Provided is a multi-functional well completion apparatus and method of operation thereof that offers the ability, in a single trip and with limited running tool manipulation, to perform a sand control frac or other fluid stimulation operation and reverse out operations that has improved reverse out flow rates. Furthermore, a combination of dropped balls and hydraulic pressure open one or more sleeves for selective access to a plurality of isolated zones. Additionally, a combination of concentric pipe and internal flow paths creates a reverse flow path. This reverse flow path provides a live annulus during treating, the ability to take returns, and the ability to reverse excess proppant from the wellbore.

A system for determining a borehole shape may comprise a measurement assembly, wherein the measurement assembly may comprise a housing with an outer surface, a transducer disposed flush along the outer surface of the housing, and an extruded boss that connects to the outer surface of the housing. A method may comprise disposing a downhole tool that includes an instrument section into a wellbore and transmitting an excitation from the transducer into the wellbore, wherein the excitation is reflected off a wellbore wall as an echo.

A perforating tool and method of use in a wellbore. The perforating tool is placed at the end of a coiled tubing or other conveyance string. The perforating tool comprises a tubular housing providing an elongated bore through which fluid flows. The tubular housing has jetting ports used for hydraulic perforating. The tool operates in a flow-through mode when working fluid is pumped into the tubular housing at a first flow rate, with all of the fluid flowing through the end of the tool. The perforating tool operates in a perforating mode when the working fluid is pumped into the bore of the tubular housing at a second flow rate. In this mode, all of the working fluid flows through the jetting ports. The perforating tool may include a sequencing mechanism responsive to a sequence of flow rates to cycle the tool through operating modes.

A device for generating pressure waves in a well or a wellbore. The device includes a housing containing an impact-generating mechanism for generating the pressure waves and a connector for connecting the housing to a conveyor for transporting the device to any desired location within the well or the wellbore. The device may be used for a number of downhole applications such as cleaning perforations, fracturing processes, vibration of a casing to prevent fluid flow in a cemented annulus, hydraulic jar operations for freeing stuck downhole objects, generating data to optimize pumping parameters and as an enhancement to percussion drilling techniques.

A downhole displacement impact method and an impact drilling tool are provided, which relates to the field of drilling tools. The downhole displacement impact drilling tool includes a flow passing sleeve, a first main shaft, an impact-bearing seat, and a second main shaft that are all formed by annular structures and are connected in sequence from top to bottom. A vibration sleeve, a vibration starting seat, and an impact head are connected in sequence from top to bottom on the impact-bearing seat. The vibration sleeve is connected and fixed to the impact head through a connecting sleeve. The vibration starting seat synchronously rotates with the impact-bearing seat through a spline connection therebetween. The vibration starting seat generates an up-down periodic displacement along an axial direction of the vibration starting seat during rotating.

A downhole displacement impact method and an impact drilling tool are provided, which relates to the field of drilling tools. The downhole displacement impact drilling tool includes a flow passing sleeve, a first main shaft, an impact-bearing seat, and a second main shaft that are all formed by annular structures and are connected in sequence from top to bottom. A vibration sleeve, a vibration starting seat, and an impact head are connected in sequence from top to bottom on the impact-bearing seat. The vibration sleeve is connected and fixed to the impact head through a connecting sleeve. The vibration starting seat synchronously rotates with the impact-bearing seat through a spline connection therebetween. The vibration starting seat generates an up-down periodic displacement along an axial direction of the vibration starting seat during rotating.

A polycrystalline diamond drill bit for percussion drilling, in small hole high silica ground is disclosed which has a cutting face having an inner flat face and an outer beveled peripheral surface, a number of first polycrystalline diamond tipped inserts having a first diameter inserted into the inner flat face and the outer beveled peripheral surface, and a number of second polycrystalline diamond tipped inserts having a second diameter inserted into the inner flat face, with the second diameter being different than the first diameter. The cutting angle and the radius of the tip of each insert in addition to the diameter of the inserts, provide for use of a machine thrust pressure and machine torque pressure at low ranges when the PCD bits are used in percussion drilling. The percussion drilling, with larger bits, may be used for rotary oil drilling, and operating at a machine thrust and torque of less than 20 Bar.

A guide for a top drive unit includes a lower track member connected to a lower mast section and an upper track member connected to an upper mast section and telescoped with the lower track section. A slider is slidably positioned about the upper track member so the slider is movable along the upper track member. The slider has a lateral cross-sectional profile substantially the same size and shape as a lateral cross-sectional profile of the lower track member. The skate is slidably positioned about the lower track member to be movable along the lower track member and onto the slider. The skate travels along the upper track member via the slider. The skate is connectable to a top drive unit so the top drive unit is movable along the lower track member and the upper track member.

A connection for use in percussion drilling includes a male coupling and a female coupling. Each coupling includes a body and a respective screw thread formed on a respective inner or outer surface of the respective body. Each thread has a thread-form including a crest, a root, a contact flank and a non-contact flank. Each thread-form has a contact flank angle and a non-contact flank angle inclined relative to a respective baseline located at a respective minor or major diameter thereof. Each non-contact flank angle is greater than the respective contact flank angle. The crest of each thread-form is inclined from the respective contact flank to the respective non-contact flank such that an apex of the respective thread-form defining a respective minor or major diameter thereof is located adjacent to the respective non-contact flank.

The present invention relates to a hydraulically powered percussion mechanism (12), comprising a piston (6) to impact a percussion bit (8). The percussion mechanism also includes a first accumulator assembly (3a) for hydraulic fluid. The first accumulator assembly comprises a plurality of first accumulator elements (27). In a first aspect, the plurality of first accumulator elements are arranged in a common housing (14). In a second aspect, each of the first accumulator elements is arranged at the same proximity to the piston. In a third aspect, each of the first accumulator elements comprises an accumulator membrane (32) or piston, and wherein the primary direction of movement of the membrane or piston in contact with the hydraulic fluid is substantially parallel to a longitudinal axis of the mechanism.