US 6,044,325 A · Conductivity anisotropy estimation method for inversion processing of measurements made by a transverse electromagnetic induction logging instrument

Abstract

A method for generating an improved estimate of horizontal conductivity, dip angle, azimuth and anisotropy parameter of an earth formation penetrated by a wellbore from dual-frequency transverse electromagnetic induction measurements, comprising generating an initial estimate of the horizontal conductivity, dip angle, azimuth and anisotropy parameter from the dual-frequency transverse induction measurements made at each one of a plurality of base frequencies. The initial estimates from each of the plurality of base frequencies are input into a primary trained neural network, and the improved estimate is calculated by the trained neural network. The network is trained by generating models of earth formations each having a known value of horizontal conductivity, anisotropy parameter, dip angle and azimuth. Voltages which would be measured by the transverse electromagnetic induction instrument in response to each model are synthesized. Initial estimates from the synthesized voltages are calculated and the initial estimates and known values from each of the models are input to the neural network to cause it to learn a relationship between the initial estimates and the known values.

Claims8

Dependent claims

A method for generating an improved estimate of at least one of horizontal conductivity, dip angle, azimuth and anisotropy parameter of an earth formation penetrated by a wellbore, from dual-frequency transverse electromagnetic induction measurements of said formations, comprising:

generating an initial estimate of said at least one of horizontal conductivity, dip angle, azimuth and anisotropy parameter from said dual-frequency transverse induction measurements made at each one of a plurality of base frequencies;
imparting said initial estimates from each of said plurality of base frequencies into a trained neural network;
and
calculating said improved estimate using said trained neural network.

1 more element

A method for generating an improved estimate of at least one of horizontal conductivity, dip angle, azimuth and anisotropy parameter of an earth formation penetrated by a wellbore, comprising:

inserting a transverse electromagnetic induction logging instrument comprising mutually orthogonal transmitters and receivers and a dual-frequency alternating current source selectively connectable to each of said transmitters to induce alternating magnetic fields in said formations along an axis parallel thereto, said dual frequency source comprising a plurality of base frequencies;
detecting voltages at each said receiver corresponding to electromagnetic induction phenomena in said earth formation, said voltages including one component corresponding to reception along the same axis as each of said induced magnetic fields, and reception orthogonal to said induced magnetic fields;
generating an initial estimate of said at least one of horizontal conductivity, apparent dip angle, apparent azimuth and anisotropy parameter from said detected voltages at each one of said plurality of base frequencies;
imparting said initial estimates from each of said plurality of base frequencies into a trained neural network;
and
calculating said improved estimate using said trained neural network.

3 more elements

Dependencies are inferred from the claim text.

Conductivity anisotropy estimation method for inversion processing of measurements made by a transverse electromagnetic induction logging instrument

Life of this patent

Conductivity anisotropy estimation method for inversion processing of measurements made by a transverse electromagnetic induction logging instrument

Life of this patent

Abstract

Claims8