A modular anti-rotation device for preventing rotation with respect to the central axis of a drilling tool in a borehole and for producing a notch in a borehole surface. The anti-rotation device includes an upper fixture portion and a lower fixture portion in axial alignment. The upper fixture portion and the lower fixture portion are connected by yoke assemblies. Each yoke assembly is connected to the fixture portion and fixture portion at one end, and forming an articulated joint of the upper yoke assembly and the lower yoke assembly at a distal end opposite the first end. A roller is connected at each joint, connecting the upper and lower yoke assemblies. The rollers engage vertically with a borehole surface, the rollers travelling axially, as a drill shaft penetrates into the borehole, the rollers simultaneously preventing radial movement of the anti-rotation device and prevent rotation with respect to the central axis of the borehole.

A perforating gun is disclosed with shaped charges at a preferential orientation. An example includes a gun body and a charge carrier disposed within the gun body. The charge carrier defines a longitudinal carrier axis and has a plurality of axially-spaced charge mounting locations. A plurality of charges are each pivotally mounted to the charge carrier at one of the respective charge mounting locations about a charge pivot axis transverse to the longitudinal carrier axis. The charges may preferentially align in response to gravity so their orientation remains constant throughout a range of inclination of the wellbore.

A downhole tool and method for reducing friction between a tool string and a sidewall of a wellbore. The downhole tool includes a first wheel, a second wheel, and a hump. When the downhole tool is connected to the tool string, the first wheel, the second wheel, and the hump each extend away from the tool string and collectively define a curved outer profile extending circumferentially around at least a portion of a circumference of the tool string, and the curved outer profile has a geometric center that is offset from a central axis of the tool string.

A wheel assembly and a method for detachably connecting the wheel assembly to a downhole tool to reduce friction between the downhole tool and a sidewall of a wellbore through which the downhole tool is conveyed. The wheel assembly may include an axle configured to contact a sidewall of the downhole tool, a wheel rotatably connected with the axle, and a fastener configured to extend into the sidewall of the downhole tool to detachably connect the axle to the downhole tool.

A drill string for drilling a borehole. The drill string may include a downhole motor operable to rotate the drill string and a centralizer assembly. The centralizer assembly may include an outer housing, a lower sub threadably engaged with the outer housing, and a centralizer. The centralizer may include a single eccentric blade, an internal shoulder positioned between the outer housing and the lower sub, and an alignment profile to align the centralizer in an azimuthal position relative to the drill string. The centralizer may be retainable in the aligned azimuthal position by the alignment profile and the internal shoulder being engaged by the outer housing and the lower sub.

A device for measuring strain on the exterior of a pipe includes a body comprising a top portion and a bottom portion; one or more elastically deformable members coupled between the top portion and the bottom portion, wherein each of the one or more elastically deformable members have an outer contact surface and an inner non-contact surface. One or more sensors are disposed on the inner non-contact surface of one or more of the elastically deformable members. The sensors, during use, provide data that can be used to determine changes in strain on the exterior of the pipe. In another embodiment, one or more sensors are embedded in, or attached to, a casing disposed in a wellbore. In an embodiment, a method includes pressurizing or depressurizing the wellbore with a fluid and measuring the strain induced in the casing (or in an open wellbore) in response to this change in wellbore pressure.

A hydraulic casing centralizer device includes a cylindrical housing having a central chamber extending through a portion of the cylindrical housing and along a central axis thereof. The hydraulic casing centralizer device includes a locking mechanism that reacts to a hydraulic force when the hydraulic force is applied from an inside of the central chamber. The hydraulic casing centralizer device includes a threaded section that is configured for screwing the device into a casing joint. The threaded section may be disposed in the cylindrical housing.

The present invention provides a spacer (11) and a spacer segment (13). One or more spacer segments (13) form the spacer (11). The one or more spacer segments (13) are adapted to be interconnected and fitted to/on a first surface. The spacer segment (13) comprises a first collar portion (17), a second collar portion (19), and at least one support assembly (15) extending between the first collar portion and the second collar portion. The at least one support assembly is movable from a normal position, wherein no or minimal force is exerted on the support assembly, to a compressed position, wherein the support assembly supports a load or a portion of a load.

A system includes a flexi-string having a first lateral end, a second lateral end, and an outer diameter. The outer diameter defines an outer circumferential surface, and the outer diameter is smaller than an inner diameter of a casing shoe. The system further includes an anchor disposed on the outer circumferential surface of the first lateral end, where the anchor interacts with the casing shoe, or a last joint of casing, to hold the first lateral end of the flexi-string within the casing shoe. The system also has centralizers located between the first lateral end and the second lateral end of the flexi-string. The centralizers are configured to center the flexi-string within the casing shoe and the washout section. Finally, the system includes a roller guide for lowering the flexi-string inside the casing shoe and to a depth below the washout section of the well.

One method includes temporarily sealing and isolating a portion of a wellbore with a reusable sealing and isolation element, performing a fracturing process in the portion of the wellbore that is isolated, and after the fracturing process is complete, unsealing or de-isolating the portion of the wellbore by temporarily changing a configuration of the reusable sealing and isolation element. Use of the reusable sealing and isolation element may reduce, or eliminate, the need for remediation operations, such as the removal of sealing plugs.