Abstract: Systems and methods provide a mechanism to provide enhanced features for riserless drilling. Various embodiments may include wellbore analysis to predict and quantify vibrations for riserless conditions. Additional apparatus, systems, and methods are disclosed.

Abstract: This disclosure is related to real-time calibration of drilling modeling programs and to the estimation of pipe stretch to perform corrections for the inclination and azimuth measurements and the estimation of pipe twist to perform corrections to the tool face setting. A measurement tool with a plurality of sensors is disposed along the drill string. Measurements are taken continuously during the drilling process from each of the sensors to determine torque, bending moment, and axial force data. This information is iteratively coupled with a mechanical torque-drag model (based on standard mechanics of deformable materials and on wellbore mechanics) to accurately estimate stretching and twisting of the drill string in real-time or near-real-time and thereby promote accurate wellbore placement.

Abstract: A method for estimating an axial force transfer efficiency of a drillstring in a borehole includes lifting the drillstring so that the drill bit is off the bottom of the borehole, measuring a hook load, slacking off a first reference amount of the hook load, determining a first weight on bit at the bottom of the drillstring and determining the axial force transfer efficiency based, at least in part, on the measured hook load, the first weight on bit, and the first reference amount of hook load.

Abstract: Drilling system and methods may employ a weight-on-bit optimization for an existing drilling mode and, upon transitioning to a different drilling mode, determine an initial weight-on-bit within a range derived from: a sinusoidal buckling ratio, a helical buckling ratio, and the weight-on-bit value for the prior drilling mode. The sinusoidal buckling ratio is the ratio of a minimum weight-on-bit to induce sinusoidal buckling in a sliding mode to a minimum weight-on-bit to induce sinusoidal buckling in a rotating mode, and the helical buckling ratio is the ratio of a minimum weight-on-bit to induce helical buckling in the sliding mode to a minimum weight-on-bit to induce helical buckling in the rotating mode. The ratios are a function of the length of the drill string and hence vary with the position of the drill bit along the borehole.

Abstract: The subject matter of this specification can be embodied in, among other things, a method that includes providing an outer tubular member having a bore with an inner surface, applying a lubricant layer to at least a portion of the inner surface of the outer tubular member, positioning the outer tubular member in at least a portion of the wellbore, providing a drilling assembly including an inner member having an outer surface, applying a lubricant layer to at least a portion of the outer surface of the inner member, inserting the inner member into the bore of the outer tubular member, providing a drilling fluid through the bore of the drilling assembly, rotating the inner member relative to the outer member, measuring an indicator of mechanical wear between the outer member and the inner member, determining that the measured indicator exceeds a predetermined threshold level, and triggering a subsequent operation.

Abstract: The disclosed embodiments include a method, apparatus, and computer program product for determining a suitable casing design for a well. For example, one disclosed embodiment includes a system that includes at least one processor and at least one memory coupled to the at least one processor and storing instructions that when executed by the at least one processor performs operations for receiving historical data associated with previously drilled wells; in response to a determination that the historical data associated with previously drilled well is relevant to the well, generating a first set of casing designs using a probabilistic approach and generating a second set of casing designs using a combination approach that combines the probabilistic approach with a deterministic approach; and selecting a suitable casing design from a resulting set of casing designs.

Abstract: Disclosed are systems and methods of balancing weight distribution between downhole cutting tools. One system includes a drill bit arranged at a distal end of the bottom-hole assembly, a first sensor sub arranged proximate to the drill bit and configured to monitor one or more operational parameters corresponding to the drill bit, a reamer axially-offset from the drill bit on the bottom-hole assembly, a second sensor sub arranged proximate to the reamer and configured to monitor one or more operational parameters of the reamer, and a communications module communicably coupled to the first and second sensor subs and configured to communicate one or more corrective action signals when the one or more operational parameters of the drill bit and the reamer surpass a predetermined operating threshold.

Abstract: Various embodiments include apparatus and methods to perform a load analysis for multi-off-center tools. Off-center components of a completion string experience additional downhole side and drag forces due to contact with casing and liner walls which may lead to excessive loading and stresses leading to failures. Systems and techniques are provided to analyze such situations. Additional apparatus, systems, and methods are disclosed.

Abstract: Displaying data associated with drilling a borehole. At least some of the illustrative embodiments are methods including: reading data associated with drilling of a first borehole, at least one datum of the data based on a controllable parameter; calculating an operational value related to drilling the first borehole, the calculating in real-time with reading the data and the operational value based on the data; determining a target value of the operational value, the determining in real-time with reading the data and the target value at least in part based on the data; displaying a first borehole trajectory on a display device; superimposing a first coordinate system over the first borehole trajectory on the display device, the superimposing proximate to a distal end of the first borehole trajectory; and plotting, within the first coordinate system, an indication of the operational value and an indication of the target value.

Abstract: A downhole drilling motor comprises a first elastomer stator molded to an inner surface of a housing in a drillstring where the first elastomer stator has a first number of lobes. A dual purpose, helical shaped hollow member is positioned within the first elastomer stator, where the dual purpose hollow member has a second number of lobes formed on an external surface to form a first rotor. The second number of lobes is one less than the first number of lobes. A second elastomer stator is adhered to an inner surface of the dual purpose helical shaped hollow member, where the second elastomer stator has a second helical shaped cavity with the second number of lobes. A second helical shaped rotor is positioned within the second helical cavity, and has a third number of lobes one less than the second number of lobes.

Abstract: Estimating casing wear. At least some of the illustrative embodiments are methods including: capturing an image comprising cuttings and casing wear particles on a shale shaker in a drilling operation, the capturing by at least one camera associated with the shale shaker; identifying casing wear particles shown in the image, the identifying by a computer system; and estimating a volume of casing wear based on the identifying.

Abstract: Systems and methods for determining manufacturing or operating parameters for a deviated downhole well component, including a method that includes representing a tubular string as nodes separated by segments, determining transfer matrices for determining an ith node's state vector from an ith?1 node's state vector, and defining initial state vector values for the reference node. The nodes are numerable from 1 to N with an initial, mechanically constrained reference node representable with i=0, and each is associated with a state vector describing a corresponding node position and one or more forces present at said node. The method further includes applying the transfer matrices to obtain each of the state vectors' values, deriving from at least one of the state vectors a parameter value for said component, and specifying a component having said parameter value. The parameter value can include a centralizer or stabilizer composition, manufacturing dimensions, or position.

Abstract: Disclosed are systems and methods for automatic weight on bit sensor calibration and regulating buckling of a drillstring. One method includes taking a first survey recording at a first depth within a borehole, the first survey recording providing inclination and azimuth of a drillstring at the first depth, measuring a weight on a drill bit at the first depth with a sensor sub arranged on a bottom hole assembly, the bottom hole assembly forming part of the drillstring and the drill bit being disposed at an end of the drillstring, calculating a predicted borehole curvature at a second depth within the borehole, the predicted curvature including a predicted inclination and a predicted azimuth of the drillstring at the second depth, calculating a weight correction value based on the predicted hole curvature, and calibrating the sensor sub with the weight correction value.

Abstract: A drill bit includes a bit body and one or more cutters positioned on the bit body at select locations. At least one vibrational device is positioned on the bit body to impart vibration to the bit body and thereby mitigate stick-slip.

Abstract: A bottom-hole assembly includes a drill string extendable within a wellbore and a drill bit positioned at a distal end of the drill string. A vibration sub is positioned in the drill string axially adjacent the drill bit and includes one or more vibratory devices that impart vibration to the drill bit.

Abstract: Calculating wellbore energy. At least some of the illustrative embodiments are methods including: calculating an expected wellbore energy for a planned wellpath, the calculating by a computer system; calculating an expected tortuosity of the planned wellpath; calculating a first value indicative of probability of occurrence of a drilling event for drilling along the planned wellpath, the first value based on the expected wellbore energy and the expected tortuosity; and then drilling a wellbore along at least a first portion of the planned wellpath if the first value indicates the probability of the drilling event is less than a predetermined threshold.

Abstract: Calibrating Friction Factors. At least some of the illustrative embodiments are methods including: calibrating friction factor for a drilling operation by: plotting on a display device the expected hook load versus depth for the drilling operation; displaying plot points on the display device, each plot point indicative of a measured hook load versus depth for the drilling operation; selecting a plot point associated with a depth, the selecting responsive to a cursor hovering over the plot point on the display device; displaying a friction factor values which correlates the expected hook load versus depth for the particular depth to the measured hook load versus depth for the plot point, selecting the value responsive to the cursor hovering over the value; and then shifting on the display device at least a portion of the indication of expected hook load versus depth based on the value of friction factor.

Abstract: A plurality of input data to be used to compute a first output is received. The first output is computed. It is determined that the computed first output is outside a pre-determined first-output limit. A plurality of hyperlinks is displayed on a display device. Each hyperlink provides a link to a process for making adjustments to the plurality of input data to bring the first output within the pre-determined first-output limit. Selection of one of the plurality of hyperlinks (the “selected hyperlink”) is detected. A process associated with the selected hyperlink is followed to produce an adjustment to the plurality of input data to bring the first output within the first pre-determined first-output limit. The adjusted plurality of input data is used to plan implementation of a system. The sequence of selection of hyperlinks is tracked in order to reinforce the prioritization and order of future suggestions. The system is implemented.

Abstract: A method of regulating downhole pressure using managed pressure drilling may include calculating an elasticity of a drill string during a drilling operation using a torque and drag model included in a managed pressure drilling (MPD) control system and calculating a surge pressure and a swab pressure acting on the drill string during the drilling operation using a hydraulics model included in the MPD control system. The surge and swab pressures may be based on movement of the drill string and in accordance with the elasticity of the drill string. The method may further include determining a set point pressure using a real-time hydraulics model and the torque and drag model, and operating a MPD choke system based on the set point pressure to regulate a predetermined downhole pressure at a predetermined location in a wellbore.

Abstract: Disclosed are systems and methods of balancing weight distribution between downhole cutting tools. One system includes a drill bit arranged at a distal end of the bottom-hole assembly, a first sensor sub arranged proximate to the drill bit and configured to monitor one or more operational parameters corresponding to the drill bit, a reamer axially-offset from the drill bit on the bottom-hole assembly, a second sensor sub arranged proximate to the reamer and configured to monitor one or more operational parameters of the reamer, and a communications module communicably coupled to the first and second sensor subs and configured to communicate one or more corrective action signals when the one or more operational parameters of the drill bit and the reamer surpass a predetermined operating threshold.