Methods and systems for calibrating depth in a well to seismic data in a subsurface volume of interest

Patent metadata

Field	Value
Publication number	US-11275193-B2
Application number	US-201816227944-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Dec 20, 2018
Publication date	Mar 15, 2022
Grant date	Mar 15, 2022

Abstract

Methods and systems for calibrating depth in a well to seismic data in a subsurface volume of interest are disclosed. Exemplary implementations may: obtain well data corresponding to the well in the subsurface volume of interest; convert the well data to converted well data; obtain a seismic trace and a corresponding wavelet; generate a transform model; apply the transform model to the converted well data to transform the converted well data into transformed well data; apply the corresponding wavelet to the transformed well data to generate a modified signal; generate a correspondence between the modified signal and the seismic trace; repeat one or more steps to select a given modified signal; and calibrate the well data to the seismic trace.

First claim

What is claimed is:

1. A computer-implemented method for calibrating depth in a well to seismic data in a subsurface volume of interest, the method being implemented in a computer system that includes one or more physical computer processors and non-transient electronic storage, comprising:
a) obtaining, from the non-transient electronic storage, well data corresponding to the well in the subsurface volume of interest, wherein the well data specifies depth values of the well in the subsurface volume of interest;
b) converting, with the one or more physical computer processors, the well data to converted well data, wherein the converted well data specifies time values corresponding to the well data;
c) obtaining, from the non-transient electronic storage, a seismic trace, corresponding to the well in the subsurface volume of interest, and a corresponding wavelet, wherein the seismic trace specifies time values as a function of energy;
d) generating, with the one or more physical computer processors, a transform model based on one or more probabilities, wherein the transform model includes a slope parameter and a shift parameter;
e) applying, with the one or more physical computer processors, the transform model to the converted well data to transform the converted well data into transformed well data, wherein the transformed well data specifies time values corresponding to the converted well data;
f) applying, with the one or more physical computer processors, the corresponding wavelet to the transformed well data to generate a modified signal;
g) generating, with the one or more physical computer processors, a correspondence between the modified signal and the seismic trace; and
h) repeating, with the one or more physical computer processors, steps d)-g) to select a given modified signal, based on the correspondence between individual ones of the modified signals and the seismic trace.

2. The computer-implemented method of claim 1 , further comprising:
calibrating, with the one or more physical computer processors, the well data to the seismic trace based on a selected set of transformed well data corresponding to a selected modified signal.

3. The computer-implemented method of claim 2 , further comprising:
generating, with the one or more physical computer processors, an uncertainty estimate for calibrating the well data to the seismic trace based on the multiple modified signals.

4. The computer-implemented method of claim 1 , wherein the correspondence is a difference between the given modified signal and the seismic trace.

5. The computer-implemented method of claim 1 , where the corresponding wavelet, is generated by using the seismic trace.

6. The computer-implemented method of claim 1 , wherein the corresponding wavelet, {circumflex over (ŝ)}, is generated by using the converted well data, such that
{circumflex over (ŝ)} = −1 (| ( {tilde over ({tilde over (G)})} −1 {tilde over ({tilde over (d)})} )|)

where represents a Fourier transform, {tilde over ({tilde over (G)})} represents a reflectivity matrix excluding columns corresponding to the one or more (n−2m)×2m rows, and {tilde over ({tilde over (d)})} represents the seismic trace.

7. The computer-implemented method of claim 1 , wherein one of the one or more probabilities used to generate a second transform model, m′, is based on a probability, α:

α
⁡

(

m
→

m
′

)

=

min
⁡

[

1
,

p
⁡

(

m
′

)

p
⁡

(
m
)

⁢

q
⁡

(

m
|

m
′

)

q
⁡

(

m
′

|
m

)

⁢

ℒ
⁡

(

m
′

)

ℒ
⁡

(
m
)

⁢


J


]

where m represents a first transform model, p( ) represents a prior model probability for a given variable, q( ) represents a proposal probability from a first variable to a second variable, represents a likelihood for a given transform model, and J represents a determinant of a Jacobian of a transformation of variables while changing a number of slopes from the first transform model to the second transform model.

8. The computer-implemented method of claim 1 , wherein one of the one or more probabilities used to generate a second transform model, m′, is based on a probability, α:

α
⁡

(

m
→

m
′

)

=

min
⁡

[

Assignees

• Chevron Usa Inc

Inventors

• Ray Anandaroop
• Greene Michael
• Edwards Mason
• Cardona Reynaldo

Classifications

• G01V2210/6222

  Velocity; travel time · CPC title

• G01V1/28

  Processing seismic data, e.g. for interpretation or for event detection (G01V1/48 takes precedence) · CPC title

• G01V1/48 Primary

  Processing data · CPC title

• G01V1/306

  for determining physical properties of the subsurface, e.g. impedance, porosity or attenuation profiles · CPC title

• G01V1/282 Primary

  Application of seismic models, synthetic seismograms · CPC title