This disclosure relates to a method and a system for sequestering carbon-containing materials in underground wells. An example method includes: obtaining a material comprising a carbon-containing liquid; optionally testing the material for compatibility with an underground well; optionally adjusting a property of the material to improve the compatibility; and providing the material for injection into the underground well.

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.

A method of predicting an output of oil and gas production in a hydrocarbon reservoir of a current and future producing well using a neural network model, includes receiving a data set comprising a plurality of parameters of the hydrocarbon reservoir at a wellsite. The method also includes using the data set to generate a plurality of simulation curves of the hydrocarbon reservoir, each parameter of the plurality of parameters has a range, and the range is adjustable, and the wellsite includes a wellbore penetrating a subterranean formation to extract reserves from the hydrocarbon reservoir. The method also includes performing a simulation, based on the range of each said parameter of the plurality of parameters, of the hydrocarbon reservoir. The method also includes downloading the plurality of simulation curves into a local server to prepare training data for training the neural network model.

Systems and methods for this disclosure describe systems and methods that are directed to monitoring active clay in water-based drilling fluid may be provided. A method for monitoring active clay concentration while drilling may be provided. The method may include providing a sample of water-based drilling fluid. The method may further include adding methylene blue to the sample in a methylene blue titration. The method may further include performing an impedance measurement on the sample during the methylene blue titration. The method may further include determining an endpoint of the methylene blue titration using a phase angle measurement from the impedance measurement. The method may further include correlating the endpoint to the active clay concentration of the sample. The method may further include determining a treatment for the water-based drilling fluid based on the active clay concentration.

A test tool attached to test string comprising a fluid conduit is deployed to a test position within a wellbore. The deployment includes hydraulically isolating a portion of the wellbore proximate the test tool to form an isolation zone containing the test position. A fluid inflow test is performed within the isolation zone and an initial formation property and a fluid property are determined based on the fluid inflow test. A fluid injection test is performed within the isolation zone including applying an injection fluid through the test string into the isolation zone, wherein the flow rate or pressure of the injection fluid application is determined based, at least in part, on the at least one of the formation property and fluid property.

The present disclosure relates to the technical field of oil-gas field development, and discloses a shale oil fracturing synchronous energizing simulation experimental device and method. The shale oil fracturing synchronous energizing simulation experimental device comprises a liquid supply system, a confining pressure loading system, a fracturing system, an energizing system and a recovery system, wherein the liquid supply system is used for storing fluid and can inject the fluid into the fracturing system; the fracturing system can bear a test piece, receive the fluid injected by the liquid supply system and serve as seepage space of the fluid; the confining pressure loading system is used for providing simulated confining pressure for the test piece; the energizing system is used for simulating an energizing effect on a test piece after fracturing liquid is injected; and the recovery system is used for collecting discharged liquid and separating and metering the discharged liquid.

A method comprises flowing a mud into a wellbore, wherein the mud has a mud composition and has a weight in a defined range. The method includes introducing a fluid pill into the mud flowing into the wellbore, wherein the fluid pill has an injection fluid with an injection composition that is different from the mud composition. A particulate has been added to the injection fluid to increase the weight of the fluid pill. After flowing the mud into the wellbore such that the fluid pill is positioned in a zone of the wellbore: filtering out the particulate from the injection fluid; injecting, after the filtering, the injection fluid into the zone; measuring a downhole parameter that changes in response to injecting the injection fluid into the zone; and determining a property of the formation of the zone based on the measured downhole parameter.

Embodiments of the disclosure provide a method for retrieving an untethered measurement device used in a subterranean well ascending from a wellbore into a Christmas tree valve. A swab valve of the Christmas tree valve is opened. An expandable meshed component is deployed into the Christmas tree valve through a swab conduit. The expandable meshed component transitions from a compressed configuration to an expanded configuration at a target height in the Christmas tree valve. A production wing valve of the Christmas tree valve is opened. The swab valve is closed. The untethered measurement device is retrieved from the Christmas tree valve through the swab conduit.

A prediction method for coal and gas outburst based on comparing borehole gas flow curves includes the following steps: constructing a seam-crossing borehole in the coal seam, measuring or calculating gas flow corresponding to critical gas pressure P, which is a reference gas flow Q(t).sub.reference; performing linear regression on the reference gas flow Q(t).sub.reference to form a reference flow curve; constructing a predicted seam-crossing borehole in a predicted area, and directly testing a gas flow at each time t in a delayed manner, which is a predicted gas flow Q(t).sub.prediction; prediction; performing linear regression on the predicted gas flow Q(t).sub.prediction to form a predicted flow curve; and judging whether the predicted flow curve is above the reference flow curve or whether the predicted flow curve intersects with the reference flow curve, and judging whether the coal seam in the predicted area has a risk of coal and gas outburst.

Systems and methods include a computer-implemented method for using first- and second-order derivatives from discrete pressure data of a well to characterize the well and intersected reservoir under dynamic conditions. Discrete data for the well and associated reservoir is arranged chronologically. First- and second-order derivatives of pressure versus a time series are determined at a first focal point using a five-point function considering beginning and ending points in a time period. First- and second-order derivatives are determined at successive focal points, applying terminal corrections. Numerical values and plots of first- and second-order derivative profiles are presented. Diagnostic plots and data for determining geological features for the associated reservoir and well parameters are generated. Reservoir simulation models are executed to generate a forecast of future production rates under different constraints. A production strategy and future development plans for the well are managed, and future sales revenue estimates are provided.