| 摘要 |
<p>A pulsed induction logging system (10) is provided including a logging sonde (14) with downhole microprocessor/controller circuitry (28) in contact with a separate host computer/controller (27) at the earth's surface. The host computer/controller (27) and two downhole microprocessor/controllers generate a digital pulsed logging code for periodically driving a radiation coil (50) with an oscillating current having high peak power. A powerful primary pulse of electromagnetic energy is periodically generated for irradiating the adjacent formation. The sonde also includes an antenna array (30) for detecting secondary induced fields in the formation around the borehole. The array includes a series of grouped, paired coils (A1-A13) axially spaced along the borehole. Each group of paired coils independently detects the secondary field. Each detected signal per group of paired coils, is digitized, reformated and transmitted to the host computer/controller (27).</p> |
