Radial Acid Flow Modeling for Subterranean Well Stimulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current acid stimulation modeling techniques are inaccurate due to the lack of consideration for radial acid flow, leading to potentially suboptimal injection rates and inefficient wormhole formation in hydrocarbon well stimulation.
Innovation Solution
Generating radial breakthrough curves that account for radial flow patterns, allowing for the selection of optimal acid types and pumping schedules based on wormhole development efficiency and cost, and real-time monitoring of acidizing treatments in subterranean wells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If linear PVBT curves are used for acid stimulation modeling, then the modeling process is simple, but the accuracy of injection rate assessment is poor
Solution Approach 1:
The patent transforms the linear PVBT curve parameters into radial PVBT curve parameters by incorporating radial flow considerations. This involves changing the mathematical model from linear to radial coordinates, adjusting the breakthrough pressure calculations to account for radial dispersion, and modifying the injection rate relationships to reflect spherical flow patterns rather than linear flow assumptions.
Solution Approach 2:
The patent transitions from one-dimensional linear flow modeling to three-dimensional radial flow modeling. By introducing radial coordinates and spherical flow geometry, the model captures the actual dispersion patterns of acid injection in the formation, accounting for flow in multiple directions from the wellbore outward through the formation matrix.
2Measurement precision
If radial PVBT curves are generated to account for radial flow, then the accuracy of acid stimulation design is improved, but the modeling complexity increases
Solution Approach 1:
The patent creates a mathematical copy of the linear PVBT curve model and adapts it to radial coordinates. Rather than developing an entirely new complex model, the existing linear model structure is replicated and transformed using radial flow equations, preserving the familiar methodology while improving accuracy through coordinate transformation and radial flow physics integration.
Solution Approach 2:
The patent replaces the simplified linear mechanical flow assumptions with radial flow mathematical relationships. By substituting the linear Darcy flow equations with radial flow equations that account for spherical dispersion patterns, the model achieves greater physical realism while maintaining a systematic approach to calculation and analysis.
3Ease of manufacture
If optimal injection rate is determined using linear modeling, then the process is cost-effective, but the wormhole formation efficiency may be suboptimal
Solution Approach 1:
The patent incorporates feedback mechanisms by using the radial PVBT curve model to predict breakthrough pressure and wormhole formation characteristics more accurately. This improved prediction capability provides feedback on the actual acid-rock interaction and flow patterns, allowing operators to optimize injection rates based on realistic expectations of wormhole development rather than oversimplified linear model predictions.
Solution Approach 2:
The patent performs preliminary radial flow modeling and breakthrough pressure calculations before actual acid injection. By pre-calculating the expected flow patterns, pressure distribution, and wormhole formation characteristics using the radial PVBT model, operators can determine optimal injection rates in advance, avoiding the need for expensive trial-and-error field testing while ensuring efficient wormhole development from the start of the treatment.
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 the accuracy of acid stimulation designs by accounting for radial flow, optimizing injection rates, and improving hydrocarbon production by forming effective wormholes, thereby increasing the efficiency and cost-effectiveness of acidizing treatments.
Implementation Method 1
the injected fluid may extend the effective wellbore drainage radius by dissolving formation rock to form channels such as wormholes
Data Source
AI summary
Matrix acidizing treatment are designed and performed in a manner that takes into account radial acid flow into the formation. Subterranean well characteristics are determined (e.g., mineralogical and petrophysical characteristics). One of more candidate acids is selected. A linear pore volume of acid to breakthrough (PVBT) curve is generated for each candidate acid. The linear PVBT curves are modified to account for radial acid flow. The optimal acid is selected by considering wormhole development and cost. An initial acid pumping schedule is generated for the formation to be acidized, including the optimal acid, the treatment volume and the injection rate. Computer software is used to consider the subterranean well characteristics, simulate the initial acid pumping schedule and compare results with the radial PVBT curve. The initial schedule is modified until the results are consistent with the radial PVBT curve. An acidizing treatment is then performed.