Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method for estimating a time at which a pressure window relevant observation occurred relating to an event that occurred in an open borehole penetrating an earth formation includes: receiving with a processor a pressure window relevant observation that provides input to adjusting a pressure window for drilling fluid for drilling the borehole; and estimating with the processor a time window in which a physical parameter, a chemical parameter, or a process that caused the pressure window relevant observation to occur, the time window having a start time and an end time.

Abstract: A method and apparatus for estimating a pressure transition zone in a borehole is disclosed. A parameter indicative of formation fluid pressure at a plurality of borehole depths is measured. A global trend of the parameter is determined over a first depth interval and a local trend of the parameter is determined over a second depth interval. A relation is determined between the global trend and the local trend, and the pressure transition zone is determined from the determined relation between the determined global trend and the determined local trend.

Abstract: Disclosed is a method for detecting a pair of opposing breakouts in a borehole penetrating an earth formation. The method includes: conveying a downhole tool configured to perform measurements of a property of the earth formation; producing an image of the earth formation from the measurements, the image comprising a plurality of sectors; dividing the sectors into radial segments, each segment corresponding to an opposite segment; rotating the segments at least one sector at a time until a specified angle is achieved; calculating an average value for the measurements associated with each segment for each rotation of the segments; stacking the average values for opposing segments to produce stack values; determining a maximum or minimum stack value; determining if the maximum or minimum stack value exceeds a threshold value; and detecting the first breakout and the second breakout if the maximum or minimum stack value exceeds the threshold value.

Abstract: Disclosed is a method for estimating a pore pressure of an earth formation penetrated by a borehole and an associated uncertainty. The method includes: conveying a carrier through the borehole; performing formation measurements at a plurality of depths in the borehole using a downhole tool coupled to the carrier; defining a first depth interval and a second depth interval deeper than the first depth interval, the first depth interval including a first set of formation measurement points and the second depth interval including a second set of formation measurement points; establishing a plurality of trendlines of depth versus formation measurements using a processor with each trendline in the plurality of trendlines extending from a point in the first depth interval through a point in the second depth interval; and calculating a pore pressure line and associated uncertainty using the plurality of trendlines.

Abstract: A method for estimating a time at which a pressure window relevant observation occurred relating to an event that occurred in an open borehole penetrating an earth formation includes: receiving with a processor a pressure window relevant observation that provides input to adjusting a pressure window for drilling fluid for drilling the borehole; and estimating with the processor a time window in which a physical parameter, a chemical parameter, or a process that caused the pressure window relevant observation to occur, the time window having a start time and an end time.

Abstract: Disclosed is a method for estimating a pore pressure of an earth formation penetrated by a borehole and an associated uncertainty. The method includes: conveying a carrier through the borehole; performing formation measurements relating to porosity at a plurality of depths in the borehole using a downhole tool coupled to the carrier; defining a first depth interval and a second depth interval deeper than the first depth interval, the first depth interval comprising a first set of formation measurement points and the second depth interval comprising a second set of formation measurement points; establishing a plurality of trendlines of depth versus porosity-related measurements using a processor with each trendline in the plurality of trendlines extending from a point in the first depth interval through a point in the second depth interval; and calculating a pore pressure line and associated uncertainty using the plurality of trendlines.

Abstract: Disclosed is a method for estimating a geometry of a borehole penetrating the earth. The method includes: performing a plurality of borehole caliper measurements with N transducers at a plurality of times, wherein for each time a measurement set comprises measurements made by the N transducers at that time; dividing a cross-section of the borehole into S sectors; obtaining an estimate of the borehole geometry by connecting representative radius points in adjacent sectors; displacing each measurement set according to a displacement vector related to an offset of each measurement set from the estimated geometry if the displacement vector exceeds a selection criterion; iterating the obtaining an estimate of the borehole geometry and the displacing each measurement set based on a latest displacement vector; and providing a latest obtained estimate as the geometry of the borehole when all of the displacement vectors no longer exceed the selection criterion for the displacing.

Abstract: Disclosed is a method for estimating a pore pressure of an earth formation penetrated by a borehole and an associated uncertainty. The method includes: conveying a carrier through the borehole; performing formation measurements relating to porosity at a plurality of depths in the borehole using a downhole tool coupled to the carrier; defining a first depth interval and a second depth interval deeper than the first depth interval, the first depth interval comprising a first set of formation measurement points and the second depth interval comprising a second set of formation measurement points; establishing a plurality of trendlines of depth versus porosity-related measurements using a processor with each trendline in the plurality of trendlines extending from a point in the first depth interval through a point in the second depth interval; and calculating a pore pressure line and associated uncertainty using the plurality of trendlines.

Abstract: Disclosed is a method for estimating a geometry of a borehole penetrating the earth. The method includes: performing a plurality of borehole caliper measurements with N transducers at a plurality of times, wherein for each time a measurement set comprises measurements made by the N transducers at that time; dividing a cross-section of the borehole into S sectors; obtaining an estimate of the borehole geometry by connecting representative radius points in adjacent sectors; displacing each measurement set according to a displacement vector related to an offset of each measurement set from the estimated geometry if the displacement vector exceeds a selection criterion; iterating the obtaining an estimate of the borehole geometry and the displacing each measurement set based on a latest displacement vector; and providing a latest obtained estimate as the geometry of the borehole when all of the displacement vectors no longer exceed the selection criterion for the displacing.

Abstract: A method and apparatus for predicting a formation parameter at a drill bit drilling a formation is disclosed. A vibration measurement is obtained at each of a plurality of depths in the borehole. A formation parameter is obtained proximate each of the plurality of depths in the borehole. A relationship is determined between the obtained vibration measurements and the measured formation parameters at the plurality of depths. A vibration measurement at a new drill bit location is obtained and the formation parameter at the new drill bit location is predicted from the vibration measurement and the determined relation. Formation type can be determined at the new drill bit location from the new vibration measurement and the determined relationship.

Abstract: A method and apparatus for estimating a pressure transition zone in a borehole is disclosed. A parameter indicative of formation fluid pressure at a plurality of borehole depths is measured. A global trend of the parameter is determined over a first depth interval and a local trend of the parameter is determined over a second depth interval. A relation is determined between the global trend and the local trend, and the pressure transition zone is determined from the determined relation between the determined global trend and the determined local trend.

Abstract: Disclosed is a method for detecting a pair of opposing breakouts in a borehole penetrating an earth formation. The method includes: conveying a downhole tool configured to perform measurements of a property of the earth formation; producing an image of the earth formation from the measurements, the image comprising a plurality of sectors; dividing the sectors into radial segments, each segment corresponding to an opposite segment; rotating the segments at least one sector at a time until a specified angle is achieved; calculating an average value for the measurements associated with each segment for each rotation of the segments; stacking the average values for opposing segments to produce stack values; determining a maximum or minimum stack value; determining if the maximum or minimum stack value exceeds a threshold value; and detecting the first breakout and the second breakout if the maximum or minimum stack value exceeds the threshold value.