fluid product of one or more fluid sources, like the shaker filtration devices 202A and 202B, through filtration media having different specifications. For example, in one case the first filtration medium 208A may be a 400 pm mesh strainer while the second filtration medium 208B may be an 800 pm mesh strainer. Filtration media having different size specifications can be used to ascertain particle profiles based on particle size. Such methods can be used, in the context of multiple shaker filtration devices, to determine which shaker filtration device has a leak, if the shaker filtration devices have different particle size specifications.

[0031] The apparatus 100 and 200 can be used to perform particle leak detection methods. A method of operating a solid liquid separation apparatus can use the apparatus 100 or 200. A fluid product of a shaker filtration device, such as the devices 202, 202A, and 202B, can be flowed through a filtration medium, such as the media 208, 208A, and 208B, which are matched to a specification of the respective shaker filtration devices, and pressure in the circulations 104 and 204 can be monitored using the pressure sensors 106. In one method, the valves 116 and 118 can bePatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. closed and the bypass valve 112 can be opened to allow fluid circulation. The pump 120 can be activated to start fluid circulation through the bypass 114. Where the apparatus 200 is used, one or both source isolation valves 254 and one or both return isolation valves 255 are opened to establish fluid flow. After fluid flow is established, the valves 116 and 118 are opened and the bypass valve 112 is closed to establish flow through the filtration medium 108. If the apparatus 200 is used, the valves 116 and 118 in the first filtration path 262A, the second filtration path 262B, or both, are opened to sample the fluid product using the first filtration medium 208A, the second filtration medium 208B, or both.

[0032] Readings from the pressure sensor 106 are monitored for a time period to determine whether any such readings indicate a particle leak at any of the shaker filtration devices. After the time period, the filter medium used for sampling can be isolated by closing the corresponding valves 116 and 118, or by closing the source and return isolation valves 254 and 255, and the backflush inlet and outlet conduits 124 and 126 can then be used to backflush the filtration medium used for the sampling. For the apparatus 100, backflushing can be performed while the valves 116 and 118 are closed. For the apparatus 200, backflushing can be performed while the source and return isolation valves 254 and 255 are closed, or alternately while the intermediate valves 264 are closed. Using either the apparatus 100 or the apparatus 200, flow of fluid product can be continued through the bypass 114 while backflushing is performed. Alternately, fluid flow can be stopped during backflushing by deactivating the pump 120 and / or closing the source and return isolation valves 254 and 255.

[0033] As noted above, statistical methods can be used to assist determination of particle leakage using the methods herein. Comparisons with historical data can be used. For example, baseline data can be generated by flowing a clean fluid through a filtration medium to be used for particle sampling and monitoring pressure using a pressure sensor. For example, using the apparatus 100 or 200, clean fluid can be provided to the flow conduits 104 or 204, and the readings from the pressure sensor 106 recorded, to establish baseline data for the apparatus. Pressure readings from sampled fluids can be compared with the baseline data to determine particle leakage.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.Pressure readings from short-duration samples, such as 60 second samples, can be compared over time to determine whether particle content of the fluid product of a shaker filtration device is increasing. The controller 122, which is a digital system capable of collecting, optionally storing, and optionally analyzing signals from the pressure sensor 106, provides remote and automated early detection of particle leakage reducing or eliminating the need for inspection of shaker filtration devices to discover particle leaks. The controller 122 can be co-located with the shaker filtration devices and particle leakage detection systems, or the controller 122 can be remote from such facilities and network connected to apply controls as needed. Additionally, robotic facilities to replace screens in shaker filtration devices can be activated by the controller 122 upon designation of a particle leak.

[0034] It should be noted that a pressure sensor and filtration medium can be located in any conduit that flows fluid product of a shaker filtration device. For example, a recycle line that routes such fluid product to an industrial operation as a recycle fluid, for example a recycle drilling fluid line, can have a pressure sensor and filtration medium to detect particle leakage. Such apparatus can also include a bypass, isolation valves, and backflush conduits as described herein. It should also be noted that, while apparatus are shown herein that use one or two filtration paths in a single particle detection system, more than one particle detection system can be coupled to a single shaker filtration device, for example to use more than one filtration medium specified for different particles sizes for a single shaker filtration device. Alternately, a particle detection system for a single shaker filtration device can use multiple filtration paths to sample using filtration media having different size specifications. In other cases, multiple particle detection systems can be used with a plurality of shaker filtration devices, in one-to-one correspondence or in one-to- many correspondence as appropriate. Each particle detection system can, independently, have one or more than one filtration path according to the needs of individual processes.

[0035] Fig. 3 and Fig. 4 are graphs showing pressure readings from a particle detection system like those described herein. The data of Fig. 3 were generated using a pressure sensor to monitor pressure on the suction side of a pump in a fluidPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. circulation of 5000 mL of drilling fluid. Mesh strainers with size specifications of 200 pm up to 1 ,000 pm were used to generate the data. To the circulating fluid was added 5g of solids of about 1 ,000 pm in size. The pressure readings are presented in a time-series at 302. At 304, a falling pressure reading indicates increasing flow restriction at the mesh strainer due to accumulating particles.

[0036] The data of Fig. 4 were generated using a pressure sensor to monitor pressure on the suction side of a pump in a fluid circulation of 3000 mL of drilling fluid. Mesh strainers with size specifications of 400 pm were used to generate the data. To the circulating fluid was added 0.045% (vol) solids with particle distribution of d10=65pm, d50=160pm, d90=381 pm. The pressure readings are presented in a time-series at 402. In this case, the system is operated in a cyclic manner using a system that automatically backflushes the strainer, or strainers. The pressure readings exhibit an abrupt upward spike 404 at the beginning of each cycle during the backflush operation. Each of these cycles is 60 seconds long. An average pressure for each cycle is plotted in time-series at 406.

[0037] In some of the cycles shown in Fig. 4, a dramatic pressure change in less than a minute, for example at 408, showed particle collection at the mesh strainer resulting in flow restriction and reduced pressure at the sensor. The data of Fig. 4 show that a system that operates cyclically using an automated backflush after a predetermined time can be used to monitor a fluid system for particles and detect the presence of particles in real time. Such a system can be configured, for example using a digital controller, to provide a signal when a pressure drop such as at 408 is detected.

[0038] The system described above can be used to analyze particles in any fluid from any source. The processes above are described in the context of sampling fluids from shaker devices that separate solids from drilling fluids surfaced from a subterranean well, but any fluid source can be sampled and analyzed for particle content and / or particle size distribution. Fig. 5 is a schematic process diagram of a particle detection and analysis apparatus 500 according to one embodiment. The apparatus 500 uses a sample portion 105 to obtain a fluid sample from a source 504.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.The source 504 can be a shaker device, as described above, or another fluid source wherein understanding the content and distribution of particles is helpful. The fluid source 504 can be a stream obtained from a subterranean well following well cleaning. In such cases, the apparatus 500 can be used to ascertain amount and characteristics of residual particles in the well. The fluid source 504 can be a stream from any subterranean source, like a mine or a buried pipe, or a surface source such as a surface water stream, where removing particles from the source is useful. In other cases, the source 504 can be a plurality of streams that are sampled and analyzed individually by the apparatus 500 or mixed and analyzed together.

[0039] The apparatus 500 has a plurality of sample stages 506i - 506N, where N can be any suitable number. The apparatus 500 could also have only one sample stage like the system 100 of Fig. 1. Each sample stage 506 has a filtration medium 108, so the system has filtration media 108i - 108N, and first and second filter isolation valves 1161 - 116N and 1181 - 118N The stages 506 are arranged in parallel flow arrangement so that one or another of the stages 506 can be selectively utilized for particle analysis by opening and closing the first and second filter isolation valves 116 and 118 for a selected stage 506. Like the apparatus 100 and 200 described above, the apparatus 500 has a return portion 111 that returns sampled material to the source 504. Instead of a return portion 111 , the apparatus 500 can have a disposition conduit that routes sampled material to any suitable disposition.

[0040] The apparatus 500 has a bypass 114 and a bypass valve 112, similar to the other apparatus 100 and 200, and a backflush capability with backflush inlet conduit 124 coupled to the return portion 111 between the bypass 114 and the last filtration stage 506N and a backflush outlet conduit 126 coupled to the sample portion 105 between the bypass 114 and the last filtration stage 506N. The backflush inlet conduit has the backflush inlet valve 128, and the backflush outlet conduit 126 has the backflush outlet valve 130. The valves 264 are included in the apparatus 500 to allow the fluid flow in the bypass 114 to be isolated from flow of backflush fluid through one or more of the stages 506.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.

[0041] The apparatus 500 has a sensor unit 520 that includes a pressure sensor and may include sensors of other types, such as temperature sensors and composition sensors, coupled to the return portion 111. Alternately, sensors, including a pressure sensor, can be individually coupled to the return portion 111. The sensor unit 520 produces signals that represent a condition of the fluid flowing in the return portion 111. The signals include a signal that represents pressure of the fluid flowing in the return portion 111. As described above, the signals from the pressure sensor of the sensor unit 520 can indicate when particles collect in one or more of the filtration media 108. Specifically, where the signals indicate a drop in pressure, such pressure drop can be interpreted as an indication that particles have collected in one or more of the filtration media 108 and are restricting fluid flow into and through the return portion 111.

[0042] The apparatus 500 includes a controller 550 to control operation of the apparatus 500. The controller 550 is operatively coupled to the sensor unit 520 to receive signals output by the sensor unit 520 and to interpret the signals, particularly signals representing pressure of the fluid flowing in the return portion 111. The controller 550 can also be operatively coupled to the isolation valves 116 and 118, the backflush valves 128 and 130, and the valves 264 to automate operation of the apparatus 500. The controller 550 is configured to interpret the signals from the sensor unit 520 and to send control signals, based on the signals from the sensor unit 520, to the various valves to adjust operation of the apparatus 500.

[0043] In particular, the controller 550 can be configured to backflush the stage 506 currently in use periodically. Thus, if one of the stages 506 is being used to sample a fluid for particles, the fluid provided through the sample portion 105, the controller 550 can be configured to backflush the stage 506 by opening the bypass valve 112, closing the valves 264 and opening the backflush valves 128 and 130. After a predetermined backflush duration, for example 60 seconds, the controller 550 can be configured to resume particle analysis by closing the backflush valves 128 and 130, opening the isolation valves 116 and 118 for the filtration stage 506 to be used, and closing the bypass valve 112. In this way, a buildup of particles in the filtration medium 108 being used will be automatically removed on a regular basis soPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. that interruption of particle analysis can be minimized. The controller 550 is operatively coupled to all the valves 112, 116, 118, 128, 130, and 264, in this case to accomplish automated control of the apparatus 500.

[0044] The controller 550 can also be configured to perform a backflush based on a signal from the sensor unit 520. For example, where one or more signals from the sensor unit 520 indicates particles collecting in the filtration medium 108 in use, the controller 550 can be configured to perform a backflush of the filtration medium 108 when the signals indicate that an endpoint has been reached. For example, where the signals indicate that pressure of the fluid flowing through the return portion 111 has dropped to a predetermined threshold, or by a predetermined amount, the controller 550 can be configured to perform the backflush as described above.

[0045] The controller 550 can also be configured to perform other functions and processes. For example, the controller 550 can be configured to perform a staged particle analysis of a fluid sample from the source 504 by sequencing flow of the fluid through the stages 506 of the apparatus 500 one at a time. For example, the controller 550 can be configured to sample fluids through a first stage 506i having the largest filtration medium 1081 for a first predetermined time, backflush the first stage 506i, sample the fluid through a second stage 5062 having a filtration medium IO82 smaller than the first filtration medium IO81 for a second predetermined time, backflush the second stage 5062, and continue through a selected number of stages 506 or through all the stages 506 to generate pressure drop data for each stage 506 that can be interpreted as indication of particle content of particular sizes. Such data can be used to represent a distribution of particles sizes found in the fluid flowing through the sample portion 105.

[0046] The apparatus 500 may include a mass flow device 560 coupled to the sample portion 105. The mass flow device 560 can be used to determine relative particle size distribution by mass using an analysis routine like that described above. Using the mass flow device 560, mass of the sample fluid can be summed between starting flow of the sample through a stage 506 and when that stage 506 reaches an end point, for example when flow through the stage 506 stops due to plugging of thePatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. filtration medium 508 of the stage 506. The masses for each stage 506 can be compared, and a relative particle size distribution, relative to the mass obtained using the largest filtration medium 108, can be ascertained.

[0047] Fig. 6 is a graph showing pressure readings from a particle detection system like the apparatus 500. The pressure readings shown in the graph are presented in a time-series at 602. The spikes at 604 indicate periodic backflush operations, similar to the data of Fig. 4, steady-state flow at 606, and incipient occlusion of a filtration medium at 608 where pressure begins dropping.

[0048] In this case, a system like the apparatus 500, using a digital controller like the controller 550, was configured to perform an automated backflush operation when the pressure reading declined by a predetermined amount. In such a system, the predetermined amount can be an absolute pressure or a relative pressure, like a percentage decline. The system thus triggers an automatic backflush in each cycle when pressure reaches a predetermined threshold.

[0049] The graph of Fig. 6 shows that a system like the apparatus 500 can be used to monitor the particle count in a sampled material on a quasi-continuous basis by repeatedly sampling for a predetermined sample period and then backflushing for a predetermined backflush period. The extent of pressure drop in each cycle can be compared, with more pressure drop indicating more particles collected and less pressure drop indicating less collection of particles. The number of cycles in a unit of time, or the frequency of cycles or cycle duration, can be monitored in such a system and actions taken or programmed based on such quantities. For example, increasing number of cycles in a unit time, or increasing cycle frequency or decreasing cycle duration, can be interpreted as increasing concentration of particles in the fluid large enough to plug the filtration medium, which in turn can be interpreted as particle leakage in a shaker system, or merely increasing particle load in any fluid source. The converse can also be detected, where decreasing cycles per unit time, decreasing frequency, or increasing cycle duration can indicate reduction of particle load in the source.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.

[0050] Additional methods can be practiced using the systems described herein. In general, the systems described herein can be used to perform particle detection methods. A fluid is obtained from a fluid source and flowed through a filtration medium. A pressure of the fluid is detected and monitored for a change that represents particle accumulation and fluid flow restriction at the filtration medium. The pressure can be detected at a high pressure side or at a low pressure side of the filtration medium. A pump can be used, as described herein, to drive flow of the fluid through the filtration medium. In one method, the pressure of the fluid at the low pressure side of the filtration medium is monitored. A drop in the pressure of the fluid at the low pressure side, whether abrupt or gradual, is detected to determine accumulation of particles at the filtration medium. Any suitable action can be taken upon detecting the particle accumulation.

[0051] In one case, as described above, the particle accumulation can indicate failure, or incipient failure, of a filtration device. In another case, the particle accumulation can indicate an increase in concentration of particles in the fluid source, which can be a fluid from a process such as a subterranean well or a mine.

[0052] A particle detection system can be operated in cyclical manner using a controller. The controller can be configured to monitor pressure readings and perform an automatic backflush operation when the pressure readings exhibit a change of predetermined magnitude. For example, where the pressure readings are at the low pressure side of the filtration medium, the controller can be configured to perform a backflush operation when the pressure readings drop by a predetermined amount. The results of the cycles can be monitored, tracked, and compared to ascertain particle concentration in the fluid source, and any trend in such concentration. In one case, such a particle detection system can be used in connection with cleaning of a subterranean well, where a fluid is flowed within the well to remove solids, such as drill cuttings and other solids, in order to prepare the well for efficient surfacing of a subterranean resource. Where the pressure readings indicate a particle content of the fluid has dropped to a predetermined value, or by a predetermined amount, an end point can be identified, well cleaning discontinued, and the well then prepared for production operation.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.

[0053] The sensor units, and specifically the pressure sensors, used in the systems described herein may be configured to be substantially isolated from flowing or circulating fluids. In one aspect, a sensor unit such as the sensor units 106, 132, and 520 may be coupled with the respective conduits 104 and 110 using a flow extension, such as a pipe, tube, or recess that fluidly connects the sensor units and sensors to the conduits 104 and 110 without exposing the various sensors to a longterm abrasive movement of a fluid containing particles.

[0054] The methods and apparatus herein may include the capability for remote monitoring and control. The controllers described herein may include remote communication capability, which can be used to send and receive signals to and from the processes described herein for control and monitoring from a remote location. Such systems can be used, for example, to control and monitor a plurality of particle detection systems at different locations, potentially in use for different applications. Thus, for example, a first plurality of particle detection systems may be in use to monitor and detect particle leakage with respect to a plurality of shaker filtration devices in a first plurality of locations, while a second plurality of particle detection systems may be in use to monitor and detect particle content of fluid streams being surfaced from a plurality of subterranean wells in a second plurality of locations. The control and monitoring of the first and second plurality of particle detection systems referred to above can be located in a single location, remote from each of the locations of the first and second plurality of locations, at one or more location of the first and / or the second plurality of locations, or at one or more of a third plurality of locations. Standard telecommunications methods can be used to connect the controllers described herein with remote monitoring and control systems, or specially designed telecommunications systems can be used.

[0055] The preceding description has been presented with reference to present embodiments. Persons skilled in the art and technology to which this disclosure pertains will appreciate that alterations and changes in the described structures and methods of operation can be practiced without meaningfully departing from the principle, and scope of this present disclosure. Accordingly, the foregoing description should not be read as pertaining only to the precise structures described and shownPatent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. in the accompanying drawings, but rather should be read as consistent with and as support for the following claims, which are to have their fullest and fairest scope.

Claims

Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.Claims1. A solid liquid separation apparatus, comprising: a fluid source; a circulation conduit to circulate a fluid of the fluid source and to return the fluid to the fluid source; a filtration medium disposed in the circulation conduit; and a pressure sensor coupled to the circulation conduit.

2. The solid liquid separation apparatus of claim 1 , further comprising a pump disposed in the circulation conduit to receive flow from the filtration medium.

3. The solid liquid separation apparatus of claim 2, further comprising a backflush inlet coupled to the circulation conduit between the filtration medium and the pump and a backflush outlet coupled to the circulation conduit between the fluid source and the filtration medium.

4. The solid liquid separation apparatus of claim 3, further comprising a bypass coupled to the circulation conduit between the fluid source and the backflush outlet and coupled to the circulation conduit between the backflush inlet and the pump.

5. The solid liquid separation apparatus of claim 4, further comprising a controller configured to receive signals from the pressure sensor representing a pressure of the fluid flowing in the circulation conduit and to identify flow restriction at the filtration medium based on the signals.

6. The solid liquid separation apparatus of claim 4, further comprising a bypass valve in the bypass, a backflush inlet valve in the backflush inlet, and a backflush outlet valve in the backflush outlet, and a controller configured to perform a backflush operation by operating the bypass valve, the backflush inlet valve, and the backflush outlet valve to flow a backflush fluid through the filtration medium.

7. The solid liquid separation apparatus of claim 6, wherein the controller is configured to perform the backflush operation periodically.Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al.

8. The solid liquid separation apparatus of claim 1 , wherein the fluid source is a shaker filtration device.

9. An apparatus for detecting particles in a fluid, comprising: a flow conduit; a filtration medium disposed in the flow conduit; a pump coupled to the flow conduit to receive flow from the filtration medium; and a pressure sensor disposed in the flow conduit between the pump and the filtration medium.

10. The apparatus of claim 9, wherein the flow conduit is coupled with a fluid product of a shaker filtration device.11 . The apparatus of claim 9, wherein the pressure sensor is coupled to the flow conduit adjacent to a suction of the pump.

12. The apparatus of claim 9, further comprising a bypass and isolation valves to isolate the filtration medium from the pump.

13. The apparatus of claim 9, further comprising a backflush system and a controller operatively coupled with the backflush system to perform an automated backflush operation.

14. The apparatus of claim 13, wherein the controller is configured to perform automated backflush operations cyclically, with a predetermined cycle duration between backflush operations.

15. The apparatus of claim 1 , wherein the controller is configured to perform each backflush operation when a pressure reading passes a threshold.

16. The apparatus of claim 15, wherein the controller is configured to monitor a duration between backflush operations.

17. A method of operating a solid liquid separation apparatus, comprising:Patent ApplicationAttorney Docket No. IS24.1831Inventors: Gulbrandsen, et al. flowing a fluid through a filtration medium selected based on a characteristic of particles to be detected in the fluid; detecting a pressure of the fluid; comparing the detected pressure to a standard; and identifying a particle accumulation event based on the comparison.

18. The method of claim 17, further comprising backflushing the filtration medium at: the time the particle accumulation event is identified; or a predetermined time.

19. The method of claim 17, wherein the filtration medium is a first filtration medium, and further comprising flowing the fluid through a second filtration medium different from the first filtration medium, wherein the first filtration medium and the second filtration medium are selected to filter particles of different sizes.

20. The method of claim 17, wherein the fluid is obtained from a shaker filtration device.

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