Freshwater Ring for CO2 Injectivity in Saline Aquifers

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The CO2 dry-out effect reduces well injectivity in subterranean saline aquifers by causing salt precipitation and pore plugging, limiting the amount of CO2 that can be injected and sequestered.

Innovation Solution

Injecting a predetermined volume of freshwater into the saline aquifer adjacent to the wellbore creates a freshwater ring, which minimizes the CO2 dry-out effect by displacing brine and reducing salt precipitation, thereby maintaining well injectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If CO2 is injected into a subterranean saline aquifer for sequestration, then carbon dioxide storage capacity is utilized, but the CO2 dry-out effect reduces well injectivity by causing salt precipitation and pore plugging

Engineering Contradiction:

ImproveCO2 storage capacityVSAvoidwell injectivity

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary action by injecting freshwater into the saline aquifer before CO2 injection to create a freshwater ring around the wellbore. This pre-established freshwater barrier prevents salt precipitation and pore plugging that would otherwise occur during CO2 injection, thereby maintaining well injectivity while enabling CO2 storage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses freshwater as an intermediary substance between the CO2 injection and the saline aquifer environment. The freshwater ring acts as a mediator that displaces brine and prevents direct interaction between CO2 and salt-bearing formation water, eliminating the CO2 dry-out effect while allowing CO2 sequestration to proceed.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a predetermined volume of freshwater is injected to create a freshwater ring, then well injectivity is maintained by reducing salt precipitation, but additional injection steps and volume calculation are required

Engineering Contradiction:

Improvewell injectivityVSAvoidinjection process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The freshwater injection is performed as a preliminary step before CO2 injection, establishing the necessary freshwater ring in advance. This pre-conditioning of the formation simplifies the overall process by preventing injectivity issues before they occur, rather than requiring complex real-time monitoring and adjustment during CO2 injection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent determines the freshwater volume based on geometric parameters of the wellbore and formation (radii, thickness) and establishes a specific ratio range (n=3-7). By defining clear parameter ranges and calculation methods, the patent transforms a potentially complex process into a systematic procedure based on measurable formation characteristics.

Inventive Principle:

Principle #35Parameter changes

3Object-affected harmful factors

If freshwater is injected prior to CO2 injection, then the CO2 dry-out effect is minimized, but injection timing and volume determination are critical

Engineering Contradiction:

ImproveCO2 dry-out effectVSAvoidinjection timing and volume precision

Core Design Contradiction:

Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent establishes specific parameter ranges to optimize the freshwater ring creation: the ratio n of wellbore radius to freshwater ring radius should be between 3 and 7. This quantitative guidance provides clear design criteria for achieving the desired effect while accounting for natural variation in formation properties.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

By performing freshwater injection as a preliminary step with predetermined volume calculations, the patent establishes optimal conditions before CO2 injection begins. This advance preparation ensures the freshwater ring is properly formed, eliminating the need for precise real-time control during the critical CO2 injection phase.

Inventive Principle:

Principle #10Preliminary action

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

The method enhances the rate and effectiveness of CO2 injection into subterranean formations by maintaining well injectivity and reducing the CO2 dry-out effect, allowing for more efficient CO2 sequestration.

Implementation Method 1

injecting, through the wellbore, a predetermined volume of freshwater into a portion of the saline aquifer adjacent the wellbore to create a freshwater ring about the wellbore in the subterranean formation

Methodology Applied

Scientific EffectFluid displacement:

Data Source

PatentUS20250067152A1Systems and methods for enhancing carbon dioxide injectivity into a subterranean formation

Publication Date: 2025.02.27 SAUDI ARABIAN OIL CO

AI summary

A method includes identifying a wellbore that extends from a terranean surface and to a subterranean formation that includes a saline aquifer; injecting, through the wellbore, a predetermined volume of freshwater into a portion of the saline aquifer adjacent the wellbore to create a freshwater ring about the wellbore in the subterranean formation; and subsequent to injecting the predetermined volume of freshwater, injecting a carbon dioxide fluid, through the wellbore, and into the subterranean formation for sequestration.