Tube Wave Acoustic Analysis for Well Interval Refracturing
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Solution Overview
Problem
Current refracturing methods in hydraulically fractured wells are costly and lack precise identification of depleted intervals, leading to inefficient hydrocarbon production and potential unnecessary treatments due to limited knowledge of fracture systems.
Innovation Solution
A method involving tube wave acoustic analysis to hydraulically isolate intervals in wells, detect reflections, determine hydraulic boundary conditions and conductivity, and perform refracture treatments only when within predetermined ranges, optimizing treatment parameters and reducing costs by targeting specific intervals for stimulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If refracturing treatments are performed on all intervals without precise identification, then treatment coverage is maximized, but costs increase and unnecessary treatments are performed
Solution Approach 1:
The patent replaces complex downhole evaluation tools and mechanical measurement systems with acoustic wave-based evaluation. By inducing tube waves and analyzing reflections, the system determines fracture conductivity and boundary conditions without requiring physical downhole tools, thereby reducing evaluation time and cost while maintaining precision.
Solution Approach 2:
The wellbore itself serves as the measurement medium. The acoustic waves propagate through the existing well structure and fracture systems, using the wellbore's own acoustic properties to provide evaluation data. This eliminates the need for separate evaluation tools and reduces intervention time.
2Measurement precision
If downhole tools are used to analyze near-wellbore regions, then measurement accuracy improves, but operational complexity and risk increase
Solution Approach 1:
The patent substitutes mechanical downhole evaluation tools with an acoustic wave-based system. Tube waves are induced in the wellbore and reflections are detected to determine fracture properties, eliminating the need for complex downhole tool deployment while maintaining measurement accuracy.
Solution Approach 2:
The acoustic evaluation system serves multiple functions: it characterizes fracture conductivity, identifies depleted intervals, and assesses refracturing candidates all through a single non-invasive measurement process, replacing multiple specialized downhole tools.
3Reliability
If permanent packers and fracture sleeves are installed for refracturing, then interval isolation is achieved, but future accessibility and well flexibility are reduced
Solution Approach 1:
The patent performs acoustic evaluation and identifies refracturing candidates before committing to permanent isolation devices. This preliminary characterization allows operators to plan future treatments more effectively and avoid unnecessary permanent installations, preserving well flexibility.
Solution Approach 2:
The acoustic evaluation provides feedback on fracture conductivity and interval conditions, enabling operators to make informed decisions about whether refracturing is needed. This feedback mechanism reduces the need for permanent isolation devices by allowing targeted, temporary treatments only where necessary.
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 targeting and optimization of refracturing treatments, reducing costs and improving hydrocarbon production by accurately identifying suitable intervals for stimulation, thereby extending well production life and reducing unnecessary treatments.
Implementation Method 1
A tube wave is induced in the first well in the isolated interval. Reflections are detected from the induced tube wave.
Data Source
AI summary
A method for treating a well includes hydraulically isolating an interval in a first well having a plurality of intervals along the first well, each interval having been fracture treated. A tube wave is induced in the first well in the isolated interval. Reflections are detected from the induced tube wave. Hydraulic boundary condition and hydraulic conductivity of a fracture connected to the first well in the isolated interval are determined using the detected reflections. A refracture treatment is performed in the isolated interval when the hydraulic boundary condition and the hydraulic conductivity are within a predetermine range.