Abstract: Specially designed apparatus is utilized to provide convenient isolation of a wellbore junction from pressure and corrosion during an acid fracturing stimulation process performed in a main or branch wellbore portion downhole from the junction. The apparatus has an outer tubular portion which may be installed, in a single trip into the main wellbore, in a straddling and sealing relationship with the junction, and an inner tubular structure sealingly and removably received within the outer tubular structure. Fracturing acid may be pumped directly down the main wellbore, and then to the formation to be stimulated, via the interior of the outer tubular structure, after the removal of the inner tubular structure subsequent to its use in facilitating a downhole pressure test of a lower end seal portion of the outer tubular structure.

Abstract: An expanding wellbore junction system, apparatus and methods are provided for forming a sealed wellbore intersection in a subterranean well. In one. described method, an expandable wellbore junction is expanded within an under-reamed cavity in a wellbore. Intersecting tubular legs of the wellbore junction are then drifted using a drifting apparatus. A deflection device may be used to direct a drift of the drifting apparatus into a selected one of the wellbore junction legs.

Abstract: A multiple tube structure provides enhanced utilization of limited cross-sectional area in a wellbore. In a described embodiment, a tube system includes multiple tubular members rigidly attached to each other along axial lengths thereof. The tubular members are configured so that they conform to an interior of a generally D-shaped portion of a circle.

Abstract: A well has a vertical casing with a window, and a lateral wellbore which communicates with the window, and which may have a casing or liner. A window assembly aligned with the window has respective passageways for first and second tubing strings, and has a concave surface for deflecting the first tubing string out into the lateral wellbore. The passageway for the second tubing string has a portion which is inclined at a very small angle with respect to a vertical centerline of the vertical casing. As the first tubing string is run into the vertical casing, a rotational locator is releasably coupled thereto by a soft release coupling mechanism. After the locator effects rotational orientation, the coupling mechanism is released and then permits the first tubing string to move therepast without damage. A seal assembly on the first tubing string is covered by a protective sleeve as it is inserted into the well, and exits the protective sleeve after entering the lateral wellbore.

Abstract: A releasable no-go tool and associated methods provide enhanced capabilities in positioning an item of equipment in a wellbore. In a described embodiment, a releasable no-go tool includes a circumferentially continuous key which is radially outwardly displaced by a series of pistons. In use, the tool is interconnected in a tubing string, which is lowered into a casing string in a wellbore. The casing string has a nipple interconnected therein, the nipple having an internal profile. The tool is positioned below the nipple, pressure is applied to the tubing string to extend the key, and the tubing string is raised to thereby engage the key with the profile.

Abstract: A well has a vertical casing with a window, and a lateral wellbore which communicates with the window, and which may have a casing or liner. A window assembly aligned with the window has respective passageways for first and second tubing strings, and has a concave surface for deflecting the first tubing string out into the lateral wellbore. The passageway for the second tubing string has a portion which is inclined at a very small angle with respect to a vertical centerline of the vertical casing. As the first tubing string is run into the vertical casing, a rotational locator is releasably coupled thereto by a soft release coupling mechanism. After the locator effects rotational orientation, the coupling mechanism is released and then permits the first tubing string to move therepast without damage. A seal assembly on the first tubing string is covered by a protective sleeve as it is inserted into the well, and exits the protective sleeve after entering the lateral wellbore.

Abstract: A self-locating reentry system is provided to allow reliable reentry from a primary wellbore into one or more secondary wellbores. The reentry system may include one or more self-locating assemblies which may be engaged with selected portions of a lateral opening disposed between the primary wellbore and a respective secondary wellbore. Each self-locating assembly and respective key or lug cooperate with each other to provide optimum location and alignment relative to the lateral opening for communication of well tools and smaller diameter tubing strings between the primary wellbore and the associated secondary wellbore. A retaining mechanism is preferably provided to maintain the locator lug or key in its first retracted position until the reentry system is at a desired downhole location relative to the selected lateral opening.

Abstract: An improved tubing exit whipstock and tools for installing and retrieving the whipstock are provided for directing movement of well tools from a first wellbore to a second wellbore extending therefrom. The tubing exit whipstock may include a generally cylindrical deflector body with a longitudinal passageway extending therethrough. The deflector body may also include a tapered surface for deflecting well tools from the first wellbore to the second wellbore. In one embodiment of the present invention, a mechanical connector may be provided for attaching the deflector body to an orienting and locking device to releasably install the whipstock at a selected downhole location. In another embodiment, a first fishing neck profile may be provided within the longitudinal passageway to provide means for releasably coupling the deflector body with a running tool for installing the tubing exit whipstock at a selected downhole location within the first wellbore.

Abstract: An indicating device is provided, especially in the form of a taximeter which comprises counter means which is clocked by time pulses applied to it and which is reset by distance pulses applied to it and when it reaches a predetermined count, the counter means being arranged to afford an output each time it is reset and means being provided operable on the distance pulse immediately following the counter means having assumed said predetermined count for producing an output in dependence upon the residual count of said counter means on the application thereto of the said distance pulse for affording a correction pulse that is effectively subtracted from the output afforded by the counter means to afford a corrected pulse train that is used to compute a fare to be charged.