Sub-Surface Mixing System for LPG Fracturing Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods using Liquefied Petroleum Gas (LPG) in hydraulic fracturing operations pose significant environmental, operational, and safety hazards due to its combustible nature and the challenges of blending it with solid particulates under high pressure.
Innovation Solution
A sub-surface mixing system where proppants are blended with a non-volatile fluid system before being mixed with LPG, utilizing two distinct flow paths and high-pressure pumps to maintain separation and safety, with blending occurring post-pressurization at pressures greater than 1000 psig, and incorporating a static mixing device to prevent hazardous reactions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If LPG is used as a fracturing fluid and blended with solid particulates under high pressure, then the fracturing operation can achieve high viscosity and miscibility with reservoir fluids, but the operational hazard risk significantly increases due to LPG's highly combustible nature
Solution Approach 1:
The system divides the fracturing fluid into separate streams: a non-volatile fluid stream (containing proppants and gelling agents) and a volatile fluid stream (LPG). These streams are kept separate through distinct flow paths and only mixed downhole, preventing surface-level hazards associated with handling combustible LPG with solid particulates.
Solution Approach 2:
A non-volatile fluid acts as an intermediary carrier for proppants and gelling agents. This intermediary allows safe surface handling and blending of solid particulates without direct contact with LPG, while still enabling the desired fracturing fluid properties to be achieved through downhole mixing.
2Ease of manufacture
If LPG is blended with solid particulates (proppants) at the surface under high pressure, then the fracturing slurry can be prepared and pumped, but the engineering challenges and safety risks of preventing and managing LPG leaks are greatly amplified
Solution Approach 1:
The system uses separate flow paths for volatile and non-volatile fluid streams, with dedicated blending sections for each. This segmentation allows standard, simpler equipment to be used for handling proppants and non-volatile fluids at the surface, while LPG is handled separately through its own flow path, reducing the overall engineering complexity for leak prevention.
Solution Approach 2:
Proppants and gelling agents are blended with the non-volatile fluid stream at the surface before the volatile stream is introduced. This preliminary blending action completes the solid particulate mixing task without requiring LPG to be present, thereby simplifying the engineering design requirements for leak prevention and hazard management.
3Speed
If LPG is pressurized to greater than 100 psig for mobilization through fracturing equipment, then the gas can be delivered to the formation, but the operational hazards increase due to the highly combustible nature of pressurized LPG
Solution Approach 1:
The system separates the pressurization function into two independent streams: the non-volatile fluid stream is pressurized with proppants, and the volatile LPG stream is pressurized separately. This segmentation ensures that pressurized combustible gas is never in contact with solid particulates or gelling agents during surface operations, reducing hazardous conditions while maintaining delivery speed.
Solution Approach 2:
The system applies different handling conditions to different fluid streams at different locations. The non-volatile stream handles solid particulates and gelling agents under pressure at the surface, while the volatile LPG stream is pressurized and delivered through a separate path. The hazardous mixing only occurs in the controlled downhole environment where local conditions are appropriate for combustion.
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 significantly reduces operational hazards and enhances safety by separating the LPG stream from gelling agents and proppants, allowing for efficient and safe fracturing operations while maintaining the advantages of LPG in achieving high viscosities and miscibility with reservoir fluids, thereby improving hydrocarbon extraction rates.
Implementation Method 1
a static mixing device to prevent hazardous reactions
Implementation Method 2
high-pressure pumps to maintain separation and safety, with blending occurring post-pressurization at pressures greater than 1000 psig
Data Source
AI summary
Improved methods and systems for treating subterranean formations using a sub-surface mixing system are disclosed. The disclosed system includes a well head and a first flow line that directs a blender fluid from a blender to the well head. A second flow line directs a Liquefied Petroleum Gas stream to the well head. A static mixer is positioned downhole and is fluidically coupled to the well head. The well head directs the blender fluid to the static mixer through a first flow path and it directs the Liquefied Petroleum Gas stream from the well head to the static mixer through a second flow path. The static mixer then mixes the blender fluid and the Liquefied Petroleum Gas stream.