Print this page Synthetic 
Array
Curves from Dual Induction Logs
Hu, Guoyu 1; Geldmacher, Ingo 1
(1)
Weatherford International, Houston, TX.
Description
The traditional dual induction tool makes two apparent resistivity
measurements at two different depths of investigations. In Weatherford’s
Simultaneous Triple Induction (STI) instrument, these are combined with an SFL
to deliver three curves. Typical presentation of these measurements is by means
of an enhanced resolution algorithm. However, it is more desirable to
illustrate multiple depths of investigation curves with a variety of fixed
depths of investigations. Based on the use of multiple frequencies at which the
STI operates, we can derive an additional “synthetic” array logging response.
Application
This is achieved through a non-linear processing approach. Here,
rigorous non-linear 2D modeling is used to forward model the induction tool
response. The synthetic array curves are an improved version of the
presentation of the traditional dual induction measurement at multiple
frequencies by creating a “pseudo” array response. Usefulness and limitations
of the method will also be discussed.
Results
We will show how synthetic array
curves are generated through
modeled examples and on field test examples.
Significance
Combined use of multi-frequency data for traditional induction tools, e.g., the dual induction tools, has not been adequately addressed at least in published work. Our work shows that there is information untapped for in this area and with understanding of its limitations, more information on the near borehole region can be inferred than using the single frequency approach.
AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.