Abstract: Stratigraphic analysis includes determining misfit values between stratigraphic vertical depth of an offset wellbore, SVDow and measured depth of a subject wellbore. A likelihood that the target measured depth is equal to or within a tolerance of stratigraphic vertical depth of the subject wellbore, SVDsw, for sequences of stratigraphic vertical depth is calculated. A probability weighted average and an uncertainty that the target measured depth for the subject wellbore, TMDsw, is equal to or within a tolerance of stratigraphic vertical depth of the subject wellbore, is calculated. A continuous probability function over a range of measured depth that the target measured depth for the subject wellbore, TMDsw, is equal to or within a tolerance of stratigraphic vertical depth of the subject wellbore, SVDsw, is calculated.

Abstract: Systems and methods for using stratigraphic heat maps to steer a well being drilled. Data from one or more offset wells can be provided to a computer system and used with data from a well being drilled to generate one or more stratigraphic heat maps during the drilling of the subject well. The stratigraphic heat maps can be displayed and used to determine the location of the wellbore relative to one or more geological formations, including one or more target formations or within a target formation. Based on the use of the heat maps and the location of the wellbore relative to a target, the drill plan can be adjusted or updated and/or one or more drilling parameters or operations may be adjusted to drill the wellbore, such as to drill the wellbore to the target or to maximize the length of the wellbore within a target zone.

Abstract: An improved typelog alignment for automated or interactive geosteering may use multi-stage penalized optimization.

Abstract: Systems and methods determine friction in a borehole during drilling operations. A drilling system applies oscillatory angular movement at the top of a drill string in a wellbore during drilling by the drilling system, and measures a torque applied to the drill string and an angular position of the drill string. Based on the measured torque and the measured angular position, the drilling system computes a friction between the borehole and the drill string. This can be repeated during drilling of the wellbore to determine multiple friction values, corresponding to various depths of the borehole. Based on the computed friction, the drilling system can perform one or more actions resulting in modified drilling operation. The systems and methods also include oscillating a casing in the borehole, measuring the torque and angular position of the casing, and determining a friction value, which can be repeated to develop a wellbore friction profile.

Abstract: Systems and methods for automated filtering and normalization of logging data for improved drilling performance may enable smoothing and amplitude scaling of log data for meaningful comparison and analysis without scaling artefacts. The logging data may be collected from downhole sensors or may be recorded by a control system used for drilling. A computer implemented method may enable industrial scale automated filtering and normalization of logging data, including calibration to a known standard. In particular, the filtering and normalization may be used for stratigraphic analysis to correlate true vertical depth to measured depth along a wellbore.

Abstract: A method of drilling a wellbore to a target includes measuring attitudes at two adjacent survey stations along a wellbore using a downhole surveying tool. An actual change in wellbore position over a survey leg linking the two survey stations is determined. Corrections are applied to the measured attitude at one or both of the survey stations such that a modeled well path joining the survey stations reflects the determined actual change in wellbore positon between the two survey stations.

Abstract: An improved typelog alignment for automated or interactive geosteering may use multi-stage penalized optimization.

Abstract: A system and method of drilling a wellbore to a target may include measuring attitudes at two adjacent survey stations along a wellbore using a downhole surveying tool. An actual change in wellbore position over a survey leg linking the two survey stations may be determined. Corrections may be applied to the measured attitude at one or both of the survey stations such that an estimated well path joining the survey stations indicates the determined actual change in wellbore position between the two survey stations.

Abstract: A method of validating a directional survey includes measuring the gravity and magnetic field vectors using a surveying tool and computing an overall statistical distance of the measurement. The statistical distance may be calculated from reference values associated with the surveying tool using corresponding surveying tool codes with error values. In a further aspect, an error covariance matrix may be used to determine whether the new errors m a survey are consistent or not with errors from one or more previous surveys.

Abstract: A method and system for simulating reservoir recovery include taking into account inaccuracies in well spacing due to wellbore positional uncertainty.

Abstract: A method for correcting geomagnetic reference field includes measuring Earth magnetic field elements at least one known geodetic position. Earth magnetic field elements are measured at a position proximate the location. A disturbance function is determined from the Earth magnetic field measurements made at the at least one known geodetic position. A magnetic disturbance field measurement transfer function is estimated between the at the at least one known geodetic and proximate positions to estimate a disturbance function at the proximate position. The estimated magnetic disturbance function is used to correct geomagnetic reference field or measurements made at the location.

Abstract: A method of drilling a wellbore to a target includes measuring attitudes at two adjacent survey stations along a wellbore using a downhole surveying tool. An actual change in wellbore position over a survey leg linking the two survey stations is determined. Corrections are applied to the measured attitude at one or both of the survey stations such that a modeled well path joining the survey stations reflects the determined actual change in wellbore positon between the two survey stations.

Abstract: A method of assigning geophysical reference values to a well trajectory includes defining a set of geophysical reference parameters and assigning a range threshold to each geophysical reference parameter. A Geomodel is processed to determine values of the geophysical reference parameters at a plurality of locations along the well trajectory. The well trajectory is partitioned into a plurality of segments such that variations in the values of the geophysical reference parameters within each segment do not exceed the respective range thresholds. A representative value of each geophysical reference parameter is calculated for each segment and stored or displayed along with the segments.