Abstract: A restrictor device for controlling a return flow of drilling fluid from a borehole where drilling fluid is provided from a surface installation via a drill string to a bottom-hole assembly is disclosed. Drill pipes forming the drill string are provided with pipe joints including enlarged-diameter pipe portions. An annulus is formed between a riser and the drill string. The annulus is in fluid communication with a drilling-fluid flow path. The restrictor device is arranged in the annulus. The restrictor device includes a restrictor pipe anchored to the riser and surrounds at least one restrictor element placed on an intermediate pipe portion that connects two enlarged-diameter pipe portions. The length of the restrictor device exceeds the largest distance between two consecutive restrictor elements. The restrictor element is a drill-pipe/casing protector with an external diameter larger than a diameter of the pipe joints.

Abstract: A restrictor device (6) for controlling a return flow of drilling fluid from a borehole (51) where drilling fluid is provided from a surface installation (3) via a drill string (4) to a bottom-hole assembly (45), drill pipes (41) forming the drill string (4) being provided with pipe joints (42) including enlarged-diameter pipe portions (43), and where an annulus (22) is formed between a pipe, for example a marine riser (1), and the drill string (4), and where the annulus (22) is in fluid communication with or forms parts of a drilling-fluid flow path (23), and where the restrictor device (6) is arranged in the annulus (22), the restrictor device (6) being formed of a restrictor pipe (61) anchored to said riser (1) and surrounding at least one restrictor element (64) placed on an intermediate pipe portion (44) that connects two enlarged-diameter pipe portions (43), and the length (L) of the restrictor device (6) exceeding the largest distance (M) between two consecutive restrictor elements (64), the restrictor

Abstract: A method for assembling a marine drilling riser includes assembling a predetermined number of sections of the marine drilling riser and extending them into a body of water from a drilling platform. The assembling including affixing a selected number of external line guides to the riser at selected longitudinal positions. The line guides are initially closed to be substantially at most equal a diameter of buoyancy devices on the riser. The line guides are subsequently opened to extend beyond the buoyancy device diameter. A predetermined length of fluid external line is moved to adjacent the assembled riser and the fluid conduit is coupled to the external line guides. The external line guides are locked and assembly of the riser is completed and tension is applied thereto.

Abstract: A subsea mudlift pump includes a pressure sealed housing disposed in a body of water in which a wellbore is being drilled by a drilling rig disposed above the surface of the body of water. A motor (44) is configured to generate linear motion is coupled to at least one piston (46) disposed within the housing such that operation of the motor causes linear motion of the piston within the housing. One side of the piston is within a pumped fluid chamber that changes volume when the piston is moved within the housing.

Abstract: A subsea mudlift pump includes a pressure sealed housing disposed in a body of water in which a wellbore is being drilled by a drilling rig disposed above the surface of the body of water. A motor (44) is configured to generate linear motion is coupled to at least one piston (46) disposed within the housing such that operation of the motor causes linear motion of the piston within the housing. One side of the piston is within a pumped fluid chamber that changes volume when the piston is moved within the housing.

Abstract: The present invention is directed toward a method for preventing, suppressing or mitigating explosions in a confined subterranean chamber, access opening, or entryway of an underground structure such as the manhole of sewers, service boxes, and mining tunnels. The method utilizes a flexible bladder filled with an inert gas or explosion suppressing agent, wherein the bladder is maintained in the chamber in an inflated condition and the volume of the inflated bladder occupies greater than 70% of the volume of the chamber to significantly reduce the amount of space in which an explosive fuel/air mixture may otherwise accumulate. The bladder is heat critical to disintegrate at a predetermined temperature and release a volume of the explosion suppressing agent or inert gas relative to the volume of the chamber which is sufficient to alter the ratio of the fuel/air mixture in the chamber to prevent, suppress or mitigate the explosive reaction.

Abstract: An apparatus and method for supporting pipe main repair tools in an excavation while repairs are being made requires only exposure of the top surface of a buried main and utilizes an anchoring system installed in or above the excavation and an elongate support member that spans the excavation in a generally horizontal position above the pipe main and supports an elongate tubular seal tube against the exposed surface of the pipe main. The elongate support member is secured and supported at opposite ends on the ground surface on opposed sides of the excavation by a pair of parallel laterally spaced shoring members firmly engaged on opposed sides of the excavation, or by a pair of parallel laterally spaced anchor plates firmly engaged on the ground surface on opposed sides of the excavation.

Abstract: An apparatus and method for shutting off fluid flow in a pipe main while repairs are being made requires only exposure of the top surface of a buried main and utilizes an anchor system installed in or above the excavation which supports an elongate tubular seal tube against the exposed surface of the main to extend radially therefrom. A jack mechanism compresses the lower end of the seal tube containing a seal member against the exterior surface of the main. A tubular cutting tool installed inside the seal tube is rotated by an air motor to cut a hole in the side wall of the main. A tubular sealant application tool installed inside the seal tube has a nozzle at its bottom end that sprays liquid sealant material onto the interior surface of the main and is then removed. A tubular bladder deployment tool installed inside the seal tube carries a pair of deflated bladders.

Abstract: A method of rapid earth excavation without damaging buried pipe, cable or other underground objects utilizes drills and augers having soft cutting edges and/or control of the torque and weight of the boring apparatus. In one embodiment, the bit of a drill, or bottom end of an earth auger is equipped with inserts formed of soft polymeric material. Another embodiment of an earth auger apparatus has soft polymeric material on the leading cutting surface of the flight, or the auger flight may be formed of soft polymeric material. The flexibility and low abrasion of the polymeric material prevents damage to the object contacted. Another embodiment has a dual concentric auger with a small earth-auger rotatably mounted inside the shaft of a larger auger and driven independently such that each is capable of providing and maintaining a torque adequate to create a given hole diameter but sufficiently below that which would damage the object expected to be encountered.

Abstract: A steering system is disclosed for percussion boring tools for boring in the earth at an angle or in a generally horizontal direction. The steering mechanism comprises a slanted-face nose member attached to the anvil of the tool to produce a turning force on the tool and movable tail fins incorporated into the trailing end of the tool which are adapted to be selectively positioned relative to the body of the tool to negate the turning force. The fins are constructed to assume a neutral position relative to the housing of the tool when the tool is allowed to turn and to assume a spin inducing position relative to the housing of the tool to cause it to rotate when the tool is to move in a straight direction. Turning force may also be imparted to the tool by an eccentric hammer which delivers an off-axis impact to the tool anvil. For straight boring, the tail fins are fixed to induce spin of the tool about its longitudinal axis to compensate for the turning effect of the slanted nose member or eccentric hammer.

Abstract: A percussion boring tool is disclosed for boring in the earth at an angle or in a generally horizontal direction. The tool has a steering mechanism substantially as shown in a copending patent application and a cylindrical body with overgage sleeves located over a portion of the outer body affixed so that they can rotate but cannot slide axially. The overgage areas at the front and back of the tool, or alternately, an undergage section in the center of the tool body permits a 2-point contact (front and rear) of the outer housing with the soil wall as opposed to the line contact which occurs without the undercut. The 2-point contact allows the tool to deviate in an arc without distorting the round cross-sectional profile of the pierced hole. Thus, for a given steering force at the front and/or back of the tool, a higher rate of turning is possible since a smaller volume of soil needs to be displaced.

Abstract: A casing hanger for supporting a casing from a casing head within a well bore having a split ring with sealing means attached thereto, a plurality of gripping assemblies supported from the split ring and each of said assemblies including a body with an inwardly facing recess and an exterior surface which tapers downward and inward, to seat in the casing head bowl a plurality of gripping dogs having a generally horizontal gripping edge extending radially inward from the body, and a deformable backing positioned within the space between the outer edge of said dogs and the body recess, the backing partially filling the space behind the dogs and having space into which the backing may move on deformation, the backing providing varying areas in support of each gripping dog and being relatively yieldable.