Abstract: In some examples, a system can include a computer-readable medium storing computer-executable instructions and one or more processors communicatively coupled to a computer-readable medium storing computer-executable instructions, which, when executed by the one or more processors cause the one or processors to receive data of a fracking stage, determine a penetration gradient of the fracking stage based on the data, and classify the fracking stage based on the penetration gradient.

Abstract: A well tool for generating a notch in an open-hole wellbore, includes a tool body having a housing defining at least one slot and an interior volume. The tool body includes a cutting device disposed in the interior volume, configured to form a notch in a formation. The cutting device includes a shaft disposed in the interior volume of the housing having a first portion with a first exterior threads that extend around the first portion in a first direction, and a second portion having second exterior threads that extend around the second portion in a second direction opposite the first direction. The cutting device includes multiple blades configured to extend radially outward toward the formation through the slot or inward away from the formation and having a first blade extending from the first portion of the shaft and a second blade extending from a second portion of the shaft.

Abstract: A method for stabilizing a wellbore includes introducing a hardening agent into the wellbore, mixing the hardening agent with a carrier fluid in the wellbore to produce a wellbore stabilizing fluid, and treating a wellbore wall of the wellbore by contacting the wellbore stabilizing fluid to a surface of the wellbore wall for at least 48 hours. A wellbore stabilizing fluid includes a hardening agent and a carrier fluid. The hardening agent is selected from one of 10 to 100 g/L of the calcium hydroxide nanocrystals, 5 to 99.9% by volume of tetraethyl orthosilicate (TEOS), and 10 to 50 g/L of zinc sulfate. A stabilized wellbore includes a wellbore having a wellbore wall treated with a wellbore stabilizing fluid comprising a hardening agent. The Young's modulus of the treated wellbore wall is at least 5% higher than a Young's modulus of a non-treated wellbore wall.

Abstract: In some examples, a system can include a computer-readable medium storing computer-executable instructions and one or more processors communicatively coupled to a computer-readable medium storing computer-executable instructions, which, when executed by the one or more processors cause the one or processors to receive data of a fracking stage, determine a penetration gradient of the fracking stage based on the data, and classify the fracking stage based on the penetration gradient.

Abstract: A method for reducing breakdown pressure at a formation includes detecting a tight reservoir formation in a well and providing hydraulic fracturing equipment assembled together as a hydraulic fracturing system at a surface of the well. The hydraulic fracturing system includes a fluid source containing a base fluid and fluidly connected to a blender and a pump and manifold system fluidly connecting an outlet of the blender to a wellhead of the well. The method further includes connecting a cooling system to the hydraulic fracturing system, using the cooling system to cool the base fluid to a cooled base temperature upstream of the pump and manifold system, pumping the cooled base fluid down the well to the tight reservoir formation, and using the cooled base fluid to lower a temperature of the tight reservoir formation and reduce a breakdown pressure of the tight reservoir formation.

Abstract: A computer-implemented method may include obtaining well logs data pertaining to a well of interest. The method may further include training a physics-constrained machine learning (PCML) model using the obtained well logs data as inputs. The method may further include outputting one or more sonic logs and mechanical properties of interest determined by using the trained PCML model and the obtained well logs data for the well of interest. The method may further include updating the determined sonic logs and mechanical properties of interest based on a breakout model and field breakout data for the well of interest. The method may further include outputting the final sonic logs for the well of interest. The method may further include determining one or more mechanical properties for well planning based on the final sonic logs for the well of interest.

Abstract: A method to predict wireline caliper log data from logging-while-drilling data which includes collecting logging-while-drilling logs and caliper logs from a plurality of wells. The caliper log contains at least one channel. The method further includes pre-processing the logging-while-drilling data, selecting a subset of logs within the logging-while-drilling data, and aggregating the channels of the caliper logs forming aggregate logs. The method further includes splitting the pre-processed logging-while-drilling data and aggregate logs into train, validation, and test sets, wherein the validation and test sets may be the same, selecting a machine-learned model and architecture, and training the machine-learned model to form predicted aggregate logs from the logging-while-drilling data using the training set. Additionally, the method consists of using the machine-learned model to predict the aggregate logs using pre-processed logging-while-drilling data.

Abstract: A wellbore stimulation operation method includes conveying a downhole assembly into a wellbore. The downhole assembly includes one or more perforating guns and a pressure wave resonator. The perforating guns are axially aligned with a production zone and fired to create a plurality of perforations in the production zone. The pressure wave resonator is axially aligned with the perforations and actuated to emit pressure waves that propagate radially outward and into the production zone. The pressure waves help remove debris from the perforations.

Abstract: A method of treating a carbonate formation includes introducing a stimulation fluid into the carbonate formation at a pressure greater than a fracture pressure of the formation and creating openings in the carbonate formation via the stimulation fluid. Then, a fluoride salt solution, optionally including a proppant, may be introduced into the carbonate formation such that it at least partially penetrates into the openings. The fluoride salt may then be reacted with a carbonate surface in the carbonate formation to form fluorite on a surface of the formation thereby increasing a hardness of the carbonate formation.

Abstract: A method for stabilizing a wellbore includes introducing a hardening agent into the wellbore, mixing the hardening agent with a carrier fluid in the wellbore to produce a wellbore stabilizing fluid, and treating a wellbore wall of the wellbore by contacting the wellbore stabilizing fluid to a surface of the wellbore wall for at least 48 hours. A wellbore stabilizing fluid includes a hardening agent and a carrier fluid. The hardening agent is selected from one of 10 to 100 g/L of the calcium hydroxide nanocrystals, 5 to 99.9% by volume of tetraethyl orthosilicate (TEOS), and 10 to 50 g/L of zinc sulfate. A stabilized wellbore includes a wellbore having a wellbore wall treated with a wellbore stabilizing fluid comprising a hardening agent. The Young's modulus of the treated wellbore wall is at least 5% higher than a Young's modulus of a non-treated wellbore wall.

Abstract: A method includes preparing a rocklike core sample for compressive testing, the rocklike core sample defining a longitudinal axis and having first and second axial ends. Preparing the rocklike core sample includes providing a throughhole in the rocklike core sample, the throughhole extending between a first opening at the first axial end and a second opening at the second axial end, wherein the first opening and the second opening are dimensioned differently. The rocklike core sample is mounted in a compressive testing apparatus, and a compressive test is performed on the rocklike core sample in the compressive testing apparatus. The compressive test includes compression in axial and radial directions. A related system includes a compressive testing apparatus and a sample preparation apparatus which prepares a rocklike core sample for compressive testing in the compressive testing apparatus, via providing a throughhole in the rocklike core sample.

Abstract: A method and an apparatus for determining a collapse pressure of a well using a drill stem test tool (DSTT). The method includes isolating a zone of interest in the wellbore, then reducing and recording pressure inside the drill string while recording acoustic emissions from the sensors on the DSTT, then correlating the recordings of the acoustic emissions with the pressure. The method includes using the processed acoustic emissions to determine a candidate sound of interest and a pressure at which the candidate sound of interest is recorded, then comparing the candidate sound of interest with a reference lookup table of known lithology classifications. The method includes determining a collapse pressure of the wellbore using the lithology of the wellbore and the pressure at which the candidate sound of interest is recorded.

Abstract: A method includes preparing a rocklike core sample for compressive testing, the rocklike core sample defining a longitudinal axis and having first and second axial ends. Preparing the rocklike core sample includes providing a throughhole in the rocklike core sample, the throughhole extending between a first opening at the first axial end and a second opening at the second axial end, wherein the first opening and the second opening are dimensioned differently. The rocklike core sample is mounted in a compressive testing apparatus, and a compressive test is performed on the rocklike core sample in the compressive testing apparatus. The compressive test includes compression in axial and radial directions. A related system includes a compressive testing apparatus and a sample preparation apparatus which prepares a rocklike core sample for compressive testing in the compressive testing apparatus, via providing a throughhole in the rocklike core sample.

Abstract: A method may include determining time-derivative pressure data based on pressure data regarding a pump system that is performing a hydraulic stimulation operation in a geological region. The method may further include determining a moving average value based on the time-derivative pressure data and a predetermined time window. The method may further include determining a flow rate adjustment for the pump system based on the moving average value, an update interval for adjusting flow rates, and a predetermined flow rate rule. A size of the predetermined time window may be different from the update interval. The method may further include using smoothed pressure data to determine time-derivative pressure data. The method may further include determining a flow rate adjustment for the pump system based on the time-derivative pressure data derived from the smoothed pressure data.

Abstract: A method for reducing breakdown pressure at a formation includes detecting a tight reservoir formation in a well and providing hydraulic fracturing equipment assembled together as a hydraulic fracturing system at a surface of the well. The hydraulic fracturing system includes a fluid source containing a base fluid and fluidly connected to a blender and a pump and manifold system fluidly connecting an outlet of the blender to a wellhead of the well. The method further includes connecting a cooling system to the hydraulic fracturing system, using the cooling system to cool the base fluid to a cooled base temperature upstream of the pump and manifold system, pumping the cooled base fluid down the well to the tight reservoir formation, and using the cooled base fluid to lower a temperature of the tight reservoir formation and reduce a breakdown pressure of the tight reservoir formation.

Abstract: This disclosure presents a method and an apparatus for improving production performance of a well using a drill stem test tool (DSTT). The method includes isolating a zone of interest in the wellbore, then reducing and recording pressure inside the drill string while recording acoustic emissions from the sensors on the DSTT, then correlating the recordings of the acoustic emissions with the pressure. The method includes using the processed acoustic emissions to determine a candidate sound of interest and a pressure at which the candidate sound of interest is recorded, then comparing the candidate sound of interest with a reference lookup table of known lithology classifications. The method includes determining a collapse pressure of the wellbore using the lithology of the wellbore and the pressure at which the candidate sound of interest is recorded.

Abstract: A fracturing fluid composition includes an aqueous fluid, a proppant particle, and a date tree fiber. A method of treating a hydrocarbon-bearing formation is also provided. The method includes injecting a fracturing fluid in the hydrocarbon-bearing formation, where the fracturing fluid includes an aqueous fluid, a proppant particle, and a date tree fiber.

Abstract: A well tool for generating a shaped perforation in a cased wellbore includes a tool body. The told body has at least one wall, a fluid channel, a first perforation device, and a second perforation device. The at least one wall defines an opening and an interior volume. The fluid channel extends from the opening of the at least one wall into the interior volume. The first perforation device is configured to form a perforation tunnel in the cased wellbore disposed in a formation. The second perforation device is coupled to the first perforation device and to the fluid channel. The second perforation device is configured to form the shaped perforation in the formation by flowing fluid received through the fluid channel to the formation through the perforation tunnel.

Abstract: To monitor hydraulic fracturing operations, an acoustic insulation tool acoustically insulates a wellhead installed at a surface of a wellbore. Multiple acoustic sensors attached to the wellhead sense acoustic signals generated responsive to operation of hydraulic fracturing components. The components perform hydraulic fracturing operations within the wellbore. The acoustic insulation tool acoustically insulates the wellhead from acoustic signals generated by sources other than the hydraulic fracturing components. The multiple acoustic sensors transmit the sensed acoustic signals to a computer system. Using the received acoustic signals, the computer system monitors the hydraulic fracturing operations performed within the wellbore.

Abstract: A computer-implemented method may include obtaining well logs data pertaining to a well of interest. The method may further include training a physics-constrained machine learning (PCML) model using the obtained well logs data as inputs. The method may further include outputting one or more sonic logs and mechanical properties of interest determined by using the trained PCML model and the obtained well logs data for the well of interest. The method may further include updating the determined sonic logs and mechanical properties of interest based on a breakout model and field breakout data for the well of interest. The method may further include outputting the final sonic logs for the well of interest. The method may further include determining one or more mechanical properties for well planning based on the final sonic logs for the well of interest.