A method to perform a well maintenance operation is disclosed. The method includes obtaining, using a downhole camera, a downhole image comprising a pixel-based dimension of an object inside the wellbore, generating, using a laser distance pointer, a distance measurement of the object with respect to the downhole camera, determining, based on the distance measurement, a physical dimension of the object from the pixel-based dimension of the object, and performing the well maintenance operation based at least on the physical dimension of the object.

A method to perform a well maintenance operation is disclosed. The method includes obtaining, using a downhole camera, a downhole image comprising a pixel-based dimension of an object inside the wellbore, generating, using a laser distance pointer, a distance measurement of the object with respect to the downhole camera, determining, based on the distance measurement, a physical dimension of the object from the pixel-based dimension of the object, and performing the well maintenance operation based at least on the physical dimension of the object.

A casing string is augmented with one or more variable flow resistance devices or “vibrating tools” to facilitate advancement of the casing and distribution of the cement in the annulus once the casing is properly positioned. Vibrating tools in the form of plugs can be pumped down and landed inside the casing string. The method includes vibrating the casing string while advancing the casing down the wellbore or while the cement is pumped into the annulus, or both. After the cementing operation is completed, the devices may be drilled out or retrieved with fishing tools to reopen the casing string for further operations. One or more wipers may be provided on the plugs, but the section housing the flow path may be free of wipers to allow the size and flow capacity of the flow path to be optimized.

A non-electric explosive device includes a primary body containing cutting material and including a primary charge positioned in the cutting material; an explosive body at a first axial end of the primary body and including explosive material; and a firing head at a second axial end of the primary body, the firing head including a firing pin secured at least partially inside the firing head via securing device, the firing pin comprising an activating end proximate the primary charge and a blunt end protruding from a distal end of the firing head. A force applied to the blunt end of the firing pin causes the firing pin to retract toward the primary charge and break the securing device so that the activating end of the retracting firing pin impacts the primary charge which ignites the explosive material that causes the cutting material in the primary body to travel radially outward.

A pulsation valve system and method can include a mandrel, an oscillating valve head and a stationary valve head. The mandrel can be operably coupled to a rotor of a pulsation assembly, and can include bypass bores controlled by a spring biased piston that moves in response to a predetermined fluid pressure acting thereon. The oscillating valve head can be attached to and rotatable with the mandrel. The stationary valve head can be positioned adjacent and stationary with respect to the oscillating valve head. The stationary valve head can include a stationary valve bore defined therethrough. The oscillating valve head can include an oscillating valve bore defined therethrough that is alignable with the stationary valve bore at a predetermined rotational position. The stationary valve bore can have a radial length greater than the oscillating valve bore.

A technique facilitates controlled creation of pressure waves in a downhole environment. The technique enables creation of, for example, dynamic underbalance (DUB) pressure waves or dynamic overbalance (DOB) pressure waves which can be used to perform desired activities downhole. According to an embodiment, a pump is coupled with a pressure chamber and conveyed downhole into a borehole to a desired location. The pump may be operated downhole to change a pressure level in the pressure chamber until a sufficient pressure differential exists between an interior and an exterior of the pressure chamber. A release mechanism in communication with the pressure chamber is then rapidly opened to establish the desired pressure wave as the differing pressures equalize.

A baffle system for use in well casing having a plurality of landed subs therein, for progressive injection of a fracking or treating fluid into a hydrocarbon formation via existing or created perforations in the well casing. The baffle members provide a plug seat, and are each frangibly affixed to a conveying tool and have collet finger protuberances thereon. The collet finger protuberances of each baffle are of a different width, and respectively engage only one annular recess of a corresponding width in a respective landing sub. Each annular recess and/or collet finger protuberance on an uphole edge thereof has a chamfer which allows disengagement of the collet finger protuberances and thus removal of the baffle member from the well casing upon upward force being applied to the baffle member. A method of using the baffle system is also disclosed.

Techniques for removing a tubular from a wellbore include running a downhole tool on a downhole conveyance into a wellbore formed from a terranean surface into a subterranean formation; activating a piston sub-assembly to repeatedly move pistons to contact a portion of a casing installed in the wellbore to at least de-bond a cement layer installed between the portion of the casing and the subterranean formation from the portion of the casing; activating a cutting sub-assembly to move a cutting blade to cut through the portion of the casing adjacent the de-bonded portion of the cement layer; activating a hanger sub-assembly to move a set of slips into contacting engagement with the cut portion of the casing; and running the downhole tool on the downhole conveyance out of the wellbore with the cut portion of the casing engaged with the set of slips.

A method for dissipating force within a tubing string including providing a severing device to a desired location within a tubing string; a cut zone along the length of the tubing, and a housing disposed along the length of tubing and sized to enclose the cut zone therein, wherein the housing includes a first end and a second end each forming a housing shoulder, severing the tubing at the cut zone using the severing device creating a first tubing section and a second tubing section; wherein the first tubing section and the second tubing section slide apart within the housing.

A method for dissipating force within a tubing string including providing a severing device to a desired location within a tubing string; a cut zone along the length of the tubing, and a housing disposed along the length of tubing and sized to enclose the cut zone therein, wherein the housing includes a first end and a second end each forming a housing shoulder, severing the tubing at the cut zone using the severing device creating a first tubing section and a second tubing section; wherein the first tubing section and the second tubing section slide apart within the housing.