CONVEYANCE PIPE

BACKGROUND

[0001] This section is intended to provide relevant background information to facilitate a better understanding of the various aspects of the described embodiments. Accordingly, these statements are to be read in this light and not as admissions of prior art.

[0002] Conveyance pipes are used for the transport of materials in a variety of situations in multiple industries, both onshore and offshore, including sewage, construction (environmental and civil), irrigation (farms/ranches), dredging, oil and gas, and mining. Current industry practice is to combine solids and fresh water or seawater as a slurry into conveyance pipe for the transport of these materials.

[0003] The following is a description of current industry practices in overcoming obstructions preventing a slurry from being transported in conveyance pipe. The types of solids being pumped as a slurry mixture in conveyance pipe during a project can be homogenous in density or heterogeneous in density. In a slurry mixture, a critical velocity is required for each type of solid being pumped in conveyance. Transport velocities below each solid’s critical velocity causes the solids to settle out of the slurry mixture. If this happens, a barrier or obstruction can be formed restricting the transport of the slurry mixture in conveyance due to the settling solids. When a project encounters an obstruction while pumping in a conveyance pipe, the entire operation must shutdown due to the obstruction restricting the slurry mixture from being transported through the conveyance pipe. If a shutdown is not quickly initiated when an obstruction is formed, then operational hazards can occur due to pumps overheating and pipe pressures increasing to the point of failure, potentially causing harm to people and the environment. Once a project is shutdown, current practices are to locate the obstruction, then cut and discard the obstructed section of the conveyance pipe. The discarded section is replaced with a new section of conveyance pipe. Some discarded sections of pipe can be hundreds of feet in length and costly. Onshore, this conveyance replacement process has the advantage of accessibility to the obstructed location. Offshore, especially with submerged conveyance pipe, this process of replacing the obstructed section of conveyance pipe can take days or weeks due to water depth, weather, and ongoing ship traffic. Days or weeks of a project being shutdown can incur high labor and equipment costs while the project is not generating revenue. SUMMARY

[0004] Some embodiments disclosed herein are directed to methods of dislodging at least a portion of an obstruction in a conveyance pipe for flowing a slurry. The methods include injecting either a dislodging pipe or rods into the conveyance pipe. The dislodging pipe or rods include a tip at a distal end of the dislodging pipe or rods. The methods include contacting the obstruction with the tip by moving the dislodging pipe or rods within the conveyance pipe, and using mechanical force, hydraulic force, or a combination thereof through the dislodging pipe or rods to dislodge at least a portion of the obstruction.

[0005] Other embodiments disclosed herein are directed to systems for dislodging at least a portion of an obstruction in a conveyance pipe for flowing a slurry. The systems include a dislodging pipe or rods injectable into the conveyance. The dislodging pipe or rods include a tip at an end. The dislodging pipe or rods are movable within the conveyance pipe to contact the obstruction with the tip, and mechanical force, hydraulic force, or a combination thereof is producible through the dislodging pipe or rods to dislodge at least a portion of the obstruction.

[0006] Still other embodiments disclosed herein are directed to methods of dislodging at least a portion of an obstruction in a conveyance pipe for flowing a slurry. The methods include injecting a dislodging pipe into the conveyance pipe. The dislodging pipe includes a tip at a distal end of the dislodging pipe. The methods further include moving the dislodging pipe within the conveyance pipe to apply mechanical force with the tip to the obstruction to dislodge at least a portion of the obstruction, pumping a fluid from a pump to the obstruction via a supply pipe, flowing the fluid and the dislodged portion of the obstruction through the dislodging pipe, and removing the dislodging pipe from the conveyance.

[0007] Aspects of one or more embodiments disclosed herein are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.

[0008] Various refinements of the features noted above may exist in relation to various aspects of the present embodiments. Additional features may also be incorporated in these various aspects. These refinements and additional features may exist individually or in any combination. For instance, various features discussed in relation to one or more of the illustrated embodiments may be incorporated into any of the other described aspects of the present disclosure alone or in any combination. Again, the brief summary presented is intended only to familiarize the reader with certain aspects and contexts without limitation to the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS [0009] Illustrative embodiments of the present disclosure are described in detail below with reference to the attached drawing figures, which are incorporated by reference herein and wherein:

[0010] FIG. 1 is an top view of a dredging system that includes an embodiment of a system for removing obstructions within a conveyance pipe, in accordance with the present disclosure;

[0011] FIG. 2 is a partial cross-sectional view of the system of FIG. 1 that uses mechanical force to remove obstructions within a conveyance pipe, in accordance with the present disclosure;

[0012] FIG.3 is a schematic view of a tip that may be used to apply mechanical forces to remove obstructions within a conveyance pipe, in accordance with the present disclosure;

[0013] FIG. 4 is a schematic view of another tip that may be used to apply mechanical forces to remove obstructions within a conveyance pipe, in accordance with the present disclosure;

[0014] FIG. 5 is a partial cross-sectional view of another embodiment of the system of FIG. 1 that uses mechanical force to remove obstructions within a conveyance pipe, in accordance with the present disclosure;

[0015] FIG. 6 is a partial cross-sectional view of another embodiment of the system of FIG. 1 that uses hydraulic force to remove obstructions within a conveyance pipe, in accordance with the present disclosure;

[0016] FIG. 7 is a partial cross-sectional view of another embodiment of the system of FIG. 1 that uses both hydraulic force and mechanical force to remove obstructions within a conveyance pipe, in accordance with the present disclosure; and

[0017] FIG. 8 is a partial cross-sectional view of another embodiment of the system of FIG. 1 that uses mechanical force to remove obstructions within a conveyance pipe, in accordance with the present disclosure. DETAILED DESCRIPTION

[0018] One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation may be described. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system- related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0019] When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. As used herein, the terms “approximately,” “about,” “substantially,” and the like mean within 10% (i.e., plus or minus 10%) of the recited value. Thus, for example, a recited angle of “about 80 degrees” refers to an angle ranging from 72 degrees to 88 degrees.

[0020] Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be interpreted to include only commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary.

[0021] Referring to FIG. 1, a dredging system 10 is shown that is used to transfer a slurry within a conveyance pipe 140 between a first end 140a of the conveyance pipe 140 and a second end 140b of the conveyance pipe 140. A barge 12 is shown that transports pumps and related equipment (not shown) of the dredging system 10. The dredging system 10 is configured to collect solids from the seafloor, mix the solids with a volume of fresh water or seawater to form a slurry, and then pump the slurry along the conveyance pipe 140. The conveyance pipe 140 is shown along a curved path in the example of FIG. 1, however the conveyance pipe 140 may also be positioned along a straight path. Optionally, portions of the conveyance pipe 140 between the ends 140a, 140b may be at the same or at different elevations than the ends 140a, 140b (e.g., central portions may have a rise, a dip, or combinations thereof). Optionally, the elevation between the first end 140a and the second end 140b may also be different.

[0022] During operations of the dredging system 10, two obstructions 150 have formed within the conveyance pipe 140 at two positions between the first end 140a and the second end 140b. As a result of the obstructions 150, the dredging system 10 has been shut down to cease slurry transport and a system 100 has been positioned proximate the first end 140a to clear the obstructions 150. Alternatively, the system 100 may be deployed from a separate vessel or platform (not shown) as needed for the particular implementation. Although FIG.1 depicts a dredging system located offshore, it should be appreciated that the methods and systems disclosed may also be used onshore and may be used for other types of conveyance pipes as previously described.

[0023] Referring to FIG.2, the system 100 of FIG. 1 is shown in a partial cross-sectional view and illustrates the obstruction 150 that has formed within the conveyance pipe 140. The system 100 has been placed proximate the first end 140a to provide access to the inner bore of the conveyance pipe 140, and the inner bore is exposed (e.g., “open to”) to atmospheric pressure. Optionally, no seal may be used between the system 100 and the conveyance pipe 140, which thus may be described as an “open system”. Optionally, the system may also gain access to the inner bore of the conveyance pipe 140 via a cut-out-point through the wall of the conveyance pipe 140. Optionally, the conveyance pipe 140 may also be a “closed system” whereby the volume within the inner bore is isolated from the environment surrounding the conveyance pipe 140. To allow access for the system 100 to the inner bore of the conveyance pipe 140, commercially available dynamic seals can be installed at the access position (e.g., at the first end 140a or at the cut-out- point along the conveyance pipe 140).

[0024] During operations of the system 100, an injector 120 is used to insert a dislodging pipe 110 into the conveyance pipe 140. The dislodging pipe 110 of FIG. 2 is shown formed as a hollow cylinder, however the dislodging pipe 110 may also be solid and/ or include other non-circular cross-sectional shapes. The length of the dislodging pipe 110 is continuous in FIG. 2 and thus may be coiled on a spool (not shown) to store long lengths within the system 100 ahead of the injector 120. However, the length of the dislodging pipe 110 may also be formed by joining sections end- to-end in other embodiments. Additionally, the dislodging pipe 110 may include a tip 112 at a distal end that is used to contact the obstruction 150. The injector 120 comprises injector drives 122 that are operable to advance the axial position of the dislodging pipe 110 between the access position, here the first end 140a, towards the obstruction 150. The injector drives 122 may optionally be operated in either direction to either advance or retract the dislodging pipe 110 relative to the obstruction 150. As best shown in FIG.l, the path of the conveyance pipe 140 may be arcuate between ends 140a, 140b and thus the dislodging pipe 110 is configured to also follow the arcuate path of the conveyance pipe 140 as needed. The bending flexibility of the dislodging pipe 110 together with the path of the conveyance pipe 140 may define the alignment between a central axis 115 of the dislodging pipe 110 relative to a central axis 145 of the conveyance pipe 140. Referring again to FIG. 2, the horizontal position of the central axis 115 may also tend to be below the central axis 145 due to gravity and due to potentially long lengths between the first end 140a and the obstruction 150. While not shown in the example of FIG. 2, a centralizer could also be used to bring axes 115, 145 into concentric alignment or closer alignment by establishing an offset between the axis 115 and the inner bore of the conveyance pipe 140. Thus, the centralizer (not shown) may interface along a complete circumferential section of the conveyance pipe 140 inner bore or may interface with a partial circumferential section of the conveyance pipe 140 to steer the direction of the dislodging pipe 110.

[0025] Referring still to FIG. 2, to remove the obstruction 150, the injector 120 may advance the dislodging pipe 110 until the tip 112 is proximate to or in contact with the obstruction 150. The tip 112 can comprise a solid shape such as a cone, a partial cone, a flat chisel tip, a star chisel tip, or any other shape for focusing impact forces. The injector 120 may then be operated to impart reciprocal motion to the dislodging pipe 110 and apply mechanical forces 130 to the obstruction 150 through the tip 112 that physically dislodge, e.g., disturb and/or break down at least a portion of the obstruction 150 until the solids reenter the slurry.

[0026] Optionally or additionally, the tip 112 may be configured to move independently from the motion of the dislodging pipe 110. In particular, the tip 112 may comprise a fit for purpose tool that is pneumatically, hydraulically, or electrically driven to apply the mechanical forces 130. For example, the tip 112 may comprise an impact hammer, an impact drill, or a drill bit each fitted with any variety of bit tips 180 such as a star chisel bit, flat chisel, a cone, a roller cone, etc. FIG 3 presents an exemplary fit for purpose tool that may be used as the tip 112. In particular, the tip 112 is an impact drill that operates pneumatically in response to air delivered (by a compressed source not shown) via the inner bore of the dislodging pipe 110. Generally speaking the air from the dislodging pipe 110 operates a turbine 182 that rotates the bit tip 180 about the axis 115 as shown by the rotation 184. Additionally, the air from the dislodging pipe 110 operated a translation member 186 that provides reciprocal motion 188 along the axis 115. In this manner, the tip 112 (e.g., impact drill) operates to move independently from the motion of the dislodging pipe 110 and applies mechanical forces 130 to the obstruction 150 that physically dislodge, e.g., disturb and/or break down at least a portion of the obstruction 150 until the solids reenter the slurry. Similarly, the tip 112 may operate as an impact hammer, whereby only reciprocal motion 188 along the axis 115 is imparted by the translation member 186, while the bit tip 180 does not rotate about the axis 115. Still further, the tip 112 may operate as a drill bit, whereby only rotation 184 is provided by the turbine 182, while no translation motion 188 is provided along the axis 115. Alternatively, rather than supplying air pressure within the inner bore of the dislodging pipe 110, fluid pressure may be supplied (by a compressed source not shown) and the tip 112 may be configured to operate hydraulically. Hydraulic pressure may be used to operate an impact hammer, an impact drill, or a drill bit in the same manner previously described. Alternatively, an electrical signal via a conductive path such as a wire (not shown) within the inner bore of the dislodging pipe 110 may be used to electrically operate the tip 112. Electrical power (from a source not shown) may be used to operate one or both of the turbine 182 and the translation member 186. In this manner, electrical power may be used to operate an impact hammer, an impact drill, or a drill bit in the same manner previously described.

[0027] Optionally or additionally, the tip 112 may operate to increase the mechanical forces applied by the dislodging pipe 110 such as an impact jar fitting with any variety of bit tips 190 such as a star chisel bit, flat chisel, a cone, etc. An example of the tip 112 is an impact jar as shown in FIG. 4. Generally speaking the mechanical force 130 acts on the first end 112a to compressively load and store energy within a spring 192. Once a set mechanical force 130 is reached along the first end 112a, a catch 194 releases the spring 192 compression and the stored energy of the spring 192 rapidly translates a hammer 196 along a direction 198 into contact with the bit tip 190. The bit tip 190 in turn delivers an impact force to the obstruction 150 that physically dislodges, e.g., disturbs and/or breaks down at least a portion the obstruction 150 until the solids reenter the slurry. In addition, other mechanisms that operate in response to the mechanical force 130 applied to the dislodging pipe 110 are also contemplated. For example a mechanism that claws, extends, translates, rotates, or otherwise moves in response to the reciprocal motion imparted by the injector 120 to the dislodging pipe 110. [0028] The system 100 may thus be configured to remove the obstruction 150 in the conveyance pipe 140 to again allow for the flow and transfer of slurry therein. The systems and methods described are an advantage over conventional pipe replacement practices and offer both cost and time savings. The section of the conveyance pipe 140 with the obstruction 150 no longer needs to be discarded, and the methods described can be performed in a shorter duration of time.

[0029] Referring to FIG.3, an alternative embodiment system 200 is shown. Generally speaking, some of the components of the system 200 are similar to the components of the system 100, and thus the same or similar reference numerals are used. In addition, the operational description is not repeated in the interest of brevity, but instead will focus on features of the system 200 that are different from the system 100. In particular, the system 200 comprises a plurality of rods (shown as a rod 210 and a rod 214) that are coupled together by a coupler 216 and used in place of the dislodging pipe 110 of the system 100. The rods 210, 214 are formed as solid tubular sections and may be threadably coupled end-to-end by the couplers 216. Only two rods 210, 214 and one coupler 216 are shown for clarity. However, multiple rods and couplers may be used to extend the length of the rod 210, 214 assembly to reach the obstruction 150 within the conveyance pipe 140. It should be appreciated that the rods 210, 214 may also be coupled end-to-end without separate couplers 216. For example, rods 210, 214 may be directly coupled by threading.

[0030] As shown in FIG. 3, the system 200 has been placed proximate the first end 140a to provide access to the inner bore of the “open system” conveyance pipe 140. Alternatively, the system 200 may also enter the conveyance pipe 140 as a “closed system” via a seal in the first end 140a or a seal in a cut-out-point through the wall of the conveyance pipe 140 as previously described.

[0031] During operations of the system 200, the injector 120 may be used to insert the assembled rods 210, 214 into the conveyance pipe 140 to reach the obstruction 150. The coupler 216 used to join the rods 210, 214 may be affixed before or after the injector 120 relative to the rod 210 insertion direction into the conveyance pipe 140. When the coupler 216 is attached before the injector 120, the injector drive 122 is configured to allow passage of the coupler 216 therethrough. To facilitate passage of the couplers 216 through the injector drive 122, the diameter of the coupler 216 may approximate the diameter of the rods 210, 214. In an example, the rods 210, 214 may include a reduced diameter at one or more ends to accommodate the coupler 216. Optionally, the couplers 216 may include one or more male threads that connect to threaded female threads on the rods 210, 214. Additionally, the rod 210 may couple to a tip 212 that is used to contact the obstruction 150. [0032] As previously described, the injector 120 comprising the injector drives 122 is configured to advance the axial position of the rod 210, 214 assembly from the first end 140a to the obstruction 150. The injector drives 122 again may optionally be operated in either direction to either advance or retract the rod 210, 214 assembly along the straight and/ or arcuate path of the conveyance pipe 140 as needed. The position of a central axis 215 of the rods 210, 214 relative to the central axis 145 is established by the bending flexibility of the rods 210, 214 together with the path of the conveyance pipe 140. Similar to system 100, the horizontal position of the central axis 215 may also tend to be below the central axis 145 due to gravity and due to potentially long lengths between the first end 140a and the obstruction 150. While not shown in the example of FIG. 3, a centralizer could also be used to bring axes 215, 145 into concentric alignment or closer alignment by establishing an offset between the axis 215 and the inner bore of the conveyance pipe 140. Thus, the centralizer (not shown) may interface along a complete circumferential section of the conveyance pipe 140 inner bore or may interface with a partial circumferential section of the conveyance pipe 140 to steer the direction of the rod 210, 214 assembly.

[0033] Referring still to FIG. 3, to remove the obstruction 150, the injector 120 advances the rod 210, 214 assembly until the tip 212 is proximate to or is in contact with the obstruction 150. The tip 212 can comprise a solid shape such as a cone, a partial cone, a flat chisel tip, or any other shape known to focus impact forces. The injector 120 may then be operated to impart reciprocal motion to the dislodging pipe 110 and apply mechanical forces 230 that move the tip 212 into repeated physical contact with the obstruction 150 to physically dislodge, e.g., disturb and/or break down at least a portion of the obstruction 150 until the solids reenter the slurry.

[0034] Optionally or additionally, the tip 212 may also be configured to move independent from the motion of the rod 210, 214 assembly. In particular, the tip 212 may comprise a fit for purpose tool that is pneumatically, hydraulically, or electrically driven to apply the mechanical forces 230, as previously described for the tip 112 and shown in FIG. 3. However, because rods 210, 214 are formed as solid tubular sections, external lines (not shown) may be used to deliver air, hydraulic fluids, or electrical signals as needed to the tip 112.

[0035] Optionally or additionally, the tip 212 may operate to increase the mechanical forces applied by the rod 210, 214 assembly as previously described for the tip 112 and shown in FIG. 4. In addition, other mechanisms that operate in response to the mechanical force 230 applied to the dislodging pipe 210 are also contemplated. For example a mechanism that claws, extends, translates, rotates, or otherwise moves in response to the reciprocal motion imparted by the injector 120 to the rod 210, 214 assembly.

[0036] The system 200 may thus be configured to remove the obstruction 150 in the conveyance pipe 140 to again allow for the flow and transfer of slurry therein. The systems and methods described are an advantage over conventional pipe replacement practices and offer both cost and time savings. The section of the conveyance pipe 140 with the obstruction 150 no longer needs to be discarded, and the methods described can be performed in a shorter duration of time.

[0037] Referring to FIG.4, another alternative embodiment system 300 is shown that may be used in place of the systems 100, 200 previously described. Generally speaking, some of the components of the system 300 are similar to the components of the systems 100, 200, and thus the same or similar reference numerals are used. In addition, the operational description is not repeated in the interest of brevity, but instead will focus on features of the system 300 that are different from the systems 100, 200. In particular, the system 300 comprises a pump 360 and a plurality of jets 318 through a tip 312. As described further herein, the pump 360 is operable to supply fluid through the jets 318 of the tip 312 to hydraulically dislodge, e.g., disturb and/or break down at least a portion of the obstruction 150 until the solids reenter the slurry.

[0038] As shown in FIG. 6, the system 300 has been placed proximate the first end 140a to provide access to the inner bore of the “open system” conveyance pipe 140. Alternatively, the system 300 may also enter the conveyance pipe 140 as a “closed system” via a seal in the first end 140a or a seal in a cut-out-point through the wall of the conveyance pipe 140 as previously described.

[0039] During operations of the system 300, the injector 120 and the injector drives 122 may be used to insert a dislodging pipe 310 into the conveyance pipe 140 to reach the obstruction 150. While not shown, a rotating seal may be used to fluidically couple between the dislodging pipe 310 and the pump 360. In this manner, the pump 360 can remain stationary while rotation is imparted to the spool storing the dislodging pipe 310 and as the injector 120 extends a length of the dislodging pipe 310 into the conveyance pipe 140. The injector drives 122 may optionally be operated in either direction to either advance or retract the dislodging pipe 310 along the straight and/ or arcuate path of the conveyance pipe 140 as needed. The position of a central axis 315 of the dislodging pipe 310 relative to the central axis 145 is established by the bending flexibility of the dislodging pipe 310 together with the path of the conveyance pipe 140. Similar to systems 100, 200 the horizontal position of the central axis 315 may also tend to be below the central axis 145 due to gravity and due to potentially long lengths between the first end 140a and the obstruction 150. While not shown in the example of FIG. 6, a centralizer could also be used to bring axes 315, 145 into concentric alignment or closer alignment by establishing an offset between the axis 315 and the inner bore of the conveyance pipe 140. Thus, the centralizer (not shown) may interface along a complete circumferential section of the conveyance pipe 140 inner bore or may interface with a partial circumferential section of the conveyance pipe 140 to steer the direction of the dislodging pipe 310.

[0040] The dislodging pipe 310 is formed as a hollow cylinder so that fluids can be provided along a supply flow path 332 between the pump 360 and the jets 318 of the tip 312. Optionally, the dislodging pipe 310 may also include a non-circular cross-sectional shape. The length of the dislodging pipe 310 is continuous in FIG. 6 and thus may be coiled on a spool (not shown) to store long lengths within the system 300 ahead of the injector 120. However, the length of the dislodging pipe 310 may also be formed by joining sections end-to-end in other embodiments. The pump 360 is coupled to the dislodging pipe 310 upstream of the injector 120 and provides pressurized fluids into the inner bore of the dislodging pipe 310. The pressurized fluids may be water, seawater, surfactants, dispersants, or combinations thereof. The pressurized fluids from the pump 360 are transferred along the supply flow path 332 within the dislodging pipe 310 and are directed into the obstruction 150 via the jets 318 of the tip 312. As the pressurized fluids exit the jets 318, at least a portion of the obstruction 150 is hydraulically dislodged, e.g., disturbed and/or broken apart so as to be able to reenter the slurry. Particles within the slurry flow along a return flow path 334 in the annulus between the conveyance pipe 140 and the dislodging pipe 310 and exit at the first end 140a. Storage containers (not shown) may be used as needed to catch and store the flushed portions of the obstruction 150.

[0041] Surfactants and/or dispersants added to the pressurized fluids within the dislodging pipe 310 may be beneficial in preventing subsequent formations of additional obstructions 150 along the return flow path 334. In an example, the surfactants and/or dispersant may include the commercially available CAPSTONE™ FS-3000 made by the CHEMOURS™ Company, and may be used to reduce the surface tension of the water or seawater within the slurry. In addition, the surfactants and/or dispersant may neutralize or reduce the ionic attraction of clay sediments to reduce the tenancy of clay sediments to bind together. In this manner, the portions of the obstruction 150 that are dislodged may more readily remain in suspension within the slurry as the obstruction 150 is cleared from the conveyance pipe 140. [0042] As described, the system 300 may be configured to remove the obstruction 150 in the conveyance pipe 140 to again allow for the flow and transfer of slurry therein. The systems and methods described are an advantage over conventional pipe replacement practices and offer both cost and time savings. The section of the conveyance pipe 140 with the obstruction 150 no longer needs to be discarded, and the methods described can be performed in a shorter duration of time.

[0043] Referring to FIG.5, another embodiment system 400 is shown that may be used in place of the systems 100, 200, 300 previously described. Generally speaking, some of the components of the system 400 are similar to the components of the systems 100, 200, 300, and thus the same or similar reference numerals are used. In addition, the operational description is not repeated in the interest of brevity, but instead will focus on features of the system 400 that are different from the systems 100, 200, 300. In particular, the system 400 may be configured to use both hydraulic force and a mechanical force 430 to remove the obstruction 150 within the conveyance pipe 140.

[0044] Similar to the system 300, the system 400 comprises a pump 460 and a plurality of jets 418 through a tip 412. The pump 460 may be configured to supply fluid through the jets 418 of the tip 412 to hydraulically dislodge, e.g., disturb and/or break down at least a portion of the obstruction 150 until the solids reenter the slurry.

[0045] As shown in FIG. 7, the system 400 has been placed proximate the first end 140a to provide access to the inner bore of the “open system” conveyance pipe 140. Alternatively, the system 300 may also enter the conveyance pipe 140 as a “closed system” via a seal in the first end 140a or a seal in a cut-out-point through the wall of the conveyance pipe 140 as previously described.

[0046] During operations of the system 400, the injector 120 and the injector drives 122 may be used to insert a dislodging pipe 410 into the conveyance pipe 140 to reach the obstruction 150. While not shown, a rotating seal may be used to fluidically couple between the dislodging pipe 410 and the pump 460. In this manner, the pump 460 can remain stationary while rotation is imparted to the spool storing the dislodging pipe 410 and as the injector 120 extends a length of the dislodging pipe 410 into the conveyance pipe 140. The injector drives 122 may optionally be operated in either direction to either advance or retract the dislodging pipe 410 along the straight and/ or arcuate path of the conveyance pipe 140 as needed. The position of a central axis 415 of the dislodging pipe 410 relative to the central axis 145 is established by the bending flexibility of the dislodging pipe 410 together with the path of the conveyance pipe 140. Similar to systems 100, 200, 300 the horizontal position of the central axis 415 may also tend to be below the central axis 145 due to gravity and due to potentially long lengths between the first end 140a and the obstruction 150. While not shown in the example of FIG. 7, a centralizer could also be used to bring axes 415, 145 into concentric alignment or closer alignment by establishing an offset between the axis 415 and the inner bore of the conveyance pipe 140. Thus, the centralizer (not shown) may interface along a complete circumferential section of the conveyance pipe 140 inner bore or may interface with a partial circumferential section of the conveyance pipe 140 to steer the direction of the dislodging pipe 410.

[0047] As described for systems 100, 200 the injector 120 may operate to impart reciprocal motion to the dislodging pipe 410 and apply mechanical forces 430 that move the tip 412 into repeated physical contact with the obstruction 150 to physically dislodge, e.g., disturb and/or break down at least a portion of the obstruction 150 until the solids reenter the slurry.

[0048] Optionally or additionally, the tip 412 may be configured to move independently from the motion of the dislodging pipe 410. In particular, the tip 412 may comprise a fit for purpose tool that is pneumatically, hydraulically, or electrically driven to apply the mechanical forces 430 as previously described for the tip 112 and shown in FIG. 3.

[0049] Optionally or additionally, the tip 412 may operate to increase the mechanical forces applied by the dislodging pipe 410 as previously described for the tip 112 and shown in FIG. 4. In addition, other mechanisms that operate in response to the mechanical force 430 applied to the dislodging pipe 410 are also contemplated. For example a mechanism that claws, extends, translates, rotates, or otherwise moves in response to the reciprocal motion imparted by the injector 120 to the dislodging pipe 410.

[0050] In addition to the applied mechanical forces 430, the system 400 may also operate to hydraulically disturb and/or break down the obstruction 150. The dislodging pipe 410 is formed as a hollow cylinder so that fluids can be provided along a supply flow path 432 between the pump 460 and the jets 418 of the tip 412. Optionally, the dislodging pipe 410 may also include a non circular cross-sectional shape. The length of the dislodging pipe 410 is continuous in FIG. 7 and thus may be coiled on a spool (not shown) to store long lengths within the system 400 ahead of the injector 120. However, the length of the dislodging pipe 410 may also be formed by joining sections end-to-end in other embodiments. The pump 460 is coupled to the dislodging pipe 410 upstream of the injector 120 and provides pressurized fluids into the inner bore of the dislodging pipe 410. The pressurized fluids may be water, seawater, surfactants, dispersants, or combinations thereof. The pressurized fluids from the pump 460 are transferred along the supply flow path 432 within the dislodging pipe 410 and are directed into the obstruction 150 via the jets 418 of the tip 412. As the pressurized fluids exit the jets 418, at least a portion of the obstruction 150 is hydraulically dislodged, e.g, disturbed and/or broken apart so as to be able to reenter the slurry.

[0051] Particles within the slurry, as freed from the obstruction 150 by both the mechanical and hydraulic forces, flow along a return flow path 434 in the annulus between the conveyance pipe 140 and the dislodging pipe 410 and exit along the first end 140a. Storage containers (not shown) may be used as needed to catch and store the flushed portions of the obstruction 150. Surfactants and/or dispersants added to the pressurized fluids within the dislodging pipe 410 may be beneficial in preventing subsequent formations of additional obstructions 150 along the return flow path 434. In an example, the surfactants and/or dispersant may include the commercially available CAPSTONE™ FS-3000 made by the CHEMOURS™ Company, and may be used to reduce the surface tension of the water or seawater within the slurry. In addition, the surfactants and/or dispersant may neutralize or reduce the ionic attraction of clay sediments to reduce the tenancy of clay sediments to bind together. In this manner, the portions of the obstruction 150 that are dislodged may more readily remain in suspension within the slurry as the obstruction 150 is cleared from the conveyance pipe 140.

[0052] As described, the system 400 may be configured to remove the obstruction 150 in the conveyance pipe 140 to again allow for the flow and transfer of slurry therein. The systems and methods described are an advantage over conventional pipe replacement practices and offer both cost and time savings. The section of the conveyance pipe 140 with the obstruction 150 no longer needs to be discarded, and the methods described can be performed in a shorter duration of time.

[0053] Referring to FIG.6, another embodiment system 500 is shown that may be used in place of the systems 100, 200, 300, 400 previously described. Generally speaking, some of the components of the system 500 are similar to the components of the systems 100, 200, 300, 400 and thus the same or similar reference numerals are used. In addition, the operational description is not repeated in the interest of brevity, but instead will focus on features of the system 500 that are different from the systems 100, 200, 300, 400. In particular, the system 500 may be configured to use a mechanical force 530 to remove the obstruction 150 within the conveyance pipe 140. In addition, the direction of the fluid flow within a dislodging pipe 510 is reversed relative to the fluid flow of the systems 300, 400. [0054] Similar to the systems 300, 400 the system 500 comprises a pump 560 configured to supply fluid to the conveyance pipe 140. However, in the system 500 a supply pipe 562 provides a supply flow path 532 to an annulus between the conveyance pipe 140 and the dislodging pipe 510, while a return flow path 534 is provided within the dislodging pipe 510.

[0055] As shown in FIG. 8, the system 500 has been placed proximate the first end 140a to provide access to the inner bore of the “open system” conveyance pipe 140. Alternatively, the system 500 may also enter the conveyance pipe 140 as a “closed system” via a seal (not shown) in the first end 140a or a seal in a cut-out-point through the wall of the conveyance pipe 140 as previously described. In an example, a seal (not shown) between a supply pipe 562 and the conveyance pipe 140 allows the pump 560 to pressurize the conveyance pipe 140 and force a flow along the return flow path 534 within the dislodging pipe 510.

[0056] During operations of the system 500, the injector 120 and the injector drives 122 may be used to insert a dislodging pipe 510 into the conveyance pipe 140 to reach the obstruction 150. While not shown, a rotating seal may be used to fluidically couple between the dislodging pipe 510 and one or more of the valves 566, 568, 570. In this manner, the values 566, 568, 570 can remain stationary while rotation is imparted to the spool storing the dislodging pipe 510 and as the injector 120 extends a length of the dislodging pipe 510 into the conveyance pipe 140.

[0057] The injector drives 122 may optionally be operated in either direction to either advance or retract the dislodging pipe 510 along the straight and/ or arcuate path of the conveyance pipe 140 as needed. The position of a central axis 515 of the dislodging pipe 510 relative to the central axis 145 is established by the bending flexibility of the dislodging pipe 510 together with the path of the conveyance pipe 140. Similar to systems 100, 200, 300, 400 the horizontal position of the central axis 515 may also tend to be below the central axis 145 due to gravity and due to potentially long lengths between the first end 140a and the obstruction 150. While not shown in the example of FIG. 8, a centralizer could also be used to bring axes 515, 145 into concentric alignment or closer alignment by establishing an offset between the axis 515 and the inner bore of the conveyance pipe 140. Thus, the centralizer (not shown) may interface along a complete circumferential section of the conveyance pipe 140 inner bore or may interface with a partial circumferential section of the conveyance pipe 140 to steer the direction of the dislodging pipe 510. [0058] As described for systems 100, 200, 400 the injector 120 may operate to impart reciprocal motion to the dislodging pipe 510 and apply mechanical forces 530 that move the dislodging pipe 510 into repeated physical contact with the obstruction 150 to physically disturb and/or break down the obstruction 150 until the solids reenter the slurry.

[0059] Optionally or additionally, a tip 512 at the end of the dislodging pipe 510 may be included and configured to move independently from the motion of the dislodging pipe 510. In particular, the tip 512 may comprise a fit for purpose tool that is pneumatically, hydraulically, or electrically driven to apply the mechanical forces 530, as previously described for the tip 112 and shown in FIG. 3. Optionally, external lines (not shown) may be used to deliver air, hydraulic fluids, or electrical signals as needed to the tip 512.

[0060] Optionally or additionally, the tip 512 may operate to increase the mechanical forces applied by the dislodging pipe 510 as previously described for the tip 112 and shown in FIG. 4. In addition, other mechanisms that operate in response to the mechanical force 530 applied to the dislodging pipe 510 are also contemplated. For example a mechanism that claws, extends, translates, rotates, or otherwise moves in response to the reciprocal motion imparted by the injector 120 to the dislodging pipe 510.

[0061] In addition to the applied mechanical forces 530, the system 500 is operable to flow fluids from the pump 560 along the supply flow path 532 and clear any freed portions of the obstruction 150 along the return flow path 534 via the dislodging pipe 510. The pressurized fluids from the pump 560 may be water, seawater, surfactants, dispersants, or combinations thereof. The dislodging pipe 510 is formed as a hollow cylinder in the example of FIG. 8, however the dislodging pipe 510 may also include a non-circular cross-sectional shape. The length of the dislodging pipe 510 is continuous in FIG. 8 and thus may be coiled on a spool (not shown) to store long lengths within the system 500 ahead of the injector 120. However, the length of the dislodging pipe 510 may also be formed by joining sections end-to-end in other embodiments.

[0062] To control the flow of the fluids from the pump 560, the system 500 may comprise a valve 566 operatively connected with the supply pipe 562, a valve 568 operatively connected with the dislodging pipe 510, and a valve 570 operatively connected with an outlet pipe 564. To flow the fluids of the pump 560 along the supply flow path 532 and the return flow path 534, the valve 566 is opened, the valve 568 is closed, and the valve 570 is opened. In this manner particles freed from the obstruction 150 by the mechanical force 530 flow within the dislodging pipe 510 along the return flow path 534. The outlet pipe 564 and the opened valve 570 then allow the freed particles a flow path that does not pass through and damage the pump 560. The outlet pipe 564 may be directed into storage containers (not shown) as needed to capture the particles from the obstruction 150. While the valves 566, 568, 570 are shown as individual valves in the example of FIG. 8, it should be appreciated that the valves 566, 568, 570 may also be coupled together in a manifold (not shown).

[0063] Surfactants and/or dispersants added to the pressurized fluids of the pump 560 may be beneficial in preventing subsequent formations of additional obstructions 150 along the return flow path 534 within the dislodging pipe 510. In an example, the surfactants and/or dispersant may include the commercially available CAPSTONE™ FS-3000 made by the CHEMOURS™ Company, and may be used to reduce the surface tension of the water or seawater within the slurry. In addition, the surfactants and/or dispersant may neutralize or reduce the ionic attraction of clay sediments to reduce the tenancy of clay sediments to bind together. In this manner, the portions of the obstruction 150 that are dislodged may more readily remain in suspension within the slurry as the obstruction 150 is cleared from the conveyance pipe 140.

[0064] Optionally, if an obstruction (similar to the obstruction 150) forms within the dislodging pipe 510, the flow direction within the dislodging pipe 510 may be reversed. To achieve the reversed flow, relative to the illustrated direction of the return flow path 534, the valve 568 may be opened, while the valves 566, 570 are closed. Over pressurization of the conveyance pipe 140 may be avoided with short durations of reversed flow, by cleared flow paths through the obstruction 150, or by an additional pressure relief valve (not shown) operatively connected to the conveyance pipe 140. Optionally, if the reversed flow along the dislodging pipe 510 is not needed, the dislodging pipe 510 may not be connect to the pump 560 and the valve 568 may be omitted.

[0065] As described, the system 500 may be operable to remove the obstruction 150 in the conveyance pipe 140 to again allow for the flow and transfer of slurry therein. The systems and methods described are an advantage over conventional pipe replacement practices and offer both cost and time savings. The section of the conveyance pipe 140 with the obstruction 150 no longer needs to be discarded, and the methods described can be performed in a shorter duration of time.

[0066] One or more specific embodiments of the present disclosure have been described. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers’ specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.

[0067] Certain terms are used throughout the description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function.

[0068] Reference throughout this specification to “one embodiment,” “an embodiment,” “an embodiment,” “embodiments,” “some embodiments,” “certain embodiments,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. Thus, these phrases or similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0069] The embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It is to be fully recognized that the different teachings of the embodiments discussed may be employed separately or in any suitable combination to produce desired results. In addition, one skilled in the art will understand that the description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.