measurement while drilling

The purpose of this paper is to demonstrate how inaccuracy in standard directional-surveying methods affects wellbore position and to recommend practices to improve surveying accuracy for greater confidence in lateral spacing.

Wellbore position is computed from survey measurements taken by a measurement-while-drilling (MWD) tool in the bottomhole assembly (BHA).

A new measurement-while-drilling (MWD) tool has been designed that can operate reliably at 200°C and 207 MPa, providing real-time direction and inclination surveys, azimuthal gamma ray, annular and internal pressure while drilling, and shock and vibration measurements.