A method can include acquiring data during rig operations for a specified drillstring for drilling a specified borehole in a geologic environment, where the data include downhole survey data; determining a drillstring load based on at least a portion of the data; comparing the drillstring load to a plurality of modeled loads, where the plurality of modeled loads depend on the specified drillstring, the specified borehole, and at least a portion of the survey data and correspond to a plurality of different friction factor values; and, based on the comparing, estimating a friction factor value that corresponds to the drillstring load.

A method can include acquiring data during rig operations for a specified drillstring for drilling a specified borehole in a geologic environment, where the data include downhole survey data; determining a drillstring load based on at least a portion of the data; comparing the drillstring load to a plurality of modeled loads, where the plurality of modeled loads depend on the specified drillstring, the specified borehole, and at least a portion of the survey data and correspond to a plurality of different friction factor values; and, based on the comparing, estimating a friction factor value that corresponds to the drillstring load.

Aspects of the disclosed technology provide techniques for determining frictional forces bearing on a downhole drill string. In some implementations, a method of the disclosed technology can include steps for segmenting a plurality of continuous nodes of the drilling string into a first segment and a second segment, computing a first set of values corresponding with one or more nodes in the first segment using a first model, computing a second set of values corresponding with one or more nodes in the second segment using a second model, and determining a torque of the drill string based on the first set of values and the second set of values. In some aspects, the method can further include steps for determining a drag force on the drill string based on the first set of values and the second set of values. Systems and machine-readable media are also provided.

Impedance is used to determine the performance of paraffin inhibitors in oil containing paraffin. The method and system can use a specially designed impedance cell having a cell constant of less than 1 cm.sup.−1. Further, the method can include obtaining at least impedance measurements above the wax appearance temperature (WAT) for an oil sample treated with a paraffin inhibitor and an oil sample not treated, and impedance measurements below the WAT for the treated oil sample and the untreated oil sample. Thereafter, the impedance measurements are correlated to determine paraffin inhibitor performance.

A drill bit for drilling a subterranean formation. The drill bit includes a drill bit body, at least one cutting element disposed on the drill bit body, and an optical sensor disposed on the drill bit body and configured to generate an environmental parameter measurement while drilling the subterranean formation. The optical sensor includes a fiber bragg grating embedded in an optical fiber that passes through a first channel in the drill bit body and a second channel in the drill string to couple to a surface logging station for analyzing the environmental parameter measurement, where the environmental parameter measurement represents at least a downhole chemical composition measured by the fiber bragg grating, and an analysis result of the surface logging station is presented to a user to facilitate a drilling operation.

The disclosure discloses a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

The disclosure discloses a method for constructing a pumping-injection well of a groundwater reservoir in a dump of an open-pit mine. The pumping-injection well includes a bottom pipe, intermediate pipes, and a top pipe in sequence from bottom to top connected from bottom to top. The method includes: arranging a rubble barrier around the pumping-injection well, and installing the bottom pipe of the pumping-injection well at a designed position of the pumping-injection well as a center of circle; continuing to install an intermediate pipe on the bottom pipe, and pile up a rubble pile; continuing to stack multiple intermediate pipes, and starting the construction of the groundwater reservoir; discarding discarded materials from the open-pit mine to form a dump; continuing to stack intermediate pipes to build an inverted trapezoidal surface sump around the pumping-injection well; and installing the top pipe and a well cover to form a complete pumping-injection well.

A nuclear density tool may comprise a gamma source, a gamma detector, wherein the gamma detector and the gamma source are disposed on a longitudinal axis of the nuclear density tool, and a housing, wherein the gamma source and the gamma detector are disposed in the housing. The nuclear density tool may further comprise a first cutout in the housing positioned to allow the gamma source to emit an energy through the housing and a second cutout in the housing posited to allow the gamma detector to detect the energy through the housing. A method for determining a density may comprise disposing a nuclear density tool into a wellbore, transmitting an energy from the gamma source, detecting the energy reflected with the gamma detector, recording a count rate of the energy at the gamma detector, determining an average density based at least in part on the count rate, creating one or more layers from the average density, forming a layer construction using at least in part the one or more layers from the average density, comparing the layer construction to count rates form individual energy channels, and determining a final layer density for each of the one or more layers.

A method for performing a maintenance operation of a well in an oil/gas field is disclosed. The method includes identifying an extent of corrosion deposit of the well, predicting, using a descaling model of the oil/gas field and based on the extent of corrosion deposit, expected descaling metal loss in a tubular of the well, calculating, based on the expected descaling metal loss, a tubular burst/collapse pressure for a predicted thickness of the tubular, comparing the tubular burst/collapse pressure against a well operating pressure to generate a comparison result, and performing the maintenance operation of the well based on the comparison result.

A well bore fluid sensor is provided that includes an inner plate, a plurality of outer plates, first and second cable fixtures, and an electronics module. The inner plate defines a sensor interior cavity. The outer plates include a first outer plate and a second outer plate. The electronics module includes a resonant circuit and a power supply and is in signal communication with the inner plate and at least one of the first and second cable fixtures. The inner plate, the first and second outer plates, and the first and second cable fixtures are coupled together to form a unitary structure. The inner plate is electrically insulated from the first and second outer plates, the first and second cable fixtures. The first and second outer plates are electrically insulated from one another. The inner plate is capacitively coupled to the first and second outer plates.