Abstract: A calibration quality associated with a well-drilling apparatus can be determined. A projected value and a calculated value based upon a data set corresponding to a time interval section of a rig state of the well-drilling apparatus can be determined. A difference can be calculated between the projected value and the calculated value. A quality indicator can be applied to the difference, and a calibration quality based upon the application of the quality indicator can be determined.

Abstract: The disclosure relates to a method for analysing cuttings exiting a borehole. The method comprises taking at least an image of a sample of cuttings on a background surface, obtaining spectra representative of the image in the (hue, saturation, brightness) coordinate space, wherein each spectrum is associated to a coordinate and is representative of the distribution of the values of the pixels for the coordinate. Based on the spectrum and the values of each pixel for the associated coordinate, classifying the pixel in one of a plurality of groups, wherein each group is representative of a type of objects within the image, i.e. cuttings and background surface. The method also comprises determining at least a cuttings zone in the image based on the classification of the pixels.

Abstract: A method includes receiving information during a drilling operation for a drillstring disposed in a bore in a formation; estimating uncertainty associated with the information; analyzing at least a portion of the information using a physics-based model to generate a result; computing, via a Bayesian network, a risk probability of the drilling string sticking in the bore in the formation based at least in part on the result and the estimated uncertainty; and, based at least in part on the risk probability, issuing a signal.

Abstract: The disclosure relates to a method for estimating a transit time of an element circulating in a borehole during the drilling of the borehole. The transit time is representative of a time period for the element to move from the bottom of the borehole to its exit at the surface. The method comprises measuring a plurality of drilling parameters, computing a first signal of a first indicator based on a first set of measured drilling parameters and a second signal of a second indicator based on a second set of measured drilling parameters versus time. The first indicator is representative of a first type of events happening at the bottom of the borehole and the second indicator is representative of a second type of events happening at the exit of the borehole linked to the first type of events. The method also comprises characterizing a correlation between the first and second signals and determining a shift between the first and second signals. An estimated transit time is then determined from the shift.

Abstract: Systems and methods are provided for estimating and/or using drilling efficiency parameters of a drilling operation. A method for estimating drilling efficiency parameters may include using a borehole assembly that includes a drill bit to drill into a geological formation. A number of measurements of weight-on-bit and torque-on-bit may be obtained during a period in which weight-on-bit and torque-on-bit are non-steady-state. The measurements of weight-on-bit and torque-on-bit may be used to estimate one or more drilling efficiency parameters relating to the drilling of the geological formation during the period.

Abstract: Optimizing the operation of a hydraulically powered rotor and stator driven drill as it drills a wellbore into the earth is described. Drilling optimization is provided measuring a first set of rotor and stator operating parameters including the speed of rotation of the rotor and rotor torque for a first period of time, generating a first set of relationships from the first set of operating parameters to enable the rotor speed and rotor torque to be predicted over a range of operating parameter values, determining from the relationships a first more optimal mode of operation, and changing at least one operating parameter to move the operation of the rotor and stator towards the more optimal mode of operation.

Abstract: A drill string suitable for use in directional drilling of a borehole, comprising a rotatable shaft at the leading end of which is a drill bit, and wherein the shaft comprises a variable friction inducing member, which provides rotational friction by physical contact with an inside face of the borehole, the friction inducing member being arranged to exert a first rotational frictional force when the shaft in the vicinity of the member is substantially rotating and a second rotational frictional force when the shaft in the vicinity of the member is substantially not rotating, wherein the first rotational frictional force is less than the second rotational frictional force.

Abstract: The invention provides a method of optimizing the rate of penetration of a hydraulically or pneumatically powered rotor and stator driven drill as it drills a wellbore into the earth, the method comprising: (a) measuring a first set of rotor and stator operating parameters including the weight applied to the drill bit, the speed of rotation of the rotor and rotor torque for a first period of time, (b) generating a first set of relationships from the first set of operating parameters to enable the rotor speed and rotor torque to be predicted over a range of operating parameter values, (c) determining the rate of penetration for the first period of time from measurements of weight applied to the bit and rotation speed of the bit, (d) determining whether any other combination of weight applied to bit and rotation speed of bit, provided by the relationships determined in step (b) are capable of providing a greater rate of penetration, and (e) adjusting at least one operating parameter to move the weight applied t

Abstract: The invention relates to downhole motors for rotating drill bits. The downhole motors may comprise stators, turbines or the like. The drilling motor may comprise a drilling apparatus comprising a drill bit connected to a rotor rotatably housed within a stator (or a turbine rotor in a housing), the rotor comprising at least one magnetic field source or magnetic field detector, and the stator comprising at least one magnetic field source if the rotor comprises a magnetic field detector or comprising at least one magnetic field detector if the rotor comprises a magnetic field source, thereby allowing the rotation speed of the rotor relative to the stator to be measured.

Abstract: A method for directional drilling a subterranean borehole includes transforming surface sensor measurements from time domain sensor data to frequency domain sensor data. A rotary drilling parameter may be changed when a parameter of the frequency domain sensor data reaches a threshold or is within a predetermined range of values.

Abstract: A method for determining hydraulic compliance of a wellbore during a managed pressure drilling procedure. Measurements are made of the pressure of a drilling fluid being circulated in the wellbore during the procedure at the top of a drilling annulus, the flow rate qin of the drilling fluid into the wellbore and the flow rate qout of the fluid out of the wellbore. These three measurements are used to determine the difference of the flow rates and a discrete time derivative (Pt?Pt-?t)/?t of the pressure, where t is time and ?t is a time interval. The differences in flow rates and the time derivatives are then processed by applying a low pass filter to determine the hydraulic compliance of the wellbore.

Abstract: Method for controlling bottomhole pressure in a borehole during managed pressure drilling. In the drilling procedure fluid is circulated down a drillstring and to surface through an annulus between the drillstring and an inner-wall of the borehole. A compressor/pump is used to inject gas into the returning drilling fluid at a gas injection point. The method comprises receiving a target bottomhole pressure; determining actual bottomhole pressure during the procedure; and adjusting a variable as directed by a feedback controller, which operates to reduce the difference between the target pressure and the measured pressure. The manipulated variable may be one or any combination of: (1) pressure of drilling fluid at the entry of the fluid into the drillstring, (2) the flow rate of drilling fluid out of the drillstring into the annulus, (3) pressure of the gas exiting from the compressor, and (4) the injection rate of the gas.

Abstract: Systems, methods, and devices are provided for compressing a variety of signals, such as measured signals from a hydrocarbon operation, that may be stored and/or transmitted in compressed form. Segmentation tools and techniques are used to compress the signals. Segmentation techniques include breaking a signal into segments and representing the data samples of the signal as segment boundary points, which may reflect where changes occur in the signal, and segment parameters, which may be utilized to model the segmented data. Embodiments can be used in real-time or in batch modes. New data samples can influence previous segment boundary points and/or segment parameters in some cases. Systems may modify what has already been stored or displayed as a result in revising segmentation information based on analysis utilizing the new data samples. Embodiments may utilize different Bayesian analysis techniques including the use of prior probability distributions and maximum a posteriori analyses.

Abstract: A calibration quality associated with a well-drilling apparatus can be determined. A projected value and a calculated value based upon a data set corresponding to a time interval section of a rig state of the well-drilling apparatus can be determined. A difference can be calculated between the projected value and the calculated value. A quality indicator can be applied to the difference, and a calibration quality based upon the application of the quality indicator can be determined.

Abstract: A feedback control system for steering a tool along a well-plan. Optimum steering instructions may be generated by a recursive optimization of multiple objectives. These objectives can include accuracy and quality. The quality objective can include the objective of drilling a smooth borehole by minimizing strain energy and torsion. The accuracy objective can include the objective of minimizing the deviation of the borehole trajectory during the real-time drilling process from a predefined well-plan. The trajectory control problem, therefore, can be a multi-objective problem where, in some embodiments, the weightings of the individual objectives can be adjusted along the process.

Abstract: Methods and systems for generating a well-plan with respect to geological targets. The well plan can be optimized for strain energy and torsion, to generate a smooth borehole. The resultant path can be constrained for curvature which is a design parameter and can produces a path feasible for a directional steering tool to achieve. The method can be constructed as a convex optimization problem, and/or provide a unique solution by interior point methods.

Abstract: A method is provided for controlling a managed pressure drilling system. The method comprises providing a fast system interpretation model for the operation of the managed pressure drilling system, obtaining real-time measurements from one or more sensors regarding the operation of the managed pressure drilling system, using the measurements to calibrate the fast system interpretation model for the managed pressure drilling system in real-time and using a predictive controller to run the calibrated fast system interpretation model to a time horizon in the future.

Abstract: In monitoring/control of drilling operation a dimensionality of a full-scale model (e.g., characterizing variables related to cuttings transport, gas migration and/or the like) is reduced and data from a plurality of geographically distributed (e.g., depth varying) sensors is received, and a surrogate model is used to estimate variables in real-time. Use of the surrogate model may enable, e.g., particle-filtering processes to be employed during the estimation while still allowing for real-time estimations, avoiding excessive use of reasonable computational resources (e.g., memory and processing speeds) and/or the like. Operating controls or the like may then be set based on the estimated variables. For example, drilling control parameters may be adjusted based on estimated variables to avoid lost circulation, kicks, stuck pipe, and catastrophic events, optimize drilling parameters such as rate of penetration, improve drilling success probabilities and efficiency and/or the like.

Abstract: A method for detecting a drill string washout event. The method includes locating a drill string in a wellbore formed in a subterranean formation. A drilling fluid is pumped into the drill string. The drill string includes a turbine that spins in response to the drilling fluid flowing therethrough. A comparison is made between a rate that the drilling fluid is pumped into the drill string and a spin rate of the turbine. A defect is determined to be formed in the drill string based upon the comparison.

Abstract: The invention provides a method of optimising the rate of penetration of a hydraulically or pneumatically powered rotor and stator driven drill as it drills a wellbore into the earth, the method comprising: (a) measuring a first set of rotor and stator operating parameters including the weight applied to the drill bit, the speed of rotation of the rotor and rotor torque for a first period of time, (b) generating a first set of relationships from the first set of operating parameters to enable the rotor speed and rotor torque to be predicted over a range of operating parameter values, (c) determining the rate of penetration for the first period of time from measurements of weight applied to the bit and rotation speed of the bit, (d) determining whether any other combination of weight applied to bit and rotation speed of bit, provided by the relationships determined in step (b) are capable of providing a greater rate of penetration, and (e) adjusting at least one operating parameter to move the weight applied t