Patent ID: 11940588
Assignee: SCHLUMBERGER TECHNOLOGY CORPORATION
Field: Measurement (Instruments)
Classification: CPC G  C | IPC C  G

Claim 17:
18. A system for characterizing clay content of a subsurface formation of interest, the system comprising:
a downhole logging tool that is configured to conduct an electromagnetic measurement on the formation of interest at a frequency less than 5000 Hertz, wherein the electromagnetic measurement measures and stores conductivity data that characterizes complex conductivity of the formation of interest at the frequency less than 5000 Hertz; and
at least one processor that, when executing program instructions stored in memory, is configured to:
i) obtain the conductivity data that characterizes complex conductivity of the formation of interest at the frequency less than 5000 Hertz,
ii) process the conductivity data of i) to determine permittivity data that characterizes permittivity of the formation of interest at the frequency less than 5000 Hertz;

iii) extract a parameter from the permittivity data of ii); and
iv) use the parameter extracted from the permittivity data in iii) as an input to a computational model, wherein the computational model compares the parameter extracted from the permittivity data in ii) to measured data from at least one formation known to not have clay and, if the model determines the formation of interest contains clay, the computational model compares the parameter extracted from the permittivity data in ii) to at least one formation known to have clay, wherein the computation model further characterizes at least one clay type and corresponding clay volume fraction for the formation of interest.