A set of manifold string members usable to selectively control separate flowing fluid streams of varying velocities for operations of well construction, injection or production of fluid mixtures of liquids, gases and/or solids, that can be injected into, or taken from, one or more proximal regions of a subterranean passageway, underground cavern, hydrocarbon or geothermal reservoir. Fluid communicated through a manifold string radial passageway of a manifold crossover, between conduit strings and at least one other conduit, can be controlled with at least one flow controlling member, communicating with a passageway member from an innermost, concentric, and/or annular passageway. Fluid communication can be selectively controlled for various configurations of one or more substantially hydrocarbon and/or substantially water wells, below a single main bore and wellhead.

A dual coiled tubing head has an outer coiled tubing connector, an inner coiled tubing connector, a central housing, a first piston and a bottom housing. The outer coiled tubing connector and inner coil connect to the outer coil and inner coil of dual coiled tubing. The inner coiled tubing connector fits within the outer coiled tubing connector such that a passage is created between an outer surface of the inner coiled tubing connector and an inner surface of the outer coiled tubing connector to allow for the passage of fluid through the outer coiled tubing connector. A central housing is connected to the outer coiled tubing connector and inner coiled tubing connector. The central housing has a central passage, at least one peripheral downhole passage and at least one outlet. The peripheral downhole passages are in fluid communication with the outer coiled tubing connector. A piston is housed within the central passage of the central housing. The piston has an inlet end, a sealed bottom end, at least one orifice and a hollow interior. The inlet end is in fluid communication with the inner coiled tubing connector and the hollow interior. The hollow interior houses a one-way valve that permits downward flow. The orifice is in fluid communication with the outlets of the central housing. The bottom housing connects to the central housing. The bottom housing has a central passage, a bottom end and a top end. The central passage is in fluid communication with the peripheral downhole passages and houses a one-way valve for permitting downhole flow of fluid from the exterior coiled tubing connector.

A pulser for generating pressure pulses propagating through a column of drilling fluid in the drill string to the surface during drilling. The pulser may include a screen in the surface of a tubular housing to permit mud from the mud stream to enter into the pulser; an adjustable servo valve configured to receive the mud and including a removable servo poppet and a removable servo orifice member positioned in the tubular housing, wherein the adjustable servo valve is configured to allow the removable servo poppet and the removable servo orifice member to be replaced by another removable servo poppet and another removable servo orifice member to alter an inner diameter of an orifice of the adjustable servo valve to accommodate drilling conditions to increase a performance of the pulser generating pressure pulses for the mud stream returning to the surface.

A pulser for generating pressure pulses propagating through a column of drilling fluid in the drill string to the surface during drilling. The pulser may include a screen in the surface of a tubular housing to permit mud from the mud stream to enter into the pulser; an adjustable servo valve configured to receive the mud and including a removable servo poppet and a removable servo orifice member positioned in the tubular housing, wherein the adjustable servo valve is configured to allow the removable servo poppet and the removable servo orifice member to be replaced by another removable servo poppet and another removable servo orifice member to alter an inner diameter of an orifice of the adjustable servo valve to accommodate drilling conditions to increase a performance of the pulser generating pressure pulses for the mud stream returning to the surface.

A pipe assembly has a hollow inner member nested within a hollow outer member. A series of pipe assemblies are connected end-to-end to form a dual-member drill string useful in horizontal directional drilling operations. The drill string has mutually exclusive first and second fluid paths. Fluid seals, interposed between adjacent inner members of the string, isolate the first fluid path from the second fluid path. Compressed air is delivered into the first fluid path from above ground level, and routed to an underground boring tool. The expelled air and spoils are returned to above ground level by way of the second fluid path. One or more baffle elements are supported on the drill string adjacent the boring tool. The baffle elements are configured to prevent compressed air and spoils from flowing between the walls of the borehole and the drill string.

Geologic material in a borehole is weakened by accelerating a projectile into contact with the material. A drill bit is then used to bore through the weakened material. To accelerate the projectile, an endcap is placed in a conduit using a source of gas. The endcap isolates the conduit from the external environment. A projectile is then positioned in the conduit above the endcap. Movable members within the conduit are operated in sequence to enable single endcaps and projectiles to be moved into the conduit. Gas from the conduit is evacuated into an annulus between the conduit and a surrounding conduit, and a propellant material is provided into the conduit. The propellant material applies a force to the projectile to accelerate the projectile into contact with the geologic material. A fluid is circulated down a second annulus outside of the surrounding conduit to contact the drill bit and remove debris.

Geologic material in a borehole is weakened by accelerating a projectile into contact with the material. A drill bit is then used to bore through the weakened material. To accelerate the projectile, an endcap is placed in a conduit using a source of gas. The endcap isolates the conduit from the external environment. A projectile is then positioned in the conduit above the endcap. Movable members within the conduit are operated in sequence to enable single endcaps and projectiles to be moved into the conduit. Gas from the conduit is evacuated into an annulus between the conduit and a surrounding conduit, and a propellant material is provided into the conduit. The propellant material applies a force to the projectile to accelerate the projectile into contact with the geologic material. A fluid is circulated down a second annulus outside of the surrounding conduit to contact the drill bit and remove debris.

A fluid operated drilling device for drilling a hole said device having a hammer, a rotation device and a drill rod. The hammer includes a tubular main body, a back head, a cylindrical piston housing, a reciprocating piston, a space, a valve unit and a fluid pressure supply unit. A hollow portion of the piston is open to lead pressurized operating fluid directly to the hollow portion from the fluid pressure supply passage. The hammer includes an axial exhaust passage formed between the main body and the piston housing. The valve unit includes a valve exhaust passage and the piston has a lower part and an upper part detachably connected to each other. The invention also relates to a method for drilling a hole using the fluid operated drilling device.

A pipe assembly has a hollow inner member nested within a hollow outer member. A series of pipe assemblies are connected end-to-end to form a dual-member drill string useful in horizontal directional drilling operations. The drill string has mutually exclusive first and second fluid paths. Fluid seals, interposed between adjacent inner members of the string, isolate the first fluid path from the second fluid path. Compressed air is delivered into the first fluid path from above ground level, and routed to an underground boring tool. The expelled air and spoils are returned to above ground level by way of the second fluid path. One or more baffle elements are supported on the drill string adjacent the boring tool. The baffle elements are configured to prevent compressed air and spoils from flowing between the walls of the borehole and the drill string.

A composite drill pipe including an inner pipe having a first diameter, an outer pipe having a second diameter greater than the first diameter, and a plurality of flow channels formed between the inner pipe and the outer pipe. The plurality of flow channels are formed by a plurality of walls extending radially between an outer diameter of the inner pipe and an inner diameter of the outer pipe. A method of forming a composite drill pipe includes pultruding a drill pipe comprising an inner pipe having a first diameter, an outer pipe having a second diameter greater than the first diameter, and a plurality of flow channels formed between the inner pipe and the outer pipe. The method also includes providing a multi-directional reinforcement over an outer diameter of the outer pipe.