Removal of diurnal tidal effects from an ultra‐high‐resolution 3-D marine seismic survey on the continental shelf offshore New Jersey

Geophysics ◽  
1998 ◽  
Vol 63 (3) ◽  
pp. 1036-1040 ◽  
Author(s):  
Eddy C. Luhurbudi ◽  
Jay Pulliam ◽  
James A. Austin ◽  
Steffen Saustrup ◽  
Paul L. Stoffa
Keyword(s):  
New Jersey ◽  
High Resolution ◽  
Single Channel ◽  
Late Quaternary ◽  
Seismic Survey ◽  
Spatial Density ◽  
Naval Research ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Office Of Naval Research

An ultra‐high‐resolution 3-D, single‐channel seismic survey was performed off the coast of New Jersey in 1993 to study the late Quaternary history of sedimentation on the northwest Atlantic continental margin (see Davies et al., 1992) as a part of the Office of Naval Research STRATAFORM initiative (Nittrouer and Kravitz, 1995). Three different sets of profiles were acquired (Figure 1), but only the set with highest spatial density is discussed here. A single ten‐element receiver recorded 300 ms of data for every shot during the survey, which covers a total area of 0.6 km (north‐south) × 7.75 km (east‐west) (see Table 1). The deep‐towed Huntec™ source (deployed at ∼30 m depth) produced frequencies of 500 to 3500 Hz; a band‐pass filter with corner frequencies at 1000 and 3500 Hz was applied during preprocessing.

Single-channel high-transmission optical band-pass filter based on plasmonic nanocavities

2020 ◽  
Vol 37 (8) ◽  
pp. 2329
Author(s):  
Masoud Mardani Najafabadi ◽  
Samane Vahidi ◽  
Hassan Ghafoorifard ◽  
Mahsa Valizadeh
Keyword(s):  
Single Channel ◽  
Band Pass Filter ◽  
Pass Filter ◽  
High Transmission ◽  
Band Pass

PC‐based acquisition and processing of high‐resolution marine seismic data

Geophysics ◽  
1996 ◽  
Vol 61 (6) ◽  
pp. 1804-1812 ◽  
Author(s):  
Ho‐Young Lee ◽  
Byung‐Koo Hyun ◽  
Young‐Sae Kong
Keyword(s):  
High Resolution ◽  
Seismic Data ◽  
Spectral Characteristics ◽  
Processing System ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Optical Disk Drive ◽  
Air Gun ◽  
Marine Seismic

We have improved the quality of high‐resolution marine seismic data using a simple PC‐based acquisition and processing system. The system consists of a PC, an A/D converter, and a magneto‐optical disk drive. The system has been designed to acquire single‐channel data at up to 60,000 samples per second and to perform data processing of seismic data by a simple procedure. Test surveys have been carried out off Pohang, southern East Sea of Korea. The seismic systems used for the test were an air gun and a 3.5 kHz sub‐bottom profiling system. Spectral characteristics of the sources were analyzed. Simple digital signal processes which include gain recovery, deconvolution, band‐pass filter, and swell filter were performed. The quality of seismic sections produced by the system is greatly enhanced in comparison to analog sections. The PC‐based system for acquisition and processing of high‐resolution marine seismic data is economical and versatile.

A comparative study of multi-scaled high-resolution seismic surveys in shallow marine environments: examples from three sites, offshore Korea

2020 ◽  
Author(s):  
Young Jun Kim ◽  
Snons Cheong ◽  
Deniz Cukur ◽  
Dong-Geun Yoo
Keyword(s):  
High Resolution ◽  
Data Processing ◽  
Seismic Data ◽  
Single Channel ◽  
Seismic Source ◽  
Seismic Survey ◽  
Minimum Length ◽  
Seismic Surveys ◽  
Air Gun ◽  
Target Depth

<p>In marine seismic surveys, various acquisition systems are used depending on the survey purpose, target depth, survey environment, and conditions. A 3D survey of oil and/or gas exploration, for instance, require large-capacity air-gun arrays and six or more streamers with a minimum length of 6 km. In contrast, a high-resolution seismic survey for the shallow-water geological research and engineering needs a small capacity source such as air-gun, sparker, and boomer, deployed with a single-channel or multi-channel (24-channel) streamers. The main purpose of our seismic survey was to investigate the Quaternary geology and stratigraphy of offshore, Korea. Because the Quaternary is the most recent geological period, our target depth was very shallow at about 50 m below the sea-bottom. We used a high-frequency seismic source including a sparker of 2,000 J capacity or a 60 in<sup>3</sup> mini GI-gun and an eight-channel streamer with a 3.125 m group interval or a single-channel streamer that included 96 elements. To compare the resolution of seismic data according to the seismic source, a boomer or sparker systems were used with the single-channel streamer on a small survey ship. The seismic data processing was performed at the Korea Institute of Geoscience and Mineral Resources (KIGAM) with ProMAX, and the data processing and resolution of each survey were compared based on their acquisition systems.</p>

Foraminiferal Constraints on Very High-Resolution Seismic Stratigraphy and Late Quaternary Glacial History, New Jersey Continental Shelf

Palaios ◽  
1997 ◽  
Vol 12 (3) ◽  
pp. 249 ◽  
Author(s):  
Martin B. Lagoe ◽  
Thomas A. Davies ◽  
James A. Austin ◽  
Hilary C. Olson
Keyword(s):  
New Jersey ◽  
High Resolution ◽  
Continental Shelf ◽  
Late Quaternary ◽  
Seismic Stratigraphy ◽  
Glacial History ◽  
Very High

Analysis of Vertical Velocities Development through High-resolution Simulation and Glider Observations in the Alboran Sea

2021 ◽  
Author(s):  
Maximo Garcia-Jove ◽  
Baptiste Mourre ◽  
Nikolaos Zarokanellos ◽  
Pierre F. J. Lermusiaux ◽  
Daniel L. Rudnick ◽  
...  
Keyword(s):  
High Resolution ◽  
Three Dimensional ◽  
Naval Research ◽  
Alboran Sea ◽  
Surface Ocean ◽  
Office Of Naval Research ◽  
Research Initiative ◽  
Spatio Temporal ◽  
Alborán Sea ◽  
Resolution Simulation

<p>Vertical velocities associated with meso- and submeso-scale structures generate important vertical fluxes of carbon and other biogeochemical tracers from the surface layer to depths below the mixed layer. Vertical velocities are very weak and characterized by small scales which make them difficult to measure. The project entitled Coherent Lagrangian Pathways from the Surface Ocean to Interior (CALYPSO, Office of Naval Research initiative) addresses the challenge of observing, understanding, and predicting the vertical velocities and three-dimensional pathways on subduction processes in the frontal regions of the Alboran Sea. Within the framework of the CALYPSO project, we analysed the processes that give rise to vertical velocities in the Western Alboran Gyre Front (WAGF) and Eastern Alboran Gyre Front (EAGF). The periods of frontal intensification were analyzed in the perspective of the frontogenesis, instabilities, non-linear Ekman effects, and filamentogenesis using multi-platform in-situ observations and a high-resolution simulation in spring 2018. The spatio-temporal characteristics of the WAGF indicate a wider, deeper, and longer-lasting front than the EAGF. The WAGF intensification and vertical velocities development are explained through i) frontogenesis, ii) conditions for symmetric and ageostrophic baroclinic instabilities generation, and iii) nonlinear Ekman effects. These mechanisms participate to generate and strengthen an ageostrophic secondary circulation responsible for vertical velocities intensification in the front. In the case of the EAGF, the intensification and vertical velocities development are explained by filamentogenesis in both the model and glider observations. The EAGF intensification is characterized by a sharp and outcropping density gradient at the center of the filament, where two asymmetrical ageostrophic cells develop across the front with narrow upwelling region in the middle.</p>

A NEW PSEUDO-VELOCITY-BASED METHOD TO MITIGATE LWD IMAGE INTERPRETATION RISKS

2021 ◽  
Author(s):  
Tianhua Zhang ◽  
◽  
Shiduo Yang ◽  
Chandramani Shrivastava ◽  
Nadege Bize-Forest ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Image Interpretation ◽  
Image Feature ◽  
Depth Image ◽  
Band Pass Filter ◽  
Slip Effect ◽  
Pass Filter ◽  
Time Motion ◽  
Drilling Time

Borehole Imaging technology is often key for reservoir characterization and becomes more relevant when images are acquired while drilling to capture reservoir geology and petrophysical property distributions around the borehole. Logging While Drilling (LWD) high-resolution electrical/acoustics images of the borehole can resolve formation layers and heterogeneity down to 5mm (0.2in) scale and can detect response from far smaller features. This allows both, improved operational efficiency and better-informed drilling as well as shortening of the geological interpretation turn-around time from wireline logging time (days after drilling) to semi-real time (drilling time or hours after drilling). LWD high resolution images often suffer from the lack of direct downhole velocity measurements against the sensors. Depth tracking is on surface, referenced to the surface block movement. The imaging sensor acquiring data can be thousands of feet away from this surface reference. Imaging sensors on the bottom-hole assembly (BHA) are located not too far away from the drill bit. They are also subject to complex drilling-time motion such as tool whirling, stick and slip, vibration, mode coupling etc. This can make the downhole sensor movement dis-synchronized with the surface pipe depth increment. The Time-Depth conversion may accordingly get dis-synchronized to generate LWD depth image with missing features and distorted feature-integrity in depth. In severe conditions distorted image impacts real time image feature interpretation and leads to increased interpretation uncertainties. In this paper we investigate two main dis-synchronization problems using synthetic data: heave effect and BHA stick and slip effect. Pseudo velocity is computed from the surface measurement due to the lack of downhole sensor velocity direct measurement. In order to minimize heave effect, an advanced band-pass filter is proposed. The filter order is chosen in consistency with the sensor’s pseudo velocity behavior. Other properties of this advanced filter are also presented. In order to minimize the BHA stick and slip effect, pseudo velocity is analyzed as a delayed and minimized representative of the downhole sensor movement. A windowed-thresholding method is proposed to restore the compressed and stretched image features. Dip error analysis is performed by picking bed and fracture surface on the synthetic image data, before and after image distortion correction. The analysis results show a non-negligible effect on the accuracy of the true dip computed if the distortions are left un-corrected. Even in favorable logging conditions, the apparent dip error can contribute up to 50% of the total error. In this case, the image post-processing method proposed in this paper can not only improve the image quality but also reduce image interpretation uncertainties.

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