The disclosure relates to a carriage apparatus for carrying a tool string down a wellbore in a wireline logging, and an orientation apparatus and hole finder device for a wireline logging tool string. In some embodiments the carriage includes a protection structure which extends longitudinally around a wheel of the apparatus to thereby prevent a side of the wheel from contacting a wall of the wellbore. In some embodiments an orientation apparatus and hole finder are arranged so that the orientation apparatus orientates the hole finder device in the wellbore so that a tip of a nose section of the hole finder is elevated above a low side of the wellbore by a height and offset from and above a longitudinal axis of the tool string.

A downhole tractor for operational use in well casing of a wellbore. The tractor comprising a tractor body, at least one actuator assembly, and at least one tractor wheel. The actuator assembly is actionable to shift the axis of rotation of the tractor wheel. The at least one tractor wheel includes at least one bifurcated tract having a leading and trailing edge for engaging the well casing. The at least one actuator assembly causes the at least one tractor wheel to switch from traversing a first vertical plane of the well casing to a second vertical plane of the well casing when actuated.

Provided in some embodiments is a method of distributed acoustic sensing in a subterranean well. The method including advancing a torpedo into a first portion of a wellbore of a subterranean well (the torpedo including a distributed acoustic sensing (DAS) fiber-optic (FO) umbilical that is physically coupled to a surface component and adapted to unspool from the torpedo as the torpedo advances in the wellbore, and an engine adapted to generate thrust to propel the torpedo), and activating the engine to generate thrust to propel advancement of the torpedo within a second portion of the wellbore such that at least some of the DAS FO umbilical is disposed in the second portion of the wellbore.

A well system includes a perforating gun having shaped charges and a detonator to controllably detonate the shaped charges. The well system further includes a propulsion head coupled to the perforating gun. The propulsion head is operable to apply thrust to the perforating gun such that the well system is self-propelling.

An inflatable multifunctional downhole tool includes a body having an outer shell and a threaded connection at an axial end of the body, at least one pressurized container disposed inside the outer shell, the pressurized container containing compressed gas, a plurality of floatation chambers fluidly connected through connection lines to the at least one pressurized container, a dissolvable plug positioned along each of the connection lines between the floatation chambers and the at least one pressurized container, and a tool sub threadably connected to the threaded connection of the body.

A wellbore tractor is capable of being positioned in a wellbore that includes a cased section, a first uncased section downhole of the cased section, and a second uncased section downhole of the first uncased section. The wellbore tractor is capable of self-propelling itself through the wellbore. An anchoring system is connected to the wellbore tractor. The anchoring system includes an appendage. When the wellbore tractor is in the cased section, the anchoring system is capable of extending the appendage from the cased section through the first uncased section into the second uncased section, anchoring the appendage in the second uncased section, and guiding the wellbore tractor from the cased section past the first uncased section and into the second uncased section.

A downhole probe can be utilized in a wellbore to accurately determine a relative depth between measurement locations. The downhole probe includes a measurement unit for taking downhole measurements and a detachable anchor that can grip a wellbore wall to maintain a fixed location. The measurement unit may be moved relative to anchor between the measurement locations to unspool a tether coupled between the anchor and the measurement unit. The length of the tether unspooled may provide a more accurate indication of the relative distance between the measurement locations than surface-based measurements. The detachable anchor may be retrieved for deployment at additional measurement locations or may be abandoned in the wellbore.

A downhole tool system may include one or more containers to hold waste product and a tractor to convey the one or more containers to a storage location within a wellbore. The downhole tool system may also include an anchor to seal against the wellbore and secure the containers at the storage location. Additionally, the downhole tool system may include a disconnect tool to separate the tractor from the containers such that the tractor may be removed from the wellbore while leaving the containers at the storage location.

Techniques according to the present disclosure include moving an untethered downhole tool through a wellbore between a terranean surface and a particular depth in the wellbore; during the moving the untethered downhole tool through the wellbore, acquiring a set of sensed data from one or more sensors in the untethered downhole tool in a time domain; transforming the plurality of data values associated with the wellbore parameter in the time-domain into a plurality of data values associated with the wellbore parameter in a depth-domain based at least in part on at least one accelerometer output and the locations of a plurality of casing collars; and preparing the plurality of data values associated with the wellbore parameter in the depth-domain for presentation on a graphical user interface (GUI).

An apparatus for traveling between an earth surface and a wellbore in an earth formation contains an instrument sub, a thruster for generating a motive force, and a power source that provides power to the instrument sub and the thruster. The instrument sub contains well logging instruments. The instrument sub, the thruster, and the power source are connected to form or are disposed in a substantially tubular body. The apparatus further contains a buoyance-generating device.