Method for rapid calibration of seismic interval attributes to rock properties for assessment uncertainty

Patent metadata

Field	Value
Publication number	US-10816684-B2
Application number	US-201715835711-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Feb 2, 2017
Publication date	Oct 27, 2020
Grant date	Oct 27, 2020

Abstract

A method, including: calibrating a linear rock physics model to well log properties; generating a plurality of pseudo-well models for a subsurface region using a Monte Carlo approach; generating synthetic seismic traces from each of the plurality of pseudo-well models; computing top and base isochron from the synthetic seismic traces; computing seismic attributes in an interval specified by the top and base isochron on the synthetic seismic traces; correlating the seismic attributes to rock properties; and transforming seismic data into low-side, most-likely, and high-side estimates of rock properties.

First claim

What is claimed is:

1. A method, comprising:
calibrating a linear rock physics model to well log properties;
generating a plurality of pseudo-well models for a subsurface region using a Monte Carlo approach;
generating synthetic seismic traces from each of the plurality of pseudo-well models;
computing top and base isochron from the synthetic seismic traces;
computing seismic attributes in an interval specified by the top and base isochron on the synthetic seismic traces;
correlating the seismic attributes to rock properties, wherein the correlating includes predicting pore thickness and porosity from a correlation between at least one of the seismic attributes and rock properties;
predicting net sand thickness from the pore thickness and porosity predictions; and
transforming seismic data into low-side, most-likely, and high-side estimates of rock properties.

2. The method of claim 1 , further comprising:
refining the porosity prediction based on the net sand thickness prediction through generation of a tuning curve; and
recomputing the net sand thickness by taking a quotient of the predicted pore pressure and a corrected porosity prediction.

3. The method of claim 2 , further comprising:
generating the tuning curve by examining cross-plots of model thickness vs. predicted porosity residual.

4. The method of claim 1 , wherein the computing seismic attributes includes analyzing cross-plots of pore thickness vs. each of the seismic attributes, determining a most predictive seismic attribute, and generating a calibrated seismic attribute to pore thickness prediction function.

5. The method of claim 1 , further comprising:
extracting hydrocarbons from a location in a reservoir determined from the net sand thickness.

6. The method of claim 1 , further comprising calibrating interbedded shale thickness and number of sands with a cross-plot of net sand thickness to isochron thickness.

7. The method of claim 1 , further comprising distributing predicted rock properties into a seismic-consistent 3D geologic model with a variogram.

8. A method, comprising:
calibrating a linear rock physics model to well log properties;
generating a plurality of pseudo-well models for a subsurface region using a Monte Carlo approach;
generating synthetic seismic traces from each of the plurality of pseudo-well models;
computing seismic attributes on the synthetic seismic traces;
correlating the seismic attributes to net hydrocarbon pore thickness;
transforming seismic data into low-side, most-likely, and high-side net hydrocarbon pore thickness maps; and
estimating an oil volume from a product of a mean of the net hydrocarbon pore thickness from a given one of the maps and an area of a region on the given one of the maps.

9. The method of claim 8 , further comprising causing oil to be extracted from a reservoir corresponding to the region on the given one of the maps.

Assignees

• Basler Reeder Kyle J
• Matheney Michael P
• Donaldson Edward B
• Exxonmobil Upstream Res Co

Inventors

• Basler-Reeder Kyle J
• Matheney Michael P
• Donaldson Edward B

Classifications

• 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

• G01V1/307

  for determining seismic attributes, e.g. amplitude, instantaneous phase or frequency, reflection strength or polarity · CPC title

• G01V1/302

  in 3D data cubes · CPC title

• G01V2210/66

  Subsurface modeling · CPC title