GB2593520A

GB2593520A - Apparatus for removing material from a conduit

Info

Publication number: GB2593520A
Application number: GB2004393.1A
Authority: GB
Inventors: William Mcnay Graeme; Simmister Nicholas; Lawrence Ray
Original assignee: Cavitas Energy Ltd
Current assignee: Cavitas Energy Ltd
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2021-09-29
Anticipated expiration: 2040-03-26
Also published as: GB2593520B; GB202004393D0

Abstract

An apparatus for use in removing material from a conduit comprises a heater 42 locatable within the conduit to be in thermal communication with a flow path to facilitate heating of a first fluid flowing along said flow path, the heater includes a heating chamber 48 and an agitator mechanism 50 operable to agitate a second fluid within the heating chamber to generate thermal energy within the second fluid. The apparatus preferably includes a housing 18 having a fluid inlet 20 and a fluid outlet 24, wherein the flow path extends between the fluid inlet and fluid outlet and the heater facilitates heating of the first fluid prior to exiting the housing via the outlet. The agitator mechanism preferably comprises a fluid agitator configured to be moved within or relative to the second fluid within the heating chamber to agitate said second fluid and may include a first rotary fluid agitator 52 and a second rotary fluid agitator 54 which circumscribes the first rotary fluid agitator, such that the first rotary fluid agitator defines an inner fluid agitator and the second rotary agitator defines an outer fluid agitator. The first and second agitators may contra-rotate. The flow path may alternatively be external to the apparatus. A method of use is also disclosed.

Description

APPARATUS FOR REMOVING MATERIAL FROM A CONDUIT

FIELD

Some described examples relate to an apparatus for use in the removal of material from inside a conduit.

BACKGROUND

In operations involving fluid conduits such as pipelines, for example oil and gas pipelines carrying hydrocarbons, debris may build up in the fluid conduit over time. The debris may be, for example, wax, tar, material deposited from the fluid flowing in the conduit, and/or the like.

Build-up of debris in a fluid conduit may cause an undesired pressure drop in a fluid under transport which may cause significant issues, and may minimise the maximum possible flow rate that is possible through the conduit, and in some cases may block the fluid conduit altogether. In order to avoid having to continuously replace or repair blocked fluid conduits, it is advantageous to be able to remove any accumulated debris.

Many apparatuses and methods for the removal of debris from inside of a fluid conduit exist. For example, chemical means of debris removal are known. Such means may involve the application of a chemical as a foam, liquid and/or powder. The applied chemical would then assist to remove debris from inside a fluid conduit by, for example, dissolution. This, however, requires the use of specialist equipment and specialist chemicals, which may be expensive, and which may require to be tailored to a specific type of debris.

Mechanical means of debris removal are also known. Such means may involve physically breaking up and/or dislodging debris, for example via rotating rods, scrapers and/or the like. Mechanical means of debris removal may require a high energy input, and may require supplemental methods, for example flushing, to effectively remove debris.

Hydraulic means of debris removal are known, such as flushing or jetting. However, this involves generating fluid at a very high pressure, which can be challenging, and can create a difficult working environment for operators.

SUMMARY

An aspect of the present disclosure relates to an apparatus for use in removing material from a conduit, comprising: a heater locatable within the conduit to be in thermal communication with a flow path to facilitate heating of a first fluid flowing along said flow path, the heater comprising a heating chamber and an agitator mechanism operable to agitate a second fluid within the heating chamber to generate thermal energy within the second fluid.

In use, the apparatus may be deployed into a conduit and the heater operated such that the heat generated within the second fluid may be used to heat the first fluid flowing along the flow path by virtue of the heater being in thermal communication with the flow path. In this respect, any portion of the flow path which is in thermal communication with the heater may be defined as a heated portion of the flow path. Thus, a heated fluid stream may be created which may then be used in a process for removing material from within the conduit. Such material may include anything which a user may wish to remove, which may vary depending on the specific application. For example, in conduits associated with oil and gas operations the apparatus may be for use in the removal of materials such as precipitates, hydrates, sulphates, salts, waxes, viscous hydrocarbons, consolidated particulates, debris and/or the like.

The apparatus may be used in combination with any first fluid delivered along the flow path to be heated and subsequently used in the process of removing material from a conduit. As the first fluid is ultimately used in material removal, the first fluid may thus be defined as a cleaning fluid. The first fluid may comprise water, a solvent, detergent, cleansing agent, viscosity modifier, foaming agent and/or any other fluid having desirable properties. The first fluid may comprise any fluid already resident or flowing within the conduit. For example, the first fluid may simply comprise a fluid normally under transport along the conduit (e.g., hydrocarbons, water etc.).

The heat imparted to the first fluid when flowing along the flow path (e.g., the heated portion of the flow path) may improve the ability of the first fluid to remove material. In some examples the thermal condition of the first fluid may provide a primary removal mechanism. For example, the heated first fluid may act to melt the material, disrupt adhesion of the material to a wall of the conduit, and/or the like. The heat imparted to the first fluid may increase the efficacy of any chemical effect provided by the first fluid in removing material. For example, the thermal condition of the first fluid may increase its effectiveness as a solvent, viscosity modifier, detergent, cleaning agent, and/or the like. In some examples the heat imparted to the first fluid may assist in preventing material, such as salts, waxes etc. from dropping out of the first fluid, for example by crystallisation, precipitation etc., thus assisting to prevent material initially being deposited within the conduit. This might have particular application where the first fluid comprises a fluid normally under transport along the conduit.

As the apparatus comprises a heating arrangement located therein, the apparatus is able to provide a means of heating the first fluid inside the conduit at or very close to the point of use. This may avoid issues with transporting a heated fluid any significant distance from a remote location, which might otherwise require significant energy and insulation requirements etc. Further, generating heat by agitating the second fluid may remove the need for any electrical heating, and therefore any electrical connection or supply associated with such electrical heating (e.g., resistance heating), thus allowing a far simpler apparatus to be provided. Removing the need for any electrical heating components may additionally provide for a compact apparatus that is able to fit easily within a fluid conduit, including relatively small fluid conduits.

The apparatus may be configured for fluid communication with a source of the first fluid.

The source of the first fluid may be provided within the conduit in which the apparatus is located. In this example the apparatus may be immersed within the first fluid. The first fluid may thus comprise an ambient fluid surrounding the apparatus when in use (i.e., the first fluid may comprise any fluid already present in the conduit).

The source of the first fluid may be provided at a location remote from the apparatus, for example a location external of the conduit, such as a surface location. The first fluid may be delivered from source to the apparatus via a delivery conduit. The delivery conduit may be in fluid communication with the flow path. The delivery conduit may be connected to the apparatus. The delivery conduit may supply the first fluid externally of the apparatus. The delivery conduit may define an outlet which permits the first fluid to be delivered to the flow path. In some examples the delivery conduit may comprise tubing, such as jointed tubing, coiled tubing and the like. The delivery conduit may define a velocity string. The delivery conduit may be used in some examples to deploy and move the apparatus within the conduit.

The flow path may be defined externally of the apparatus. In one example the heater may define an outer surface of the apparatus to provide thermal communication with the flow path. In one example the flow path may be defined between the apparatus and an inner wall of the conduit. In this respect, first fluid may pass over the outer surface of the apparatus to be heated.

In one example, the flow path may be defined within the apparatus. For example, the apparatus may comprise a housing having a fluid inlet and a fluid outlet, wherein the flow path extends between the fluid inlet and fluid outlet. In this example the heater may facilitate heating of the first fluid prior to exiting the housing via the outlet. Thus, a heated fluid stream may be created which exits the apparatus via the fluid outlet, wherein this heated fluid stream may then be used in a process for removing material from within the conduit.

The apparatus of the present aspect may thus be defined as comprising: a housing having a fluid inlet, a fluid outlet and a flow path extending therebetween for accommodating flow of a first fluid; and a heater within the housing and comprising a heating chamber and an agitator mechanism operable to agitate a second fluid within the heating chamber to generate thermal energy within the second fluid, wherein the heater is in thermal communication with the flow path to facilitate heating of the first fluid flowing along the flow path prior to exiting the housing via the outlet.

The fluid inlet may be configured for fluid communication with a source of the first fluid.

The source of the first fluid may be provided within the conduit in which the apparatus is located. In this example the apparatus may be immersed within the first fluid. The first fluid may thus comprise an ambient fluid surrounding the apparatus when in use (i.e., the first fluid may comprise any fluid already present in the conduit). The apparatus may be configured to draw the first fluid from the conduit through the fluid inlet. In some examples drawing of the first fluid through the fluid inlet may be facilitated by a fluid displacement arrangement (e.g., a pump) associated with the apparatus, such as described below.

The fluid inlet may be configured for fluid communication with a source of the first fluid provided at a location remote from the apparatus, for example a location external of the conduit, such as a surface location. The first fluid may be delivered from source to the fluid inlet of the housing via a delivery conduit. The fluid inlet may thus be configured to be connected to the delivery conduit, for example via any suitable type of connection. In some examples the delivery conduit may comprise tubing, such as jointed tubing, coiled tubing and the like. The delivery conduit may define a velocity string. The delivery conduit may be used in some examples to deploy and move the apparatus within the conduit.

The apparatus may comprise a fluid displacement arrangement for drawing the first fluid along the flow path (e.g., into a fluid inlet of a housing). The fluid displacement arrangement may cause or contribute to driving of the first fluid along the first flow path and possibly through a fluid outlet of a housing. The fluid displacement arrangement may comprise a pump arrangement. The fluid displacement arrangement may comprise an impeller or the like.

In some examples, the apparatus may be configured to receive the first fluid delivered via an external drive arrangement, such as an external pump or pump system. In this example the apparatus may not require a separate fluid displacement arrangement, thus simplifying construction. In some examples, however, the apparatus may additionally comprise a fluid displacement arrangement to supplement any external drive arrangement.

The first fluid may be delivered to the apparatus (e.g., a fluid inlet of the apparatus) at a desired flow rate and/or pressure, for example delivered directly via the conduit in which the apparatus is located or via a separate delivery conduit. As described in more detail below, the heater, and more specifically the agitator mechanism, may be driven or operated by the first fluid delivered to the apparatus.

The apparatus may comprise a drive arrangement configured to operate the agitator mechanism of the heater. The drive arrangement may comprise a motor, such as an electrical motor, hydraulic motor and/or the like. In one example the drive arrangement may be configured to be operated by electrical power, for example from an on-board power supply, external power supply and/or the like. Where an external power supply is utilised power may be communicated via a suitable power conductor, such as e-line. In some examples the power conductor may be used in the deployment, retrieval and or repositioning of the apparatus within the conduit.

The drive arrangement may comprise a hydraulic drive arrangement. The drive arrangement may be configured to be operated by flow of the first fluid. As such, the first fluid may have a dual function as providing the power source for operation of the heater, while also being subject to heating to thus define a heated fluid for use in removal of material from the conduit. This may provide an efficient system, avoiding or minimising the requirement to provide a separate supply of power, such as hydraulic and/or electrical power for operation of the heater, facilitating a more simple construction with associated benefits in terms of costs and reliability.

The drive arrangement may be configured to provide a rotary drive to the agitator mechanism. In this respect the drive arrangement may be or define a rotary drive arrangement.

The drive arrangement may comprise a hydraulic turbine configured to convert kinetic and/or pressure energy of a fluid (e.g., the first fluid) into mechanical energy and provide a suitable drive motion (e.g., a rotary drive) for operation of the agitator mechanism. The drive arrangement may comprise a rotary turbine configured to rotate upon exposure to flow. The turbine may comprise an impeller configured to be rotated by a drive fluid, for example by the first fluid. Such an impeller may define a turbine inlet for receiving a drive fluid, and a turbine outlet for accommodating exit of the drive fluid. Where the drive fluid is the first fluid the exit of the turbine may deliver the first fluid towards the flow path, and, for example where present, through a fluid exit of the apparatus.

The drive arrangement may be located within the flow path. In this respect, the drive arrangement may form part of the flow path. The drive arrangement may be in communication with a fluid inlet (for example provided in a housing), wherein some or all of the first fluid received at the fluid inlet may be used to drive the drive arrangement.

In some examples the drive arrangement may be located downstream of the heater (e.g., downstream of a heated portion of the flow path). In this example heated first fluid may be used to drive the drive arrangement, for example prior to exiting the apparatus via a fluid outlet.

The drive arrangement may be located upstream of the heater (e.g., upstream of a heated portion of the flow path). In this arrangement the first fluid used to drive the drive arrangement may subsequently be heated by the heater. Positioning the drive arrangement upstream of the heater or heated portion of the flow path may provide particular advantages. For example, a first volume of the first fluid may be delivered into the flow path, for example via a fluid inlet, and used to drive the drive arrangement, with a proportion then diverted from the flow path to ensure a lower second volume of the first fluid continues along the flow path and heated by the heater. The lower second fluid volume may permit a higher degree of heating to be achieved. The provision of such diversion of a proportion for the first fluid may thus permit conflicting design requirements to be achieved with a single fluid supply.

The apparatus may comprise a fluid diverter configured to divert a portion of the first fluid from the flow path. The fluid diverter may be located upstream of the heater (e.g., upstream of a heated portion of the flow path) such that a diverted portion of the first fluid is not subject to heating, or is subjected only to minimal heating. In this example, a first volume of the first fluid may be delivered into the flow path, for example via a fluid inlet, with a proportion then diverted from the flow path to ensure a lower second volume of the first fluid continues along the flow path and heated by the heater. The lower second fluid volume may permit a higher degree of heating to be achieved. That is, the flow diverter may assist to reduce the volume of fluid presented in thermal communication with the heater (i.e., the volume of the heated fluid portion may be less than the volume of fluid entering the fluid inlet). The reduced volume of fluid in thermal communication with the heater may be more efficiently heated, and may minimise the energy requirements to elevate and maintain the heater (i.e., the second fluid) at a desired target temperature. As suggested above, this arrangement may permit advantages in terms of allowing a greater volume of the first fluid to drive a drive arrangement, while presenting a lower volume of the first fluid for heating.

The fluid diverter may be configured to divide the flow of first fluid into a retained portion which is directed along the flow path to be heated, and a diverted portion which is directed away from the flow path and thus not subject to heating, or subjected to minimal heating. The diverted portion may be diverted outwardly from the apparatus, for example into the conduit in which the apparatus is located.

The fluid diverter may comprise a flow splitter configured to divide the flow of first fluid into the retained portion an the diverted portion. The fluid diverter may be at least partially defined by a drive arrangement, such as a hydraulic turbine arrangement. In one example the drive arrangement may define a first drive outlet for accommodating flow of the retained portion, and a second drive outlet for accommodating flow of the diverted portion.

The fluid diverter may comprise a diverter outlet for accommodating the diverted portion of the first fluid to exit the apparatus. The diverter outlet may be in the form of, or may comprise, a fluid outlet in a housing of the apparatus, for example an aperture in the housing. The diverter outlet may be in the form of a plurality of apertures in the housing. The plurality of apertures may be arranged in the form of an array, for example a circumferential array. The circumferential array may be concentric with the longitudinal axis of the apparatus. The circumferential array may circumscribe the fluid inlet.

The diverter outlet may be in the form of or comprise an aperture that is provided in the housing at an angle that is oblique to the longitudinal axis of the housing. For example, the flow diversion outlet may extend through the housing at a 45 degree angle relative to the longitudinal axis of the housing.

The diverter outlet may be located on an axial end of the housing, for example an end face of the housing. The diverter outlet may be located on the same axial end face as the fluid inlet. As such, the diverter outlet may divert fluid flow from inside the housing, to a region outside the housing and adjacent the fluid inlet.

The heater may be configured to impart thermal energy to the first fluid to an extent so as to heat the flow of fluid but without, or with minimal, change in state of a fluid from a liquid state to a gaseous state. For example the heater may be configured to heat a flow of fluid by around 50 degrees Celsius.

The heater may comprise an external heat transfer surface. The external heat transfer surface may define, be inside, form a part of and/or be adjacent the flow path. As such, the heat transfer surface may facilitate thermal communication with the flow path.

The external heat transfer surface may comprise a surface feature to assist in the transfer of thermal energy from the heat transfer surface to the flow path. For example, the surface feature may assist to increase the surface area of the heat transfer surface, thereby assisting with heat transfer by increasing the available surface through which heat may be transferred. The heat transfer surface may comprise a protrusion, depression and/or the like. The heat transfer surface may comprise any one or more of a fin, a node, a nipple, a ridge, a dimple, a groove, a trough, a channel, and/or the like. The surface feature, or the plurality of surface features, may be shaped and/or spaced to encourage a desirable flow of fluid along the heat transfer surface. For example, even circumferential spacing of the plurality of surface features may encourage an even flow distribution across the heat transfer surface.

The external heat transfer surface may extend along the length of the heater, for example the axial length of the heater.

The heater may define a boundary of at least part of the flow path. This arrangement may facilitate thermal communication with the flow path. That portion of the flow path which is bounded by the heater may be defined as a heated portion of the flow path. As noted above, in some examples the apparatus may comprise a housing having a fluid inlet and a fluid outlet, wherein the flow path is defined between the fluid inlet and fluid outlet. The housing may be of a unitary construction. Alternatively, the housing may comprise an assembly of components. The housing may be generally cylindrical in form. For example, the housing may comprise an axially extending cylindrical wall structure closed or capped at opposite axial ends. In one example, the fluid inlet and outlet may be provided in opposing axial ends of the housing.

The housing may define a heater cavity, such as a cylindrical heater cavity, wherein the heater is mounted within said heater cavity. The heater may be generally cylindrical in form. The heater may be complimentary in form to the heater cavity.

The heater may be secured within the housing, for example rigidly secured within the housing. In some examples a compliant mounting of the heater within the housing may be provided, for example to dampen vibrations and the like. The heater may be secured to the housing via one or more connectors, such as threaded connectors.

The heater may be concentrically mounted with the housing. Alternatively, the heater may be eccentrically mounted, or may be mounted to be laterally offset from a longitudinal axis of the housing.

In some examples a portion of an outer surface of the heater may be in intimate contact with a portion of an inner surface within the housing. Such an arrangement may assist to locate and support, for example centrally support, the heater within the housing.

The heater may be mounted within the housing to define at least a portion of the flow path therebetween. At least a portion of the flow path may be defined between an outer surface of the heater and an inner surface within the housing. In this respect an outer surface of the heater may define a boundary of at least part of the flow path, and thus may facilitate thermal communication with the flow path. The outer surface of the heater may define a heat transfer surface.

In one example the heater may be mounted within the housing to define a separation gap therebetween, wherein the separation gap defines at least part of the flow path. In one example the heater may be mounted within the housing to define an axially extending annular flow path.

One or both of the outer surface of the heater and the inner surface within the housing may define at least one profile which defines part of the flow path. The at least one profile may comprise a channel, recess and/or the like. A plurality of profiles may be provided, for example a circumferential array of profiles. The at least one profile may extend axially. In some examples the at least one profile may extend in a spiral or helical direction. Such an arrangement may function to increase the length of the flow path and thus assist to maximise the surface area of contact between the first fluid and the heater.

In one example, the heater may be provided in the form of a heater cartridge which is mounted within the housing. The heater cartridge may comprise a central section with opposing axial ends. The flow path may extend over the central section and optionally over one or both axial ends.

The heater may be generally cylindrical in form.

The heater may comprise a casing, wherein the casing defines an outer surface of the heater, which may be defined as a heat transfer surface of the heater. At least a portion of the casing may define a boundary of the flow path (e.g., a heated portion of the flow path). The casing may be of a unitary construction. Alternatively, the casing may comprise an assembly of components. The casing may be generally cylindrical in form.

For example, the casing may comprise an axially extending cylindrical wall structure closed or capped at opposite axial ends.

The casing may define or contain the heating chamber.

As defined above, the heater functions by the second fluid within the heating chamber being agitated by the agitator mechanism. As heating is achieved by fluid agitation, the heater may be defined as a mechanical heater. The agitator mechanism may agitate the second fluid by application of a force thereto, for example the application of a shear force to the second fluid. Agitation of the second fluid may provide localised regions of reduced pressure. Such localised regions of reduced pressure may result in, for example, cavitation of the fluid. Cavitation of the fluid may, in turn, result in an increase in thermal energy, thereby causing the second fluid to become heated.

The heating chamber may be sealed. Alternatively, the heating chamber may permit flow of the second fluid therethrough. In some examples continuous flow may be present. Such continuous flow may be controlled to ensure sufficient heating of the second fluid is provided. In an alternatively example, intermittent flow may be present. This arrangement may facilitate replenishment or the like of the second fluid.

In some examples the second fluid may be defined as a heat transfer fluid. The second fluid may be selected so as to provide an optimal degree of heating when agitated. The second fluid may be, for example, an oil such as viscous gear oil. The second fluid may be the same as the first fluid. In some examples the second fluid may also function to lubricate the agitator mechanism of the heater.

The agitator mechanism may be driven by a drive arrangement, such as a rotary drive arrangement, for example as described above.

The agitator mechanism may comprise a fluid agitator configured to be moved within or relative to the second fluid within the heating chamber to agitate said second fluid. The fluid agitator may be rotatable within the heating chamber. In this example the fluid agitator may define an agitator rotor.

The fluid agitator may comprise an agitator surface configured to interact with and agitate the second fluid within the heating chamber when the fluid agitator is moved, for example rotated. The agitator surface may define an outer surface of the fluid agitator. Alternatively, or additionally, the agitator surface may define an inner surface.

The agitator surface may comprise one or more surface features for causing fluid agitation. In some examples at least one surface feature may be provided at a discrete location on the fluid agitator. At least one surface feature may extend longitudinally along the fluid agitator. The agitator surface may comprise a plurality of surface features. The plurality of surface features may be distributed over the agitator surface. Where the fluid agitator is rotatable the plurality of surface features may be circumferentially distributed, evenly or otherwise, around the fluid agitator.

At least one surface feature may comprise a protrusion extending from the fluid agitator. Such a protrusion may extend generally radially relative to the fluid agitator, for example radially inwardly and/or outwardly of the fluid agitator. The protrusion may comprise a fin, paddle, arm and/or the like.

At least one surface feature may comprise a depression extending into a surface of the fluid agitator Such a depression may extend generally radially relative to the fluid agitator, for example radially inwardly and/or outwardly of the fluid agitator.

The agitator surface may comprise an array, for example a circumferential array, of protrusions and depressions, for example in alternating arrangement.

The agitator mechanism may comprise a static agitator profile. The static agitator profile may be provided on a static surface within the heater. The static agitator profile may be provided on an inner wall surface of the heater, for example on an inner wall surface of a heater casing. The static agitator profile may be provided on a circumferential surface of the heater. The static agitator profile may function to increase agitation of the second fluid during movement of the fluid agitator. For example, fluid positioned between the fluid agitator and the static agitator profile may be subject to a greater level of agitation and thus heating.

The static agitator profile may be located radially outwardly of the fluid agitator. For example, the static agitator profile may circumscribe the fluid agitator. Alternatively, or additionally, the static agitator profile may be located radially inwardly of the fluid agitator.

The static agitator profile may comprise one or more surface features, such as one or more of protrusions, depressions and/or the like.

In one example a single fluid agitator may be provided, for example in the form of a rotary fluid agitator.

The agitator mechanism may comprise a plurality of fluid agitators each configured to be moved within or relative to the second fluid within the heating chamber to agitate said second fluid. One or more, for example all, of the fluid agitators may be rotatable within the heating chamber. At least two fluid agitators may be arranged to be rotated in a common direction. At least two fluid agitators may be arranged to rotate in opposite directions, thus providing contra rotation therebetween. Such contra rotation may increase or maximise the agitation effect on the second fluid.

The agitator mechanism may comprise a first rotary fluid agitator and a second rotary fluid agitator. The first and second rotary fluid agitators may be axially arranged relative to each other, for example along a common rotation axis. Alternatively, the first and second rotary fluid agitators may be arranged radially relative to each other. For example, the first rotary fluid agitator may be located within the second rotary fluid agitator, for example coaxially within the second rotary fluid agitator, such that the second rotary fluid agitator circumscribes the first rotary fluid agitator. The second fluid agitator may define an annular rotor form. The first rotary fluid agitator may define an inner fluid agitator and the second rotary agitator may define an outer fluid agitator.

The first rotary fluid agitator may comprise an outer facing agitator surface, whereas the second rotary fluid agitator may comprise an inner facing agitator surface. The agitator surfaces of the first and second rotary agitators may be arranged in close proximity, which may increase or maximise the agitation effect on the second fluid.

The first and second rotary agitators may be configured for rotation in a common direction. Alternatively, the first and second rotary fluid agitators may be rotatable in opposite direction, thus providing contra rotation therebetween.

The first and second rotary agitators may be driven to rotate by separate drive arrangements. Alternatively, the first and second rotary fluid agitators may be driven by a common drive arrangement. In this example the common drive arrangement may be directly coupled to both the first and second rotary agitators. Such an arrangement may be provided when the first and second rotary agitators are to be rotated in a common direction.

The apparatus may comprise a transmission arrangement coupled between the drive arrangement and the first and second rotary fluid agitators. The transmission arrangement may be configured to permit the drive arrangement to rotate the first and second rotary fluid agitators in opposite directions.

The transmission arrangement may be at least partially located within the heating chamber. In this example the second fluid may function to lubricate the transmission arrangement.

The transmission arrangement may comprise a gearing system configured to permit the drive arrangement to rotate the first and second rotary fluid agitators in opposite directions.

The transmission arrangement may comprise a planetary gear system. The planetary gear system may comprise a central or sun gear rotatably coupled to the first rotary fluid agitator, and a ring gear which circumscribes the sun gear and is rotatably coupled to the second rotary fluid agitator. The planetary gear system may further comprise a planet gear radially interposed and meshed between the sun and ring gears. In one example a plurality of planet gears may be provided, for example two, three, four, five etc. The plurality of planet gears may be evenly circumferentially distributed between the sun and ring gears.

The planet gear may be secured against orbiting motion relative to the sun and ring gears. In this respect the planet gear may define an idler gear configured to reverse rotation between the sun and ring gears, thus facilitating contra rotation via a common drive. By the planet gear functioning as an idler gear both the sun and ring gears may rotate, in opposite directions, at the same rotational speed. However, in other examples a gear train may be provided between the sun and ring gear to provide a change in rotational speed.

One of the sun and ring gears may be coupled to a rotary drive arrangement, with the other of the sun and ring gears being driven in an opposite direction via the planet or idler gear. In one example the sun gear may be coupled to a rotary drive, such that the sun gear defines a drive gear and the ring gear defines a driven gear. Alternatively, the ring gear may be coupled to a rotary drive, such that the ring gear defines a drive gear and the sun gear defines a driven gear.

The planetary gear system may be mounted about a support shaft. In one example the sun gear may be mounted on the support shaft. The support shaft may be rotatable, with such rotation permitting rotation of the sun gear. Alternatively, the support shaft may be static, wherein the sun gear is rotatably mounted on the static support shaft, for example via a bearing.

In some examples the ring gear may be mounted on the support shaft. For example, the ring gear may comprise or be connected to a hub structure which is mounted to the shaft.

In some examples this hub structure may be connected to a drive arrangement.

The support shaft may be supported within a casing of the heater. In one example the support shaft may extend from an internal wall, such as an axial end wall, within the casing of the heater. The support shaft may be cantilevered. Alternatively, the support shaft may be supported at opposing ends thereof, and/or supported at one or more positions intermediate opposing axial ends. The support shaft may extend through, for example axially through, the first rotary fluid agitator. In this respect the first rotary fluid agitator may comprise a through bore to accommodate the support shaft.

The planet gear may be mounted on a static carrier. The static carrier may be fixed relative to a casing of the heater. In one example the static carrier may be mounted on a static support shaft, such as described above.

The planet gear may be mounted on a spindle (such as a rod, peg etc.) mounted on the static carrier. The spindle may extend in cantilever form from the static carrier. In some examples the spindle may be rotatable, thus facilitating rotation of the planet gear. Alternatively, the spindle may be static and the planet gear rotatably mounted on the spindle, for example via a bearing.

As noted above, in some examples the apparatus may comprise a housing having a fluid inlet and a fluid outlet, wherein the flow path is defined between the fluid inlet and fluid outlet. The fluid inlet may be located on the housing, for example an axial end of the housing. For example, where the housing has a cylindrical shape, the fluid inlet may be located on an axial end face of the housing.

The fluid inlet may be centrally located relative to the apparatus, for example the fluid inlet may be located on the housing on a central axis of the apparatus and, optionally, of the housing. The fluid inlet may be located at one axial end of the apparatus. The fluid inlet may be or comprise an aperture extending through the housing (e.g. through a wall of the housing), permitting fluid communication from an external location to an internal location in the housing. The fluid inlet may be or comprise a plurality of apertures in the housing. The fluid inlet may comprise a circular cross section, and the longitudinal axis of the fluid inlet may be aligned with the longitudinal axis of the apparatus, and/or of the housing of the apparatus. The fluid inlet may comprise an attachment portion The attachment portion may comprise a profile for attachment to a delivery conduit. The attachment portion may be threaded, for example.

The apparatus may comprise a single fluid outlet. Alternatively, the apparatus may comprise multiple fluid outlets. At least one fluid outlet may be located on an axial end of the housing, for example on an opposite axial end of the housing relative to the fluid inlet. At least one fluid outlet may be located on a circumferential face of the housing.

At least one fluid outlet may be may be centrally located relative to the apparatus, for example the fluid outlet may be located on the housing on a central axis of the apparatus.

At least one fluid outlet may be defined by an aperture or a port.

At least one fluid outlet may comprise a nozzle. The nozzle may be configured to condition heated first fluid during exit from the apparatus. For example, the nozzle may produce a high velocity jet of heated fluid. Such a jet of heated fluid may provide a form of mechanical removal of material from within the conduit.

The fluid outlet may be configured to direct heated first fluid in a desired direction. In examples where multiple fluid outlets are provided at least two fluid outlets may be configured to direct heated first fluid in the same or different directions The fluid outlet may be formed through a wall structure of the housing, for example via one or more ports formed through a wall structure of the housing.

The housing may comprise an outlet assembly, wherein at least one fluid outlet is provided on said outlet assembly. The outlet assembly may be rigidly mounted relative to the remainder of the housing. Alternatively, the outlet assembly may be moveable relative to the remainder of the housing. In one examples the outlet assembly may be rotatably mounted, for example via a bearing arrangement, relative to the remainder of the housing. Such rotational capability of the outlet assembly, and of the at least one fluid outlet provided thereon, may permit a desired spray patter to be achieved. In some examples a drive arrangement may cause the outlet assembly to rotate. The drive arrangement may comprise a motor, such as an electric motor, hydraulic motor and/or the like. In one example the outlet assembly may be configured to be driven by flow of the first fluid. For example, the outlet assembly may comprise a fluid turbine mounted therein. Alternatively, or additionally, thrust generated by fluid exiting via the at least one fluid outlet may cause the outlet assembly to rotate. In this respect the at least one fluid outlet may be directed in a manner which encourages such rotation.

The outlet assembly may be interchangeable.

The apparatus may comprise a thermal expansion arrangement for accommodating thermal expansion of the second fluid within the heating chamber. In one example the thermal expansion arrangement may comprise a pressure transfer mechanism in pressure communication with the heating chamber and an external region, for example the flow path. In such an example the pressure transfer mechanism may function to maintain the heating chamber pressure balanced relative to the external region, thus accommodating any pressure variations which might be caused by thermal expansion (or contraction) of the second fluid. Pressure balancing may include equalising pressures. However, pressure balancing may include maintaining the heating chamber at a fixed pressure above or below the external region, for example to accommodate preferential leakage direction and/or the like. This arrangement may be achieved by incorporating a force bias within the pressure transfer mechanism.

The pressure transfer mechanism may comprise a moveable barrier in pressure communication with the heating chamber and the external region. The moveable barrier may comprise a or be defined by a diaphragm, piston, bladder, bellows and/or the like.

The apparatus may comprise an external flow separator. The external flow separator may be located on a housing, for example on an exterior surface of the housing. The external flow separator may be located between a fluid outlet and a diversion outlet of the housing, so as to prevent or restrict mixing of fluid flowing from the fluid outlet and the diversion outlet. Having such an external flow separator may enhance operation of the apparatus by reducing or preventing mixing of a heated fluid exiting the fluid outlet with a cool fluid exiting the diversion outlet. As such, the heated fluid exiting the fluid outlet may more effectively be able to remove material from the fluid conduit.

When the apparatus is positioned in a fluid conduit, the external flow separator may provide a fluid seal, or at least a restriction to fluid flow, in the annulus between the apparatus and the fluid conduit. The external flow separator may be in the form of a fin, or a plurality of fins, extending from the housing. The external flow separator may comprise one or more cups, such as swab cups.

The external flow separator may be integrally formed with the housing, or may be separate from the housing. For example, the flow separator may be slipped over the housing and held in place by end rings that are affixed to the surface of the housing, for example by clamping, bolting, or the like.

The external flow separator may be made from a flexible or resilient material to enhance flow restriction. For example the external flow separator may be made from rubber.

The apparatus may be configured for use within any conduit in any location, for example subterranean, subsea, topside and/or the like.

The apparatus may be dimensioned to facilitate deployment through deviated conduit sections, such as conduits including bends.

The apparatus may comprise one or more material removal profiles, for example on an outer surface of the apparatus. Such an arrangement may assist in providing mechanical removal of material from the conduit. At least one material removal profile may comprise one or more teeth, scrapers, and/or the like.

An aspect of the present disclosure relates to a method for removing material from a conduit, comprising: locating an apparatus comprising a heater at a desired location within the conduit; delivering a first fluid along a flow path which is in thermal communication with the heater; agitating a second fluid within a heating chamber of the heater to generate thermal energy within the second fluid; and heating the first fluid flowing along the flow path with heat generated within the second fluid, wherein the heated first fluid is for use in removing a material from the conduit.

The method may comprise delivering the first fluid along a flow path which is external to the apparatus.

The method may comprise delivering the first fluid into the apparatus via a fluid inlet to be flowed along a flow path within the apparatus. The method may comprise ejecting the heated first fluid from the apparatus via a fluid outlet for use in removing a material from the conduit.

The method defined above may be performed using the apparatus of any other aspect.

As such, any features defined in relation to the apparatus, or any functionality or use described, may be applied to the present method.

The method may comprise operating an agitator mechanism to agitate the second fluid. The method may comprise operating the agitator mechanism via a drive arrangement.

The drive arrangement may be driven by flow of the first fluid.

The method may comprise: delivering a first volume of the first fluid (e.g., through a fluid inlet)to drive the drive arrangement; and diverting a proportion of the first fluid away from the flow path to provide a second lower volume of first fluid to be heated.

An aspect of the present disclosure relates to an apparatus for use in removing material from a conduit, comprising: a fluid inlet for receiving a cleaning fluid into a flow path; a heating arrangement comprising a heating chamber and an agitator mechanism operable to agitate a heat transfer fluid within the heating chamber so as to heat the heat transfer fluid, wherein the heating arrangement is in thermal communication with the flow path to heat cleaning fluid flowing along the flow path; and a fluid outlet for delivering heated cleaning fluid into the conduit.

An aspect of the present disclosure relates to an apparatus for use in removing material from a conduit, comprising: a fluid inlet, a fluid outlet and a flow path therebetween; and a heating arrangement in thermal communication with the flow path to heat fluid flowing along the flow path prior to exiting the housing via the outlet.

An aspect of the present disclosure relates to a method for use in removing material from a conduit, comprising: locating an apparatus at a desired location within the conduit; delivering a first fluid along a flow path; and heating the first fluid flowing along the flow path.

The method may comprise delivering the first fluid into the apparatus via a fluid inlet to be flowed along the flow path, wherein the flow path is defined within the apparatus. The method may comprise ejecting the heated first fluid from the apparatus via a fluid outlet for use in removing a material from the conduit.

An aspect of the present disclosure relates to an apparatus for producing a stream of a heated fluid, comprising: a housing having a fluid inlet, a fluid outlet and a flow path extending therebetween for accommodating flow of a first fluid; and a heater within the housing and comprising a heating chamber and an agitator mechanism operable to agitate a second fluid within the heating chamber to generate thermal energy within the second fluid, wherein the heater is in thermal communication with the flow path to facilitate heating of the first fluid flowing along the flow path prior to exiting the housing via the outlet.

An aspect of the present disclosure relates to a method for producing a stream of heated fluid, comprising: delivering a first fluid into an apparatus via a fluid inlet to be flowed along a flow path within the apparatus; agitating a second fluid within a heating chamber of the apparatus to generate thermal energy within the second fluid; heating the first fluid flowing along the flow path with heat generated within the second fluid; and ejecting the heated first fluid from the apparatus via a fluid outlet.

An aspect of the present disclosure relates to a heater apparatus, comprising: a heating chamber containing a heater fluid therein; an agitator mechanism operable to agitate the heater fluid within the heating chamber to generate thermal energy within the heater fluid, wherein the agitator mechanism comprises first and second rotary fluid agitators.

The first and second rotary fluid agitators may be axially arranged relative to each other, for example along a common rotation axis. Alternatively, the first and second rotary fluid agitators may be arranged radially relative to each other. For example, the first rotary fluid agitator may be located within the second rotary fluid agitator, for example coaxially within the second rotary fluid agitator, such that the second rotary fluid agitator circumscribes the first rotary fluid agitator. The second fluid agitator may define an annular rotor form. The first rotary fluid agitator may define an inner fluid agitator and the second rotary agitator may define an outer fluid agitator.

The first rotary fluid agitator may comprise an outer facing agitator surface, whereas the second rotary fluid agitator may comprise an inner facing agitator surface. The agitator surfaces of the first and second rotary agitators may be arranged in close proximity, which may increase or maximise the agitation effect on the heater fluid.

The heater apparatus may comprise a transmission arrangement coupled between a drive arrangement and the first and second rotary fluid agitators. The transmission arrangement may be configured to permit the drive arrangement to rotate the first and second rotary fluid agitators in opposite directions.

The transmission arrangement may be at least partially located within the heating chamber. In this example the heater fluid may function to lubricate the transmission arrangement.

In some examples this hub structure may be connected to a drive arrangement.

The planet gear may be mounted on a spindle (such as a rod, peg etc.) mounted on the static carrier. The spindle may extend in cantilever form from the static carrier. In some examples the spindle may be rotatable, thus facilitating rotation of the planet gear.

Alternatively, the spindle may be static and the planet gear rotatably mounted on the spindle, for example via a bearing.

An aspect of the present disclosure relates to a method for generating heat, comprising agitating a heater fluid within a heating chamber by rotating first and second fluid agitators Features defined in relation to one aspect may be applicable in any other aspect.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present disclosure will be exemplified with reference to the drawings, in which: Figure 1 illustrates an apparatus deployed in a conduit for use in removing material therefrom; Figure 2 is an isometric view of the apparatus of Figure 1; Figure 3 is a longitudinal sectional view of the apparatus of Figure 1; Figure 4 is a lateral sectional view of the apparatus taken along line 4-4 in Figure 3; Figure 5 is an enlarged sectional view of one end region of the apparatus of Figure 1; Figures 6 and 7 illustrate different features of a transmission arrangement of the apparatus of Figure 1; Figure 8 is an isometric view of an alternative apparatus for use in removing material from a conduit; Figure 9 is an isometric view of an alternative apparatus for use in removing material from a conduit; Figure 10 is a longitudinal sectional view of the apparatus of Figure 9 shown located in a conduit; and Figure 11 is a lateral sectional view of the apparatus taken through line 11-11 of Figure 10.

DETAILED DESCRIPTION OF THE DRAWINGS

Generally, the present disclosure relates to apparatus and methods of producing heat.

In some examples, as presented herein, the present disclosure relates to apparatus and methods which utilise the heating of a fluid in the process of removing material from a conduit.

Figure 1 illustrates an apparatus, generally identified by reference numeral 10, deployed within a conduit 12 (such as a pipeline, wellbore, tubing string etc.) and operated in a process to remove a material 14 from within the conduit 12. The material 14 may include anything which a user may wish to remove, which may vary depending on the specific application. For example, in conduits associated with oil and gas operations the apparatus 10 may be for use in the removal of materials such as precipitates, hydrates, sulphates, salts, waxes, viscous hydrocarbons, consolidated particulates, debris and/or the like.

Generally, the apparatus 10 is operated to produce one or more jets 16 of a heated fluid (which may be defined as a cleaning fluid) which is directed into the conduit 12 to assist in material removal. The cleaning fluid may comprise anything selected by a user for the specific application and may, for example, comprise water, brine, a solvent, detergent, cleansing agent, viscosity modifier, foaming agent and/or any other fluid having desirable properties. Impingement of the jets 16 on the material 14 may provide mechanical means of removal. However, the heat within the cleaning fluid may improve the ability of the fluid to remove material 14. For example, the heated cleaning fluid may act to melt the material 14, disrupt adhesion of the material 14 to a wall of the conduit 12, and/or the like. The heat imparted to the cleaning fluid may increase the efficacy of any chemical action provided by the fluid to remove the material 14. For example, the thermal condition of the cleaning fluid may increase its effectiveness as a solvent, viscosity modifier, detergent, cleaning agent, and/or the like.

The apparatus 10 comprises a generally cylindrical housing 18 which includes a fluid inlet 20 provided at a first axial end 21 thereof. In the present example the fluid inlet 20 is connected to a delivery conduit 22 (shown in broken outline), such as coiled tubing, which permits cleaning fluid to be delivered in the direction of arrow 23 to the apparatus 10 from a suitable source, for example a source located externally of the conduit. The cleaning fluid may be delivered to the apparatus 10 at a desired flow rate and/or pressure. Delivery of the cleaning fluid may be controlled by a pump (not shown). The delivery conduit 22 may also be used to manipulate and move the apparatus 10 within the conduit 12.

The apparatus 10 further comprises a plurality of fluid outlets 24 provided at a second axial end 25 of the housing 18, opposite the first axial end 21, wherein the fluid outlets 24 facilitate outflow of the cleaning fluid from the apparatus 10 to form the jets 16. In the present example the fluid outlets 24 are provided on an outlet assembly 26 mounted on or forming part of the housing 18. The outlet assembly 26 may be fixed relative to the housing 18. Alternatively, and as is the case in the present example, the outlet assembly 26 may be rotatable relative to the housing 18, with rotation caused by thrust generated from the jets 16. Such rotation may provide a desired spray pattern into the conduit 12.

In some examples the outlet assembly may be interchangeable, for example to provide a different form or arrangement of outlets 24.

As will be described in further detail below, the apparatus 10 includes an internal flow path (not visible in Figure 1) which extends between the fluid inlet 20 and fluid outlets 24. The apparatus 10 further comprises an internal heater (not visible in Figure 1) which is operated to heat the cleaning fluid flowing along the flow path. A such, the cleaning fluid is heated at the point of use, rather than at a remote location, thus improving efficiency.

Referring additionally to Figure 2, which is an isometric view of the apparatus 10, the first axial end 21 of the housing 18 further comprises a circumferential array of diverter outlets 28 which circumscribe the fluid inlet 20. As will be described in more detail below, the diverter outlets 28 permit a proportion of the cleaning fluid delivered to the fluid inlet 20 of the apparatus 10 to be diverted out into the conduit 12 without being subjected to heating prior to being heated. The benefits of providing this diverter facility will become apparent from further description below.

The apparatus 10 further comprises an optional sealing assembly 30 comprising a plurality of axially arranged sealing members 32 (e.g., swab cups) held in place by fixing rings 34. In use, the sealing assembly 30 may be in close proximity or intimate contact with the inner surface of the conduit 12, and may function to at least partially isolate the outlet ports 24 from the diverter ports 28. This may therefore prevent or minimise intimate mixing of the heated cleaning fluid jetted from the outlet ports 24 with cooler, unheated cleaning fluid which exits the apparatus 10 via the diverter ports 28. As such, cooling of the heated cleaning fluid is minimised.

Reference is now made to Figure 3 which is a longitudinal cross sectional view of the apparatus 10. A flow path 40 is defined within the housing 18 and extends between the fluid inlet 20 and the fluid outlets 24. A heater 42 in the form of a cylindrical heater cartridge is mounted within the housing 18 and secured in place via bolts 44, wherein the flow path 40 extends around an outer surface of the heater 42, such that the heater 42 is presented in thermal communication with the flow path 40 to facilitate heating of cleaning fluid therein. In the present example, that portion of the flow path 40 which extends over the heater 42 may be defined as a heated flow path section 40a.

The heater 42 comprises an outer cylindrical casing 46 which is closed and sealed at opposite axial ends thereof via respective first and second end caps 45, 47 to define an internal heating chamber 48, wherein the heating chamber 48 holds a volume of a heating fluid, such as oil. The heater 42 further comprises an agitator mechanism 50 mounted within the heating chamber 48 which is operated to agitate the heating fluid to generate heat therein such that the heating fluid may in turn be used to provide heating within the heated flow path section 40a, via the casing 46.

In the present example the agitator mechanism 50 comprises a first rotary fluid agitator 52 and a second rotary fluid agitator 54 which circumscribes the first rotary agitator 52. That is, the first rotary fluid agitator 52 is located within the second rotary fluid agitator 54. During use, the first and second fluid agitators 52, 54 are rotated in opposite directions to agitate and heat the heating fluid within the heating chamber 48.

The apparatus 10 further comprises a drive arrangement 58 mounted within the housing 18 for use in driving the first and second rotary fluid agitators 52, 54. The drive arrangement 58 comprises an impeller 60 located within the flow path upstream of the heated flow path section 40a. In this respect the impeller 60 is caused to rotate by the flow of cleaning fluid along the flow path 40. As such, the cleaning fluid has a dual function as providing the power source for operation of the heater 42, while also being subject to heating to thus define a heated fluid for use in removal of material 14 from the conduit 12 (Figure 1). This may provide an efficient system, avoiding or minimising the requirement to provide a separate supply of power, such as hydraulic and/or electrical power for operation of the heater 42, facilitating a more simple construction with associated benefits in terms of costs and reliability.

However, in other examples an electrical motor may be provided for use in driving the first and second rotary fluid agitators 52, 54. Ion some examples both a fluid operated drive arrangement and an electrical motor may be provided, either working together or to provide contingency/redundancy.

The apparatus 10 further comprises a transmission arrangement 56 which is interposed between the agitator mechanism 50 and the drive arrangement 58. As will be described in more detail below, the transmission arrangement 56 functions to apply a single rotary drive from the drive arrangement 58 to contra rotate the agitators 52, 54. In the present example the transmission arrangement 56 is located within the heating chamber 48, and may be lubricated by the heating fluid. A drive shaft 62 extends between the impeller 60 of the drive arrangement 58 and the transmission arrangement 56, extending through the first end cap 45 of the heater 42, with appropriate rotary seals provided.

The heater 42 further comprises an axially extending static shaft 64 which is supported at one end by the second end cap 47 and at an opposite end by the drive shaft 62, wherein the drive shaft 62 is in turn is supported by the first end cap 45. Various rotary components within the heater 42 may be mounted along the shaft, such as the first and second rotary agitators 52, 54, one or more components of the transmission arrangement 56, the drive shaft 62 and the like. Relative rotation between the rotary components and the static shaft 64 may be provided via one or more bearings (not individually illustrated), such as roller bearings.

The heater 42 further comprises a pressure balancing mechanism in the form of one or more (two in the present example) balancing piston 66 which are in pressure communication with both the heating chamber 48 and the flow path 40. The balancing pistons 66 thus self-adjust to ensure that the pressure between the heating chamber 48 and the flow path 40 is balanced. This arrangement may accommodate thermal expansion of the heating fluid within the heating chamber 48.

Reference is additionally made to Figure 4 which is a lateral sectional view taken along line 4-4 of Figure 3. The heater 42 is formed such that an outer surface of the heater casing 46 is in close or intimate contact with the inner surface of the housing 18. This arrangement may centralise and support the heater 42 within the housing 12. The outer surface of the casing 46 comprises a circumferential array of axially extending channels 68 which, together with the inner surface of the housing 18, define portions of the flow path 40, and more specifically portions of the heated flow path section 40a. Such an arrangement may facilitate even distribution of the cleaning fluid around the outer surface of the heater 42, which may encourage more uniform heating. In alternatively examples the inner surface of the housing 18 may additionally or alternatively define flow channels. Further, flow channels need not extend axially, and may extend helically, for example. Also, a single annular space may alternatively be defined between the heater 42 and the housing 18.

The first or inner rotary fluid agitator 52 includes a central hub 52a mounted about the static shaft 64, and a plurality of agitator fins 52b which extend both axially and radially relative to the central hub 52a.

The second or outer rotary fluid agitator 54 is generally annular in form and includes an agitator profile on an inner surface thereof, specifically a circumferential array of axially extending ribs 54a with respective grooves 54b therebetween. As illustrated, the tips of the fins 52b and the tips of the ribs 54a on the respective rotary fluid agitators 52, 54 run or rotate in close proximity to each other, thus enhancing the agitation effect on the heating fluid within the heating chamber 48.

While in the present example the first and second rotary fluid agitators 52, 54 are rotatable in opposite directions, in other examples the agitators 52, 54 may rotate in a common direction, at the same or a different rotational speed. Further, in some examples only one of the first and second rotary fluid agitators 52, 54 may rotate, with the other remaining stafionary.

An enlarged cross-sectional view of the first axial end 21 of the apparatus 10 is illustrated in Figure 5. The impeller 60 of the drive arrangement 58 is mounted adjacent the fluid inlet 20 and secured to the drive shaft 62 via a non-rotating coupling (e.g., a square profile) and a bolt 72. The impeller 60 defines a central inlet 74 for receiving cleaning fluid and a radial channel 76 which includes a series of impeller blades or fins 78, with the flow direction of the cleaning fluid indicated by arrows 79. The impeller functions by converting fluid pressure to kinetic energy resulting in the impeller 60 being driven to rotate, thus also rotating the drive shaft 62 and providing a drive input to the transmission arrangement 56 which will be described in more detail below. In alternative example the apparatus may comprise a separate motor used to drive the impeller and draw fluid into the apparatus.

The impeller 60 also comprise a series of outlets 80 positioned circumferentially around the outer periphery or rim of the impeller 60. The apparatus 10 further comprises a diverter arrangement which includes a flow splitter 82 provided on the housing 18 adjacent the rim of the impeller 60. Cleaning fluid exiting the outlets 80 of the impeller 60 will impinge on the flow splitter 82 causing the flow to be divided, with a first portion being directed towards the heated flow path section 40a, as illustrated by arrows 84, and a second portion being directed to exit the apparatus 10 via the array of diverter outlets 28, as illustrated by arrows 86. The positioning and form of the outlets 80 relative to the flow splitter 82 may dictate the proportion of split between the first and second portions 84, 86. For example, in the present example a larger proportion of the cleaning fluid is diverted towards the diverter outlet 28, as illustrated by the thickness of the arrows 84, 86.

Thus, a first flow volume of cleaning fluid may be delivered to the apparatus 10 with the entirety of this used to drive the impeller 60 to rotate. However, this first volume is then split, allowing a lower second flow volume of the cleaning fluid to continue along the flow path 40 to be heated by the heater 42. As such, the volume of cleaning fluid presented in thermal communication with the heater 42 is reduced relative to the total volume received by the apparatus, such that the reduced volume of fluid in thermal communication with the heater may be more efficiently heated, and may minimise the energy requirements to elevate and maintain the heater (i.e., the second fluid) at a desired target temperature. This arrangement may permit advantages in terms of allowing a greater volume of the first fluid to drive a drive arrangement, while presenting a lower volume of the first fluid for heating, meeting two potentially conflicting design requirements.

It should be understood that any other form of flow diverter may be provided, such as the use of one or more baffles and/or the like. Further, in some examples the diverter arrangement may be adjustable.

The transmission arrangement 56 comprises an input member in the form of a can 90 which is coupled at a central hub thereof to the drive shaft 62. In the present example the drive shaft 62 is integrally formed with the can 90 and thus may be considered to form part of the transmission arrangement 56. The can 90 is directly secured to the second or outer rotary fluid agitator 54, for example via connection 92, such that the second rotary fluid agitator is driven in the same direction as the impeller 60.

Referring additionally to Figure 6, which is an isometric view of parts of the transmission arrangement 56, a ring gear 94 is formed or secured to an inner surface of the can 90 and is meshed with a plurality of planet gears 96 (5 in the example presented) which are mounted on a static carrier 98 secured to the static shaft 64. As such, the planet gears 96 do not orbit relative to the ring gear 94. Each planet gear 96 is rotatably mounted on a respective axle 100 extending from the static carrier 98, with rotation facilitated via bearings 102, as illustrated in Figure 7.

The transmission arrangement 56 further comprises a central or sun gear 104 which is secured to the first or inner rotary fluid agitator 52 and which is meshed with the planet gears 96, such that rotation of the ring gear 94 imparts rotation on the sun gear 104, and thus agitator 52, via the planet gears 96. As the planet gears 96 are secured against orbiting motion said planet gears 96 may thus define idler gears configured to reverse rotation between the ring and sun gears 94, 104, thus facilitating contra rotation via a common drive. By the planet gears 96 functioning as idler gears both the ring and sun gears 94, 104 may rotate, in opposite directions, at the same rotational speed. However, in other examples a gear train may be provided between the sun and ring gear to provide a change in rotational speed.

Referring again to Figure 3, and as noted above, the fluid outlets 24 are provided on an outlet assembly 26 which is rotatable to provide a desired outlet spray pattern. A bearing arrangement 106 accommodates rotation of the outlet assembly 26. However, in other examples the outlet assembly may be fixed. Alternatively, the fluid outlets may be provided in a different form. In this respect, Figure 8 illustrates an alternative apparatus, generally identified by reference numeral 110, which includes a circumferential array of fluid outlets 124 formed in one axial end face 125 of the apparatus 110. The fluid outlets 124 may be formed of ports or apertures, and may or may not include flow nozzles.

Further, the fluid outlet may be oriented in any desired direction.

In the example presented above a heater 42 is located within a housing 18, with a flow path defined within the housing such that fluid flowing therethrough may be subject to heating. However, in other examples the housing may be omitted, such that the heater may function to heat a fluid in an external flow path. Such an alternative example will now be described, initially with reference to Figure 9 which is an isometric view of an alternative apparatus, generally identified by reference numeral 200, for use in a process to remove a material from within a conduit.

The apparatus 200 includes a casing 202 which includes an outer heat transfer surface 204 comprising a plurality of axially extending and circumferentially distributed ribs 205 which function to increase the heat transfer surface area. As will be described in more detail below, the outer heat transfer surface 204 is presented in thermal communication with a flow path when the apparatus 200 is located within a conduit. The apparatus 200 further includes a drive shaft 206 which, as described below, is coupled to a drive arrangement for applying a rotary drive to an agitator mechanism within the casing 202 for generating heat.

Figure 10 is a longitudinal cross-sectional view of the apparatus 200 of Figure 9, diagrammatically illustrated within a conduit 208 which includes a material 210 to be removed. The conduit 208 accommodates flow of a fluid (illustrated by arrows 212), such that a flow path (or bypass flow path) 214 extends around the apparatus 200, between an outer surface of the apparatus 200 and an inner surface of the conduit 208.

In this respect the heat transfer surface 204 of the apparatus 200 defines a portion of the flow path 214, which may thus be defined as a heated portion 214a. During use, fluid flowing along the flow path 214 is heated, and may then be used in the removal of the material 210, in a similar manner to that described above.

An electric motor 216 (which is diagrammatically illustrated) is drivingly engaged with the drive shaft 206, wherein the electric motor 216 receives electrical power (and optionally communication signals) via a power conductor 218, such as e-line. The power conductor 218 may also be used to deploy, retrieve and or manoeuvre the apparatus 200. In some examples an engagement mechanism, such as a centraliser, slip system and/or the like may be provided to at least partially rotatably fix the motor 216 relative to the casing.

However, other examples may not require this. Furthermore, in some examples the apparatus 200 may be deployed on tubing, such as jointed tubing, coiled tubing and/or the like, wherein the tubing may accommodate any torque reaction. In this case the tubing may also be utilised to deliver a fluid towards the apparatus 200, to then be flowed within the flow path 214. Of course, any tubing may be provided with the primary function of delivering fluid, rather than any torque reaction requirements The casing 202 of the apparatus 200 is closed and sealed at opposite axial ends thereof via respective first and second end caps 220, 222 to define an internal heating chamber 224, wherein the heating chamber 224 holds a volume of a heating fluid, such as a viscous gear oil. The apparatus 200 further comprises an agitator mechanism 226 mounted within the heating chamber 224 which functions to agitate the heating fluid to generate heat therein such that the heating fluid may in turn be used to provide heating within the heated flow path section 214a, via the casing 202 and heat transfer surface 204.

Reference is additionally made to Figure 11 which is a lateral sectional view taken along line 11-11 of Figure 10. In the present example the agitator mechanism 226 comprises a rotary agitator 228 which is coupled, via the drive shaft 206, to the motor 216. The agitator mechanism 226 further comprises a static agitator 230 located around the inner surface of the casing 202 to circumscribe the rotary agitator 228. During use, the rotary agitator 228 is rotated by the motor 206 to run in close proximity to the static agitator 230 to agitate and heat the fluid within the heating chamber 224. While the static agitator 230 n the present example is provided separately from the casing 202, in other examples these components may be integrally formed.

The rotary fluid agitator 228 includes a central hub 228a and a plurality of agitator fins 228b which extend both axially and radially relative to the central hub 228a. The static fluid agitator 230 is generally annular in form and includes an agitator profile on an inner surface thereof, specifically a circumferential array of axially extending ribs 230a with respective grooves 230b therebetween. As illustrated, the tips of the fins 228b on the rotary agitator 228 run or rotate in close proximity to the tips of the ribs 230a on the static agitator 230, thus enhancing the agitation effect on the heating fluid within the heating chamber 224.

In a further alternative, the agitator mechanism within apparatus 200 may include first and second rotary fluid agitators, which may rotate in the same direction, or be configured for contra rotation. In some examples separate drives may be provided for each rotary fluid actuator, and/or a suitable transmission system may be provided to permit a common drive to be used.

In the examples presented above an apparatus is provided for use in the removal of a material from within a conduit. However, the apparatus may be used in any application, and may simply be deemed to relate to an apparatus for use in providing a stream of a heated fluid. Further, the apparatus may be provided to heat a fluid for any subsequent use The heater defined herein is not limited for use only in the described apparatus. Instead, the heater may be used in combination or as part of any other apparatus where heating is required.

It should be understood that the examples provided herein are indeed merely exemplary of the present disclosure and are not intended to be limiting.

Claims

CLAIMS1. An apparatus for use in removing material from a conduit, comprising: a heater locatable within the conduit to be in thermal communication with a flow path to facilitate heating of a first fluid flowing along said flow path, the heater comprising a heating chamber and an agitator mechanism operable to agitate a second fluid within the heating chamber to generate thermal energy within the second fluid.
2. The apparatus according to claim 1, wherein the flow path is at least partially defined externally of the apparatus
3. The apparatus according to claim 1 or 2, wherein the flow path is at least partially defined within the apparatus.
4. The apparatus according to any preceding claim, wherein the heater defines a boundary of at least part of the flow path to facilitate thermal communication of the heater with the flow path.
5. The apparatus according to any preceding claim, comprising a housing having a fluid inlet and a fluid outlet, wherein the flow path extends between the fluid inlet and fluid outlet and the heater facilitates heating of the first fluid prior to exiting the housing via the outlet.
6. The apparatus according to any preceding claim, wherein the heater is mounted within the housing to define at least a portion of the flow path therebetween.
7. The apparatus according to any preceding claim, comprising a drive arrangement operable to provide a rotary drive to the agitator mechanism.
8. The apparatus according to claim 7, wherein the drive arrangement comprises a rotary turbine configured to rotate upon exposure to flow of a drive fluid.
9. The apparatus according to claim 8, wherein the drive fluid comprises the first fluid such that the drive arrangement is operated by the flow of the first fluid flow.
10. The apparatus according to any one of claims 7 to 9, wherein the drive arrangement is located upstream of the heater.
11. The apparatus according to any one of claims 7 to 10, wherein the drive arrangement comprises an electrical motor.
12. The apparatus according to any preceding claim, comprising a fluid diverter located upstream of the heater and configured to divert a portion of the first fluid from the flow path such that, in use, the fluid diverter divides the flow of first fluid into a retained portion which is directed along the flow path to be heated, and a diverted portion which is directed away from the flow path.
13. The apparatus according to claim 12, wherein the fluid diverter comprises a flow splitter configured to divide the flow of first fluid into the retained portion an the diverted portion.
14. The apparatus according to claim 12 or 13, wherein the fluid diverter comprises a diverter outlet for accommodating the diverted portion of the first fluid to exit the apparatus.
15. The apparatus according to any preceding claim, wherein the agitator mechanism comprises a fluid agitator configured to be moved within or relative to the second fluid within the heating chamber to agitate said second fluid.
16. The apparatus according to claim 15, wherein the agitator mechanism comprises a plurality of fluid agitators each configured to be moved within or relative to the second fluid within the heating chamber to agitate said second fluid.
17. The apparatus according to any preceding claim, wherein the agitator mechanism comprises a first rotary fluid agitator and a second rotary fluid agitator which circumscribes the first rotary fluid agitator, such that the first rotary fluid agitator defines an inner fluid agitator and the second rotary agitator defines an outer fluid agitator.
18. The apparatus according to claim 17, wherein the first and second rotary fluid agitators are rotatable in opposite directions.
19. The apparatus according to claim 17 or 18, comprising a transmission arrangement coupled between a drive arrangement and the first and second rotary fluid agitators.
20. The apparatus according to claim 19, wherein the transmission arrangement is configured to permit the drive arrangement to rotate the first and second rotary fluid agitators in opposite directions via a common drive arrangement.
21. The apparatus according to claim 19 or 20, wherein the transmission arrangement comprise a planetary gear system comprising: a sun gear rotatably coupled to the first rotary fluid agitator; a ring gear which circumscribes the sun gear and is rotatably coupled to the second rotary fluid agitator; and a planet gear radially interposed and meshed between the sun and ring gears wherein one of the sun and ring gears is coupled to a rotary drive input, with the other of the sun and ring gears being driven in an opposite direction via the planet gear.
22. The apparatus according to claim 21, wherein the planet gear is secured against orbiting motion relative to the sun and ring gears such that the planet gear defines an idler gear configured to reverse rotation between the sun and ring gears, thus facilitating contra rotation via a common drive.
23. A method for removing material from a conduit, comprising: locating an apparatus comprising a heater at a desired location within the conduit; delivering a first fluid along a flow path which is in thermal communication with the heater; agitating a second fluid within a heating chamber of the heater to generate thermal energy within the second fluid; and heating the first fluid flowing along the flow path with heat generated within the second fluid, wherein the heated first fluid is for use in removing a material from the conduit.
24. The method according to claim 23, comprising delivering the first fluid along a flow path which is external to the apparatus.
25. The method according claim 23 or 24, comprising: delivering the first fluid into the apparatus via a fluid inlet to be flowed along a flow path within the apparatus; and ejecting the heated first fluid from the apparatus via a fluid outlet for use in removing a material from the conduit.