Downhole Pressure Pulse Tools for Uniform Acid Stimulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Optimal acid stimulation in wellbores is challenging due to uneven acid distribution caused by formation heterogeneity, with acid tending to flow through higher permeability zones, leaving lower permeability zones unswept, and existing pressure pulse devices produce asymmetric pulses with insufficient power for efficient acid permeation.
Innovation Solution
The use of systems and methods involving downhole devices like rotary jet tools and fluidic oscillator tools to deliver periodic streams of fluid, with real-time monitoring and adjustment of pressure pulses based on reflected energy pulses to optimize acid permeation, ensuring uniform distribution across the wellbore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If acid is sprayed at high pressure to permeate formations, then acid can penetrate damaged zones, but formation heterogeneity leads to uneven distribution with acid flowing only through higher permeability zones
Solution Approach 1:
The patent applies periodic pressure pulses instead of continuous high-pressure spraying. The downhole device delivers periodic streams of fluid at different pressures, creating oscillating pressure waves that propagate through the formation. This periodic action allows acid to penetrate both high and low permeability zones by exploiting pressure differentials that change over time, achieving more uniform distribution while maintaining effective permeation.
Solution Approach 2:
The system dynamically adjusts pressure parameters in real-time based on formation response. The downhole device modifies pressure characteristics (amplitude, frequency, duration) of the periodic streams according to actual formation conditions, allowing adaptive optimization of acid distribution across heterogeneous zones rather than using fixed high-pressure parameters.
2Productivity
If commercial pulse devices are used to create pressure pulses, then acid flow into formation is improved, but the asymmetric pulses with sharp increase and slow decrease provide insufficient power for efficient permeation
Solution Approach 1:
The patent deliberately creates asymmetric pressure pulses but with reversed characteristics from commercial devices. Instead of sharp increase followed by slow decrease, the system generates pulses with rapid pressure drop and slower rise, or adjusts the asymmetry to optimize power delivery. This reversed asymmetry pattern concentrates energy more effectively during the permeation phase, providing sufficient power for efficient acid penetration into the formation.
3Adaptability or versatility
If real-time monitoring of pressure pulses is implemented, then pressure rate changes can optimize acid stimulation, but determining optimal pressure at each wellbore position remains challenging
Solution Approach 1:
The system implements real-time feedback by monitoring pressure pulse characteristics as they interact with the formation. Sensors detect reflected or transmitted pressure wave properties, and this information feeds back to the downhole device which automatically adjusts subsequent pulse parameters. This closed-loop feedback mechanism enables real-time optimization of acid stimulation without requiring complex manual intervention or predetermined pressure schedules.
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 enables uniform acid permeation across the wellbore by adjusting pressure pulses in real-time, effectively addressing the issue of uneven distribution and enhancing acid stimulation by utilizing tools like the EasyReach Extended-Reach Tool and Roto-Jet jetting tool.
Implementation Method 1
deliver a periodic stream of fluid... modifying a pressure of the periodic stream of fluid
Implementation Method 2
at least one sensor configured to detect reflected energy pulses associated with the periodic stream of fluid
Implementation Method 3
the fluidic oscillator tool comprises a Coanda-effect oscillator device
Data Source
AI summary
A wellbore system may include a work string and at least one downhole device connected to a portion of the work string, the downhole device configured to deliver a periodic stream of fluid to a portion of a wellbore. The system may further include at least one sensor configured to detect reflected energy pulses associated with the periodic stream of fluid. The at least one downhole device may be configured to modify a pressure of the periodic stream of fluid in real time based on the reflected energy pulses received in real time.