A bolt tensioning assembly has a bolt with a first end portion and a second end portion at an opposite side of the bolt. The first end portion has an enlarged diameter to form a counter-pressure surface facing the second end portion. The first end portion has external threads to receive a lock nut. A hydraulic bolt tensioning device is for tensioning of the bolt. The hydraulic bolt tensioning device is arranged for enclosing a portion of the bolt such that it abuts the counter pressure surface. A lock nut is arranged on the first end portion of the bolt. The hydraulic bolt tensioning device and lock nut are dimensioned such that upon tightening of the lock nut, the lock nut will tighten against a portion of the hydraulic bolt tensioning device.

A lifting system (10) for a subsea pipeline (18) comprises paired subsea foundations (20) that are spaced apart from each other to define a gap between them through which the pipeline extends. A removable lifting frame (12) is mounted on the foundations to bridge over the pipeline disposed in the gap. The lifting frame comprises a pair of feet (32) that are cooperable with respective support formations (34, 36) on the foundations. One support formation defines a hinge component to restrain one of the feet for pivotal movement. The other support formation defines a platform on which the other foot can rest in any of various positions within a support area. This compensates for differences in level, spacing or alignment between the foundations. The lifting frame (12) can be transferred to another location by dismounting it from a first pair of foundations and then mounting it onto a second pair of like foundations in a corresponding manner.

A lifting system (10) for a subsea pipeline (18) comprises paired subsea foundations (20) that are spaced apart from each other to define a gap between them through which the pipeline extends. A removable lifting frame (12) is mounted on the foundations to bridge over the pipeline disposed in the gap. The lifting frame comprises a pair of feet (32) that are cooperable with respective support formations (34, 36) on the foundations. One support formation defines a hinge component to restrain one of the feet for pivotal movement. The other support formation defines a platform on which the other foot can rest in any of various positions within a support area. This compensates for differences in level, spacing or alignment between the foundations. The lifting frame (12) can be transferred to another location by dismounting it from a first pair of foundations and then mounting it onto a second pair of like foundations in a corresponding manner.

A method of determining a minimum wall thickness for a pipe joint for use in a subsea pipeline comprises the steps of: i) determining an internal diameter of the pipe joint; ii) determining a minimum allowable hydrostatic pressure at the depth at which the pipe joint is to be used; iii) determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure; iv) manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness; v) carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse; vi) determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory; vii) determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10.sup.−5 or lower; and, viii) determining a wall thickness of the pipe joint corresponding to the internal diameter and the hydrostatic collapse pressure.

A method of determining a minimum wall thickness for a pipe joint for use in a subsea pipeline comprises the steps of: i) determining an internal diameter of the pipe joint; ii) determining a minimum allowable hydrostatic pressure at the depth at which the pipe joint is to be used; iii) determining a target wall thickness for the pipe joint, the target wall thickness corresponding to the internal diameter and the minimum allowable hydrostatic pressure; iv) manufacturing a plurality of preliminary pipe joints having the internal diameter and the target wall thickness; v) carrying out external pressure collapse tests resulting in data representative of the hydrostatic collapse pressures at which the plurality of preliminary pipe joints collapse; vi) determining a probability distribution corresponding to the data based on a statistical tail model derived from Extreme Value Theory; vii) determining from the probability distribution a hydrostatic collapse pressure occurring with a probability of 10.sup.−5 or lower; and, viii) determining a wall thickness of the pipe joint corresponding to the internal diameter and the hydrostatic collapse pressure.

A subsea well intervention cap is provided. The subsea well intervention cap includes a frame, a first clamp segment coupled to the frame and configured to be fitted over a horizontally oriented flowpath of a subsea well equipment component, and a second clamp segment having a rim segment configured to interface with the first clamp segment, wherein the second clamp segment is movable with respect to the first clamp segment. The subsea well intervention cap also includes an actuation mechanism coupled to the frame that actuates the second clamp segment in a vertically upward direction and in an axial direction with respect to the frame toward the first clamp segment. The subsea well intervention cap is lightweight and able to be installed on subsea well equipment using a standard remote operated vehicle (ROV).

A system and method for detecting passage of a pipeline pig, the system and method including a passive impulse detector (10) having a housing (13); a non-intrusive connection (15) of the housing to an exterior wall (17) of a pipeline (P), at least one vibration sensor (11) housed by the housing, and signal processing (23) including at least one band pass filter (27) configured to receive data collected by the vibration sensor, the vibration sensor and band pass filter configured to monitor frequencies in a predetermined range indicating a series of impulses caused by start-and-stop movement of the pipeline pig. The selected frequencies should be those more easily detectable above the baseline (signature or natural resonance) frequency of the section of pipeline being monitored. In some embodiments, the selected frequencies are lower frequencies. No portion of the passive pipeline pig signal intrudes into an interior of the pipeline.

A system and method for detecting passage of a pipeline pig, the system and method including a passive impulse detector (10) having a housing (13); a non-intrusive connection (15) of the housing to an exterior wall (17) of a pipeline (P), at least one vibration sensor (11) housed by the housing, and signal processing (23) including at least one band pass filter (27) configured to receive data collected by the vibration sensor, the vibration sensor and band pass filter configured to monitor frequencies in a predetermined range indicating a series of impulses caused by start-and-stop movement of the pipeline pig. The selected frequencies should be those more easily detectable above the baseline (signature or natural resonance) frequency of the section of pipeline being monitored. In some embodiments, the selected frequencies are lower frequencies. No portion of the passive pipeline pig signal intrudes into an interior of the pipeline.

The invention concerns a pipe joint formed between a pin section (10) and a box section (20); the pin and box sections each having a tubular pipe section, engaging at respective first ends in end-to-end arrangement and having a seal element partially therebetween, the box section including a collar extending from the first end, the collar being generally cylindrical, axially aligned with the tubular box pipe section and having an inner diameter of the same size as the outer diameter of the pin section, enabling the collar to be placed about the pin section, the pin and the box sections being secured together by means of a plurality of securing means housed in the collar and actuable to exert radial pressure to urge the pin and box into sealing arrangement, the collar (22) of the box section (20) including a test port, comprising a housing atrium, defined by an atrium wall, housing a test plug (60); the housing atrium (61) and the seal element (53) being fluidly linked by a box conduit; the plug comprising a plug body and a plug seal housed between the plug body and the housing atrium wall to seal the housing atrium from atmosphere and having therethrough a plug conduit connectable at a first end to a pressure test apparatus and fluidly linkable at a second end to the box conduit; the plug being moveable between a first position forming a fluid link between the plug conduit and the box conduit, and a second position closing the fluid link.

The invention concerns a pipe joint formed between a pin section (10) and a box section (20); the pin and box sections each having a tubular pipe section, engaging at respective first ends in end-to-end arrangement and having a seal element partially therebetween, the box section including a collar extending from the first end, the collar being generally cylindrical, axially aligned with the tubular box pipe section and having an inner diameter of the same size as the outer diameter of the pin section, enabling the collar to be placed about the pin section, the pin and the box sections being secured together by means of a plurality of securing means housed in the collar and actuable to exert radial pressure to urge the pin and box into sealing arrangement, the collar (22) of the box section (20) including a test port, comprising a housing atrium, defined by an atrium wall, housing a test plug (60); the housing atrium (61) and the seal element (53) being fluidly linked by a box conduit; the plug comprising a plug body and a plug seal housed between the plug body and the housing atrium wall to seal the housing atrium from atmosphere and having therethrough a plug conduit connectable at a first end to a pressure test apparatus and fluidly linkable at a second end to the box conduit; the plug being moveable between a first position forming a fluid link between the plug conduit and the box conduit, and a second position closing the fluid link.