Method and system for using multiple-point statistics simulation to model reservoir property trends

A computer system for modeling reservoir property trends, the system comprising:

• a computer storage device for storing well data, sampled from a portion of a reservoir volume of interest and corresponding to a reservoir property, and a training image that describes expected trends of the reservoir property;
• and
• at least one processor, configured to communicate with the computer storage device and to execute one or more computer programs configured for performing operations comprising:
• discretizing a range of values of the reservoir property to be modeled into at least two categories;
• discretizing the well data into the categories to create categorical well data, and discretizing the training image into the categories to create a categorical training image;
• applying a multiple-point statistics simulation using the categorical training image on a stratigraphic grid of nodes discretizing the reservoir volume to create a categorical property model conditioned to the categorical well data;
• creating for each category in the categorical property model, a sub-region comprising the nodes of the stratigraphic grid where that category has been simulated in the categorical property model;
• and
• applying variogram-based simulation in each sub-region to create a reservoir property model that reproduces the category histogram of each associated sub-region and models the reservoir property trends.

A computer-implemented model of reservoir property trends, prepared by a method comprising the operations of:

• storing in a computer storage device, well data, sampled from a portion of a reservoir volume of interest and corresponding to a reservoir property to be modeled, and a training image that describes expected trends of the reservoir property;
• utilizing a computer system comprising one or more processors configured to communicate with the computer storage device and to execute one or more computer programs configured for performing operations comprising:
• discretizing a range of values of the reservoir property to be modeled into at least two categories;
• discretizing the well data into the categories to create categorical well data, and discretizing the training image into the categories to create a categorical training image;
• applying a multiple-point statistics simulation using the categorical training image on a stratigraphic grid of nodes discretizing the reservoir volume to create a categorical property model conditioned to the categorical well data;
• creating for each category in the categorical property model, a sub-region comprising the nodes of the stratigraphic grid where that category has been simulated in the categorical property model;
• and
• applying variogram-based simulation in each sub-region to create a reservoir property model that reproduces the category histogram of each associated sub-region and models the reservoir property trends.

An article of manufacture, comprising:

• a computer useable medium having computer readable program code means embodied therein for modeling reservoir property trends, the computer readable program code means in said article of manufacture comprising:
• computer readable program means for discretizing a range of values of a reservoir property to be modeled into at least two categories;
• computer readable program means for discretizing well data into the categories to create categorical well data, and discretizing a training image into the categories to create a categorical training image;
• computer readable program means for applying a multiple-point statistics simulation using the categorical training image on a stratigraphic grid of nodes discretizing the reservoir volume to create a categorical property model conditioned to the categorical well data;
• computer readable program means for creating for each category in the categorical property model, a sub-region comprising the nodes of the stratigraphic grid where that category has been simulated in the categorical property model;
• and
• computer readable program means for applying variogram-based simulation in each sub-region to create a reservoir property model that reproduces the category histogram of each associated sub-region and models the reservoir property trends.