Abstract: A method for drilling a subterranean wellbore includes rotating a drill string in the subterranean wellbore. The drill string includes a drill collar, a drill bit, and survey sensors (e.g., a triaxial accelerometer set and a triaxial magnetometer set) deployed therein. The triaxial accelerometer set and the triaxial magnetometer set make corresponding accelerometer and magnetometer measurements while drilling (rotating). These measurements are synchronized to obtain synchronized accelerometer and magnetometer measurements and then further processed to compute at least an inclination and an azimuth of the subterranean wellbore while drilling. The method may further optionally include changing a direction of drilling the subterranean wellbore in response to the computed inclination and azimuth.

Abstract: A method for drilling a subterranean wellbore includes rotating a drill string in the subterranean wellbore. The drill string includes a drill collar, a drill bit, and survey sensors (e.g., a triaxial accelerometer set and a triaxial magnetometer set) deployed therein. The triaxial accelerometer set and the triaxial magnetometer set make corresponding accelerometer and magnetometer measurements while drilling (rotating). These measurements are synchronized to obtain synchronized accelerometer and magnetometer measurements and then further processed to compute at least an inclination and an azimuth of the subterranean wellbore while drilling. The method may further optionally include changing a direction of drilling the subterranean wellbore in response to the computed inclination and azimuth.

Abstract: A drilling tool in accordance to one or more aspects includes a processor and a steering device. The processor determines a demand attitude and an instantaneous drilling tool attitude, evaluates a control law to derive a control law tool face, and converts the control law tool face to an equivalent tool face. The steering device applies the equivalent tool face to control a drill attitude of the drilling tool.

Abstract: A method for automatically evaluating a survey of a subterranean wellbore includes receiving downhole navigation sensor measurements and automatically evaluating surface sensor data obtained at substantially the same time as the navigation sensor measurements to determine whether or not the navigation sensor measurements were obtained during satisfactory wellbore survey conditions. The navigation sensor measurements are evaluated to determine whether or not they meet certain predetermined conditions necessary for obtaining a satisfactory survey. A survey recommendation is automatically generating based on the automatic evaluations performed.

Abstract: A drilling tool in accordance to one or more aspects includes a processor to determine a demand attitude and an instantaneous drilling tool attitude, evaluate a control law to derive a control law tool face, and to convert the control law tool face to an equivalent tool face, and a steering device to apply the equivalent tool face to control a drill attitude of the drilling tool.

Abstract: An attitude hold controller method includes receiving at a navigable apparatus a demand inclination and a demand azimuth with respect to a global coordinate system and determining at the navigable apparatus a demand attitude vector according to the received demand inclination and the demand azimuth. Determining at the navigable apparatus a current navigable apparatus attitude vector. Evaluating a control law using the current navigable apparatus vector and the navigable apparatus demand attitude to derive a control law tool face, converting the control law tool face to an equivalent tool face, and applying the equivalent tool face with the navigable apparatus to control the navigable apparatus attitude.

Abstract: Methods for drilling a new well in a field having a plurality of existing cased wells using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a new well in a field having an existing cased well includes drilling the new well using a bottom hole assembly (BHA) having a drill collar having by an insulated gap, generating a current on the BHA while drilling the new well, such that some of the current passes through a surrounding formation and travels along a casing of the existing cased well, measuring from the BHA a magnetic field caused by the current traveling along the casing of the existing cased well, and adjusting a trajectory of the BHA to avoid a collision between the new well and the existing cased well based on measurements of the magnetic field.

Abstract: Various methods are disclosed, comprising obtaining a plurality of raw depth measurements for a wellbore; obtaining survey data about a bottom hole assembly; obtaining depth compensation information; calculating a plurality of compensated depth measurements from the raw depth measurements and the depth compensation information and one or more additional corrections for residual pipe compliance, tide, and rig heave; calculating sag angle and correcting the survey data with the sag angle; determining a high fidelity wellbore trajectory from the compensated depth measurements and the survey data; and then employing the high fidelity wellbore trajectory in various drilling, formation evaluation, and production and reservoir analysis applications. Depth compensation information may comprise at least one of weight on bit, a friction factor, temperature profile, borehole profile, drill string mechanical properties, hookload, and drilling fluid property. The surveys may include both static and continuous surveys.

Abstract: A method includes obtaining a first set of survey data at a first point along a wellbore, estimating a present wellbore position based on at least the first set of survey data, determining a related ellipse of uncertainty at the present wellbore position, comparing the related ellipse of uncertainty of the present wellbore position to a threshold, and selecting a methodology for a subsequent survey based on a comparison of the related ellipse of uncertainty to the threshold.

Abstract: Various methods are disclosed, comprising obtaining a plurality of raw depth measurements for a wellbore; obtaining survey data about a bottom hole assembly; obtaining depth compensation information; calculating a plurality of compensated depth measurements from the raw depth measurements and the depth compensation information and one or more additional corrections for residual pipe compliance, tide, and rig heave; calculating sag angle and correcting the survey data with the sag angle; determining a high fidelity wellbore trajectory from the compensated depth measurements and the survey data; and then employing the high fidelity wellbore trajectory in various drilling, formation evaluation, and production and reservoir analysis applications. Depth compensation information may comprise at least one of weight on bit, a friction factor, temperature profile, borehole profile, drill string mechanical properties, hookload, and drilling fluid property. The surveys may include both static and continuous surveys.

Abstract: Methods for drilling a new well in a field having a plurality of existing cased wells using magnetic ranging while drilling are provided. In accordance with one embodiment, a method of drilling a new well in a field having an existing cased well includes drilling the new well using a bottom hole assembly (BHA) having a drill collar having by an insulated gap, generating a current on the BHA while drilling the new well, such that some of the current passes through a surrounding formation and travels along a casing of the existing cased well, measuring from the BHA a magnetic field caused by the current traveling along the casing of the existing cased well, and adjusting a trajectory of the BHA to avoid a collision between the new well and the existing cased well based on measurements of the magnetic field.

Abstract: A method for surveying a wellbore may include deploying a deployable wellbore survey tool into the wellbore, collecting survey data as the deployable survey tool traverses the wellbore, and determining wellbore position information based on the survey data. In one example the method may include landing the deployable wellbore survey tool on a component of a bottom hole assembly.

Abstract: A method includes obtaining a first set of survey data at a first point along a wellbore, estimating a present wellbore position based on at least the first set of survey data, determining a related ellipse of uncertainty at the present wellbore position, comparing the related ellipse of uncertainty of the present wellbore position to a threshold, and selecting a methodology for a subsequent survey based on a comparison of the related ellipse of uncertainty to the threshold.

Abstract: A method for surveying a wellbore may include deploying a deployable wellbore survey tool into the wellbore, collecting survey data as the deployable survey tool traverses the wellbore, and determining wellbore position information based on the survey data. In one example the method may include landing the deployable wellbore survey tool on a component of a bottom hole assembly.

Abstract: A method is disclosed which utilizes multiple overlapping surveys to estimate a position in a wellbore and related position uncertainty. Multiple surveys are often taken over the same portion of a wellbore either concurrently or sequentially and/or using various instruments. Each survey generates an estimated survey position and related uncertainty for a given location in the wellbore. By combining the estimated survey positions and uncertainties for these overlapping surveys, a resultant position and related ellipsoid of uncertainty is estimated. This resultant position estimates a position in the wellbore by incorporating the estimated survey positions and uncertainties of multiple overlapping surveys.

Abstract: A method is disclosed which utilizes multiple overlapping surveys to estimate a position in a wellbore and related position uncertainty. Multiple surveys are often taken over the same portion of a wellbore either concurrently or sequentially and/or using various instruments. Each survey generates an estimated survey position and related uncertainty for a given location in the wellbore. By combining the estimated survey positions and uncertainties for these overlapping surveys, a resultant position and related ellipsoid of uncertainty is estimated. This resultant position estimates a position in the wellbore by incorporating the estimated survey positions and uncertainties of multiple overlapping surveys.

Abstract: A method and apparatus is disclosed for measuring motion signals of gyroscopes in downhole instruments used to determine the heading of a borehole. An illustrative embodiment of the invention includes a measuring-while-drilling system which may experience motion even while the drill string is suspended in rotary table slips when the heading of the drill string is being determined. Accelerometer and magnetometer data along three orthogonal axes of a measurement sub are used to obtain unit gravitational vectors g at a first time and at a second time and unit magnetic vectors h at the first time and the second time. The difference between the two unit gravitational vectors at the different times, .DELTA.g, and the difference between the two unit magnetic vectors at the different times, .DELTA.h, are used along with the unit vectors g and h and the difference in time .DELTA.t to determine the rotation vector of the probe .OMEGA..sup.p which has occurred during such time difference.