Systems and methods for electromagnetic detection of a formation anomaly from a near bit location while drilling

摘要

A drill string is disposed in the borehole having a BHA and a drill bit advancing the borehole. Among other BHA components, including a telemetry unit and a data acquisition unit, in a surface-to-borehole configuration a receiver (or receiver array) is positioned immediately proximate the drill bit in the borehole, while a source (or source array) is positioned at the Earth's surface. Alternatively, in a borehole-to-surface configuration the source may be positioned immediately proximate the drill bit in the borehole while a receiver (or receiver array) is positioned at the surface. The surface-to-borehole, or borehole-to-surface, system enables an electromagnetic look about while drilling operations are underway.

主权项

1. A while-drilling method, comprising:
a) providing an electromagnetic (EM) field source at an Earth surface location; b) providing a near-bit electromagnetic (EM) field receiver on a drill string in a borehole at a location proximate a drill bit; c) generating an electromagnetic (EM) field at the source; d) during drilling of the borehole, measuring a plurality of components of the EM field at the near-bit receiver; e) during drilling of the borehole, analyzing in real-time the measured components of the EM field as representative of a distance between the drill bit and a formation anomaly located ahead of the drill bit, the formation anomaly comprising a salt entrance; and f) adjusting at least one drilling parameter based on the measured components of the EM field prior to the drill bit reaching the formation anomaly.