Marine Electromagnetic Sensor Cable Reversible Wiring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Marine electromagnetic surveying faces challenges in designing a single streamer wiring configuration that can accommodate varying electrode pair spacings, as short spacings are required near the source and longer spacings are needed at greater distances, making it difficult to effectively measure electromagnetic field responses.
Innovation Solution
A marine electromagnetic survey system with sensor cables that utilize reversible wiring and signal processing modules with multipole switches, allowing for selectable electrode spacing and offset, enabling flexible measurement configurations by interconnecting sensor cable segments and synthesizing voltage measurements across selected electrode pairs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If short electrode pair spacing is used near the source, then amplifier saturation is avoided, but measurement capability at long offsets is limited
Solution Approach 1:
The patent implements dynamic electrode pairing through a switching network that can reconfigure which electrodes are paired together. The system transitions from fixed wiring to dynamically selectable electrode pairs, allowing the same physical electrodes to function as both short-spaced and long-spaced pairs depending on the measurement requirements. This resolves the contradiction by making the electrode spacing adaptable rather than static.
Solution Approach 2:
The patent makes each electrode multi-functional by enabling it to participate in multiple different pairings. A single electrode can be paired with different electrodes at different offsets, serving multiple measurement functions. This universal design allows the system to handle both near-offset and far-offset measurements with the same physical hardware, eliminating the need for dedicated short-spaced and long-spaced electrode pairs.
2Measurement precision
If long electrode pair spacing is used at greater distances, then weaker electric potential components can be measured, but amplifier saturation occurs near the source
Solution Approach 1:
The switching network dynamically selects appropriate electrode pairs based on the offset from the source. When measuring near the source, the system activates short-spaced electrode pairs to avoid saturation. When measuring at greater distances, the system switches to long-spaced electrode pairs to detect the weaker signals. This dynamic adaptation prevents amplifier saturation while maintaining measurement precision across all offsets.
Solution Approach 2:
The system changes the spatial parameter (electrode spacing) based on the measurement conditions. By varying which electrodes are paired together, the effective baseline length changes adaptively. Short baselines are used near the source where field strength is high, while long baselines are used at greater distances where field strength is low, optimizing the signal-to-noise ratio and preventing saturation at all ranges.
3Device complexity
If a single streamer wiring configuration is designed, then device complexity is reduced, but flexibility in electrode spacing selection is lost
Solution Approach 1:
The patent segments the streamer into multiple 75-meter modules, each containing a subset of electrodes. The switching network is organized hierarchically, with each module having its own switching capability. This segmentation allows the system to maintain a standardized, manageable wiring structure while still providing flexible electrode pairing options. The modular approach keeps individual module complexity low while achieving system-level versatility through combination of modules.
Solution Approach 2:
The switching network acts as an intermediary between the fixed physical electrode positions and the measurement requirements. Rather than redesigning the physical wiring for different spacing configurations, the switching network provides a logical reconfiguration layer that enables multiple electrode pairing patterns from a single physical wiring arrangement, maintaining simplicity while adding flexibility.
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 configuration provides flexibility in selecting electrode spacing, optimizing measurements for both near and far offsets, simplifying the construction of sensor cables and signal processing modules, and enhancing the ability to detect electric potential components in the electromagnetic field.
Implementation Method 1
measuring one or more parameters related to a response of the subsurface rock formations to the induced electromagnetic field
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A marine electromagnetic sensor cable system includes a first sensor cable subsystem including at least a first sensor cable segment. The first sensor cable segment includes a plurality of spaced apart electrodes which electrically contact a body of water when the first sensor cable segment is immersed therein, and an electrical conductor coupled to each electrode, each electrical conductor extending from one longitudinal end of the sensor cable segment to the other. The system includes a first signal processing module electrically coupled to a longitudinal end of the first sensor cable segment, and including a voltage measuring circuit electrically connected between two or more electrodes from the first plurality of electrodes. Marine electromagnetic surveys are conducted using the marine electromagnetic sensor cable system.