Modified Silica Nanoparticles for Shale Drilling Fluid Plugging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nanometer plugging agents used in drilling fluids for shale gas wells tend to agglomerate, losing their effectiveness due to high surface activity and size issues, failing to adequately plug micro-crevices in shale formations, which leads to well-bore instability and reservoir damage.
Innovation Solution
Modified silicon dioxide nano-particles with a modifying polymer chain composed of specific monomers, which prevents agglomeration and maintains high dispersity, are used as a plugging agent in drilling fluids, ensuring effective plugging of micro-crevices without increasing solid content or damaging the reservoir.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If nanometer plugging agents are added into drilling fluid, then plugging performance is improved, but solid content and sub-micrometer particle content increase causing reservoir damage
Solution Approach 1:
The patent modifies the surface properties of nanometer particles through chemical treatment, changing their surface charge and wettability parameters. This allows the particles to maintain effective plugging performance while reducing their harmful interactions with reservoir rock, thereby preventing reservoir damage despite increased solid content.
Solution Approach 2:
The patent uses composite nanometer particles consisting of core materials coated with functional layers. The core provides the necessary size for plugging micro-crevices, while the functional coating reduces adhesion to reservoir rock and minimizes reservoir damage, thus resolving the contradiction between effective plugging and reservoir protection.
2Reliability
If nanometer plugging agents are added into drilling fluid, then plugging performance is improved, but material agglomerates easily losing nanometer properties
Solution Approach 1:
The patent introduces surface-modifying agents as intermediaries between the nanometer particles and the drilling fluid. These modifiers create a protective interface that prevents particle-aggregate formation while maintaining the nanometer size and plugging effectiveness, thus resolving the agglomeration issue.
Solution Approach 2:
The patent changes the surface electrical charge and hydrophobicity parameters of nanometer particles through chemical modification. This parameter change creates electrostatic repulsion and steric hindrance between particles, preventing agglomeration and maintaining stable dispersion in the drilling fluid while preserving plugging performance.
3Ease of operation
If conventional plugging agents are used, then material is easier to handle, but particle size is too large to plug micro-crevices effectively
Solution Approach 1:
The patent segments conventional large particles into nanometer-sized particles, creating multiple smaller units that can penetrate and plug micro-crevices effectively. The segmentation is achieved through controlled particle size reduction while maintaining material properties that allow easy handling and dispersion in drilling fluid.
Solution Approach 2:
The patent changes the particle size parameter from micrometer to nanometer scale, which fundamentally alters the plugging mechanism to enable effective entry into micro-crevices. Simultaneously, surface modification maintains handling characteristics similar to conventional materials, resolving the contradiction between size requirements and ease of operation.
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
The modified silicon dioxide nano-particles effectively prevent well-bore instability and reservoir damage by maintaining a good plugging effect, improving formation bearing capacity and reducing filter loss, while maintaining high ion compatibility and temperature stability.
Implementation Method 1
the modifying group comprises a modifying polymer chain... prevents agglomeration and maintains high dispersity
Implementation Method 2
one of R1-R5 is -L''-SO3H... high ion compatibility
Implementation Method 3
effective plugging of micro-crevices... can effective plug the beddings and crevices, so that the drilling fluid and its filtrate can't infiltrate into the formation
Implementation Method 4
since the materials added into the drilling fluid have high surface activity, they will absorb a part of drilling fluid adhesives
Data Source
AI summary
The present invention relates to the petroleum drilling fluid field, and discloses a modified silicon dioxide nano-particle comprising a modifying polymer chain composed of structural units provided by one or more of monomers represented by the following formula (1) and one or more of monomers represented by the following formula (2). The present invention provides a method for preparing modified silicon dioxide nano-particles and a drilling fluid suitable for shale gas wells containing the modified silicon dioxide nano-particles as a plugging agent. When the modified silicon dioxide nano-particles provided in the present invention are used as a plugging agent in a drilling fluid, they will not agglomerate into large-size particles, and can achieve a good plugging effect.