Abstract: A unitized wellhead assembly includes a lower wellhead housing and an upper wellhead housing interconnected by internal and external threads and pressure sealed via a housing seal that creates a unitized body. The unitized wellhead assembly accepts casing and tubing hanger assemblies containing a plurality of individual retainer segments that engage mating grooves in the unitized body and also retains the casing and tubing hangers in place while containing the wellbore pressure. By eliminating the porting for external actuation devices that pass through the wall section of a wellhead housing, the potential for accidental release of wellbore gasses or fluids to the atmosphere and creation of a potentially hazardous or deadly situation is eliminated. Additionally, the configuration of the segmented retainers reduces high stresses when the retainers are forced outward and eliminates the potential to yield a retainer ring beyond the point of being able to return to its original shape.

Abstract: A method for snubbing a wellhead hanger into a wellhead is provided. In one embodiment, a snubbing method includes snubbing a tubing hanger into a wellhead housing from a snubbing unit. Snubbing the tubing hanger into the wellhead housing can include lowering the tubing hanger into a bore of the wellhead housing under pressure and allowing fluid in the bore to pass along an exterior of the tubing hanger to balance fluid pressure above and below the tubing hanger as the tubing hanger is lowered. The tubing hanger can be positioned at a location in the bore of the wellhead housing, which can be elastically deformed to grip and secure the tubing hanger at the location in the bore. Additional methods, systems, and devices are also disclosed.

Abstract: A casing head support system (CHSS) for a casing head includes a casing head support unit (CHSU) having a tubular body with a support unit top end (SUTE) and a support unit bottom end (SUBE); a first conductor string extension joint coaxially fastened to the SUBE; and an internal load profile machined into an inner circumferential surface of the CHSU. The SUTE forms a coaxial connection with the casing head. The internal load profile supports a corresponding load shoulder on a conductor hanger. The CHSU contains a CHSU top preparation machined into the inner circumferential surface of the support unit. The CHSU top preparation is located at the SUTE. The CHSU top preparation mates with a corresponding casing head support unit running tool (CHRT) bottom preparation.

Abstract: An apparatus (10) for downhole data acquisition and/or monitoring is configured to be disposed within a completion (12) and comprises a hanger (36) configured to latch into a control line spool (38), a retrofit valve (40) for location within the subsurface safety valve (16) of the completion (12), and a sensing arrangement (42) including an optical fiber line (44). In use, the apparatus (10) is configured to be run into the completion (12) and is operable to provide data acquisition and/or monitoring capability in the well, including up or near total depth and in particular but not exclusively in the region of the well subjected to an intervention operation, such as a chemical injection operation.

Abstract: A wellhead assembly having an insert that is disposed between a wellhead housing and casing hanger. Axial slots through the insert define a flow path between the wellhead housing and casing hanger. The insert is made from a higher strength material and supports a load exerted between the casing hanger and wellhead housing. The insert is a ring like member, and the slots can more easily be machined in the insert than in the wellhead housing.

Abstract: A wellhead assembly is disclosed which has a gas flow control valve with a tubular inlet into which a fluid from a well tube flows, and a gas flow line through which the fluid flows out from the gas flow control valve. An inlet tube has a first end operably coupled to the well tube, and a second coupled to the inlet of the valve. The inlet has a first groove formed on a surface thereof, and the inlet tube has a second groove formed on a surface thereof. A split lock ring is used which partially rests in, and which is substantially fully compressed into, one of the grooves, when the inlet tube is telescopically coupled to the inlet. The lock ring engages with the other one of the grooves as the two grooves become axially aligned during coupling, to lock the inlet tube to the inlet while permitting rotational movement of the inlet tube relative to the inlet.

Abstract: A running tool for use in the insertion of an object such as a casing hanger into a subsea well includes a body and a hollow mandrel moveable within the body. Engagement dogs are supported within the body and are moveable to engage the object, the mandrel having a first part and a transition part, the transition part being shaped to cause out-ward movement of the dogs when the mandrel is in a given position within the body and to allow movement of the dogs for position of the mandrel spaced form the given position. The tool has an emergency release feature wherein the transition part is releasably attached to the first part by shear pins which shear in response to a sufficient increase in pressure within the mandrel to allow the transition part to separate from the first part.

Abstract: A sealing system between a relatively rotating element and a stationary element has at least three sealing elements arranged between the rotating element and the stationary element and arranged in series between a process fluid and an environment, and a barrier fluid arrangement to provide a barrier fluid to spaces formed between the sealing elements. The barrier fluid arrangement has at least two compensator devices where under use the pressure in the process fluid is acting on one side of a piston in the compensator device and the pressure in the barrier fluid is acting on the opposite side of the piston. There is a difference between cross sectional areas of the two sides of the piston and the difference varies between the at least two compensator devices.

Abstract: A drilling system employing a main tubular having a plurality of fluid inlet and outlet conduits positioned thereon and a concentric inner tubular having a plurality seals for sealing the annular space between the concentric inner and main tubulars. The fluid inlet and outlet conduits work in cooperation with the annular seals to selectively open and close for effective management of pressure within the tubulars.

Abstract: A conduit assembly for use in a drilling system that may include an upper section, an intermediate section and a lower section. The upper section may include a first seal. The first seal may include an opening that may be sized and configured to receive and form a seal with an inner drill string. The first seal may include one or more slits that may extend from an outer edge of the first seal to the opening of the first seal. The intermediate section may include an outlet for a flushing medium. The outlet may include a projection that may extend into a hollow interior of the intermediate section. The lower section may be sized and configured to be connected to and disconnected from a connecting portion of an outer drill string. The lower section may be sized and configured to be connected to and disconnected from the intermediate section.

Abstract: A well system comprising, in combination, a recipient ground area, a surface casing, a source well casing, a return well casing, and a return pipe. The return pipe is located within the return well casing, and the return well casing is located within the source well casing. This arrangement allows the removal of water from, and the return of water to different strata through the same drilled well hole, while also monitoring different aquifers water quality and/or aquifer parameters.

Abstract: A string of conduit extending from a subsea wellhead assembly to a surface wellhead assembly on a platform has a plurality of grooved profiles on an upper portion of the conduit. Each profile is spaced axially from another of the grooved profiles. After a lower end of the conduit is secured to the subsea wellhead assembly, the operator pulls on the conduit to apply a selected tension to the conduit. The operator attaches a support ring to the profile that was closest to and above a load shoulder in the surface wellhead assembly when the desired tension was reached. After landing the support ring on the load shoulder, the operator may cut off any excess portion of the upper portion of the conduit located above the support ring. A seal ring is set between the upper portion of the conduit and the surface wellhead housing.

Abstract: A wellhead system comprising an outer wellhead housing, an inner wellhead member, and an annulus therebetween. The inner wellhead member, such as a casing hanger, is adapted to land in the outer wellhead housing. The outer wellhead housing may comprise a wickers formed in a hardened metal inlay. Alternatively, or in addition to the wickers formed in the outer wellhead housing, wickers may be formed in a hardened metal inlay in the inner wellhead member. An annular metal seal may be disposed in the annulus and driven into the wickers to seal the annulus between the inner wellhead member and the outer wellhead housing and to axially restrain the seal within the annulus.

Abstract: A casing mandrel for an independent screwed wellhead includes a seal bore for receiving a fixed-point packoff connected to a high-pressure mandrel of a pressure isolation tool, and a pin thread adapted for engagement with a box thread of a tubing head supported by the casing mandrel.

Abstract: A hybrid wellhead system for a hydrocarbon well, having a wellhead supported by a conductor; an intermediate head spool secured to the wellhead by a hammer union; and a tubing head spool secured to the intermediate head spool by a hammer union.

Abstract: A casing mandrel for an independent screwed wellhead includes a seal bore for receiving a fixed-point packoff connected to a high-pressure mandrel of a pressure isolation tool, and a pin thread adapted for engagement with a box thread of a tubing head supported by the casing mandrel.

Abstract: A hybrid wellhead system is assembled using a plurality of threaded unions, such as spanner nuts or hammer unions, for securing respective tubular heads and a flanged connection for securing a flow control stack to a top of a tubing head spool. The tubing head spool is secured by a threaded union to an intermediate head spool. The intermediate head spool is secured by another threaded union to a wellhead. Each tubular head secures and suspends a tubular string in the well bore. The hybrid wellhead system is capable of withstanding higher fluid pressures than a conventional independent screwed wellhead, while providing a more economical alternative to a flanged, or ranged, wellhead system because it is less expensive to construct and faster to assemble.

Abstract: A low-pressure wellhead system with tubular heads and mandrels secured independently using threaded unions. A casing mandrel is secured to a wellhead by a first threaded union. Likewise, a tubing head spool is secured to the casing mandrel using a threaded union. A tubing hanger is also secured to the tubing head spool using a threaded union. An adapter flange may also be secured to the tubing hanger by a threaded union. Because this low-pressure wellhead is faster and easier to assemble and provides full bore access, there is less rig downtime, thus rendering the well completion process faster and more economical.

Abstract: A drilling system employing a main tubular having a plurality of fluid inlet and outlet conduits positioned thereon and a concentric inner tubular having a plurality seals for sealing the annular space between the concentric inner and main tubulars. The fluid inlet and outlet conduits work in cooperation with the annular seals to selectively open and close for effective management of pressure within the tubulars.

Abstract: A method and apparatus for installing casing hangers in a wellbore utilizing an externally activated gripping system to temporarily bind wearbushings secured to casing and tubing hangers in order to lock-down such hangers during various wellbore drilling activities, thereby minimizing the size of landing shoulders and eliminating additional lock down equipment and simplifying running procedures.

Abstract: A hybrid wellhead system is assembled using a plurality of threaded unions, such as spanner nuts or hammer unions, for securing respective tubular heads and a flanged connection for securing a flow control stack to a top of a tubing head spool. The tubing head spool is secured by a threaded union to an intermediate head spool. The intermediate head spool is secured by another threaded union to a wellhead. Each tubular head secures and suspends a tubular string in the well bore. The hybrid wellhead system is capable of withstanding higher fluid pressures than a conventional independent screwed wellhead, while providing a more economical alternative to a flanged, or ranged, wellhead system because it is less expensive to construct and faster to assemble.

Abstract: A Christmas tree is used between production tubing elevation and flow line elevation. The tree has a lower portion, an intermediate portion, and an upper portion. The intermediate portion is positioned between the production tubing elevation and the flow line elevation and has an axial dimension configured to substantially maintain the axial dimension between the elevations. The intermediate portion has first and second shut-off valves for closing fluid communication of the axial bore. A hanger is positioned in the axial bore of the intermediate portion between the first and second shut-off valves. The hanger defines a bore and a port. The port communicates a side of the hanger with the lower end of the hanger. The coil tubing attaches to the port at the lower end of the hanger, and the port at the side of the hanger communicates with the feed line of the intermediate portion.

Abstract: An improved hanger assembly and method for its use is described herein, along with various examples of alternative constructions for the hangar assembly. Also described are examples of new tool strings having improved capabilities that are facilitated as a result of use of the described hanger assemblies. The described hanger includes a deformable section having improved engagement capabilities. In preferred examples, these improved engagement capabilities are achieved by use of a first deformable section of the hanger that extends radially outwardly from the remainder of the hangar body, when the hanger is set; and a contact member that is further urged radially outwardly relative to that deformable section when the hanger is set.

Abstract: A casing mandrel for an independent screwed wellhead includes a seal bore for receiving a fixed-point packoff connected to a high-pressure mandrel of a pressure isolation tool, and a pin thread adapted for engagement with a box thread of a tubing head supported by the casing mandrel.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A casing mandrel for an independent screwed wellhead includes a pin thread adapted for engagement with a box thread of a well stimulation tool lockdown nut for securing the well stimulation tool against the casing mandrel top end. A well stimulation tool and a tubing head spool for use with the casing mandrel are also provided.

Abstract: A hybrid wellhead system is assembled using a plurality of threaded unions, such as spanner nuts or hammer unions, for securing respective tubular heads and a flanged connection for securing a flow control stack to a top of a tubing head spool. The tubing head spool is secured by a threaded union to an intermediate head spool. The intermediate head spool is secured by another threaded union to a wellhead. Each tubular head secures and suspends a tubular string in the well bore. The hybrid wellhead system is capable of withstanding higher fluid pressures than a conventional independent screwed wellhead, while providing a more economical alternative to a flanged, or ranged, wellhead system because it is less expensive to construct and faster to assemble.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree in which a tubing hanger is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree in which a tubing hanger is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A low-pressure wellhead system with tubular heads and mandrels secured independently using threaded unions. A casing mandrel is secured to a wellhead by a first threaded union. Likewise, a tubing head spool is secured to the casing mandrel using a threaded union. A tubing hanger is also secured to the tubing head spool using a threaded union. An adapter flange may also be secured to the tubing hanger by a threaded union. Because this low-pressure wellhead is faster and easier to assemble and provides full bore access, there is less rig downtime, thus rendering the well completion process faster and more economical.

Abstract: A casing mandrel for an independent screwed wellhead includes a pin thread adapted for engagement with a box thread of a well stimulation tool lockdown nut for securing the well stimulation tool against the casing mandrel top end. A well stimulation tool and a tubing head spool for use with the casing mandrel are also provided. Safety of well stimulation procedures is thereby improved and well completion time is significantly reduced.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree (34) in which a tubing hanger (54) is landed at a predetermined angular orientation As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger (21) for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A casing mandrel for an independent screwed wellhead includes a pin thread adapted for engagement with a box thread of a well stimulation tool lockdown nut for securing the well stimulation tool against the casing mandrel top end. A well stimulation tool and a tubing head spool for use with the casing mandrel are also provided. Safety of well stimulation procedures is thereby improved and well completion time is significantly reduced.

Abstract: In a subsea wellhead assembly, a tubing hanger in communication with the subsea well has a hanger port extending through its side. A diverter surrounds the tubing hanger and diverts well fluid transmitted from the hanger port around a portion of the tubing hanger. The diverter transmits the well fluid to the inner surface of a wellhead member. A production port extending through a side of the wellhead member transmits the well fluid from the tubing hanger and diverter to an exterior of the wellhead member.

Abstract: A large bore Christmas tree includes a production outlet that is split into multiple separate outlets, each controlled by a separate, standard sized valve and valve actuator.

Abstract: A completion system comprises a christmas tree (10) mounted on a wellhead housing (11), a tubing hanger (12) landed in the tree or wellhead housing, the wellhead housing (11) being mounted on a casing string (100) and a tubing string (14) being suspended from the tubing hanger within the casing string; wherein, in use, the annulus defined between the tubing (14) and the casing (100) serves as a production bore. A second tubing string (98) is expanded into sealing engagement with the casing string (100) over at least a portion of their lengths. The annulus normally used to provide well service functions is thus eliminated. Well servicing is instead provided via the tubing string (14), which may be coiled tubing.

Abstract: A wellhead has, instead of a conventional Christmas tree, a spool tree in which a tubing hanger is landed at a predetermined angular orientation. As the tubing string can be pulled without disturbing the tree, many advantages follow, including access to the production casing hanger for monitoring production casing annulus pressure, and the introduction of larger tools into the well hole without breaching the integrity of the well.

Abstract: A wellhead assembly has an inner wellhead that lands in an outer wellhead, the inner wellhead having first and second internal passages. Each passage has an upper opening at the outer surface of the inner housing and a lower opening at the inner surface. An external shoulder of a casing hanger lands on an internal shoulder of the inner housing, the lower opening of the first passage being below the internal shoulder, the lower opening of the second passage being above the internal shoulder. The casing hanger has a substantially-vertical passage located in its sidewall, an upper port registering with the lower opening of the second passage, a lower port being located below the external shoulder for communicating with the annulus. Valve assemblies at the upper openings control the flow of heavy fluid injected into a casing annulus through the second passage and of cuttings injected into the annulus through the first passage.

Abstract: A connector head, for transferring at least a portion of the load from an inner tubular body onto an outer tubular body, comprises a generally tubular connector head formed with a central bore through which the inner tubular body extends. The connector head has an inwardly extending stop shoulder to allow the connector head to rest on the upper end of the inner tubular body. A slip connecting means is located in the connector head for gripping the outer wall of the inner tubular body. A base plate, formed with a central bore therethrough, is located below the connector head and is adapted to rest on the upper end of the outer tubular body. A retainer ring, formed with a central bore therethrough, is located between the connector head and the base plate and includes a plurality of threaded stud members extending therethrough allowing the retainer ring to slide upwardly and downwardly on the threaded stud members.

Abstract: Apparatus and a system for accessing one or more of the annuli defined between casing strings in a subsea wellhead that are usually sealed for the production stage of the well. Access to an annulus (30) is made via the wall of the wellhead housing (12) at a location where is communicates with the annulus. The access is a passageway (31) having a first opening in communication with the annulus and a second opening either at the external surface of the wall or at a location on the inner surface of the wall above the casing hangar seal for the inner casing (14), which is not in communication with the annulus apart from the passageway. An isolation valve (32) communicates with the passageway and with apparatus for monitoring or controlling pressure of flow in the annulus. The passageway may be used with an open lower end to the annulus during drilling stages for material transfer and during production stage to monitor/control a sealed annulus.

Abstract: A rotary drilling head assembly for a well bore, including an erosion resistant bowl apparatus. The bowl comprises a bowl member, the bowl member having a central receiving cavity configured to receive a rotary sealed bearing assembly, the bowl member having a discharge nozzle extending therefrom, the discharge nozzle fluidly communicating with the receiving cavity, and at least one diverter member extending from an inner surface of the receiving cavity of the bowl, the diverter member formed and configured to disrupt patterns of fluid flow within the bowl during drilling operations. The apparatus preferably includes at least one nozzle diverter member extending from an inner surface of the discharge nozzle. A plurality of diverter members preferably extend from an inner surface of the receiving cavity of the bowl and from the discharge nozzle.

Abstract: A clamp for clamping two concentric tubes, typically two concentric tubes in an oil or gas well. The clamp has two axially movable tapered components which can be pulled over one another in an axial direction to provide a contraction of internal diameter which grips the smaller diameter tube. In one embodiment, a spacer is fitted to allow the tapered components to be held apart until the tubes have been correctly positioned. The spacer is then removed, and the tapered components are drawn together to effect the clamping. A hydraulic ram can be provided to separate the tapered components should readjustment be required. In another embodiment, the larger diameter tube is made with a relatively thin wall, so that it can be distorted inwards to grip the smaller tube.

Abstract: A wellhead system for petroleum producing wells comprises a “stack-down” casing hanger configuration. In this stack-down system, the hanger for each successively smaller diameter casing string is landed or “nested” within the hanger for the next larger casing string. This approach allows the pack-off for each casing hanger to be retrieved independently, thus allowing fluid communication to be established with any of the casing annuli after all of the casing strings and hangers have been installed. Thus the pressure in each annulus may be monitored while the well is in production mode.

Abstract: This invention provides a tubing hanger system which permits isolation of the production tubing from the electrical power cable, thereby isolating the electrical power cable from high pressures encountered in the production tubing. Further, the tubing hanger system enables pressure testing of the integrity of both the production and cable seals, without requiring disassembly of any components of the tubing hanger assembly or damaging the electrical power cable, in advance of high pressure operations. Specifically, the invention provides a tubing hanger assembly for use in a tubing head of a production well, and which provides for passage of production fluids from the production tubing mounted therebelow, through a central bore in the tubing head and through the tubing hanger assembly, while also providing isolation of the production tubing from an electrical power cable passing through the tubing hanger assembly.

Abstract: An injection spool for use in the injection of a fluid, for example a slurry of drilling cuttings, into a subsea wellhead assembly has an outer housing having a central bore therethrough. The housing has a first end for connection to a wellhead assembly such that the central bore of the housing is aligned with the central bore of the wellhead assembly. An inner housing, for example an isolation sleeve, having a central bore therethrough is disposed within the central bore in the outer housing, whereby a cavity is formed between the inner housing and the outer housing. A port in the outer housing has an opening into the cavity between the inner housing and the outer housing, through which a fluid may be injected. The inner housing has a portion extending from within the outer housing beyond the first end of the outer housing for forming a cavity within a wellhead assembly to which the injection spool is connected.

Abstract: The consequences of any failure of a blow out preventer assembly to operate correctly in an emergency can be far reaching. Thus, there is provided an apparatus for registering parameters in the bore of a member which is, in use, connected to a pressurised housing, the apparatus comprising: an electro-control package for attachment, in use, to the member; a test assembly placed, in use, in the member; the electro-control package and the test assembly having means for sending signals to and receiving signals from one another.

Abstract: A wellhead assembly comprises an outer housing having a central bore therethrough and an inner housing having a central bore therethrough secured in the central bore of the outer housing. The inner housing has a first end within the outer housing. A first inner casing having a central bore therethrough is secured at a first end in the outer housing and spaced from the first end of the inner housing. A port is provided through the outer housing in communication with the central bore therethrough, the port opening into the central bore of the outer housing between the first end of the inner housing and the first end of the first inner casing. A second inner casing is secured in the wellhead assembly at a first end, whereby the port opens into the central bore of the outer housing between the first end of the first inner housing and the first end of the second inner housing. An annulus is formed between the first and second inner casings.

Abstract: A wellhead assembly comprises a central bore through the wellhead assembly having a pressure boundary region. A port is provided in the wellhead assembly having an opening in the central bore in the pressure boundary region of the wellhead assembly. The port preferably extends through the high pressure housing into the bore of the wellhead assembly. A first casing string is secured at a first end within the wellhead assembly below the opening of the port in the central bore of the wellhead assembly. A second casing string is secured at a first end within the wellhead assembly above the opening of the port in the central bore of the wellhead assembly. A fluid flowpath is thereby formed comprising the port in the wellhead assembly and an annulus between the first and second casing strings. In this way, access is provided to an annulus within the well.

Abstract: A subterranean oil or gas well apparatus is provided. The apparatus includes a single-bore production tubing hanger arranged concentric with a wellhead. The tubing hanger includes a plurality of ports and channels arranged about the tubing hanger to give operators access to the production tubing annulus and provide chemical injection capability. The ports are closable by a sliding valve. The apparatus also includes annulus and production radial-bore stab assemblies between a christmas tree and an internal crossover assembly. The stab assemblies are extendable and retractable between the chirstmas tree and the crossover assembly to allow the retrieval and installation of each independently.