APPARATUS AND METHOD FOR MEASURING VELOCITY AND COMPOSITION OF MATERIAL IN AND ADJACENT TO A BOREHOLE

摘要

This disclosure provides systems, methods, and apparatus for measuring flow in and around a borehole of an earth formation. A flow measurement device can include a magnet configured to generate a static solenoidal magnetic field with a field intensity that decreases in strength peripherally from the magnet, an electromagnet disposed around the magnet and configured to generate a time varying solenoidal magnetic field, and a radio frequency (RF) coil disposed around the magnet and configured to generate an RF magnetic field transverse to the static solenoidal magnetic field. The flow measurement device can calculate a flow velocity in and around the flow measurement device based upon a signal received by the RF coil.

主权项

1. A flow measurement device for measuring flow in or around a borehole of an earth formation, comprising:
a magnet configured to generate a static solenoidal magnetic field with a field intensity that decreases in strength peripherally from the magnet; an electromagnet disposed around the magnet and configured to generate a time varying solenoidal magnetic field; and a radio frequency (RF) coil disposed around the magnet and configured to:
generate an RF magnetic field transverse to the static solenoidal magnetic field and rotating at the Larmor radio frequency corresponding to the field intensity in a region of interest around the flow measurement device; andoutput a received signal, the received signal induced by a magnetic field around the RF coil.