Vertical Electric Dipole Source for Fracture Zone Mapping

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Solution Overview

Problem

Inaccurate characterization of fracture zone dimensions in hydrocarbon reservoirs leads to inefficient well placement and drilling during hydraulic fracturing, resulting in unnecessary well placement.

Innovation Solution

A system and method using an electromagnetic source with electric dipole sources to generate a vertical electric field, coupled with a receiver to measure and process electromagnetic field responses, providing information on fracture characteristics such as orientation, location, and dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional electromagnetic methods are used to detect fracture zones, then measurement capability is provided, but measurement precision is insufficient for accurate fracture zone dimension characterization

Engineering Contradiction:
Improvefracture zone dimension characterizationVSAvoidfracture zone characteristics information
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The electromagnetic source is segmented into multiple electric dipole sources arranged in specific geometries (vertical dipoles, horizontal dipoles, or combinations) to generate controlled electromagnetic field patterns. This segmentation allows different dipole configurations to probe different aspects of fracture zone characteristics, improving measurement precision through multi-component field interactions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the parameters of the electromagnetic source by using electric dipole sources with specific orientations (vertical or horizontal) and configurations. This parameter change enables the generation of substantially vertical electric fields that interact differently with fracture zones, thereby improving the precision of fracture zone dimension characterization and reducing information loss.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If multiple wells are drilled to ensure adequate reservoir drainage, then productivity is maintained, but loss of substance increases due to unnecessary drilling

Engineering Contradiction:
Improvereservoir drainage efficiencyVSAvoidunnecessary well placement
Core Design Contradiction:
ProductivityVSLoss of substance

Solution Approach 1:

The electromagnetic detection system performs preliminary characterization of fracture zone dimensions, orientation, and location before well placement decisions are made. This preliminary action provides accurate subsurface information that enables optimized well spacing and placement, ensuring adequate reservoir drainage while avoiding unnecessary well drilling and the associated resource consumption.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If electromagnetic sources are placed at depth to improve fracture zone detection, then measurement capability improves, but device complexity and cost increase

Engineering Contradiction:
Improvefracture zone detection accuracyVSAvoidsource placement complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention uses electric dipole sources as intermediaries that can be placed at or near the surface to generate electromagnetic fields that penetrate and interact with deep fracture zones. This intermediary approach allows accurate deep fracture zone detection without requiring physical placement of sources at great depths, thereby reducing device complexity and associated costs while maintaining measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables accurate mapping and monitoring of fracture zones from surface measurements, reducing drilling inefficiencies and costs by providing detailed characteristics of fracture zones.

Implementation Method 1

an electromagnetic source configured to generate an electromagnetic field in the vicinity of or at the surface of the rock formation. The electromagnetic source includes one or more electric dipole sources that are arranged in the vicinity of the surface or at the surface so as to generate a substantially vertical electric field

Methodology Applied
Scientific EffectElectromagnetic field generation: Electromagnetic Induction

Implementation Method 2

an electromagnetic receiver associated with the electromagnetic source, the electromagnetic receiver being configured to measure a component of the electromagnetic field at the surface of the rock formation

Methodology Applied
Scientific EffectElectromagnetic field measurement: Electromagnetic Induction

Data Source

PatentEP2962135B1System and method for detecting a fracture in a rock formation using an electromagnetic source
Publication Date: 2020.08.05 CHEVRON USA INC
  • EP2962135B1 patent drawingFigure 1A
  • EP2962135B1 patent drawingFigure 1B
  • EP2962135B1 patent drawingFigure 2

AI summary

A surface electromagnetic survey system and method for detecting a fracture or fracture zone in a rock formation are provided. The system includes an electromagnetic source configured to generate an electromagnetic field in the vicinity of or at a surface of the rock formation. The electromagnetic source includes one or more electric dipole sources that are arranged so as to generate a substantially vertical electric field. The system also includes an electromagnetic receiver associated with the electromagnetic source, the electromagnetic receiver being configured to measure a component of the electromagnetic field at the surface of the rock formation; and a processor configured to convert the measured component of the electromagnetic field measured at the electromagnetic receiver into an electromagnetic field response per unit moment of the electromagnetic source. The electromagnetic field response provides information about characteristics parameters of the fracture or fracture zone.