Acoustic Isolator Features for Drill Collar Wave Damping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing acoustic measurement systems in oil and gas production are hindered by acoustic waves traveling through drill strings, which distort measurements and overshadow formation arrivals, particularly in high-frequency excitations, making it difficult to determine formation properties accurately.
Innovation Solution
Incorporation of aperiodically spaced isolator features within the drill collar, such as chambers, cavities, or grooves, that are positioned between the outer and inner diameters to dampen collar waves, thereby reducing their amplitude and widening the stop-band to improve data acquisition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acoustic waves are emitted through the drill string for formation measurement, then formation properties can be determined, but collar waves are generated that distort measurements and overshadow formation arrivals
Solution Approach 1:
An isolator component is introduced as an intermediary element between the acoustic source and the drill string collar. This isolator absorbs or dampens the collar waves generated by the acoustic source, preventing them from propagating and interfering with formation arrival measurements, thereby resolving the contradiction between obtaining formation data and avoiding collar wave interference
Solution Approach 2:
The harmful collar wave energy is extracted or removed from the system by the isolator. The isolator specifically targets and removes the unwanted collar wave vibrations that would otherwise contaminate the formation arrival signals, allowing clean formation measurement data to be obtained
2Object-generated harmful factors
If traditional isolator designs are used with features near the bore or outer diameter, then collar wave damping is achieved, but the isolator thickness is increased and manufacturing complexity rises
Solution Approach 1:
The isolator features are positioned in the radial dimension between the bore and outer diameter rather than at the extreme surfaces. This dimensional repositioning allows the features to be embedded within the isolator thickness, reducing the overall isolator thickness requirement while maintaining effective collar wave damping through strategic radial placement
Solution Approach 2:
The isolator features are strategically positioned at specific radial locations between the bore and outer diameter where they can most effectively interact with collar waves. This localized positioning optimizes the damping effect while minimizing the overall isolator thickness and structural 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
The isolator features effectively reduce collar wave interference, allowing for accurate determination of formation properties by minimizing overshadowing and enhancing the accuracy of acoustic data acquisition.
Implementation Method 1
a first isolator feature positioned between the outer housing surface and the outer bore surface, the first isolator feature configured to reduce a collar wave transmitted by the acoustic source
Data Source
AI summary
An isolator for an acoustic logging system includes an outer housing surface, a bore, an outer bore surface, and a first isolator feature positioned between the outer housing surface and the outer bore surface to reduce a collar wave transmitted by the acoustic source.