Fracturing Fluid Wettability Control for Tight Formation Recovery
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Solution Overview
Problem
Liquid hydrocarbon recovery from tight formations is typically less than 10% of the original amount due to hydrocarbons being attached to mineral surfaces, making it difficult to extract using traditional methods, as these formations are not easily waterflooded due to low permeability.
Innovation Solution
The method involves modifying the chemistry of fracturing fluids and overflushes to increase water wettability of rock surfaces by altering pH, salinity, and hardness, allowing for real-time measurement and adjustment to maximize hydrocarbon recovery, and utilizing low-value saline waters for fracturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional waterflooding methods are used in tight formations, then the process is simple and easy to implement, but liquid hydrocarbon recovery remains less than 10% due to hydrocarbons being attached to mineral surfaces
Solution Approach 1:
The patent modifies chemical parameters of fracturing fluids including pH (adjusting to alkaline conditions), salinity (using low-value saline waters), and hardness to alter rock surface wettability from oil-wet to water-wet, thereby enabling hydrocarbon detachment and recovery
Solution Approach 2:
The patent uses modified fracturing fluids as intermediaries that contain chemicals capable of breaking the attachment between hydrocarbons and mineral surfaces, facilitating the transfer of hydrocarbons from the formation to the produced fluid
2Productivity
If water wettability of rock surfaces is increased through chemistry modification, then liquid hydrocarbon recovery is enhanced by breaking chemical bonds, but the complexity of determining optimal chemistry increases
Solution Approach 1:
The patent implements a feedback mechanism where real-time measurement of flowback volume and composition provides information about in situ wettability, which is then used to adjust the chemistry of subsequent injectates to optimize recovery
Solution Approach 2:
The patent replaces direct mechanical measurement of wettability with indirect measurement through flowback analysis, using chemical and volumetric data to infer wettability conditions without requiring direct subsurface measurement tools
3Ease of manufacture
If low-value saline waters are used for fracturing, then cost is reduced and resource utilization is improved, but the challenge of removing chemical attachments between hydrocarbons and rock surfaces remains
Solution Approach 1:
The patent specifically adjusts the pH of saline waters to alkaline conditions and modifies hardness parameters to create chemical environments that reduce the strength of attachment between hydrocarbons and mineral surfaces, enabling effective recovery despite using low-value waters
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 enhances liquid hydrocarbon recovery by breaking chemical bonds, increasing water wettability, and optimizing injectate chemistry, potentially increasing recovery by 53% compared to traditional methods.
Implementation Method 1
modifying the chemistry of fracturing fluids and overflushes to increase water wettability of rock surfaces by altering pH, salinity, and hardness
Implementation Method 2
break the chemical bonds that hold liquid hydrocarbons to reservoir surfaces
Data Source
AI summary
A method of increasing recovery of liquid hydrocarbons from subsurface reservoirs, and particularly from those located in tight formations, is disclosed. One aspect includes calculating the in situ fractured formation wettability from real-time measurement of flowback volume and composition. Another aspect includes determining the composition of the fracturing fluid, the overflush or both, that will achieve higher liquid hydrocarbon recovery by increasing the water wettability of rock surfaces within the reservoir. Monitoring of rock-surface wettability through flowback volume and composition profiles allows the above mentioned injectates to be adjusted in the field to achieve maximal recovery. Other methods, apparatuses, and systems are disclosed.