Subsurface Mapping via Seismic Emission Tomography

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Solution Overview

Problem

Current methods for passive seismic emission tomography struggle to effectively map spatially continuous flow paths for reservoir fluids in the Earth's subsurface without induced fracturing activity, limiting the accuracy of reservoir fluid movement and production volume estimation.

Innovation Solution

A method involving a three-dimensional grid of voxels is used to transform detected seismic signals, allowing for the mapping of spatially continuous flow paths by identifying voxels with high seismic energy emission, which indicates the presence of fractures conducive to fluid flow, thereby estimating production volumes in the subsurface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If passive seismic emission tomography is used to map subsurface flow paths, then fluid movement can be detected, but mapping accuracy is insufficient without induced fracturing activity

Engineering Contradiction:

Improveflow path mapping accuracyVSAvoidreservoir fluid movement detection reliability

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The subsurface volume is divided into a three-dimensional grid of voxels, allowing detailed spatial mapping of seismic energy emissions. This segmentation enables precise localization of fluid flow paths by analyzing energy emissions from individual voxels, thereby improving mapping accuracy without requiring induced fracturing.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The method transforms detected seismic signals into voxel-based energy emission data, changing the parameter representation from raw seismic waves to spatially-resolved energy distributions. This parameter transformation enhances the reliability of fluid movement detection by providing quantitative measures of seismic energy emission from specific subsurface locations.

Inventive Principle:

Principle #35Parameter changes

2Loss of information

If induced fracturing activity is used to enhance seismic signal detection, then flow path visibility improves, but the natural state of the reservoir is altered

Engineering Contradiction:

Improveflow path informationVSAvoidreservoir structure integrity

Core Design Contradiction:

Loss of informationVSStability of the object's composition

Solution Approach 1:

The method utilizes the natural seismic emissions generated by fluid movement through existing fractures and porous media. By detecting and analyzing these self-generated signals, the system obtains flow path information without requiring external intervention such as induced fracturing, thereby preserving the reservoir's natural state while still achieving comprehensive flow path mapping.

Inventive Principle:

Principle #25Self-service

3Shape

If traditional seismic survey methods are used, then subsurface structure can be mapped, but fluid flow dynamics cannot be effectively tracked

Engineering Contradiction:

Improvesubsurface structure mapVSAvoidfluid flow movement precision

Core Design Contradiction:

ShapeVSMeasurement precision

Solution Approach 1:

The method transitions from static subsurface structure mapping to dynamic fluid flow tracking by continuously monitoring temporal variations in seismic energy emissions from voxels. This dynamic approach captures the movement and evolution of fluid flow paths over time, providing precise tracking of fluid dynamics while maintaining awareness of the underlying subsurface structure.

Inventive Principle:

Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enables precise mapping of fluid flow paths and production volumes, enhancing the accuracy of reservoir fluid movement analysis and wellbore performance assessment, both before and after fracturing operations.

Implementation Method 1

an array of seismic sensors is deployed in a selected pattern on or near the Earth's surface, or in a wellbore, and seismic energy that emanates from within the Earth's subsurface is detected by the sensors

Methodology Applied

Scientific EffectSeismic energy detection: Acoustic Emission

Implementation Method 2

transforming detected seismic signals representing seismic energy originating from said volume of the Earth's subsurface when no induced fracturing activity is occurring along said selected path and conducted to a recording unit for recording into signals representing energy originating from the voxels included in said grid of voxels

Methodology Applied

Scientific EffectSeismic signal transformation: Tomography

Data Source

PatentUS9810803B2Method for subsurface mapping using seismic emissions

Publication Date: 2017.11.07 AMBIENT RESERVOIR MONITORING INC

AI summary

The invention comprises a method for mapping a volume of the Earth's subsurface encompassing a selected path within said volume, comprising dividing the volume of the Earth's subsurface into a three-dimensional grid of voxels and transforming detected seismic signals representing seismic energy originating from said volume of the Earth's subsurface when no induced fracturing activity is occurring along said selected path and conducted to a recording unit for recording into signals representing energy originating from the voxels included in said grid of voxels, and utilizing said transformed seismic signals to estimate spatially continuous flow paths for reservoir fluids through said volume of the Earth's subsurface to said selected path.