[0001] The present invention relates, generally, to debris filtration in oil and gas production platforms, and more particularly to a debris filtration assembly to provide for enhanced and efficient filtration of debris of varying sizes.
Backeround of the invention
[0002] Crude oil and natural gas produced at onshore and offshore platforms are processed via onshore and offshore platforms respectively. These platforms comprise one or more components for processing a multiphase well fluid comprising oil, gas and water. The multiphase well fluid produced from a well further comprises debris which may be part of the formation from which the oil and gas are produced. As the debris in the well fluid flows through pipelines of the one or more components, one or more problems such as plugging of production equipment are observed. This causes disruption in the process which in turn results in quality issues in oil and gas production.
[0003] Conventionally, apparatuses such as basket strainers, desanders etc. are used to remove solids from well fluids. However, due to a large quantity of well fluid coming into the platforms, the size of these apparatuses is required to be large. Moreover, the quantity of large sized debris is generally more compared to smaller sized debris, therefore it has been observed that apparatus such as a basket strainer would capture the entire range of debris sizes in a single mesh sized for smaller particles, causing higher pressure drop across the pipeline. This further leads to an increase in the frequency of cleaning and also increases equipment downtime. Additionally, installation of conventional apparatuses such as basket strainers and desanders require isolation and bypass facility, leading to larger space requirement which is generally not suitable for platforms with space constraints. Further, conventional desanders are not suitable for trapping very large sized debris in a range over 70mm.
[0004] In light of the aforementioned drawbacks, there is a need for a debris filtration assembly which provides improved filtration of debris of varying sizes. There is a

need to provide a debris filtration assembly which can be integrated with high pressure well fluid pipelines having severe space constraints. There is a need to provide a debris filtration assembly which facilitates lower pressure drop and requires less frequent cleaning, thereby increasing the availability of the assembly for operation. Also, there is a need for a debris filtration assembly which is suitable for large quantities of well fluid. Further, there is a need for a debris filtration assembly which has relatively lower cost and is simple in construction. Furthermore, there is a need for a debris filtration assembly which can be integrated with pipelines of the existing oil and gas platforms easily and with minimum infrastructure overheads.
Summary of the Invention
[0005] In various embodiments of the present invention, a debris filtration assembly (100) integrable with a fluid pipeline is provided. The assembly comprises a conduit (102) extending in the direction of an incoming fluid defining an inlet section (104). The conduit (102) extends vertically downwards from a distal end (104b) of the inlet section (102) defining a debris collection section (106). The debris collection section (106) disposed substantially perpendicular to the ground. The conduit (102) opens from a lower side portion (104') of the inlet section (104) and a corresponding upper side portion (106') of the debris collection section (106) extending in a horizontal plane to form an outlet section (108). The outlet section (108) comprises a hollow enclosure (110) disposed in the outlet section (108) for passage of the incoming fluid there through. The hollow enclosure (110) comprises a filter element (112) extending transversely across the interior of the hollow enclosure (110). Further, the debris filtration assembly (110) facilitates change in velocity profile of debris in the incoming fluid, such that larger sized debris drops in the debris collection section 106 and smaller sized debris is intercepted by the filter element (112).
[0006] In an embodiment of the present invention, the conduit (102) extends vertically downwards upto a length x to define the inlet section (104). Further, the conduit (102) extends vertically downwards upto a length y from the distal end (104b) of the inlet section (104) to define the debris collection section (106) such that the length y is greater than or equal to the length x.

[0007] In another embodiment of the present invention, the outlet section (108) of the debris filtration assembly (100) is disposed substantially perpendicularly to the inlet section (104) and the debris collection section (106).
[0008] In an embodiment of the present invention, the filter element (112) of the debris filtration assembly (100) is disposed at an angle of 60 degree across the interior of the hollow enclosure (110).
[0009] In another embodiment of the present invention, the filter element (112) comprises perforations (114) arranged in a triangular pitch such that respective centres of adjacent perforations (114) forms an equilateral triangle. Each perforation (114) is evenly spaced in relation to adjacent perforation (114).
[0010] In an embodiment of the present invention, the debris collection section (106) comprises a debris discharge valve (106a) for removal of collected lager sized debris.
[0011] In an embodiment of the present invention, the hollow enclosure (110) comprises a vent (110a) for depressurizing the hollow enclosure (110) for cleaning.
[0012] In an embodiment of the present invention, the debris filtration assembly (100) is fabricated from carbon steel.
Brief Description of the Drawings
[0013] The present invention is described by way of embodiments illustrated in the accompanying drawings wherein:
[0014] Fig. la illustrates a cross-sectional view of a debris filtration assembly in accordance with an embodiment of the present invention; and
[0015] Fig. lb illustrates a front view of a section of strainer plate of the debris filtration assembly in accordance with an embodiment of the present invention.
Detailed Description of the Invention
[0016] The present invention provides a debris filtration assembly which can be easily integrated with well fluid pipelines in oil and gas production platforms. In accordance with various embodiments of the present invention, the debris filtration assembly of the present invention facilitates change in velocity profile of debris of varying sizes

present in the incoming well fluid to separate said debris from the well fluid. Additionally, the debris filtration assembly facilitates removal of free water present in well fluid, thereby increasing the processing efficiency of downstream equipment.
[0017] The disclosure is provided in order to enable a person having ordinary skill in the art to practice the invention. Exemplary embodiments herein are provided only for illustrative purposes and various modifications will be readily apparent to persons skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. The terminology and phraseology used herein is for the purpose of describing exemplary embodiments and should not be considered limiting. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed herein. For purposes of clarity, details relating to technical material that is known in the technical fields related to the invention have been briefly described or omitted so as not to unnecessarily obscure the present invention.
[0018] It is to be noted that, as used in the specification by the term "substantially" it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those skilled in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. The terms well fluid, multiphase fluid and fluid have been used interchangeably throughout the specification. The term debris as used in the specification refers to solid particles of varying sizes, sand particles and other waste particles. The term conduit as used in the specification refers to a pipe, pipeline or any other passage means for the flow of fluid there through.
[0019] The present invention would now be discussed in context of embodiments as illustrated in the accompanying drawings.
[0020] In various embodiments of the present invention, a debris filtration assembly 100 integrable with well fluid pipelines of oil and gas production platforms is provided. The debris filtration assembly 100 effectively filters debris of varying sizes from the well fluid. The debris filtration assembly may be integrable with any existing fluid pipeline requiring filtration of debris from the well fluid.

[0021] Fig. 1 illustrates a cross-sectional view of a debris filtration assembly 100 in accordance with an embodiment of the present invention. Fig. lb illustrates a front view of a section of strainer plate of the debris filtration assembly 100 in accordance with an embodiment of the present invention.
[0022] In an embodiment of the present invention, the debris filtration assembly 100 comprises a conduit 102 extending in the direction of an incoming well fluid to define an inlet section 104. In an embodiment of the present invention as illustrated in Fig. la, the conduit 102 extends vertically downwards up to a length (x) to define the inlet section 104. The starting point of length x defines a proximal end 104a of the inlet section 104 and the endpoint of length x defines a distal end 104b of the inlet section 104. The proximal end 104a may include a coupling means (104aa) which may be coupled with a pipe upstream (not shown). The coupling means (104aa) may include but is not limited to a flange. In an exemplary embodiment of the present invention, the length x may be in the range of 100-150 cm.
[0023] The conduit 102 extends vertically downwards from the distal end 104b of the inlet section 104 to define a debris collection section 106. In an embodiment of the present invention, length of the debris collection section 106 may be y, such that the length y is greater than or equal to the length x. In an exemplary embodiment of the present invention, the length y may be in the range of 100-120 cm. The debris collection section 106 is perpendicular to the ground and traps larger sized debris present in the incoming fluid due to gravitational force. The portion of the debris collection section 106 nearer to the ground comprises a debris discharge valve 106a for removal of collected larger sized debris. In an embodiment of the present invention, the diameter of the debris discharge valve may be 10.16 cm.
[0024] In an embodiment of the present invention, the conduit 102 opens from a lower side portion 104' of the inlet section 104 and a corresponding upper side portion 106' of the debris collection section 106 to extend in a horizontal plane forming an outlet section 108. In an embodiment of the present invention, the outlet section 108 comprises a hollow enclosure 110. The hollow enclosure 110 is disposed in the outlet section 108 for passage of the incoming well fluid there through. The hollow enclosure 110 may be rectangular, spherical or of any other suitable shape. The hollow enclosure 110 comprises a filter element 112. The filter element 112
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extends transversely across the interior of the hollow enclosure 110. The filter element 110 traps smaller sized debris in the hollow enclosure 110. In various embodiments of the present invention, the flow area of the hollow enclosure 110 may exceed the cross-sectional area of the conduit 102 associated with the outlet section 108 to avoid blockage of the filter element 112. In the exemplary embodiment of the present invention, as illustrated in Fig la, the hollow enclosure 110 is rectangular in shape having dimensions 495.3mm x 711.2mm x 711.2mm, where a side surface of the hollow enclosure 110 is removably secured with enclosure body. The filter element 112 is a strainer plate removably disposed at an angle of 60 degrees in relation to the horizontal plane of hollow enclosure 110. The transverse arrangement of the filter element 112 increases the area available for filtering small sized debris. The filter element 112 may be rectangular shaped or of any other suitable shape such as trapezoidal, circular etc. As illustrated in Fig lb, in an exemplary embodiment of the present invention, the filter element 112 is rectangular shaped. The filter element 112 comprises substantially circular perforations 114 of diameter 0.9525 cm arranged in a triangular pitch such that respective centres of the adjacent perforations 114 forms an equilateral triangle. Each perforation 114 is evenly spaced in relation to adjacent perforation 114. The arrangement of the perforations 114 imparts mechanical strength to the filter element 112. In another exemplary embodiment of the present invention, the shape of the perforations 114 may be hexagonal, square or any other suitable shape. In yet another exemplary embodiment of the present invention, the perforations 114 may be arranged in any suitable pattern and may or may not be evenly spaced.
[0025] Referring to Fig la, the hollow enclosure 110 further comprises a vent 110a for depressurizing the hollow enclosure 110 for cleaning. In an exemplary embodiment of the present invention, the diameter of the vent 110a is 10.16 cm. The installation of filter element 112 in the hollow enclosure 110 facilitates periodic cleaning of the filter element 112 by sliding out the filter element 112 from the enclosure 110.
[0026] In various embodiments of the present invention, each of the inlet section 104, debris collection section 106 and the outlet section 108 are in fluid communication with each other. The incoming fluid may enter through the inlet section 104 and subsequently flow through the debris collection section 106 and the outlet section
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108. In an exemplary embodiment of the present invention, the diameter of the conduit is 66.04 cm. The diameter of the conduit 102 may be substantially consistent for each of the inlet section 104, debris collection section 106 and outlet section 108. In another exemplary embodiment of the present invention, the diameter of the conduit 102 may vary for each of the said sections (104, 106 and 108). In yet another embodiment of the present invention, the diameter of the conduit 102 may be consistent with the diameter of the pipeline with which the conduit 102 is integrated. The debris filtration assembly 100 may be fabricated from materials including, but is not limited to, carbon steel. Fabrication from carbon steel ensures robustness and efficiency under high pressure.
[0027] In operation, in an embodiment of the present invention, the multiphase well fluid enters into the debris filtration assembly 100 through the inlet section 104. In an exemplary embodiment of the present invention, the multiphase fluid enters the debris filtration assembly 100 continuously at high pressures of approximately 6-7kg/cm2. The multiphase fluid may comprise natural gas, crude oil, water and solids. The multiphase well fluid entering the inlet section 104 flows through the debris collection section 106 and the outlet section 108. The debris filtration assembly 100 facilitates change in velocity profile of debris, such that the larger sized debris drops in the debris collection section 106 and the smaller sized debris is intercepted by the filter element 112. Subsequently, the smaller sized debris is collected in the hollow enclosure 110. Therefore, the debris filtration assembly 100 filters debris of varying sizes preventing the chocking of the downstream equipment. In an embodiment of the present invention, the larger sized debris may have a size in a range of, but not limited to, 6-7 cm in length. In an exemplary embodiment of the present invention, the smaller sized debris may have a size ranging between 0.5-06 cm. The larger sized debris trapped in the debris collection section 106 may be removed via the debris discharge valve 106a. Further, the smaller sized debris collected in the hollow enclosure 110 may be removed by depressurising the hollow enclosure 100 via the vent 110a and opening the removable topside of the hollow enclosure 110 for cleaning the filter element 112.
[0028] Additionally, the debris filtration assembly facilitates removal of free water present in well fluid, thereby increasing the processing efficiency of equipment downstream. In particular, well fluid contains considerable amount of free water.
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Since inlet section 104 and debris collection section 106 are in communication, the incoming well fluid containing free water gets sufficient time to reside in the debris collection section 106 to settle out the free water in the bottom section of 106.
[0029] In an embodiment of the present invention, the debris filtration assembly 100 is integrable with pipeline of a central processing unit of an offshore platform. The central processing platform (CPP) performs the function of separating oil, gas, and water from said multiphase well head fluid among other functions, to produce the final product of the platform. The CPP includes a separation unit among other units. The incoming multiphase well fluid is delivered to the separation unit of the CPP from one or more well platforms. The multiphase well fluid is processed in multiple trains, which typically comprises a production manifold, a well fluid heater, an inlet separator, a crude oil manifold and heater, surge tanks, and main oil line (MOL) pumps.
[0030] In an exemplary embodiment of the present invention, the debris filtration assembly 100 is in fluid communication with an inlet valve (not shown) of the well fluid heater and an inlet port of well fluid heater. In operation, in an exemplary embodiment of the present invention, the well fluid is initially received in the production manifold, where a demulsified chemical is added to promote the breaking up of water-oil emulsion. Further, the incoming well fluid comprising debris is filtered via the debris filtration assembly 100 and subsequently heated in the well fluid heater. The debris filtration assembly 100 separates the debris from the incoming fluid and thereby prevents choking of the well fluid heater. Further, the debris filtration assembly 100 reduces the heat load on the well fluid heater by removing free water. Advantageously, the operation of debris filtration assembly 100 not only aids in improving the efficiency of the well fluid heater but also the separation efficiency of the inlet separator placed downstream.
[0031] It may be understood that the debris filtration assembly 100 disclosed herein can be readily incorporated into any existing well fluid pipeline and is not limited to multiphase fluids.
[0032] Advantageously, in accordance with various embodiments of the present invention, the debris filtration assembly 100, aids in improving separation of debris of
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varying sizes at a relatively low cost and with minimum space requirement. Further, as demonstrated above, the debris filtration assembly 100, improves overall efficiency of the downstream equipment such as the well fluid heater and separators.
[0033] While the exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative. It will be understood by those skilled in the art that various modifications in form and detail may be made therein without departing from the scope of the invention except as it may be described by the following claims.

We claim:

A debris filtration assembly (100) integrable with a fluid pipeline, the
assembly comprising:
a conduit (102) extending in the direction of an incoming fluid defining an inlet section (104), the conduit (102) extending vertically downwards from a distal end (104b) of the inlet section (102) defining a debris collection section (106), the debris collection section (106) disposed substantially perpendicular to the ground, the conduit (102) opens from a lower side portion (104') of the inlet section (104) and a corresponding upper side portion (106') of the debris collection section (106) extending in a horizontal plane forming an outlet section (108), the outlet section (108) comprising a hollow enclosure (110) disposed in the outlet section (108) for passage of the incoming fluid there through, said hollow enclosure (110) comprising a filter element (112) extending transversely across the interior of the hollow enclosure (110), wherein the debris filtration assembly 110 facilitates change in velocity profile of debris in the incoming fluid, such that larger sized debris drops in the debris collection section 106 and smaller sized debris is intercepted by the filter element (112).
2. The debris filtration assembly (100) as claimed in claim 1, wherein the conduit (102) extends vertically downwards upto a length x to define the inlet section (104), the conduit (102) extends vertically downwards upto a length y from the distal end (104b) of the inlet section (104) to define the debris collection section (106) such that the length y is greater than or equal to the length x.
3. The debris filtration assembly (100) as claimed in claim 2, wherein the outlet section (108) is disposed substantially perpendicularly to the inlet section (104) and the debris collection section (106).
4. The debris filtration assembly (100) as claimed in claim 1, wherein the filter element (112) is disposed at an angle of 60 degree across the interior of the hollow enclosure (110).
5. The debris filtration assembly (100) as claimed in claim 1, wherein the filter element (112) comprises perforations 114 arranged in a triangular pitch such that respective centres of adjacent perforations 114 forms an equilateral triangle.

6. The debris filtration assembly (100) as claimed in claim 1, wherein each perforation 114 is evenly spaced in relation to adjacent perforation 114.
7. The debris filtration assembly (100) as claimed in claim 1, wherein the debris collection section 106 comprises a debris discharge valve 106a for removal of collected lager sized debris.
8. The debris filtration assembly (100) as claimed in claim 1, wherein the hollow enclosure (110) comprises a vent (110a) for depressurizing the hollow enclosure (110) for cleaning.
9. The debris filtration assembly (100) as claimed in claim 1, wherein said assembly is fabricated from carbon steel.