Abstract:
In accordance with some embodiments of the present disclosure, a control system for optimizing the placement of pillars during a subterranean operation is disclosed. The method includes determining a wave function from a generalized waveform equation and calculating a coefficient for at least one wave based on the wave function to create a total wave signal. The method additionally includes combining the total wave signal with a fracture system input to create a control signal. The method further includes sending the control signal to a fracturing equipment component to control a concentration of a proppant in a fracturing fluid during an injection treatment.
Abstract:
A system for optimizing a running operation includes an interface to equipment and sensors for performing the running operation. The interface supplies control signals to the equipment and obtains measurement signals from the sensors. The system further includes a short-term optimizer that derives a current job state based at least in part on the measurement signals, and that further adjusts the control signals to optimize a short-term cost function. The short-term cost function includes a difference between the current job state and a desired job state derived from optimized values of a set of decision variables. The system further includes a long-term optimizer module that determines the optimized values based on a long-term cost function, the long-term cost function accounting for at least a long-term reward and a final state cost.
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:
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:
Techniques for controlling a bottom hole assembly (BHA) include determining a model of BHA dynamics based on sensor measurements from the BHA; determining, based on the model of BHA dynamics, an objective function including a predicted future deviation from a planned wellbore path; determining a control input to the BHA that satisfies the objective function for a set of operating conditions of the BHA; generating, at a secondary system, relational information that relates the control input to the set of operating conditions; and transmitting the relational information from the secondary system to the BHA.
Abstract:
Reducing or eliminating stick-slip and vibrations downhole may include controlling top drive torque in order to adjust drill bit angular speed in a manner that prevents, eliminates, or reduces stick-slip and vibration. Control methods and systems may include solving one or more optimization problems including an objective function. The objective function may be subject to conditions including a physical model of the drilling system. The objective function may be minimized without reference to a model, but instead by reference to estimated stick-slip frequency based upon a drill bit angular speed profile. In addition, actual downhole measurements for use in control methods and systems, such as drill bit angular speed, may be estimated using an observer.
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:
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:
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.