In this paper, we present for the first time, a classification system for naturally-occurring gas hydrate deposits existing in the permafrost and marine environment. This classification is relatively simple but highlights the salient features of a gas hydrate deposit which are important for their exploration and production such as location, porosity system, gas origin and migration path. We then show how this classification can be used to describe eight well-studied gas hydrate deposits in permafrost and marine environment. Potential implications of this classification are also discussed.
The Alvin deep-sea submersible awaits another collection run in the Guaymas Basin in November 2018. In a paper published in Nature Communications, researchers documented extensive diversity in the microbial communities living in the extremely hot, deep-sea sediments located in the Guaymas Basin in the Gulf of California. The team uncovered new microbial species that are so genetically different from those that have been previously studied that they represent new branches in the tree of life. Many of these same species possess keen pollutant-eating powers, like other, previously identified microbes in the ocean and soil. "This shows the deep oceans contain expansive unexplored biodiversity, and microscopic organisms there are capable of degrading oil and other harmful chemicals," said assistant professor of marine science Brett Baker, the paper's primary investigator.
Tyagi, Anisha (California State Polytechnic University-Pomona) | Grenier, Margaret (California State Polytechnic University-Pomona) | Kreuziger, Rachel (California State Polytechnic University-Pomona) | Kays, Jacob (California State Polytechnic University-Pomona) | Polet, Jascha (California State Polytechnic University-Pomona)
The San Gabriel and San Bernardino Basins are sedimentary basins located in southern California that are surrounded by a network of faults and comprised of soft sediments. Sedimentary basins are known to amplify earthquake ground motions and increase their duration. The San Gabriel and San Bernardino Basins are densely populated areas; therefore, it is important to determine site characteristics for seismic hazard mitigation. Furthermore, if a major rupture were to occur on the Southern San Andreas Fault, the San Gabriel and San Bernardino Basins could potentially amplify the ground motion and funnel the energy from the rupture into the Los Angeles Basin (Denolle et al., 2014), acting as a waveguide. Therefore, it is important to better characterize these basins and to understand their resonance period, amplification and site response. Three seismic profiles, containing over 200 threecomponent nodes, were installed across the San Gabriel and San Bernardino Basins in the first quarter of 2017 and collected approximately one month of continuous waveform data. We apply the Horizontal-to-Vertical Spectral Ratio (HVSR) method to the ambient noise waveform data from this experiment. The resulting spectral ratio curves show clear long period peaks (between 2 and 5 seconds) that likely correspond to basin resonance and that indicate significant variation in amplification factors and resonance frequencies across both basins. Preliminary results show these long period peaks for nodes to the South of the Raymond Fault along a profile in the Western part of the San Gabriel Basin, as well as across the central part of this basin. The peak frequencies for the Western profile suggest that the basin is relatively deeper in this area. Nodes in the Southern half of the Chino Basin indicate values for peak frequencies between those measured for the San Gabriel Basin lines. Peak amplitudes vary between 2 and 4.5, which indicates potential for significant ground motion amplification.
Presentation Date: Wednesday, October 17, 2018
Start Time: 1:50:00 PM
Location: Poster Station 14
Presentation Type: Poster
Summary There has been a need in EM exploration for interpretation tools that can model a large earth volume with fine resolution and high conductivity contrasts. In response to this, a multigrid EM solution was developed for use in practical EM modelling of time domain EM data. This solution is an extension of multigrid methods to geophysical inductive EM problems. We illustrate the use of this tool by modelling UTEM data over the Voisey's Bay Ovoid deposit. Starting with a conductivity model derived from published drill sections the methodology was successful in rendering both the early time large current channeling response generated by the host troctolite dyke and the very long late time decay of the highly conductive massive sulphide core.
Indicator ratios of the concentrations of polycyclic aromatic hydrocarbons (PAH) are wide used to determine the sources of the hydrocarbon pollutions. These estimations are used for identification of sources of PAH itself as well as of the pollutions that satellites they are (products of every combustion processes and oil pollutions). The necessity of assessments is connected with the problems of identification of the causes of the environmental damages as a result of pollution of the environments. The indicator ratios of PAH are considered as a “geochemical markers” that are used to determine the sources of the pollutants. This research is based on the multiple literature data about the PAH concentrations in natural and man-made objects. The main purpose of this research is to analyze the accuracy of the received assessments and the assessment of the possibility to use the identified of the foreign researches. Critical values of the indicator ratios in the natural conditions Russian oil and gas industry.
The results of the research allow to select the geochemical markers, mostly “sensitive” to the pollution character, indicator ratios of the concentrations of polycyclic aromatic hydrocarbons (PAH). These chemicals affects the environment with the combustion processes or together with the oil (oil product) pollution. As a result is possible the identification of the causes of the environmental damages depending on the pollution composition of the time of the pollutant emission.
The research allowed to determine and to construct the set of the most informative geochemical indicators (markers) to use in the climatic and landscape conditions of Russia for the various technogenic objects. Despite the practically half-century history of use of the indicator ratios based on PAH concentrations, in Russia such assessments are not widely used. The causes are set of complicating factors hindering the implementation of indicators developed abroad, unadjusted for domestic natural conditions. It is necessary to adjust the ratios due to the different methods of extraction of PAHs from various substances (materials burned or released to the environment during the oil spills), the technology used, climatic conditions, types of pollution.
The paper presents new data on the information content of indicators for various polluted environments and suggestions for their uses in the identification of sources of PAHs in order to identify the causes of hydrocarbon contamination.
Daungkaew, Saifon (Schlumberger) | Mullins, Oliver C. (Schlumberger) | Johan, Zailily Johfizah (Schlumberger) | Lehne, Eric (Schlumberger) | Zuo, Julian Youxiang (Schlumberger) | Sinnappu, Suresh (Schlumberger) | Pfeiffer, Thomas (Schlumberger) | Giok Lin, Tan (Petronas Carigali Sdn. Bhd.) | Tunku Abdul Muthalib, Tunku Indra (Petronas) | Hong, Teh Yat (Chulalongkorn U.) | Rameli, Hazwani | Ludwig, John Thomas
Daungkaew, Saifon (Schlumberger) | Mullins, Oliver C. (Schlumberger) | Hong, Teh Yat (Petronas Carigali Sdn Bhd) | Lin, Tan Giok (Schlumberger) | Zuo, Julian Youxiang (PCSB) | Sun, Baoli (Schlumberger) | Johan, Zailily Johfizah (Schlumberger) | Pfeiffer, Thomas (Schlumberger) | Lehne, Eric (Petronas) | Tunku Abdul Muthalib, Tunku Indra
Infiltration of shallow soils by naturally occurring hydrocarbons has been documented in several deepwater environments worldwide. The potential for significant soil modification, such as the development of authigenic carbonates and alteration of the generally expected background geotechnical properties may provide constraints to flowline routing, foundation installation and engineering lifetime performance. This paper presents a review of the current state of knowledge of the authors with special reference to recent investigations in deepwater offshore Angola, and a suggested method for identification, characterization and prediction.
Interpretation of 3D exploration seismic, enhanced by AUV (Chirp) data facilitates an initial identification of areas prone to hydrocarbon infiltration and the vertical and spatial extent of potential soil modification. A first pass geotechnical characterisation is developed by targeted seabed CPTs and soil sampling. The generation of an integrated predictive model requires a multidisciplinary advanced testing programme, including geophysical, geotechnical, geochemical and geological analyses.
Once the extent, nature, and formative processes of hydrocarbon-related soil modification are understood, an assessment can be made of the challenges posed to a field development. This provides the necessary input to foundation and /or routing feasibility and determines if there is requirement to mitigate, through avoidance or design.
Hogan, Phillip Joseph (Fugro West, Inc.) | Lane, Andrew (Woodside Energy Ltd. ) | Hooper, James (Fugro-McClelland Marine Geosciences) | Broughton, Aaron (Fugro West, Inc.) | Romans, Brian (Stanford University)
Geotechnical data, geochronologic data, and high resolution seismic data collected for Woodside's OceanWay Secure Energy LNG project allow an improved understanding of the tectonic and sedimentary processes in Santa Monica Bay and Basin, and identification of geologic hazards.
The proposed facilities are located in a deepwater basin near the collisional transform boundary of the Inner California Continental Borderland (ICB) Province with the Western Transverse Ranges (WTR) Provinces. This area is characterized by complex interactions between blind thrust faults underlying the Los Angeles Basin and strike slip faults related to the northwest motion of the Pacific Plate relative to North America. Active faults and folds crossing the proposed pipeline route present a ground rupture and deformation hazard on the continental slope.
Active sediment transport processes and high sediment accumulation rates are documented on Hueneme submarine fan in Santa Monica Basin (SMB). High-resolution seismic-reflection profiles across Ocean Drilling Program (ODP) borehole 1015 in the basin plain provide a well-dated chronostratigraphic record. Turbidity currents in Santa Monica Basin are sand-dominated, and have increased in sediment volume per event in the latest Holocene. Whilst some turbidites likely result from El Niño-Southern Oscillation (ENSO) storm events, others are believed to have been triggered by seismically-induced strong ground motions.
The potential exists for surface folding and fault rupture, seismically induced strong ground motions, and turbidity currents to affect the proposed pipeline within the lifetime of the project. These geohazards will be mitigated through appropriate analyses, risk studies, and engineering design of the OceanWay facilities, allowing safe and secure importation of natural gas to the West Coast of the USA.
Proposed LNG developments in deepwater offshore the West Coast of the United States face new challenges, both on technical issues such as facility engineering and from natural geologic processes. Many recent high-profile deepwater developments continue to encounter major geological hazards (geohazards) on an increasing scale worldwide.
Woodside Natural Gas, Inc. (Woodside) proposes to import LNG to Southern California via a Deepwater Terminal in SMB. SMB is one of several basins in the ICB, a tectonically active area along the plate boundary between the Pacific and North American Plates (Figure 1). A 56-km submarine pipeline will bring the gas ashore via a horizontal directional drill borehole at a landfall in the coastal portion of the Los Angeles Basin (Figure 2). Detailed feasibility and siting studies were performed in 2005 and 2006 to assist in the selection of the optimal location of the OceanWay Project. This paper summarizes geohazards identified during the 2006 geophysical and geotechnical surveys.