摘要:
A well barrier for sealing a downhole conduit is described. The well barrier includes a housing defining a throughbore having a longitudinal axis, a valve actuator and a flapper valve. The flapper valve includes a flapper attached to the valve actuator. The flapper valve and the valve actuator are axially movable with respect to the housing in a direction parallel to the longitudinal axis. The flapper is adapted to move from one of a throughbore open and throughbore closed positions to the other of said open and closed positions when the actuator and flapper valve move a predetermined axial distance.
摘要:
A wellbore control device for use in a blow out preventer is described. The control device comprising a housing defining a throughbore, a gate, the gate being movable between a throughbore open position and a throughbore closed position, a first stem attached to the gate and a second stem releasably engageable with the gate, the first and second stems being arranged such that a portion of each stem is exposed to an internal housing pressure and a portion of each stem is exposed to an external housing pressure. When the internal pressure is greater than the external pressure, the pressure differential results in a force being applied to the gate to move the gate to, or retain the gate in, the throughbore closed position.
摘要:
A method and system for authenticating IP source addresses by accessing one or more HTTP requests whose source client identifies itself as a legitimate web crawler. One or more IP addresses are detected from the one or more HTTP requests and each detected IP address is authenticated via a probability estimation regarding its association with a legitimate web crawler. A lookup table is preferably compiled for the authenticated IP addresses for reference, publication and authentication purposes.
摘要:
A control mechanism for use with a safety valve adapted to seal a wellbore is described. The control mechanism comprises at least one valve actuator for engaging with the safety valve, the at least one actuator being moveable, in use, between a valve open position in which the safety valve is open and a valve closed position, in which the safety valve is closed. The control mechanism further comprises biasing apparatus adapted to bias the at least one valve actuator to the valve closed position, wherein, in use, the at least one valve actuator extends from the safety valve up to a wellbore wellhead. In one described embodiment, the safety valve is moved between the open and closed positions by movement of the at least one valve actuator with respect to the wellbore.
摘要:
A tensioning apparatus for applying a substantially constant tension to a workover riser (12) includes a first portion (40) adapted to be coupled to a workover riser, a second portion (44) adapted to be coupled to a marine riser (14) and tensioning means (46) for providing relative movement between the first portion and the second portion to, in use, tension the workover riser.
摘要:
The invention provides a method and apparatus for detecting a scene transition in digitized video data. The method includes determining if a gradual transition is detected in the video data that ends with a current frame based at least on the current frame and one or more previous frames in the digitized video data. The gradual transition has a length. The method includes comparing the gradual transition to a synthetically produced gradual transition spanning a same length and generated from starting and ending frames associated with the detected gradual transition and marking the detected gradual transition only if the detected gradual transition is sufficiently similar to the synthetically produced gradual transition.
摘要:
A method and apparatus for producing video content. The method includes acquiring video data from a source. If the video data is not digitized, then the video data is digitized. The method includes generating scene indexes for the video data including a representative still image for each scene and combining the video data and scene indexes along with a media player on a video disc. The video player is operable to play the video data in accordance with the scene indexes including playing a scene from the video data on a client computer while displaying the representative stills for other of the scenes available for display on the video disc.
摘要:
A self-contained well intervention system which can be deployed from a lightweight vessel and coupled directly to a wellhead is described. The system includes valve means for providing a suitable well barrier and sealing the intervention system to allow an emergency disconnect. Within the intervention system, a tool magazine is provided which contains at least one deployable intervention tool. The intervention system also contains a tool selection and deployment means based on a winch located in close proximity to the magazine and which is operable from the surface for selecting a particular tool from the magazine and for deploying the selected tool through the intervention system and the wellhead into the well. The tool magazine has a plurality of magazine pockets each of which may have a deployable tool therein. The tool selection and deployment means can be used to select and to join the selected tools together within the intervention system to form an intervention tool string which can be run into the wellhead so that a plurality of different operations can be performed within the well during an intervention.
摘要:
The hyaluronidase, which is a hyaluronic acid-specific endo-.beta.-glucuronidase, having a molecular weight of about 28,500 in non-reduced form, is derived from buffalo leeches (that is, leeches of the sub-family Hirudinariinae, such as the species Hirudinaria manillensis or Poecilobdella granulosa).The hyaluronidase, which cleaves hyaluronic acid, but not chondroitin, chondroitin -4- sulphate, chondroitin -6- sulphate or heparin, is considerably more stable at high temperatures and extremes of pH than known leech hyaluronidase. It has a wide range of uses where breakdown of hyaluronic acid is required; of particular interest is in pharmaceutical or veterinary formulations, either as an active agent or a spreading or percutaneous factor. The hyaluronidase is useful for stimulating flow of physiological fluids in the eye (for example, in the treatment of glaucoma).