Abstract: A method for drilling a well. The method may include detecting stick-slip vibrations at a frequency via a downhole sensor. The method may further include determining a reflection coefficient of a drill bit for the frequency based on at least one of a rotational speed of the drill bit or a torque of the drill bit. The method may also include determining a reflection coefficient of a top drive for the frequency based on at least one of a rotational speed of the top drive or a torque produced by the top drive. The method may further include adjusting a control system in electronic communication with the top drive based on the reflection coefficient of the drill bit for the frequency and the reflection coefficient of the top drive for the frequency.

Abstract: A method of controlling a pumping stage of a fracturing fleet at a wellsite with a set of diesel pumps and at least one electric pump to smooth the flowrate transition to an operational setpoint with a higher flowrate. An optimization process communicatively connected to the plurality of pumping units can iterate an interim setpoint with a transfer function model to each pumping unit. The transfer function model can generate a smooth flowrate transition by decreasing the flowrate of at least one pump unit while increasing the flowrate to the remaining pump units.

Abstract: A method of controlling a pumping stage of a fracturing fleet at a wellsite with a set of diesel pumps and at least one electric pump to reduce the total operating cost by decreasing the flowrate to the pump units with the higher operating cost and increasing the flowrate to the pump units with the lower operating costs. An optimization process on a computer system communicatively connected to the plurality of pumping units can communicate a first interim setpoint to each pumping unit. The optimization process can calculate an operating cost for the diesel frac pumps based on sensor measurements of pressure, flowrate, and motor speed. The optimization process can calculate an operating cost for the electric frac pumps based on the measured power usage and cost of the power. The optimization process can lower the operating cost of fracturing fleet below a threshold operating cost value.

Abstract: A method of controlling a pumping stage of a fracturing fleet at a wellsite with at least two electric frac pumps to increase the efficiency of the electric frac pumps comprises communicating an interim flowrate to the electric frac pumps and calculating an efficiency value from measured power from the VFD and measured flow rate, intake pressure, and discharge pressure. The method can increase a total efficiency of the fracturing fleet above a threshold efficiency value by iterating the interim setpoint from a first interim setpoint to a second interim setpoint for the electric frac pumps, wherein the second interim setpoint decreases the flowrate to the less efficient electric frac pumps and increases the flowrate an equal amount to the more efficient electric frac pumps.

Abstract: The disclosure provides a solution for monitoring stick-slip vibrations without using any surface torque measurements. Instead, the disclosure provides a method to monitor stick-slip vibrations based on rotational speed. A stick-slip monitor, a top drive controller and a method of operating a drill string are provided herein that use rotational speed for monitoring stick-slip vibrations. In one example, the method of operating a drill string includes: (1) performing a frequency domain analysis of an RPM signal associated with a top drive that is used to rotate a drill string, and (2) determining a presence of torsional oscillations of the drill string based on the frequency domain analysis of the RPM signal.

Abstract: Certain aspects and features relate to a system that monitors for kick and lost circulation in the riser string of an offshore drilling rig. The system compensates for annulus outflow fluctuation induced by wave (heave) motion in order to reduce false alarms, resulting in fewer drilling operation disruptions. The system includes a sensor or sensors disposable with respect to a drilling rig subject to rig motion. A processor receives a real-time position signal indicative of the rig motion from the sensor and applies a state observer to the position signal to determine annular flow parameters. The system models an annular flow for the wellbore to produce a modeled flow signal that reflects a position of the drilling rig relative to influx flow. The system uses the modeled flow to determine kick-loss-alarm parameters that take into account the heave motion.

Abstract: A method and system for dampening a stick-slip vibration. The method may comprise determining at least one frequency of a stick-slip vibration; determining mechanical properties of the drilling system; producing a torque signal from a controller having at least a second order; controlling a rotational speed of a top drive from the torque signal produced by the controller; and damping stick-slip vibration of the drilling system. The system may further comprise a drill string and a bottom hole assembly may be connected to the drill string. A drill bit may be connected to the bottom hole assembly and an information handling system may be connected to the drilling system.

Abstract: A method for drilling a well. The method may include detecting stick-slip vibrations at a frequency via a downhole sensor. The method may further include determining a reflection coefficient of a drill bit for the frequency based on at least one of a rotational speed of the drill bit or a torque of the drill bit. The method may also include determining a reflection coefficient of a top drive for the frequency based on at least one of a rotational speed of the top drive or a torque produced by the top drive. The method may further include adjusting a control system in electronic communication with the top drive based on the reflection coefficient of the drill bit for the frequency and the reflection coefficient of the top drive for the frequency.

Abstract: Methods and systems are presented in this disclosure for evaluating whether to apply fluid flowback during a fracture closure stage of a hydraulic fracturing operation of a reservoir formation. Information collected prior to the fracture closure stage of the hydraulic fracturing operation can be first gathered. Based on the collected information, it can be determined whether to perform fluid flowback during the fracture closure stage following a treatment stage of the fracturing operation. Based on the determination, a rate of the fluid flowback can be adjusted and optimized in real-time during the fracture closure stage.

Abstract: In some aspects, the present invention comprises a system and method for optimizing the control scheme used for drilling operations based on the complex and large data sets available in realtime during operation of a wellsite and based on existing model data available at the wellsite for past similar drilling operations. Such optimizations typically require downtime to quantify how the realtime values will factor into the control model, but the present invention allows for such optimization in realtime in a closed-loop system that will reduce the non-productive time associated with reservoir operations.

Abstract: A method for controlling drilling fluid properties, in some embodiments, comprises determining a predictive model for a fluid circulation system that routes drilling fluid downhole to a drill bit to remove debris from said drill bit; determining a cost function associated with the fluid circulation system; using the predictive model and the cost function to determine a set of input values for the predictive model; operating a controlled device according to at least some of the set of input values, said controlled device changes properties of the drilling fluid in the fluid circulation system; and obtaining measurements of the properties.

Abstract: Techniques for controlling a bottom hole assembly (BHA) to follow a planned wellbore path include determining sensor measurements from the BHA; determining a model of BHA dynamics based on the sensor measurements from the BHA; determining a weighting factor that corresponds to a drilling objective; determining an objective function comprising the drilling objective, weighted by the weighting factor, and one or more constraints; determining a control input to the BHA that satisfies the objective function and the one or more constraints; and applying the control input to the BHA.

Abstract: A method of detecting a fault in an oil and gas apparatus controlled by a controller is provided. The method includes collecting a test set of data using a sensor proximate to an oil and gas apparatus during the operation of the oil and gas apparatus under test operating conditions, the test set of data being associated with an operating parameter of the controller, determining a percentage of the test set of data that falls outside a normal operation region of the oil and gas apparatus, and configuring the controller in response to the percentage being between a fault-free percentage threshold and a fault percentage threshold.

Abstract: In some aspects, the present disclosure includes systems and methods for determining and delivering diverting material to dominant fractures in a stage of a subterranean formation. The method includes creating or extending a plurality of fractures in a stage of a subterranean formation; pumping fracturing fluid to the plurality of fractures; identifying dominant fractures among the plurality of fractures; determining a desired amount of diverters to deliver to the dominant fractures; and pumping the determined amount of diverters to the dominant fractures so as to redistribute the flow of fracturing fluid between the plurality of fractures.

Abstract: During drilling operations various drilling mud properties may be measured and predicted. Uncertainties in the measured or predicted values may also be calculated. The estimated uncertainties may then be used to optimize mud sampling interval and/or control a mud mixer. A decision making algorithm may be performed to optimize a surface mud sampling interval such that the uncertainties are maintained within a bounded region with minimal number of sampling times.

Abstract: Two control strategies may be implemented to optimize mud circulation in a drilling mud circulation system. In a networked control strategy, the mud circulation system does not involve any centralized controller yet all the local controllers can exchange information in real-time via a central data storage. The master-slave control strategy involves a centralized optimizer, and the subsystems are treated as slave systems and are driven by a visual master control system.

Abstract: A method and system for dampening a stick-slip vibration. The method may comprise determining at least one frequency of a stick-slip vibration; determining mechanical properties of the drilling system; producing a torque signal from a controller having at least a second order; controlling a rotational speed of a top drive from the torque signal produced by the controller; and damping stick-slip vibration of the drilling system. The system may further comprise a drill string and a bottom hole assembly may be connected to the drill string. A drill bit may be connected to the bottom hole assembly and an information handling system may be connected to the drilling system.

Abstract: Uncertainty of microseismic monitoring results can be reduced to improve hydraulic fracture modeling. A computing device can use a fracture model to determine a predicted geometry of a hydraulic fracture in a subterranean formation based on properties of a fracturing fluid that is introduced into the subterranean formation. An uncertainty index of the predicted geometry of the hydraulic fracture can be determined based on an uncertainty value of the predicted geometry and a trend of uncertainty values. When the injection flow rate of the fracturing fluid is less than a maximum flow rate, it can be increased from an initial injection flow rate to an increased injection flow rate in response to determining the uncertainty index exceeds a pre-set maximum.

Abstract: A fracture model for a hydraulic fracture in a wellbore can be updated and calibrated. Information about a microseismic event can be received from a sensor that is monitoring a subterranean formation. The information can be received subsequent to a fracking fluid being introduced into the formation. An observed geometry of a hydraulic fracture can be determined based on the information and a predicted geometry of the fracture can be determined based on properties of the fracking fluid and a fracture model. The fracture model can be updated using the information about the microseismic event where it is determined that an uncertainty value of the observed geometry does not exceed a pre-set maximum. The uncertainty value can be based on the predicted geometry of the hydraulic fracture.

Abstract: Uncertainty in microseismic monitoring sensor data can be reduced. A computing device can receive information about at least one sensor that is monitoring a subterranean formation, including a location, after a fracturing fluid is introduced into the formation. The computing device can also receive information about a microseismic event and determine a seismic ray bath between a location of the event and the at least one sensor, and an uncertainty value of the location based on information about the formation and the information about the event. The computing device can determine a total uncertainty value associated with the locations of a plurality of microseismic events, including the microseismic event. The computing device can determine a solution to an objective function based on the total uncertainty value and a number of sensors. The computing device can determine a new location of the at least one sensor based on the solution.