A downhole device that drills a wellbore includes a stabilizer which has a body and blades. The blades are disposed on a surface of the body and each blade has a hollow space. The blades each include a dissolvable window that is disposed on a surface of each of the blades and a light source that emits light to the wellbore. The dissolvable window blocks light emitted from the light source thereby reducing or eliminating light from being transmitted to the wellbore. The dissolvable window dissolves upon exposure to a fluid containing a dissolving medium, thereby allowing the light source to transmit light to the wellbore. Methods of using the downhole device to activate downhole chemicals are also provided.

A telescopic tool is located intermediate a conveyance string and permits an uphole portion to be manipulated through reciprocation and rotation regardless of the fixed nature of a downhole portion. In embodiments, tools uphole of telescopic joint can be actuated by casing manipulation to aid in placement of cement. In other embodiments, such as during running into the wellbore, the tool can be selectively actuated to cause the uphole casing string to lock to, and rotate, the casing string located downhole.

A drilling assembly for use in drilling of a wellbore is disclosed that in one non-limiting embodiment includes a device that detects a flow-off state, a power generator that generates electrical energy in response to a fluid flowing through the drilling assembly during the flow-off state, and a circuit that utilizes such power to perform one or more selected operations in response to the detection of the flow-off state, including, but not limited to, storing data in a memory; shutting certain devices in the drilling assembly and parking a device in a desired position.

A device for supporting and guiding supplying lines used with a digging tool on a drilling machine is described. The device comprises a support branch, formed by a plurality of spacers, adjacent to one another in which a rope or tie-rod is inserted in a housing comprised in the spacers, a supplying pipe for the supplying line and a crosspiece comprising a seat adapted to support the supplying pipe. Each pair of adjacent spacers comprises retaining means. Each retaining means comprises a retaining element, associated to a first spacer of a pair of adjacent spacers, and a slot having a shape substantially matching the shape of the retaining element, associated to a second spacer of the pair of adjacent spacers. A retaining element, during use, engages with a slot allowing relative axial movement, in the longitudinal direction of the rope, of a predetermined amount.

An arrangement for a buoyant liner or casing string including a shoe plug affixed to the string and configured to hold a pressure differential from a higher pressure outside of the string to a lower pressure inside of the string and to unseat upon a pressure differential of a higher pressure inside of the string to a pressure outside of the string.

A casing/liner string buoyancy arrangement including a casing/liner string, and a material defining a volume disposed within the string, the material excluding downhole fluids from the volume, the volume being of a lower specific gravity than the same downhole fluids. A method for managing buoyancy of a casing/liner string including configuring a casing/liner string, running the string, and selectively maintaining or degrading the material to adjust buoyancy of the string. A borehole system including a borehole in a subsurface formation, and an arrangement disposed in the borehole.

A borehole tool, having a cylindrical body, the cylindrical body having an upper shank, a lower shank, and a component tool disposed between the upper shank and the lower shank, wherein the tool is configured to have an outer surface airfoil configuration, whereby lift is created as fluid passes along the cylindrical body. The component tool can be a combination stabilizer tool, a reamer tool and a cutting removal tool, wherein the stabilizer tool is configured as a helical stabilizing blade and reamer blade, a flow path disposed between the helices of the stabilizing and reamer blade, the stabilizing and reamer blade further comprising a reamer cutting element disposed where an edge of the stabilizing and reamer blade meets the flow path.

Casing centralizers and methods are described. In several exemplary embodiments, a casing centralizer has varying flow resistances; as a result, the casing centralizer has varying pressure drops thereacross when the casing centralizer is positioned within a preexisting structure such as, for example, a horizontal wellbore section that traverses one or more subterranean formations.

A connection assembly for engaging a tubular member underwater to restrain the tubular member from radial movement relative to the connection assembly includes a plurality of pads for engaging the tubular member at circumferentially spaced positions; and a plurality of biasing arrangements, each for biasing a respective pad radially inwardly into engagement with the tubular member; wherein each biasing arrangement includes a pre-loadable, mechanical, compressed spring arrangement for resiliently pressing its respective pad against the tubular member. The assembly need not employ any hydraulic components.

A downhole tool comprises a plurality of blades that extend outward from a tool body. Each blade has an under-gauge surface with a blade diameter that is less than a gauge diameter of a drill bit to be used with the downhole tool. A waterway is defined between a pair of adjacent blades and has a waterway base that is recessed from the blade diameter. One or more waterway inserts are disposed within the waterway and extend from the waterway base. Each of the one or more waterway inserts does not extend to the blade diameter. No component of the downhole tool is positioned outside the blade diameter.