摘要:
A method of and apparatus for deploying a bow spring centralizer (10) installed on an expandable casing string (30) and restrained in the collapsed configuration by restraining bands (12A, 12B) that rupture, upon expansion of the casing string (30), to deploy the bow spring centralizer (10) and provide stand-off between the expanded casing string (30') and the wall of the borehole. In one embodiment, the bow spring centralizer comprises landings (13) for receiving and retaining the bands (12A, 12B) for restraining the centralizer in the collapsed configuration. In another embodiment, the bands (12A, 12B) are secured to the centralizer (10) to prevent separation of the ruptured bands (12A', 12B') from the deployed centralizer (10').
摘要:
A bow-spring centralizer (6) includes bow springs (34), moving collars (20) secured to each end of each bow spring, and interlocked stop collars (10). Extendable collars (8) may each be formed of a moving collar (20) movably interlocked with a stop collar (10). The centralizer (6) may be formed from a tube cut using a laser to create two extendable collars coupled by bow springs. Each extendable collar may include heads (12) integrally formed on extensions (26) protruding from a collar (stop collar or moving collar). The heads may be generally rectangular, arrow, or teardrop-shaped head or some other shape. Each head may be slidably captured within a chamber (24) on the interlocked collar (moving collar or stop collar). The extensions of each interlocked tubular member define the outer walls of the chamber in which a head of the interlocked tubular member is slidably captured.
摘要:
Afin d'améliorer les conditions d'évacuation d'un fluide de lavage chargé de particules de roches dégagées pendant la phase de forage, une ancre de forage par injection comprend des tiges d'ancrage (2), des pièces d'accouplement (3), des soupapes de compression (15), un élément intermédiaire (9) contenant une soupape de non retour et une tête de forage (1) toujours vissés les uns dans les autres, de sorte que la face extérieure du tube de forage à l'état assemblé ait une structure complètement homogène depuis la tête de forage (1). Cette structure se caractérise par un filetage extérieur qui s'étend uniformément sur toute sa longueur, donc par un diamètre uniforme, de sorte que les tiges d'ancrage (2) puissent déplacer, une fois le forage achevé, une pièce d'écartement depuis l'ouverture du trou de forage jusqu'à n'importe quel point voulu sur toute la longueur du tube de forage. Les tiges d'ancrage (2) sont pourvues sur toute leur longueur d'un filetage intérieur uniforme, de sorte qu'elles puissent être utilisées avec l'ancre de forage par injection (1) même après avoir été tronçonnées. A cet effet, la pièce d'accouplement, la soupape de compression (15), l'élément intermédiaire (9) et la tête de forage (1) comprennent des cylindres tubulaires (20, 21; 10; 6) dont les filetages intérieur et extérieur ont une structure correspondante à celle des tiges d'ancrage (2) et assurent une fonction de butée permettant d'avoir des positions de vissage déterminées.
摘要:
Für die Tiefbohrtechnik wird zur zentralen Führung von Rohren ein Zentrierkorb vorgeschlagen, bei dem die die Rohre umschließenden Tragringe innere Umfangsnuten aufweisen und die zu zentrierenden Rohre im Bereich der Tragringnuten mit in Rohrumfangsnuten angeordneten Stoppringen versehen sind, die nach dem Aufschieben des Zentrierkorbs auf das Rohr durch fensterartige Öffnungen der Tragringe in die Rohrnuten schiebbar sind.
摘要:
A centralizer for well casing (16) functions in an annular space between the casing (16) and a wellbore (20). It comprises a pair of axially spaced-apart and aligned collars (12) adapted to encircle the well casing and a plurality of spring bows (14) extending between and secured to the collars. Each spring bow (14, 280) has two ends and an outwardly convex curved mid-portion. In a first form of the invention starting force is reduced by providing spring bows having outwardly projecting contact angle reduction members (282) that engage the upper edge of the wellbore (20) as the casing (16) is moved into the wellbore (20) to reduce the effective contact angle of the spring bows (14, 280) with respect to the wellbore (20) and thereby reduce the force required to insert the centralizer (10) into the wellbore (20). In a second form of the invention the spring bows are provided with casing abutment members (283) extending inwardly towards the centralizer's longitudinal axis. The casing abutment members (283) contact the casing (16) as the spring bows (14, 280) are moved towards the casing (16) during insertion of the centralizer (10) into the wellbore (20) to increase the restoring force of the spring bows. The spring bows may have both contact angle reduction members (282) and casing abutment members (283) to give a centralizer having a desirable combination of low starting force with high restoring force.
摘要:
A method of forming a centralizer where a flat plate is created into a tubular where the flat plate is typically rolled so that two sides of the plate contact one another and are then linked, typically by welding. Openings are then created in the tubular such that there are no comers or other points that stress cracks may originate. Once the openings are created the remaining material between adjacent openings forms ribs. The openings created in the tubular are generally aligned with the long axis of the tubular. The material, at the upper and lower end of the flat plate where openings were not created serve as circumferential collars. The ribs may be radially outwardly expanded in order to provide adequate stand-off. In many instances the ribs will also be hardened by heat treating or other hardening processes.
摘要:
A chemical reaction heat source for use in heaters used in down-hole applications is provided. The heat source has a fuel composition that comprises thermite and a damping agent. The use of the thermite mix enables the heaters of the present invention to generate hotter temperatures down wells. This in turn allows the use of Bismuth/Germanium alloys, which have higher melting points, to enable the production of plugs for the abandonment of deeper wells where subterranean temperatures are higher.
摘要:
A centralizer sub for cementing a tubular string in a wellbore includes: a tubular body; a centralizer disposed along an outer surface of the body and having a pair of collars and a plurality of bow springs connecting the collars; and a joint longitudinally linking the centralizer to the body. The joint has: a groove formed in and around the body outer surface, and a plurality of protrusions formed integrally with or mounted to one of the collars and extending into the groove.