Downhole Reactor for H2S Conversion in Sour Gas Wells
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Solution Overview
Problem
There is a need for new systems and methods to mitigate the contamination of hydrogen sulfide (H2S) in petroleum products while capturing chemical products produced as a result of H2S mitigation efforts, particularly in ultra-sour gas fields where H2S is prevalent.
Innovation Solution
The method involves admitting natural gas, including hydrogen sulfide, into a downhole reactor in a well, where it is reacted to produce chemical products such as hydrogen and sulfur through thermal, catalytic, or electrolytic decomposition. This process occurs in-situ, avoiding the surface presence of toxic hydrogen sulfide and optimizing energy efficiency by utilizing underground temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional H2S removal processes (chemical solvents, physical solvents, refrigeration, membranes) are used at the surface, then H2S can be removed from petroleum products, but the process complexity and cost increase, and chemical products are lost
Solution Approach 1:
The harmful H2S component is extracted and separated from the natural gas stream through thermal decomposition in a downhole reactor, isolating the toxic substance for targeted conversion while leaving the cleaned gas to proceed to production. This extraction approach simplifies surface processing by removing the problematic component before it reaches surface facilities.
Solution Approach 2:
The toxic H2S, which would normally require complex removal processes, is converted into valuable chemical products (sulfur and hydrogen) through thermal decomposition in the downhole reactor. This transforms a harmful waste product into economically valuable chemicals, eliminating the need for complex surface sweetening processes while creating additional revenue streams.
2Object-affected harmful factors
If H2S is injected down hole for disposal away from surface environments, then environmental safety is improved, but valuable chemical products are lost and disposal costs remain
Solution Approach 1:
Instead of simply disposing of H2S underground, the invention converts the toxic gas into valuable sulfur and hydrogen products through controlled thermal decomposition in a downhole reactor. This transformation maintains environmental safety by containing the reaction underground while recovering valuable chemicals that can be produced and sold, turning a disposal problem into a production opportunity.
Solution Approach 2:
The downhole reactor system performs both the sweetening function and the chemical production function in one integrated process. The H2S is converted to valuable products that can be separated and produced through existing well infrastructure, making the system self-sufficient for both environmental protection and chemical recovery without requiring separate disposal and production systems.
3Object-affected harmful factors
If surface-based H2S removal processes are used, then H2S can be mitigated, but energy efficiency decreases due to transportation and surface processing requirements
Solution Approach 1:
The H2S decomposition reaction is performed downhole before the gas reaches the surface, utilizing the naturally occurring high temperatures in the subsurface environment. This preliminary action eliminates the need for energy-intensive surface heating and processing facilities, as the thermal energy required for decomposition is already present in the formation, significantly improving overall energy efficiency.
Solution Approach 2:
The downhole reactor system utilizes the natural thermal energy of the subsurface environment to drive the H2S decomposition reaction, making the process self-heating and eliminating the need for external energy input. The system leverages the existing thermal gradient in the wellbore to provide the activation energy required for the reaction, reducing overall energy consumption compared to surface-based processes.
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 effectively converts toxic hydrogen sulfide into valuable chemical products like hydrogen and carbon disulfide, reducing environmental concerns and improving safety by containing the reaction underground. It also enhances energy efficiency and captures chemical products that can be used industrially, addressing the need for increased sulfur production.
Implementation Method 1
heating the hydrogen sulfide within the downhole reactor to thermally decompose the hydrogen sulfide to produce chemical products that include hydrogen and sulfur
Implementation Method 2
activating an electrolytic cell within the downhole reactor to electrolytically decompose the hydrogen sulfide to produce chemical products that include hydrogen and sulfur
Implementation Method 3
contacting the methane and hydrogen sulfide with a catalyst within the downhole reactor to oxidize the methane to produce chemical products that include hydrogen and carbon disulfide
Data Source
AI summary
Methods for the in-situ production of one or more chemical products in a subterranean well include the steps of admitting natural gas into the well from the surrounding subterranean formation, directing the natural gas into a downhole reactor in the well, reacting the natural gas within the downhole reactor to produce an intermediate product stream that includes the one or more chemical products, and withdrawing the intermediate product stream and the one or more chemical products from the downhole reactor. The methods can be earned out in a downhole reactor (22) that includes a reaction chamber (26) inside tubing (20) and an inlet valve (24) adapted to control the introduction of natural gas into the reaction chamber (26).