Abstract: Downhole display systems and methods. A display of one or more portions of a well log of a well during drilling may be displayed together with a display of one or more portions of one or more reference well logs, which may be presented as projected onto one or more planes, respectively. The logs may be segmented and correlated, with the segments or correlated portions displayed in different colors. A user may manipulate the display of the logs or log segments to assist in correlating them. The user may also manipulate the display so that the view provided of the wellbore and the projected logs changes in any one or all of three dimensions. In addition, the user may manipulate the display by navigating along the length of the borehole to view the projected logs at any point along the well path.

Abstract: Downhole display systems and methods. A display of one or more portions of a well log of a well during drilling may be displayed together with a display of one or more portions of one or more reference well logs, which may be presented as projected onto one or more planes, respectively. The logs may be segmented and correlated, with the segments or correlated portions displayed in different colors. A user may manipulate the display of the logs or log segments to assist in correlating them. The user may also manipulate the display so that the view provided of the wellbore and the projected logs changes in any one or all of three dimensions. In addition, the user may manipulate the display by navigating along the length of the borehole to view the projected logs at any point along the well path.

Abstract: Downhole display systems and methods. A display of one or more portions of a well log of a well during drilling may be displayed together with a display of one or more portions of one or more reference well logs, which may be presented as projected onto one or more planes, respectively. The logs may be segmented and correlated, with the segments or correlated portions displayed in different colors. A user may manipulate the display of the logs or log segments to assist in correlating them. The user may also manipulate the display so that the view provided of the wellbore and the projected logs changes in any one or all of three dimensions. In addition, the user may manipulate the display by navigating along the length of the borehole to view the projected logs at any point along the well path.

Abstract: A method and system for geosteering may generate a misfit function using a spline function. The misfit function may be used to accurately map errors or differences between TVD-based measurement data for one or more reference wells and MD-based measurement data collected during drilling of a subject well, in order to accurately determine a stratigraphic location of the subject well.

Abstract: A valve for limiting differential pressure applied to a downhole tool includes a housing and a movable piston/mandrel assembly therein. In a closed position, drilling mud or other fluid may be communicated through a central bore of the valve to the tool. When the differential pressure between the central bore and the wellbore exceeds a first predetermined value, the piston/mandrel assembly moves from a first position obstructing one or more relief ports to a second position not obstructing them, thereby providing a fluid path from the central bore of the valve to the wellbore bypassing the tool and relieving the differential pressure thereacross. When the differential pressure decreases to less than another preselected value, the piston/mandrel assembly returns to its original position again obstructing the relief ports. A trigger mechanism is provided to allow more precise control and separation of the preselected differential pressure values.

Abstract: A valve for limiting differential pressure applied to a downhole tool includes a housing and a movable piston/mandrel assembly therein. In a closed position, drilling mud or other fluid may be communicated through a central bore of the valve to the tool. When the differential pressure between the central bore and the wellbore exceeds a first predetermined value, the piston/mandrel assembly moves from a first position obstructing one or more relief ports to a second position not obstructing them, thereby providing a fluid path from the central bore of the valve to the wellbore bypassing the tool and relieving the differential pressure thereacross. When the differential pressure decreases to less than another preselected value, the piston/mandrel assembly returns to its original position again obstructing the relief ports. A trigger mechanism is provided to allow more precise control and separation of the preselected differential pressure values.

Abstract: A valve for limiting differential pressure applied to a downhole tool includes a housing and a movable piston/mandrel assembly therein. In a closed position, drilling mud or other fluid may be communicated through a central bore of the valve to the tool. When the differential pressure between the central bore and the wellbore exceeds a first predetermined value, the piston/mandrel assembly moves from a first position obstructing one or more relief ports to a second position not obstructing them, thereby providing a fluid path from the central bore of the valve to the wellbore bypassing the tool and relieving the differential pressure thereacross. When the differential pressure decreases to less than another preselected value, the piston/mandrel assembly returns to its original position again obstructing the relief ports. A trigger mechanism is provided to allow more precise control and separation of the preselected differential pressure values.