Micro-proppants for Far-field Fracture Stimulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hydraulic fracturing methods in unconventional wells fail to effectively stimulate small fractures in tight formations due to the inability of standard proppants to reach and maintain the far-field fractures, leading to rapid production decline.
Innovation Solution
The use of fracturing fluids containing a mixture of micro and macro proppants, with microproppants ranging from 0.5 micrometers to 150 micrometers in diameter and macroproppants of 100 mesh or greater, pumped throughout the fracturing process to stimulate and maintain the fracture network, including the use of degradable particles to enhance transport and prevent settling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If standard proppants (100 mesh or larger) are used in hydraulic fracturing, then the main fracture can be effectively propped open, but the proppants cannot reach or effectively stimulate the small far-field fractures due to their large size and high density
Solution Approach 1:
The proppant population is segmented into multiple size classes including fine proppants (100-200 mesh), medium proppants (40-70 mesh), and coarse proppants (20-40 mesh). This segmentation allows different proppant sizes to target different fracture types: fine proppants reach and prop the small far-field fractures, while larger proppants maintain the main fracture conductivity.
Solution Approach 2:
Different proppant sizes are distributed to different locations within the fracture network based on local requirements. Fine proppants are transported further to reach small far-field fractures where they are needed, while larger proppants remain in the main fracture where higher conductivity is required. This creates a gradient distribution that optimizes stimulation across the entire reservoir volume.
2Length of moving object
If the viscosity of fracturing fluid is increased to transport proppants further, then proppant carryover to far-field fractures improves, but the fracture width increases excessively and polymer residues damage the formation
Solution Approach 1:
The fluid system uses variable viscosity achieved through hydrocolloid additives rather than high-concentration polymer gels. The hydrocolloids provide moderate viscosity enhancement sufficient to carry fine proppants to far-field fractures without creating excessive fracture width or leaving harmful residues. This parameter change allows adequate proppant transport while avoiding formation damage.
3Productivity
If high pump rates are used to pump fracturing fluid with proppants, then proppant placement in fractures improves, but the cost and complexity of the operation increases
Solution Approach 1:
The use of hydrocolloid additives modifies the fluid rheology to achieve optimal viscosity for proppant suspension and transport at moderate pump rates. This parameter change in fluid properties allows effective proppant placement without requiring excessively high pump rates, thereby reducing operational complexity and cost while maintaining placement efficiency.
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 allows for the effective stimulation and propping open of small fractures, significantly reducing production decline by ensuring that 90% of the stimulated reservoir volume is maintained, as microproppants can reach and sustain the induced and natural fractures in the far-field.
Implementation Method 1
micro-proppants for use in a low viscosity fracturing fluid... the density of the proppants and low viscosity of the fluid... most of the proppants will settle before they can be placed in these far field fractures
Implementation Method 2
Hydraulic fracturing is used to produce oil and gas from unconventional, tight formations by increasing the fracture surface area and total stimulated reservoir volume (SRV)
Implementation Method 3
The proppant then keeps the fracture open, allowing the oil or gas to escape the formation
Data Source
AI summary
A method of stimulating petroleum production includes introducing a fracturing fluid into a petroleum formation, thereby creating at least one fracture to stimulate the petroleum production. The fracturing fluid is introduced into the petroleum formation at a pressure above the breakdown pressure of the formation. The fracturing fluid includes a plurality of proppants each including a proppant particle and a coating. The coating includes a hydrophobic coating, a cross-linked hydrogel, or both. From 1 to 50 wt. % of the plurality of proppants includes micro proppants having a particle size ranging from 0.5 to 150 μm, and from 50 to 99 wt. % of the plurality of proppants includes macro proppants having a particle size of 100 mesh or greater.