Proppant Transport Simulation with Wall-Retardation Drag Model
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing numerical simulation methods for proppant transport in hydraulic fracturing ignore the wall-retardation effect, leading to inaccuracies in predicting proppant migration and placement patterns, which affects the design and effectiveness of hydraulic fracturing in unconventional oil and gas reservoirs.
Innovation Solution
A numerical simulation method is developed that includes a drag coefficient model considering wall-retardation effects, using a physical model of a large flat-panel device, computational geometric modeling, and a two-fluid simulation method to simulate proppant transport in narrow fractures, ensuring grid independence and accurate prediction of transport characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing numerical simulation methods are used for proppant transport, then the simulation can be performed with standard models, but the prediction accuracy of proppant migration and placement patterns is reduced due to ignoring wall-retardation effect
Solution Approach 1:
The patent applies local quality by introducing a wall-retardation effect coefficient that varies with particle position relative to the fracture wall. Particles near the wall experience different drag forces compared to particles in the center, and this spatially varying coefficient captures the local flow conditions accurately without requiring complex geometry modifications throughout the entire simulation domain.
Solution Approach 2:
The patent modifies the drag coefficient parameter by introducing a wall-retardation effect coefficient that adjusts the drag force based on particle proximity to the wall. This parameter change allows the simulation to account for wall effects without fundamentally changing the simulation framework or requiring completely new mathematical models.
2Measurement precision
If physical simulation experiments are conducted to study wall-retardation effect, then detailed experimental data can be obtained, but the scale, cost and operation conditions are limited
Solution Approach 1:
The patent creates a virtual copy of the physical experiment through numerical simulation. By replicating the essential physics of proppant transport in narrow fractures with the wall-retardation effect coefficient, the simulation provides an accessible model that preserves the key experimental findings while eliminating the limitations of physical experiments.
Solution Approach 2:
The patent replaces the physical mechanical experiment system with a numerical simulation system. This substitution allows researchers to study wall-retardation effects under various conditions without being constrained by the scale, cost, and operational limitations of physical laboratory experiments.
3Device complexity
If wall-retardation effect is ignored in numerical simulation, then the simulation model is simpler, but the understanding of proppant migration laws and placement patterns becomes inaccurate
Solution Approach 1:
The patent introduces a wall-retardation effect coefficient as an additional parameter in the drag force calculation. This parameter change allows the model to account for wall effects while maintaining the overall structure and simplicity of the numerical simulation framework, thus improving reliability without excessive complexity.
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 method reliably predicts proppant migration and distribution patterns, providing accurate guidance for hydraulic fracturing design and effectiveness in unconventional oil and gas reservoirs by accounting for the wall-retardation effect on proppant transport.
Implementation Method 1
the horizontal velocity of the particles near the wall is significantly lower than that of the particles gradually approaching the center of the fracture width, which is due to the increased drag of the particles near the wall
Implementation Method 2
The migration and settlement of proppant in fractures with sand-carrying fluid is related to dense liquid-solid flow in narrow space
Implementation Method 3
the horizontal velocity of the particles near the wall is significantly lower than that of the particles gradually approaching the center of the fracture width, which is due to the increased drag of the particles near the wall and the slow settling in the longitudinal direction
Data Source
AI summary
The present invention discloses a numerical simulation method for proppant transport considering wall-retardation effect, comprising the followings: establish a physical model of laboratory experiment on proppant transport with a large flat-panel device; establish a drag coefficient model considering wall-retardation effect according to the numerical simulation experiment; establish a computational geometric model; set boundary conditions and physical parameters of the geometric model according to the two-fluid simulation method for solid proppant quasi-fluidization; verify the grid independence of the computational geometric model to obtain the transport characteristics and placement pattern of the proppant in fractures. The present invention employs a numerical simulation method to study the migration and distribution patterns of proppant under the retardation effect of narrow walls during the hydraulic fracturing. The method is reliable in principle and can accurately predict proppant transport in subsurface hydraulic fractures with consideration of the wall-retardation effect on proppant transport.