Systems and methods of robust determination of boundaries

Patent metadata

Field	Value
Publication number	US-10317560-B2
Application number	US-201114344779-A
Country	US
Kind code	B2
Filing date	Sep 27, 2011
Priority date	Sep 27, 2011
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

Various embodiments include apparatus and methods to operate a drilling operation relative to formation boundaries. The apparatus and methods can include operating one or more transmitters in a borehole in a formation having a thickness between two boundaries, selecting thickness models based on applying responses from operating the one or more transmitters such that the thickness of the formation is between the two thickness models, and generating a value of a distance to a nearest boundary based on linearization of the thickness models with respect to a long distance investigation parameter and a short distance investigation parameter. Additional apparatus, systems, and methods are disclosed.

First claim

What is claimed is:

1. A method comprising:
operating one or more transmitters of one or more tools in a borehole in a formation having a thickness between two boundaries, wherein the one or more transmitters are operated according to a first parameter and a second parameter, the first parameter causing investigation at a longer distance in the formation relative to the second parameter;
selecting a first thickness model based on applying responses from operating the one or more transmitters according to the first parameter and a second thickness model based on applying responses from operating the one or more transmitters according to the second parameter such that a thickness of the formation is between the first and second thickness models;
generating first estimated values including a distance to a nearest boundary and a thickness between the two boundaries based on linearization of the first and second thickness models with respect to the first parameter and the second parameter; and
providing the first estimated values as an initial solution to an inversion process for determining second estimated values including a distance to the nearest boundary and a thickness between the two boundaries.

2. A method of claim 1 , wherein selecting the first and second thickness models includes selecting the first and second thickness models from a set of more than two thickness models using vertical distances derived from the responses and mapping the vertical distances between thickness models on a pairwise basis with respect to the first parameter and the second parameter.

3. The method of claim 1 , wherein generating the first estimated values including the distance to a nearest boundary and the thickness between the two boundaries includes:
generating a first linear relationship between the first and second thickness models for the first parameter and a second linear relationship between the first and second thickness models for the second parameter; and
generating the first estimated values including the distance to the nearest boundary and the thickness between the two boundaries from an intersection of the first linear relationship and the second linear relationship.

4. The method of claim 1 , wherein operating one or more transmitters includes
operating the one or more transmitters at a first operating frequency as indicated by the first parameter and at a second operation frequency as indicated by the second parameter such that operating at the first operating frequency generates a long distance of investigation relative to a distance of investigation of operating at the second operation frequency.

5. The method of claim 1 , wherein operating one or more transmitters includes operating transmitter-receiver pairs, each transmitter-receiver pair having a spacing between the transmitter and the receiver of the respective pair, at least a first transmitter-receiver pair having a first spacing as indicated by the first parameter and a second transmitter-receiver pair having a second spacing as indicated by the second parameter.

6. The method of claim 5 , wherein the method includes:
generating response curves for two or more formation models of different thicknesses;
mapping selected responses from operating the one or more transmitters to the response curves and generating a vertical distance for a long spacing and a vertical distance for a short spacing for each model thickness;
determining two models corresponding to two different selected spacings such that the thickness is between the thicknesses of the two models, the two different selected spacings being a selected first spacing and a selected second spacing; and
calculating a cross point of a first line with a second line, the first line generated by a vertical distance for the selected first spacing of one of the two models and a vertical distance for the selected first spacing of the other one of the two models, the second line generated by a vertical distance for the selected second spacing of one of the two models and a vertical distance for the selected second spacing of the other one of the two models; and
generating third estimated values including a distance to the nearest boundary and a thickness between the two boundaries value of the formation from coordinates of the cross point.

7. The method of claim 1 , wherein the method includes geosteering a drilling operation based on the generated value.

8. The method of claim 1 , wherein the method includes operating the one or more transmitters and operating electronics on a logging while drilling tool, the electronics arranged to select the first and second thickness models based on applying responses from operating the one or more transmitters and to generate the first estimated values of the distance to a nearest boundary and the thickness between the two boundaries.

9. The method of claim 1 , wherein selecting the first and second thickness models based on applying responses from operating the one or more transmitters includes using geo-attenuation data from operating the one or more transmitters.

10. The method of claim 1 , wherein selecting the first and second thickness models based on applying responses from operating the one or more transmitters includes using geo-phase data from operating the one or more transmitters.

11. A non-transitory machine-readable storage device having instructions stored thereon, which, when performed by a machine, cause the machine to perform operations, the operations comprising:
operating one or more transmitters of one or more tools in a borehole in a formation having a thickness between two boundaries, wherein the one or more transmitters are operated according to a first parameter and a second parameter, the first parameter causing investigation at a longer distance in the formation relative to the second parameter;
selecting a first thickness model based on applying responses from operating the one or more transmitters according to the first parameter and a second thickness model based on applying responses from operating the one or more transmitters according to the second parameter such that a thickness of the formation is between the first and second thickness models;
generating first estimated values including a distance to a nearest boundary and a thickness between the two boundaries based on linearization of the first and second thickness models with respect to the first parameter and the second parameter; and
providing the first estimated values as an initial solution to an inversion process for determining second estimated values including a distance to the nearest boundary and a thickness between the two boundaries.

12. A system comprising:
a tool structure having a first transmitter-receiver pair set apart by a first separation distance and a second transmitter-receiver pair set apart by a second separation distance, wherein the first separation distance is greater than the second separation distance;
a data processing unit; and
a machine-readable storage device having instructions executable by the data processing unit to cause the system to:
operate the first and second transmitter-receiver pairs in a borehole in a formation having a thickness between two boundaries;
select a first thickness models based on application of responses from operation of the first transmitter-receiver pair and a second thickness model based on application of responses from operation of the second transmitter-receiver pair such that a thickness of the formation is between the first and second thickness models;
generate first estimated values including a distance to a nearest boundary and a thickness between the two boundarie

Assignees

• Tang Yumei
• Yu Wenshan
• Bittar Michael S
• Halliburton Energy Services Inc

Inventors

• Tang Yumei
• Yu Wenshan
• Bittar Michael S

Classifications

• E21B7/04

  Directional drilling · CPC title

• G01V3/26 Primary

  operating with magnetic or electric fields produced or modified either by the surrounding earth formation or by the detecting device (with electromagnetic waves G01V3/30) · CPC title

• G01B2210/58

  Wireless transmission of information between a sensor or probe and a control or evaluation unit · CPC title

• G01B7/06

  for measuring thickness {(measuring during the manufacture of coatings C23C14/54)} · CPC title