Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores)
Two sectors, Itata and Valdivia, which are located in the Chilean margin were analysed by using seismic data with the main purpose to characterize the gas hydrate concentration. Strong lateral velocity variations are recognised, showing a maximum value in Valdivia offshore (2380 ms−1 above the BSR)...
Main Authors: | , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2017-12-01
|
Series: | Energies |
Subjects: | |
Online Access: | https://www.mdpi.com/1996-1073/10/12/2154 |
id |
doaj-3db3f1b9e8324ed69144aa4a7f8e2496 |
---|---|
record_format |
Article |
spelling |
doaj-3db3f1b9e8324ed69144aa4a7f8e24962020-11-25T00:49:50ZengMDPI AGEnergies1996-10732017-12-011012215410.3390/en10122154en10122154Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores)Vargas-Cordero Iván0Tinivella Umberta1Villar-Muñoz Lucía2Facultad de Ingeniería, Universidad Andres Bello (UNAB), Quillota 980, 2531015 Viña del Mar, ChileIstituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Borgo Grotta 42C, 34010 Trieste, ItalyGEOMAR, Helmholtz Centre for Ocean Research, Wischhofstr 1-3, 24148 Kiel, GermanyTwo sectors, Itata and Valdivia, which are located in the Chilean margin were analysed by using seismic data with the main purpose to characterize the gas hydrate concentration. Strong lateral velocity variations are recognised, showing a maximum value in Valdivia offshore (2380 ms−1 above the BSR) and a minimum value in the Itata offshore (1380 m·s−1 below the BSR). In both of the sectors, the maximum hydrate concentration reaches 17% of total volume, while the maximum free gas concentration is located Valdivia offshore (0.6% of total volume) in correspondence of an uplift sector. In the Itata offshore, the geothermal gradient that is estimated is variable and ranges from 32 °C·km−1 to 87 °C·km−1, while in Valdivia offshore it is uniform and about 35 °C·km−1. When considering both sites, the highest hydrate concentration is located in the accretionary prism (Valdivia offshore) and highest free gas concentration is distributed upwards, which may be considered as a natural pathway for lateral fluid migration. The results that are presented here contribute to the global knowledge of the relationship between hydrate/free gas presence and tectonic features, such as faults and folds, and furnishes a piece of the regional hydrate potentiality Chile offshore.https://www.mdpi.com/1996-1073/10/12/2154gas hydrateBSRseismic velocitygas-phase concentrationpre-stack depth migrationChilean margin |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Vargas-Cordero Iván Tinivella Umberta Villar-Muñoz Lucía |
spellingShingle |
Vargas-Cordero Iván Tinivella Umberta Villar-Muñoz Lucía Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores) Energies gas hydrate BSR seismic velocity gas-phase concentration pre-stack depth migration Chilean margin |
author_facet |
Vargas-Cordero Iván Tinivella Umberta Villar-Muñoz Lucía |
author_sort |
Vargas-Cordero Iván |
title |
Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores) |
title_short |
Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores) |
title_full |
Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores) |
title_fullStr |
Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores) |
title_full_unstemmed |
Gas Hydrate and Free Gas Concentrations in Two Sites inside the Chilean Margin (Itata and Valdivia Offshores) |
title_sort |
gas hydrate and free gas concentrations in two sites inside the chilean margin (itata and valdivia offshores) |
publisher |
MDPI AG |
series |
Energies |
issn |
1996-1073 |
publishDate |
2017-12-01 |
description |
Two sectors, Itata and Valdivia, which are located in the Chilean margin were analysed by using seismic data with the main purpose to characterize the gas hydrate concentration. Strong lateral velocity variations are recognised, showing a maximum value in Valdivia offshore (2380 ms−1 above the BSR) and a minimum value in the Itata offshore (1380 m·s−1 below the BSR). In both of the sectors, the maximum hydrate concentration reaches 17% of total volume, while the maximum free gas concentration is located Valdivia offshore (0.6% of total volume) in correspondence of an uplift sector. In the Itata offshore, the geothermal gradient that is estimated is variable and ranges from 32 °C·km−1 to 87 °C·km−1, while in Valdivia offshore it is uniform and about 35 °C·km−1. When considering both sites, the highest hydrate concentration is located in the accretionary prism (Valdivia offshore) and highest free gas concentration is distributed upwards, which may be considered as a natural pathway for lateral fluid migration. The results that are presented here contribute to the global knowledge of the relationship between hydrate/free gas presence and tectonic features, such as faults and folds, and furnishes a piece of the regional hydrate potentiality Chile offshore. |
topic |
gas hydrate BSR seismic velocity gas-phase concentration pre-stack depth migration Chilean margin |
url |
https://www.mdpi.com/1996-1073/10/12/2154 |
work_keys_str_mv |
AT vargascorderoivan gashydrateandfreegasconcentrationsintwositesinsidethechileanmarginitataandvaldiviaoffshores AT tinivellaumberta gashydrateandfreegasconcentrationsintwositesinsidethechileanmarginitataandvaldiviaoffshores AT villarmunozlucia gashydrateandfreegasconcentrationsintwositesinsidethechileanmarginitataandvaldiviaoffshores |
_version_ |
1725250912117587968 |