Abstract: The present invention relates to methods and systems for establishing a well foundation as well as for drilling and installation of a surface casing without any use of a drilling rig.

Abstract: The systems and methods generally include a nuclear power plant unit assembled in a shipyard from a plurality of structural modules, each of the structural modules having manufactured components for use in power production when moored or fixed to a floor at least one of in and proximal to at least one of an offshore marine environment, a river environment and a coastal marine environment. The nuclear power plant unit is subdivided into at least one arrangement of structural modules that includes an electrical interface for one of transmitting electrical power generated by the nuclear unit and powering a system of the unit, a communications interface for communications internal or external to the unit, a user interface that is configured to permit a user to access a system of the unit, and a network interface for data communications to or from the unit.

Abstract: A datalink tool comprising an MWD-connected assembly disposed to move relative to an LWD-connected assembly. A hardwired electrical connection is provided between the MWD-connected and LWD-connected assemblies. An oil space is provided such that at least part of the hardwired electrical connection is configured to be immersed in a nonconductive oil contained inside the oil space. A compensator sleeve contributes at least in part to isolation of nonconductive oil in the oil space from drilling fluid residing outside the space. In some deployments, the drilling fluid may be conductive. The compensator sleeve is disposed to expand and relax in response to pressure variations in the drilling fluid, thereby attenuating a corresponding effect of the pressure variations in the nonconductive oil inside the oil space.

Abstract: A method of installing a header pipe joint 1 at a subsea structure 5 is provided, comprising providing a header pipe joint 1 having at least one valve 2 installed therein and connecting the header pipe joint 1 inline of a spool 15 or pipeline 18 prior to lowering the header pipe joint 1 to the subsea structure 5. The header pipe joint 1 is then lowered to the subsea structure 5, and the valve 2 is connected to the subsea structure (e.g. a subsea production system of the subsea structure such as a xmas tree) with a connection bridge e.g. a choke bridge 14. This provides a fluidic connection between the subsea structure and the header pipe joint. The subsea structure 5 comprises a foundation, e.g. suction anchors 11, which provide support for both a wellhead and the header pipe joint. A subsea assembly comprising a subsea structure 5, header pipe joint 1 and connection bridge 14 is also provided.

Abstract: A drilling system includes a surface system comprising a control panel. The drilling system further includes a pressure control equipment configured to be operatively coupled to the control panel, wherein the control panel comprises at least one intrusion prevention system (IPS) enabled device configured to provide for one or more IPS functions.

Abstract: The systems and methods generally include a nuclear power plant unit assembled in a shipyard from a plurality of structural modules, each of the structural modules having manufactured components for use in power production when moored or fixed to a floor at least one of in and proximal to at least one of an offshore marine environment, a river environment and a coastal marine environment. The nuclear power plant unit is subdivided into at least one arrangement of structural modules that includes an electrical interface for one of transmitting electrical power generated by the nuclear unit and powering a system of the unit, a communications interface for communications internal or external to the unit, a user interface that is configured to permit a user to access a system of the unit, and a network interface for data communications to or from the unit.

Abstract: Systems and methods for casing drilling riserless sections of a subsea bore may include casing drilling a section of a bore for a casing of the subsea bore to a predetermined depth. The method also may include, while casing drilling the section of the bore, obtaining information indicative of pore pressure and fracture pressure of a geological formation through which the section is casing drilled, and determining a pressure range based at least in part on the pore pressure, the fracture pressure, and a modification to mechanical properties of the geological formation due to the casing drilling of the section. The method further may include selecting, based at least in part on the pressure range and the predetermined depth, a pressure of the bore for casing drilling the section.

Abstract: A wellhead assembly and a method of installing a wellhead assembly. The method includes providing a well casing; providing a wellhead support structure; locating and fixing the well casing in a hole in the waterbed, wherein when the well casing is located and fixed in the hole the wellhead support structure is located a distance above the waterbed so as to leave a gap between the surface of the waterbed and the underside of the wellhead support structure; and fixing the wellhead support structure onto the surface of a waterbed with a settable material by putting the settable material into the gap when in a non-solid state to provide a rigid connection between the waterbed and the underside of the wellhead support structure. The assembly is arranged so that bending moments applied to the wellhead assembly can be at least partially transferred to the waterbed via the wellhead support structure.

Abstract: A downhole isolation tool for sealing a casing in a well, the downhole isolation including plural parts made of a composite material, each part having a preset functionality with regard to sealing the casing; and a sealing element configured to seal the casing. At least two parts of the plural parts have a single, combined body.

Abstract: The invention discloses a dynamic simulation method of circulating temperature variation in RMR subsea pump mud-lift drilling system, including steps: obtaining operating parameters, environmental parameters, well structure parameters and thermal parameters of target well; establishing temperature control equation of drill string in seawater section, temperature control equation of drill string in formation section, temperature control equation of annulus in formation section, and temperature control equation of return pipe in seawater section; re-determining initial and boundary conditions; discretizing spatial structure of the whole system with inner node method; discretizing control equations on corresponding nodes; substituting corresponding parameters into discrete expressions to obtain circulating temperature in drill string of seawater section, circulating temperature in drill string of formation section, circulating temperature in annulus of formation section, and circulating temperature in return pip

Abstract: A system and method for creating a subsea well for the production or injection of hydrocarbons, fluids, or gases which can include installing an assembly having a subsea template and at least one conductor housing installed in a slot in the template. A drill string can be passed through the at least one conductor housing and drill directly into the seafloor to create a first bore associated with the slot in the template. The bore can be of a diameter suitable for a surface casing and the surface casing can be passed through the conductor housing and into the bore.

Abstract: A quick connect system includes: a female component including: a center bore longitudinally disposed therethrough; a tooth recess disposed around an interior circumference of the center bore; and teeth circumferentially disposed within the tooth recess. The system also includes a male component including at least one cylindrical portion disposed within the center bore. The teeth engage the cylindrical portion.

Abstract: A method and apparatus according to which a hydraulic fracturing fluid is communicated to a wellhead, the apparatus including a fracturing tree connected to the wellhead and into which the hydraulic fracturing fluid is adapted to flow, a fluid conduit connected to the fracturing tree and through which the hydraulic fracturing fluid is adapted to flow before flowing into the fracturing tree, the fluid conduit defining a straight fluid flow path, and a zipper module connected to the fluid conduit and out of which the hydraulic fracturing fluid is adapted to flow before flowing through the fluid conduit. The hydraulic fracturing fluid flows along the straight fluid flow path of the fluid conduit upon flowing out of the zipper module, and continues to so flow along the straight fluid flow path until the hydraulic fracturing fluid flows into the fracturing tree.

Abstract: The present invention provides a method and system for providing on-site electrical power to a fracturing operation, and an electrically powered fracturing system. Natural gas can be used to drive a turbine generator in the production of electrical power. A scalable, electrically powered fracturing fleet is provided to pump fluids for the fracturing operation, obviating the need for a constant supply of diesel fuel to the site and reducing the site footprint and infrastructure required for the fracturing operation, when compared with conventional systems.

Abstract: The present invention provides a method and system for providing on-site electrical power to a fracturing operation, and an electrically powered fracturing system. Natural gas can be used to drive a turbine generator in the production of electrical power. A scalable, electrically powered fracturing fleet is provided to pump fluids for the fracturing operation, obviating the need for a constant supply of diesel fuel to the site and reducing the site footprint and infrastructure required for the fracturing operation, when compared with conventional systems.

Abstract: A dual gradient drilling system includes a subsea blowout preventer disposed above a wellhead, the subsea blowout preventer having a central lumen configured to provide access to a wellbore, a lower section of a marine riser fluidly connected to the subsea blowout preventer, a closed-hydraulic positive displacement subsea pump system fluidly connected to the lower section of the marine riser and disposed at a predetermined depth, an annular sealing system disposed above the closed-hydraulic positive displacement subsea pump system, and an independent mud return line fluidly connecting one or more pump heads of the closed-hydraulic positive displacement subsea pump system to a choke manifold disposed on a floating platform of a rig.

Abstract: A dual gradient drilling system includes a subsea blowout preventer disposed above a wellhead, the subsea blowout preventer having a central lumen configured to provide access to a wellbore, a lower section of a marine riser fluidly connected to the subsea blowout preventer, a closed-hydraulic positive displacement subsea pump system fluidly connected to the lower section of the marine riser and disposed at a predetermined depth, an annular sealing system disposed above the closed-hydraulic positive displacement subsea pump system, and an independent mud return line fluidly connecting one or more pump heads of the closed-hydraulic positive displacement subsea pump system to a choke manifold disposed on a floating platform of a rig.

Abstract: A dual gradient drilling system includes a subsea blowout preventer disposed above a wellhead, the subsea blowout preventer having a central lumen configured to provide access to a wellbore, a lower section of a marine riser fluidly connected to the subsea blowout preventer, a closed-hydraulic positive displacement subsea pump system fluidly connected to the lower section of the marine riser and disposed at a predetermined depth, an annular sealing system disposed above the closed-hydraulic positive displacement subsea pump system, and an independent mud return line fluidly connecting one or more pump heads of the closed-hydraulic positive displacement subsea pump system to a choke manifold disposed on a floating platform of a rig.

Abstract: An offshore system includes a vessel having a deck; a cantilever which is mounted on the deck and which is moveable in a longitudinal direction of the cantilever relative to the deck between a retracted position and an extended position, and which is rotatable relative to the deck about a substantially vertical swivel axis; and actuators to move the cantilever in longitudinal direction and to rotate the cantilever about the swivel axis. The swivel axis is provided by a single sliding and swivel assembly arranged at one end of the cantilever, including a fixed part mounted to the deck and a sliding part mounted to the cantilever. The sliding part is arranged to slide in longitudinal direction of the cantilever relative to the fixed part when the cantilever moves in the longitudinal direction. The fixed part and/or the combination of fixed part and sliding part are configured to form the swivel axis allowing the cantilever to rotate relative to the deck.

Abstract: A method for modifying a return fluid in a wellbore comprising disposing at least one valve along a drill pipe section of a drill string in the wellbore. At least one parameter of interest is determined at at least one location along the wellbore. At least one valve is controllably actuated to discharge at least a portion of at least one fluid from inside the drill string to an annulus in the wellbore to modify a local property of the return fluid in the annulus based at least in part on the measured parameter of interest.

Abstract: A method for drilling and producing a surface wellbore. The method can include drilling a conductor pipe borehole; installing a conductor pipe within the conductor pipe borehole; installing a drilling flange onto the conductor pipe; and assembling a wellhead stack on the drilling flange. The wellhead stack can include two or more blow out preventers, a kill line hub secured to and in fluid communications with a first spool located below a first blowout preventer, a choke line hub secured to and in fluid communications with a second spool located between a second blowout preventer and the first blow out preventer, a choke line, and a kill line, wherein both the kill line and choke line each have a quick connect collet connector. The kill line collet connector can be landed on the kill line and the choke line collet connector on the choke line hub.

Abstract: An offshore well system for a subsea well includes an internal riser tension device configured to apply tension to an internal riser and an external riser tension device configured to apply tension to an external riser such that the external riser is supported at least partially independent of the internal riser tension device.

Abstract: An offshore well system for a subsea well, including a floating platform, a drilling riser system connected with the well for drilling operations, and a production riser system connected with the well for production operations. The drilling system also includes a riser tension system. The riser tension system is capable of compensating for movement of the platform while adequately tensioning both drilling riser system and the production riser system when each is connected to the well.

Abstract: A riser assembly and method of supporting a riser assembly are disclosed. The riser assembly includes a riser; at least one buoyancy compensating element attached to the riser; and at least one damped biasing element for controlling movement of the riser about a neutral position with respect to an adjacent underwater structure. The biasing element is directly or indirectly connected to the riser and is directly or indirectly connectable to the adjacent underwater structure.

Abstract: A floating, offshore drilling and/or production platform is equipped with a rail-mounted transport system that can be positioned at a plurality of selected positions over the well bay of the vessel. The transport system can move a drilling riser with a drilling riser tensioner system and a blowout preventer from one drilling location to another without removing them from the well bay of the vessel. Using the transport system, the drilling riser is lifted just clear of a first well head and positioned over an adjacent, second well head using guidelines. The transport system may then move the upper end of the drilling riser (together with its attached tensioner and BOP) to a second drilling location. A dummy wellhead may be provided on the seafloor in order to secure the lower end of the drilling riser without removing it from the sea while production risers are being installed.

Abstract: A system and method for guiding a dropped suspended load includes a safety winch, safety buoy, and safety anchor spaced relative to one another and an offshore rig's lifting system so that the dropped load falls away from certain seabed locations and to a safe landing area. A safety winch cable runs from the safety winch to the safety buoy, and from the safety buoy to a connection to the load. The load, when in a run-away state, falls away from vertical and toward a predetermined safe landing spot on the seabed floor. The safety buoy is then used to locate the load.

Abstract: A noise-attenuating pile comprising a pile driving shoe, an outer tube that engages the pile driving shoe, and an inner member that extends through the outer tube and engages the pile driving shoe, wherein the pile is configured to be installed in the ground with either an impact driver or a vibratory driver that engages only the inner member. The inner member is rigidly connected to the driving shoe, and the outer tube is elastically connected to the driving shoe, such that vibrations from the outer tube is substantially isolated from vibrations in the driving shoe.

Abstract: A process for constructing a well (1) for exploiting an oil or gas reservoir, comprising the following operations: (A) drilling a formation submerged by a water head, at least 3,600 meters deep or more, reaching the formation from the surface of the water with a drilling riser (7), and a drilling tool which passes internally through the drilling riser; and evacuating through the drilling riser (7) at least one of the circulating drilling fluid, the oil or natural gas coming from the formations and the resulting drilling materials. The drilling riser (7) has an external diameter equal to or smaller than 17 inches and reaches a wellhead (3) having an internal diameter equal to or smaller than 18.75 inches, and positioned in correspondence with or close to the seabed submerged which covers the formation.

Abstract: A floating, offshore drilling and/or production platform is equipped with a rail-mounted transport system that can be positioned at a plurality of selected positions over the well bay of the vessel. The transport system can move a drilling riser with a drilling riser tensioner system and a blowout preventer from one drilling location to another without removing them from the well bay of the vessel. Using the transport system, the drilling riser is lifted just clear of a first well head and positioned over an adjacent, second well head using guidelines. The transport system may then move the upper end of the drilling riser (together with its attached tensioner and BOP) to a second drilling location. A dummy wellhead may be provided on the seafloor in order to secure the lower end of the drilling riser without removing it from the sea while production risers are being installed.

Abstract: A method for delivery of drilling fluid to a seafloor drilling assembly, the method comprising the steps of filling at least one container with drilling fluid; lowering the container through a body of water to adjacent a seafloor drilling assembly; connecting the container to the seafloor drilling assembly to deliver drilling fluid to the seafloor drilling assembly.

Abstract: The present invention relates to a gravity-based foundation system for offshore wind turbine installation that comprises three floating concrete bases built with self-floating concrete caissons, equipped with valves for filling them with water and emptying the water out enabling their ballasting and anchoring at their final location; a metal structure which connects the floating concrete bases by means of a connecting element to the wind turbine tower, and a metal element which connects the floating concrete bases to the wind turbine, metal element on which a docking area is installed, a maintenance platform and access stairs, and it also relates to a method of installation of the gravity-based foundation system.

Abstract: An apparatus including a bell nipple assembly defining a first internal passage that includes two sections forming first and second internal passages that may be aligned by a flexible connector disposed between first and second flanges in one of the sections to at least partially adjust for an offset amount caused by longitudinal axis misalignment of the other section. Methods of adjusting for longitudinal axis offset between two misaligned components, such as of a bell nipple zone, are also encompassed.

Abstract: A method for maintaining pressure in a wellbore drilled from a drilling platform floating on a body of water includes pumping fluid at a determined flow rate into a drill string disposed in a wellbore and measuring fluid pressure within a fluid discharge line of fluid returning from the wellbore. The fluid discharge line has a variable length corresponding to an elevation of the floating platform above the bottom of the body of water. The wellbore pressure is determined at a selected depth in the wellbore or at a selected position along a drilling riser or variable length portion of the fluid discharge line using known parameters/methods. The determined wellbore pressure is adjusted for changes in length of the fluid discharge line corresponding to changes in the elevation of the floating platform relative to the bottom of the body of water.

Abstract: A system and method include pumping drilling fluid through a drill string extended into a wellbore extending below the bottom of a body of water, out the bottom of the drill string and into the wellbore annulus. Fluid is discharged from the annulus into a riser and a discharge conduit. The riser is disposed above the top of the wellbore and extends to the water surface. The discharge conduit couples to the riser and includes a controllable fluid choke. A fluid return line is coupled to an outlet of the choke and extends to the water surface. Gas under pressure is pumped into the return line at a selected depth below the water surface. The controllable fluid choke may be operated to maintain a selected drilling fluid level in the riser, the selected fluid level being a selected distance below the water surface.

Abstract: A method of drilling a subsea wellbore includes drilling the wellbore by injecting drilling fluid through a tubular string extending into the wellbore from an offshore drilling unit (ODU) and rotating a drill bit disposed on a bottom of the tubular string. The method further includes, while drilling the wellbore: mixing lifting fluid with drilling returns at a flow rate proportionate to a flow rate of the drilling fluid, thereby forming a return mixture. The lifting fluid has a density substantially less than a density of the drilling fluid. The return mixture has a density substantially less than the drilling fluid density. The method further includes, while drilling the wellbore: measuring a flow rate of the returns or the return mixture; and comparing the measured flow rate to the drilling fluid flow rate to ensure control of a formation being drilled.

Abstract: A heave compensating system for a marine vessel includes a hydraulic machine configured to be coupled to a load suspended from the vessel and to vary the distance between the load and the vessel in response to heaving motion of the vessel. The system further includes a second hydraulic machine in fluid communication with a hydraulic accumulator, both the first and second hydraulic machines are mechanically connected to one another and a shared electric motor, and a controller configured to control hydraulic movement of the first and second hydraulic machines and to control the supply of power to the electric motor.

Abstract: A system compensates for heave induced pressure fluctuations on a floating rig when a drill string or tubular is lifted off bottom and suspended on the rig, such as when tubular connections are made during MPD, tripping, or when a kick is circulated out during conventional drilling. The system also compensates for heave induced pressure fluctuations on a floating rig when a riser telescoping joint located below a RCD is moving while drilling.

Abstract: A subsea pressure control system can include at least one subsea choke which variably restricts flow of drilling fluid from a well annulus to a surface location, the choke being positioned at a subsea location, and a subsea process control system which automatically operates the subsea choke, whereby a desired pressure is maintained in the well annulus. Another subsea pressure control system can include at least one subsea choke which variably restricts flow of drilling fluid from a well annulus to a surface location, the choke being positioned at a subsea location, and a subsea pump which pumps the drilling fluid from the subsea location to the surface location.

Abstract: An offshore well drilling system for drilling a subsea well, including a floating platform, an external riser extending from the subsea well, and an internal riser extending from the subsea well to the platform. The internal riser is nested within the external riser. The system also includes an external riser tension device to apply tension to the external riser. The system also includes an internal riser tension device, separate from the external riser tension device, to apply tension to the internal riser.

Abstract: Method and apparatus for extending the horizontal distance through which wells can be drilled. A horizontal tubular is used to convey a drillstring from a drilling rig toward a target location and a mud return line and pump on the surface is used to pump drilling mud returning from the bit back to the drilling rig.

Abstract: A fluid diverter system for a drilling facility comprises a diverter housing (15; 15?) fluidly connected to a tubular (3, 42, 43) extending to a subsea well. The diverter housing (15; 15?) comprising a movable diverter element (2) for closing off the diverter housing, a first fluid conduit (44) connected to a mud system and comprising a first valve (5), at least one second fluid conduit (20; 20?) leading from an outlet (46; 46?) in the diverter housing to an overboard location and comprising a second valve (1; 48), and a third fluid conduit (16) connected to a mud/gas separator (MGS) (13) and comprising a third valve (4). The MGS (13) is arranged below the outlet (50) of the diverter line, whereby riser fluids may be fed from the diverter housing (15) to the MGS (13) by means of gravity flow. The diverter valve (1; 48) on a leeward side of the drilling facility is configured to be open before the diverter element (2) closes around the tubular (3).

Abstract: An offshore universal riser system may include a valve module which selectively permits and prevents fluid flow through a flow passage extending longitudinally through a riser string. An anchoring device may releasably secure the valve module in the passage. A method of constructing a riser system may include the steps of installing the valve module in the passage, and installing at least one annular seal module in the passage. The annular seal module may prevent fluid flow through an annular space between the riser string and a tubular string positioned in the passage. Drilling methods may include injecting relatively low density fluid compositions into the annular space, and selectively varying a restriction to flow through a subsea choke in a drilling fluid return line. The riser string, including housings for the various modules and external control systems, may be dimensioned for installation through a rotary table.

Abstract: A releasable guidepost extension is used on the seabed together with a bottom fixed guidepost part. These parts make up a guidepost for use during the lowering of a component from the surface of the water to a subsea structure. The guidepost part includes an upward (in use position) projecting end designed for engagement with a lower (in use position) end of the guidepost extension. The guidepost extension is loosely connected to the bottom fixed guidepost part via a pin and socket part on respective ends. A gap, or clearance, exists between the pin and socket part in the longitudinal direction, and at least one friction forming device arranged in the gap on either the pin part or in the socket part. The friction forming device does not get in contact, or engaged, with the other part unless the guidepost extension is subjected to a lateral force.

Abstract: A system comprising a floating host located over a first drilling center in a body of water, the floating host comprising drilling facilities; a floating spar located over a second drilling center; a first fluid transfer conduit between the second drilling center and the spar; and a second fluid transfer conduit between the spar and the floating host.

Abstract: Systems for accessing a well bore including a BOP stack with a universal intervention interface are disclosed. In some embodiments, the system includes a BOP stack and a valve assembly. The BOP stack has a throughbore and is installable on a well such that the throughbore is in fluid communication with the well bore. The valve assembly is coupled to the BOP stack and includes a fluid flowpath in fluid communication with the BOP stack throughbore, two valves connected in series and disposed along the fluid flowpath, the valves operable to control flow through the fluid flowpath, and a ROV panel including ports accessible by a ROV for operation of the two valves.

Abstract: An offshore system for drilling or production includes a buoyant hull. In addition, the offshore system includes a topside mounted to the hull and positioned above the surface of the water. Further, the offshore system includes a conductor having a lower end disposed in the sea bed below the sea floor and an upper end coupled to the topside. Still further, the offshore system includes a bend restrictor disposed about the conductor. The bend restrictor has a lower end positioned in the sea bed below the sea floor and an upper end positioned above the sea floor.

Abstract: An offshore universal riser system may include a valve module which selectively permits and prevents fluid flow through a flow passage extending longitudinally through a riser string. An anchoring device may releasably secure the valve module in the passage. A method of constructing a riser system may include the steps of installing the valve module in the passage, and installing at least one annular seal module in the passage. The annular seal module may prevent fluid flow through an annular space between the riser string and a tubular string positioned in the passage. Drilling methods may include injecting relatively low density fluid compositions into the annular space, and selectively varying a restriction to flow through a subsea choke in a drilling fluid return line. The riser string, including housings for the various modules and external control systems, may be dimensioned for installation through a rotary table.

Abstract: A system for transferring fluids from a free-standing riser to a surface vessel comprises a first valve assembly including a first valve spool and a first isolation valve configured to control the flow of fluids through the first valve spool. In addition, the system comprises a second valve assembly releasably coupled to the first valve assembly with a hydraulically actuated connector. The second valve assembly includes a second valve spool and a second isolation valve configured to control the flow of fluids through the second valve spool. Further, the system comprises a deployment/retrieval rigging coupled to the first valve assembly and configured to suspend the first valve assembly and the second valve assembly from the surface vessel. Each isolation valve has an open position allowing fluid flow therethrough and a closed position restricting fluid flow therethrough, and each isolation valve is biased to the closed position.

Abstract: A subsea system for intervention or deployment comprising a spool (9, 109) adapted for mounting subsea, a carrier (4, 4, 5?, 34, 104) adapted for suspension from a surface vessel or platform, a guide line (8, 108) wound on the spool, the free end of the guide line connected to the carrier and means (11) for driving the spool in one direction to pay out a length of guide line as the distance between the spool and the carrier is increased and in the other direction to reel in the length of guide line as the distance between the spool and the carrier decreases.

Abstract: The invention relates to an underwater drilling arrangement and a method for introducing a foundation element into a bed of a body of water comprising a submersible working platform for placement onto the bed of a body of water, several ground contact elements which are arranged in an adjustable manner on the working platform for aligning the working platform on the bed of a body of water, and at least one guide pipe for receiving and guiding the drilling tool. For an improved anchoring provision is made according to the invention for the guide pipe to be supported in a longitudinally displaceable and rotatable manner on the working platform and for a guide pipe drive to be provided on the working platform for driving the guide pipe in a rotating manner.