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FEATURES OF WHILE-DRILLING TOOLS AND SYSTEMS

IP.com Disclosure Number: IPCOM000240689D
Publication Date: 2015-Feb-18
Document File: 6 page(s) / 415K

Publishing Venue

The IP.com Prior Art Database

Related People

Stephanie Chi: ATTORNEY

Related Documents

IS133016IS123462: OTHER

Abstract

Techniques relate to improved designs for a drilling system. In some embodiments, the flow tube may be integrated and the internal chassis may be anchored, thereby decoupling the chassis for improved design. In some embodiments, the tool may be suitable for more accurate depth measurement and may include multiple accelerometers orthogonal to each other for measuring acceleration of a traveling block, a signal processor for calculating current travelling block position with regards to the drilling floor, and a wireless transmitter for sending the data and a receiver, which may be hooked up with any existing surface system.

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SYSTEMS AND FEATURES OF WHILE-DRILLING TOOLS

When drilling holes in subsurface formations it may be necessary to utilize, usually as part of the bottom hole assembly, a downhole unit having one or more formation-engaging members which may be extended or retracted relative to the main body of the unit for engagement and disengagement with the wall of the borehole. Such units may also be required for performing operations in an already-drilled borehole. For example, the unit may be a stabilizer or may be part of a bias unit for imparting a lateral bias to the bottom hole assembly, including the drill bit, for the purposes of controlling the direction of drilling.

Techniques relate to improved designs for a drilling system.  In some embodiments, the flow tube may be integrated and the internal chassis may be anchored, thereby decoupling the chassis for improved design.  In some embodiments, the tool may be suitable for more accurate depth measurement and may include multiple accelerometers orthogonal to each other for measuring acceleration of a traveling block, a signal processor for calculating current travelling block position with regards to the drilling floor, and a wireless transmitter for sending the data and a receiver, which may be hooked up with any existing surface system.

For some drilling applications, it may be important to measure depth while drilling. For depth measurement, a surface system consisting of a Draw-works encoder and a tensiometer may be used in field, as shown in FIG. 1 below. This system uses an optical decoder to count turns of a draw-works to identify the length of the cable released or round by the draw-works. From known number of turns and diameter of each turn the position of a travelling block holding the entire drilling assembly can be calculated. As the cable is normally laid in several layers, the outer diameter of turns changes, as shown in FIG. 2 below, so this should be taken into account by a proper manual calibration before every job.

This system may sometimes be susceptible to human errors as it requires a manual calibration before use as well as constant corrections of depth by engineers (up to several tens centimeters per stand, or up to approximately 30 meters). Inaccuracies in these calibrations or corrections may affect the quality of data delivered by a logging company as there is typically a difference between real depth and measured depth at the same time. The number of pulses per revolution is a constant number, yet number of pulses per meter of the cable changes. Also, during a manual correction there is a sudden change of depth recorded which may create areas of uncertainty at formation property logs.  The plot of FIG. 3 represents a draw-works calibration plot.

Techniques in this disclosure may reduce problems resulting from manual depth correction, hence increasing quality of delivered data (at any moment of time the real depth will be known). The system may directly measure the positi...