Described herein are new methods and systems for profiling tunnels. A method comprises moving a shuttle within a shuttle track extending between a boring apparatus (inside a tunnel) and a base station (outside the tunnel). The shuttle is equipped with a movement sensor, which records various movement parameters (e.g., linear and/or angular accelerations) while the shuttle moves within the shuttle track. These movement parameters are then transferred to a tunnel profiler (e.g., a base station) and the profile of the tunnel is determined based on these movement parameters. For example, a shuttle track can be a flexible tube (e.g., continuous or segmented) with the shuttle positioned within the tube. The shuttle can be removed from the tube or remain in the tube while the movement parameters are transferred and, in some examples, while the shuttle is recharged.

A portable monitor used to measure landfill gas and landfill well parameters. The portable monitor includes a control unit and a measuring unit that can communicate wirelessly with one another. The control unit and/or measuring unit can include a heating arrangement to increase the temperature of one or more components in the control unit and/or measuring unit in cold environments.

A portable monitor used to measure landfill gas and landfill well parameters. The portable monitor includes a control unit and a measuring unit that can communicate wirelessly with one another. The control unit and/or measuring unit can include a heating arrangement to increase the temperature of one or more components in the control unit and/or measuring unit in cold environments.

A method includes designing a lower completion string for a multi-stage hydraulic fracturing job for a wellbore drilled into a subterranean zone. The lower completion string includes a plurality of stages and a plurality of packers configured to isolate each of the stages. Each stage of the plurality of stages includes a respective tubular stage assembly, and each stage is configured to be placed within a respective one of a plurality of frac intervals of the wellbore defined by the plurality of packers. Designing the lower completion string includes, for each stage of the plurality of stages, receiving a measured hole diameter of the respective one of the plurality of frac intervals and performing an axial safety factor analysis of the stage. The axial safety factor analysis includes a comparison of a yield strength in tension or compression of the respective tubular stage assembly of the stage with calculated effective axial tensile or compressive forces to which the respective tubular stage assembly of the stage would be subject when positioned in the frac interval in the wellbore. The axial safety factor analysis uses a predicted anchored status of the lower completion string, which includes an extent to which the respective tubular stage assembly would be predicted to elongate or contract when the lower completion string is positioned in the wellbore and the plurality of packers are set. The axial safety factor analysis also uses a distance between a first packer of the plurality of packers isolating the stage and a second packer of the plurality of packers isolating the stage, and the measured hole diameter of the respective frac interval. The method also includes determining that the axial safety factor analysis for each stage of the plurality of stages satisfies a threshold and, in response to the determining that the threshold is satisfied for each stage of the plurality of stages, inserting the lower completion string into the wellbore and performing the multi-stage hydraulic fracturing job.

A method includes designing a lower completion string for a multi-stage hydraulic fracturing job for a wellbore drilled into a subterranean zone. The lower completion string includes a plurality of stages and a plurality of packers configured to isolate each of the stages. Each stage of the plurality of stages includes a respective tubular stage assembly, and each stage is configured to be placed within a respective one of a plurality of frac intervals of the wellbore defined by the plurality of packers. Designing the lower completion string includes, for each stage of the plurality of stages, receiving a measured hole diameter of the respective one of the plurality of frac intervals and performing an axial safety factor analysis of the stage. The axial safety factor analysis includes a comparison of a yield strength in tension or compression of the respective tubular stage assembly of the stage with calculated effective axial tensile or compressive forces to which the respective tubular stage assembly of the stage would be subject when positioned in the frac interval in the wellbore. The axial safety factor analysis uses a predicted anchored status of the lower completion string, which includes an extent to which the respective tubular stage assembly would be predicted to elongate or contract when the lower completion string is positioned in the wellbore and the plurality of packers are set. The axial safety factor analysis also uses a distance between a first packer of the plurality of packers isolating the stage and a second packer of the plurality of packers isolating the stage, and the measured hole diameter of the respective frac interval. The method also includes determining that the axial safety factor analysis for each stage of the plurality of stages satisfies a threshold and, in response to the determining that the threshold is satisfied for each stage of the plurality of stages, inserting the lower completion string into the wellbore and performing the multi-stage hydraulic fracturing job.

A method includes obtaining a reservoir model for a subsurface reservoir, identifying a current state of the subsurface reservoir using the reservoir model, and a computer processor selecting an optimization function from multiple optimization functions according to the current state of the reservoir to obtain a selected optimization function. The method further includes the computer processor calculating valve positions of physical devices using the selected optimization function. The valve positions are implemented.

A method includes obtaining a reservoir model for a subsurface reservoir, identifying a current state of the subsurface reservoir using the reservoir model, and a computer processor selecting an optimization function from multiple optimization functions according to the current state of the reservoir to obtain a selected optimization function. The method further includes the computer processor calculating valve positions of physical devices using the selected optimization function. The valve positions are implemented.

Drill bit vibration data for lateral, axial, and torsional directions of a drill bit is collected for a simulated or deployed drill bit for visualization of 3D coupled vibration. A frequency converter transforms the drill bit vibration data into frequency vibration data. A drill bit analyzer identifies local maxima (“peaks”) in the frequency vibration data in each of the lateral, axial, and torsional directions. Common peaks across all 3 directions with sufficiently high frequency and sufficiently high bit rotation speed are indicated as 3D coupled vibration. A drill bit data visualizer uses the indications of 3D coupled vibration in addition to the vibration data and frequency vibration data to generate visualizations of 3D coupled vibration in the drill bit.

Drill bit vibration data for lateral, axial, and torsional directions of a drill bit is collected for a simulated or deployed drill bit for visualization of 3D coupled vibration. A frequency converter transforms the drill bit vibration data into frequency vibration data. A drill bit analyzer identifies local maxima (“peaks”) in the frequency vibration data in each of the lateral, axial, and torsional directions. Common peaks across all 3 directions with sufficiently high frequency and sufficiently high bit rotation speed are indicated as 3D coupled vibration. A drill bit data visualizer uses the indications of 3D coupled vibration in addition to the vibration data and frequency vibration data to generate visualizations of 3D coupled vibration in the drill bit.

Additive is introduced into a tubular that carries produced fluid from a wellhead; the additive addition prophylactically guards against damage to the tubular, such as from corrosion or oxidation. Gas from the wellhead is utilized as a pressure source for driving the additive into the tubular. The rate of additive injection is varied based on characteristics of the tubular or fluid in the tubular. Characteristics of the fluid in the tubular include iron content, residual additive, moisture content, and flowrate; characteristics of the tubular include its corrosion rate of the tubular. The characteristics are measured real time, measured historically, or predicted from a model.