Seabed Node Gradient Positioning for 4D Seismic Surveys
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current reflection seismology methods face challenges in accurately processing and interpreting seismic data to determine subsurface rock properties, particularly in offshore environments, due to limitations in data acquisition and processing techniques, which affect the precision of subsurface feature identification and characterization.
Innovation Solution
A system and method that utilize a network of seabed nodes equipped with seismic sensors and hydrophones, capable of acquiring and processing seismic data, including gradient measurements, to generate accurate seismic attributes and models of subsurface formations, leveraging advanced frameworks like PETREL and OCEAN@ for data interpretation and simulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If gradient sensors are deployed on seabed nodes to measure wavefield gradients, then measurement precision of seismic data is improved, but device complexity increases due to additional sensor requirements and data processing needs
Solution Approach 1:
The patent combines multiple sensor types (hydrophones for pressure measurement and accelerometers for particle velocity measurement) into a single integrated seabed node. This merging allows the system to measure both pressure wavefield components and gradient components using one unified device, thereby improving measurement precision while managing device complexity through integration rather than separate deployed units
Solution Approach 2:
The seabed node is designed as a multi-functional unit that simultaneously performs pressure measurement, particle velocity measurement, and gradient measurement. The node serves multiple purposes: it acts as both a traditional pressure sensor station and a gradient sensor station, eliminating the need for separate specialized devices and reducing overall system complexity while maintaining high measurement precision across all parameters
2Measurement precision
If 4D seismic surveys are conducted with repeated acquisitions over time, then subsurface feature characterization is improved, but loss of time and operational costs increase
Solution Approach 1:
The patent implements preliminary positioning of seabed nodes at precise locations before the main seismic acquisition. By pre-deploying the sensor network in the desired configuration and using gradient measurements to accurately determine node positions, the system eliminates time-consuming post-acquisition positioning corrections and enables faster repeated surveys for 4D monitoring while maintaining high characterization accuracy
Solution Approach 2:
The patent replaces traditional mechanical positioning methods (such as GPS or acoustic positioning systems requiring complex hardware) with a gradient-based positioning approach. By using the measured wavefield gradients to infer node positions through mathematical relationships, the system substitutes complex mechanical positioning infrastructure with computational methods, thereby reducing acquisition time and operational complexity for repeated 4D surveys
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
Enhances the accuracy and efficiency of subsurface feature identification and characterization by providing detailed seismic data processing and interpretation, enabling better management of geologic environments for drilling, injecting, and extracting resources, while reducing operational costs and improving data repeatability in 4D seismic surveys.
Implementation Method 1
Reflection seismology may provide seismic data representing waves of elastic energy as transmitted by P-waves and S-waves
Implementation Method 2
The seabed nodes can include a hydrophone and an accelerometer, the hydrophone being spaced from the accelerometer
Implementation Method 3
a gradient of the pressure wavefield sensed by the spaced seismic sensors
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A method includes receiving desired locations of nodes for deployment on a seabed of a seismic survey where each of the nodes includes a sealed housing and, within the sealed housing, at least one battery and spaced seismic sensors electrically powered by the at least one battery; determining locations of the nodes as deployed on the seabed where at least some of the determined locations differ from their corresponding desired locations; acquiring seismic data sensed by the spaced seismic sensors of the nodes where the acquired seismic data corresponds to the determined locations; and, based at least in part on the acquired seismic data, a spacing of the spaced seismic sensors and the desired locations, generating seismic data for the desired locations.