Measurement-While-Drilling System Based on Inertial Sensors for Guided Drilling and Resurveying Applications

摘要

The need for integrated solutions in the drilling and mining business is rising due to the growing requirements presented by increasingly complex and demanding underground infrastructure projects. Specifically the following applications require precise sub-surface positioning solutions: 1. Horizontal Directional Drilling (HDD) 2. Vertical Drilling for Geo-Exploration 3. Raise-Drilling for Mining Operations A new concept for a Measurement-While-Drilling (MWD) system has been introduced, which consists of a ruggedized inertial measurement system based on NG-LITEFs highly reliable FOG- and MEMS-technology in combination with an embedded processor and associated hard- & software. The following basic design goals had to be considered for the MWD system: 1. Bore Distance max. 300m (MWD), Resurveying max. 1 - 2km 2. Dead reckoning positioning based on inertial sensor data and externally provided depth To achieve the required accuracy under the demanding environmental conditions, a combination of improved Kalman filtering and application-specific mechanization techniques has been implemented and evaluated. Additionally the system incorporates extensive built-in test features ensuring the integrity of the data delivered on the output interfaces. This paper details the basic mechanical, electrical and software design of the MWD system. Furthermore, preliminary results on real-world datasets taken during drilling and resurveying test campaigns with the prototypes are presented. Finally, an outlook as to the further development of the MWD system, especially with respect to performance improvement and temperature resistance for Oil / Gas Explorations will be given.