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SUB BOTTOM PROFILERS (SBP) BENTOS – Servicios y Equipos Marinos Ltda. Avda. Suecia 3005, Ñuñoa, Santiago Telephone: (56 2) 296 373 60 Fax: (56 2) 296 373 77 E-mail: [email protected]

SUB BOTTOM PROFILERS (SBP) - Bentos

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Page 1: SUB BOTTOM PROFILERS (SBP) - Bentos

SUB BOTTOM PROFILERS (SBP)

BENTOS – Servicios y Equipos Marinos Ltda.

Avda. Suecia 3005, Ñuñoa, Santiago Telephone: (56 2) 296 373 60 Fax: (56 2) 296 373 77 E-mail: [email protected]

Page 2: SUB BOTTOM PROFILERS (SBP) - Bentos

A SUB BOTTOM PROFILER (SBP), WHAT IT IS

The seismic profiler consists of a geophysical exploration system based on the seismic principles of vertical reflection and the use of an acoustic wave generating seismic source and one or more receivers of the reflected signal. The SBP obtains recordings of the low frequency acoustic signal reflected by the marine subsoil, thereby enabling the discernment of the interfaces of the different layers or horizons of subsoil materials. Different wave generation and signal processing systems are used depending on the required penetration of the marine sub bottom, bandwidth of operation, spectral resolution and geometry, as well as the absorption of the signal by the aquatic medium and sub bottom being explored.

When viewed in terms of the differentiation of the existing types of profiler systems according to the different seismic sources and signal receivers used: The pinger type marine subsoil profilers use ceramic transducers and make it possible to obtain high resolutions with a small amount of output power, achieved by means of the modulation of the signal with CHIRP type signal emitters. The boomer type sources, which are of greater signal power, use electronic condensers to discharge high voltage electricity through a coil that contracts to produce the mechanical wave source. The plasma arc source systems, or sparkers, produce a front of waves of very low frequency by means of the discharge of a voltaic arc. The signal receiver systems, in case of ceramic sources, can be incorporated in the same ceramic transducer emitter array. For boomer or sparker type sources, an array of hydrophones is distributed to receive the signal reflected by the marine sub bottom.

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Page 3: SUB BOTTOM PROFILERS (SBP) - Bentos

THE BOOMER TYPE SBP SYSTEM, HOW IT FUNCTIONS

The general principle of functioning of the boomer type SBP system features the emission of sound waves through the boomer plate toward the marine bottom at a characteristic frequency,, with these waves then striking the existing interfaces (water-sediment, sediment-rock and between sediments of different acoustic properties), thereby generating the reflection of the waves back toward the surface at sea level where they are received by a streamer receiver. Unlike the pinger type SBP, the boomer type SBP system requires the deployment of a receiver that is a separate unit from the emission source as shown on the following figure.

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Power source Boomer plate fitted to catamaran

8-elements single channen streamer

Page 4: SUB BOTTOM PROFILERS (SBP) - Bentos

CHARACTERISTICS OF THE BOOMER SBP SYSTEM

The principal characteristic of the boomer type SBP systems, including the hybrid system that is operated by BENTOS, is the generation of a pulse on a broadband spectrum that provides a good compromise between penetration capacity and resolution. This trait makes it possible to reach an energy level of 280 Joules, a penetration depth of up to 150 m when penetrating fine grain sediments (e.g., clay) and a penetration depth of as much as 25 m when penetrating coarse grain sediments (e.g., gravel). The boomer plate, model AA200, makes it possible to achieve a vertical resolution of 10 cm in thickness at 200 Joules. In general the boomer systems make it possible to discriminate sedimentary strata of between 0.5 and 2 m in thickness.

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Page 5: SUB BOTTOM PROFILERS (SBP) - Bentos

CHARACTERISTICS OF THE BOOMER SBP SYSTEM

Geophysical descriptions of marine sedimentary strata have a wide range of applications, in which those applications that are most requested include: The determination of the thickness of unconsolidated sedimentary packets (maps of sediment thicknesses), the delineation of the rock stratum (bedrock), support for geotechnical exploration work, the preparation of dredging cost estimates, the detection of buried structures or pipelines, submarine archeology, the detection of deposits of biogas, environmental monitoring and ecological studies, among others.

Example of the detection by means of a boomer type SBP system of sets of faults that interrupt the lateral continuity of a stratified sedimentary packet. By estimating the wave propagation velocity the thicknesses in terms of depth in meters are estimated.

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Page 6: SUB BOTTOM PROFILERS (SBP) - Bentos

PRINCIPAL APPLICATIONS OF THE BOOMER SBP

Marine soil

Bedrock

Example of the delineation of bedrock and a stratified sedimentary packet laid down subparallel to the marine soil through use of the boomer type SBP system at Etén, Peru.

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Page 7: SUB BOTTOM PROFILERS (SBP) - Bentos

THE PINGER TYPE SBP, WHAT IT IS

The pinger type SBP is a profiler system based on a ceramic transducer as its seismic source, made up of four basic devices: a signal generator transmitter, a transducer (or array of transducers), a receiver and a control and data recording computer. This system can obtain greater resolution than possible when using boomer sources that have lower levels of penetration in the marine sub bottom.

BENTOS operates a monochannel pinger type system of StrataBox 3510 model made by SyQwest, which operates on two frequencies: 10 kHz (normally with one transducer) and 3.5 kHz (with an array of four transducers).

SyQwest StrataBox 3510 www.bentos.cl

10 khZ

3,5 khZ

Page 8: SUB BOTTOM PROFILERS (SBP) - Bentos

THE PINGER TYPE SBP, HOW IT FUNCTIONS

The general principle of functioning of the pinger type SBP system features the emission of sound waves through the transducer (or array of transducers) toward the marine bottom at a characteristic frequency, with the waves striking the existing interfaces (water-sediment, sediment-rock) thereby producing a wave that is reflected and returns to the transducer.

Part of the energy emitted by the transducer is reflected at it passes through the different interfaces of unconsolidated sedimentary strata (Types, I, II, III and ROCK) until the signal becomes attenuated.

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Page 9: SUB BOTTOM PROFILERS (SBP) - Bentos

CHARACTERISTICS OF THE STRATABOX 3510 SBP PINGER SYSTEM

The principal characteristic of the pinger type SBP systems is their exploration capacity for discontinuities located down to some tens of meters depth into the marine subsoil, with depth of penetration being variable in accordance with the acoustic nature of the sub bottom, which is generally correlated with sediment grain size.

The StrataBox 3510 system achieves nominal discrimination of sedimentary strata 6 cm thick when using one 10 kHz transducer, and with an array of four transducers (3.5 kHz), this system achieves the discrimination of sedimentary strata 15 cm thick. http://www.syqwestinc.com/

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Page 10: SUB BOTTOM PROFILERS (SBP) - Bentos

PRINCIPAL PINGER SBP APPLICATIONS

The pinger type profilers are used for the preparation of geophysical descriptions of the structure of the marine subsoil in a wide range of applications, including: support for geotechnical exploration work through the delineation of the thickness of unconsolidated sedimentary packets along with the delineation of bedrock, studies of the consolidation of materials for the preparation of dredging cost estimates, the detection of buried objects for submarine archeology work, the detection of deposits of biogas, pipelines and geologic or anthropogenic structures as well as for environmental monitoring and ecological studies.

Buried

pipeline

Example of the detection of a pipeline buried in an unconsolidated sedimentary packet through the use of the StrataBox 3510 system employing an array of four transducers (3.5 kHz).

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Page 11: SUB BOTTOM PROFILERS (SBP) - Bentos

PRINCIPAL APPLICATIONS OF THE PINGER SBP

Example of the detection of three shipwrecks partially buried in an unconsolidated sedimentary packet using the StrataBox 3510 system with one 10 kHz transducer in the Bahía de Valparaíso embayment, Chile.

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Shipwrecks partially buried

Page 12: SUB BOTTOM PROFILERS (SBP) - Bentos

PRINCIPAL APPLICATIONS OF THE PINGER SBP

Example of the detection of the sediment-rock interface for the purpose of estimating dredging costs in unconsolidated sediments using the StrataBox 3510 system with an array of four transducers operated at 3.5 kHz. When the Jet Probe (JP) method is used, the direct measurement of sediment thicknesses is implemented, Melchorita, Peru.

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Page 13: SUB BOTTOM PROFILERS (SBP) - Bentos

THE CHIRP TYPE SBP, WHAT IT IS

The SBP with CHIRP modulation is a profiler system that uses ceramic transducers to enable greater resolution to be obtained by means of the modulation of the waves. It is made up of four basic devices: a signal generator transmitter, a transducer (or array of transducers), a receiver and a control and data recording computer.

BENTOS operates the CHIRP profiler system with double channel resolution (3.5 and 10 kHz) model Bathy2010PC made by SyQwest, with a nominal depth resolution of 0.01 m. http://www.syqwestinc.com/

SyQwest Bathy2010PC www.bentos.cl

10 KHz

3,5 KHz

Page 14: SUB BOTTOM PROFILERS (SBP) - Bentos

PRINCIPAL APPLICATIONS OF THE CHIRP SBP

High-resolution seismic section slide, including the interpretation of the last sedimentary reflector for use in the estimation of sediment thickness (above), performed through use of the Bathy2010PC CHIRP profiler with an array of four ceramic transducers at 3.5 KHz. Map of the distribution of sediment thicknesses (on the right). Bahía de Concepción embayment, Chile.

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Page 15: SUB BOTTOM PROFILERS (SBP) - Bentos

PRINCIPAL APPLICATIONS OF THE CHIRP SBP

3D sidebar prepared by combining the model of elevations of a high-resolution multibeam bathymetry output along with two high-resolution seismic sections, acquired through use of the CHIRP profiler, Bahía de Concepción embayment, Chile (BENTOS, 2013).

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Page 16: SUB BOTTOM PROFILERS (SBP) - Bentos

EXPERIENCE CHILE Official Multibeam Bathymetry, Marine Geophysics (Sub Bottom Profiler, Side Scan Sonar, Marine Magnetometry and Piston Corer). Puerto Lirquén, Bahía Concepción, Eighth Administrative Region. OCTOPUS LNG Project. GEOVENOR EXPLORA SpA. 2013. Multibeam Bathymetric and Marine Sub Bottom Profiler Survey, Bahía Chapaco, Third Administrative Region, COMPAÑÍA MINERA DEL PACÍFICO S.A. (CAP-MINERÍA), 2012. Multibeam Bathymetric and Marine Sub Bottom Profiler Survey, Bahía Chapaco, Third Administrative Region, COMPAÑÍA MINERA DEL PACÍFICO S.A. (CAP-MINERÍA), 2011. Marine Geophysical Exploration, Mejillones, Second Administrative Region, Gas Atacama Project. GASATACAMA CHILE S.A., 2011. Marine Geophysical Exploration, First Administrative Region, Quebrada Blanca Project, Phase 2. COMPAÑÍA MINERA TECK QUEBRADA BLANCA S.A., 2011. Multibeam Bathymetric and Marine Sub Bottom Profiler Survey, Bahía Cumberland, Robinson Crusoe Island, Fifth Administrative Region, Chile. PREPARATORY COMMISSION FOR THE COMPREHENSIVE NUCLEAR TEST-BAN-TREATY ORGANIZATION (CTBTO). 2010-2011. Official Single Beam Bathymetric Survey and studies of the littoral protection zone (ZPL), beach line and currents, waves and tides; official study of sea bottom quality by means of sub bottom profiler (SBP), Punta Padrones, Bahía Caldera, Third Administrative Region, Chile, COMPAÑÍA CONTRACTUAL MINERA CANDELARIA S.A., 2010-2011. Multibeam Hydrography, Geophysics, Coastal Topography and Soil Mechanics Studies for Submarine Power Cable Studies; Alignments in the Tenth and Eleventh Administrative Regions, Chile, CENTRALES HIDROELÉCTRICAS DE AYSÉN S.A., 2009 - 2010.

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EXPERIENCE Hydrography, Geophysics (SBP), Beach Line and Coastal Topography Studies, El Morro Water Desalination Plant Project, Third Administrative Region, Chile, HALCROW GROUP LTD. CHILE, 2009. Marine Seismic Survey (SBP) at Bahía Talcahuano, Eighth Administrative Region, Chile, GEOEXPLORACIONES S.A., 2009. Official Single Beam Bathymetric Survey and studies of the littoral protection zone (ZPL), beach line and currents, waves and tides; official study of sea bottom quality by means of sub bottom profiler (SBP), Río Bravo, Estero Mitchell, Eleventh Administrative Region, Chile, CENTRALES HIDROELÉCTRICAS DE AYSÉN S.A., 2008 - 2009.

Oceanography, Hydrography, Marine Geophysics and Beach Line Studies with Approval by the Hydrographic and Oceanographic Service of the Chilean Navy (SHOA) and Study and Design for the Improvement and Maritime Connectivity of the Puerto Montt – Chiloé – Palena and Caleta La Arena network, Tenth Administrative Region, PRDW AV – PORT WORKS ADMINISTRATION (DOP), 2008 - 2009. Oceanography, Hydrography, Marine Geophysics (SBP) and Beach Line Studies with SHOA Approval and Study and Design for the Improvement and Maritime Connectivity of the Puerto Montt – Chiloé – Palena and Caleta Puelche, Tenth Administrative Region, PRDW AV - PORT WORKS ADMINISTRATION (DOP), 2008 - 2009. Location of Submarine Pipelines through Use of Marine Sub Bottom Profiler (SBP) Technology, Bahía de San Vicente, Eighth Administrative Region, Chile, CADE IDEPE INGENIERÍA Y DESARROLLO DE PROYECTOS LTDA., 2007. Marine Sub Bottom Profiler (SBP) Study Conducted in Bahía de Quintero, Fifth Administrative Region, Chile, IPS INGENIEROS LTDA., 2006. Marine Sub Bottom Profiler (SBP) (SBP) Survey, Harbor Basin, Puerto de Arica, First Administrative Region, Chile, TERMINAL PORTUARIO ARICA S.A. (TPA), 2006. Acoustic Exploration Study of the Marine Subsoil (SBP) in Bahía de Quintero, Fifth Administrative Region, Chile, Quintero Single Buoy Mooring Capacity Increase Project, GEOVENOR S.A., 2005. Study of Marine Subsoil Profiles, Bahía Quintero, Fifth Administrative Region, Chile, Chile, GEOVENOR - ENAP REFINERÍA ACONCAGUA, 2005.

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EXPERIENCE PERU Marine Geophysics Studies (SBP), Single Beam Bathymetry, Side Scan Sonar, Directional Wave Measurements; Puerto Eten, Chiclayo, Peru, LUMINA COPPER, 2009 - 2010. Study of Wave Climate and Geophysical Exploration (Side Scan Sonar, SBP Seismicity and Bathymetry), El Galeno Project, Pacasmayo, Peru, MTB PROFESSIONALS, 2008. Geophysical Exploration, Melchorita LNG Project, Peru, JAN DE NUL, 2008. Geophysical Exploration (SBP), Punta Vegueta Area, Peru, TRAMARSA S.A., 2008. Geophysical Exploration, Bahía Ancón, Peru, TRAMARSA S.A., 2007. Study of Marine Sub Bottom Profiles, Zorritos, Tumbes, Submarine Pipeline Project for Pipelining Gas, BPZ ENERGY INC., SUCURSAL PERÚ, SEHIDRO, 2006. URUGUAY Multibeam Bathymetric Survey, Side Scan Sonar and Marine Sub Bottom Profiler (SBP). Directional Wave and Current Measurements. Sedimentology Sampling, Rocha District, Uruguay, MINERA ARATIRÍ S.A. - AUSENCO MANAGEMENT, 2010-2011. BRAZIL Multibeam Bathymetry and Geophysics Study (SBP) for the URUCU-MANAUS Gas Pipeline, Amazonas, Brazil, PLANAL SERVICOS DE ENGENHARIA, 2008.

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