In-Situ Gas Composition Control for High-H2S Natural Gas Production

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing natural gas production from formations with high hydrogen sulfide (H2S) concentrations is challenging due to high capital and operating costs, environmental risks, and the need for costly anti-corrosive measures, which are exacerbated by simulation model-based approaches that lack real-time accuracy.

Innovation Solution

A system using real-time pressure, volume, and temperature (PVT) data from downhole samples and a machine learning model to predict gas injection volumes, enabling in-situ alteration of gas composition and reducing H2S production, thereby enhancing CO2 sequestration and improving gas quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If gas is produced from formations with high H2S concentrations, then natural gas can be extracted, but high capital and operating costs are incurred due to anti-corrosive facilities and H2S management

Engineering Contradiction:
Improvenatural gas productionVSAvoidanti-corrosive facilities and H2S management infrastructure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies this principle by injecting CO2 into the formation to react with H2S and convert it into elemental sulfur and water, transforming the harmful H2S into beneficial products. This eliminates the need for expensive anti-corrosive facilities and H2S management infrastructure while maintaining gas production.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent changes the chemical composition parameters of the formation by injecting CO2, which alters the H2S concentration and transforms it into other substances. This parameter change reduces H2S-related costs and complexity of infrastructure.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If simulation model-based approaches are used to predict injection volumes, then gas composition can be altered, but real-time accuracy is insufficient leading to suboptimal injection parameters

Engineering Contradiction:
Improvegas composition alterationVSAvoidinjection volume prediction accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism by continuously monitoring downhole conditions (pressure, temperature, composition) and using this real-time data to adjust CO2 injection parameters. This closed-loop control system improves both the reliability of gas composition alteration and the precision of injection volume prediction.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces simulation model-based prediction with a machine learning model that processes real-time sensor data. This substitution provides more accurate and responsive injection volume predictions, improving measurement precision.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Device complexity

If H2S concentrations are reduced through injection, then capital investment and operating costs decrease, but real-time monitoring and control are required to achieve desired gas composition

Engineering Contradiction:
Improveanti-corrosive facilities and H2S management infrastructureVSAvoidreal-time monitoring and control system
Core Design Contradiction:
Device complexityVSExtent of automation

Solution Approach 1:

The patent employs a self-regulating system where downhole sensors automatically monitor composition and trigger CO2 injection when H2S levels exceed thresholds. The machine learning model autonomously adjusts injection parameters based on real-time data, reducing the need for manual intervention and expensive infrastructure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The real-time monitoring system provides continuous feedback on formation conditions, enabling automated adjustment of injection parameters to maintain desired gas composition while minimizing infrastructure requirements.

Inventive Principle:
Principle #23Feedback

4Manufacturing precision

If CO2 is injected into formations, then H2S concentrations are reduced and gas quality improves, but the volume and timing of injection must be precisely controlled to avoid subsurface pressure issues

Engineering Contradiction:
Improvegas composition controlVSAvoidinjection gas volume and pressure management
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent uses dynamic control where CO2 injection rate and timing are continuously adjusted based on real-time downhole pressure and composition data. The machine learning model predicts optimal injection parameters that maintain subsurface pressure within safe limits while achieving precise gas composition control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Real-time monitoring of subsurface pressure and composition provides feedback that enables precise control of injection volume and timing, preventing pressure issues while achieving desired gas quality.

Inventive Principle:
Principle #23Feedback

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 reduces capital investment, minimizes H2S-related risks, and enhances gas production efficiency by monitoring subsurface compositional changes in real-time, reducing the need for surface H2S management and lowering operational costs.

Implementation Method 1

A system using real-time pressure, volume, and temperature (PVT) data from downhole samples and a machine learning model to predict gas injection volumes

Methodology Applied
Scientific EffectMachine learning prediction:

Implementation Method 2

altering gas composition in-situ during production

Methodology Applied
Scientific EffectGas mixing:

Implementation Method 3

injecting gas (e.g., methane or CO2) into a formation to adjust the composition of gas produced from the formation

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 4

reduce production of H2S or other undesired components

Methodology Applied
Scientific EffectGas separation:

Data Source

PatentUS20250347196A1Altering Natural Gas Composition In-situ During Production
Publication Date: 2025.11.13 SAUDI ARABIAN OIL CO
  • US20250347196A1 patent drawing
  • US20250347196A1 patent drawing
  • US20250347196A1 patent drawing

AI summary

Methods and systems for producing gas from a subsurface formation through a production well and/or sequestering gas in the subsurface formation through an injection well can include monitoring pressure, temperature, and composition of fluids in the subsurface formation using sensors installed downhole in an injection well. The pressure, the temperature, and the composition of fluids in the subsurface formation can be monitored using sensors installed downhole in the production well(s) and/or observation well(s). This approach can predict a volume of gas injection through required to alter the composition of fluids in the subsurface formation to provide a specific fluid composition in the production well. It can also include injecting the predicted volume of gas through the injection well using pumps associated with the injection well as well as, in some cases, producing the fluids in the subsurface formation to surface.