scholarly journals Mud Flow Dynamics at Gas Seeps (Nirano Salse, Italy)

2021 ◽  
Author(s):  
Beatrice Maria Sole Giambastiani ◽  
Marco Antonellini ◽  
Massimo Nespoli ◽  
Massimo Bacchetti ◽  
Antonino Calafato ◽  
...  
Keyword(s):  
Sedimentary Rock ◽  
Field Data ◽  
Fluid Pressure ◽  
Flow Dynamics ◽  
Mud Volcanoes ◽  
Liquid Ratio ◽  
Shallow Aquifers ◽  
Gps Rtk ◽  
Gas Seeps ◽  
Mud Flow

Abstract The Nirano Salse, known since the Roman Times, are one of the most beautiful and scenic mud volcanoes areas of Italy with thousands of visitors every year. In this work, we apply hydrogeological techniques to characterize mud levels in the Salse by means of GPS-RTK positioning and continuous level logging within mud conduits. Our results suggest that different mud levels in mud volcanoes clusters are due to the different gas-liquid ratio in the conduits and not necessarily exclude interconnection at depth, a hypothesis, on the other hand, that seems strengthened by mud level time series correlations. The presence of shallow aquifers at a depth of 5 to 30 m is also supported by our field data. These shallow aquifers may provide a temporary storage for the ascending gas and when fluid pressure in these aquifers exceeds the tensional strength of the sedimentary rock, leakage of fluids to the surface would occur.

Sea bottom characteristics and geochemistry of oil and gas seeps in the Gulf of Mexico

2021 ◽  
pp. 1-60
Author(s):  
John Decker ◽  
Philip Teas ◽  
Daniel Orange ◽  
Bernie B. Bernard
Keyword(s):  
Gulf Of Mexico ◽  
Gas Hydrates ◽  
Oil And Gas ◽  
Geochemical Analysis ◽  
Mud Volcanoes ◽  
Sea Bottom ◽  
High Backscatter ◽  
Oil Extract ◽  
Brine Pools ◽  
Gas Seeps

From 2015 to 2018, TGS conducted a comprehensive multiclient oil and gas seep hunting survey in the Gulf of Mexico. The basis for identifying seeps on the sea bottom was a high-resolution Multi-Beam Echo Sounder survey, mapping approximately 880,000 km2 of the sea bottom deeper than 750 m water depth, at a bathymetric resolution of 15 m and a backscatter resolution of 5 m. We have identified more than 5000 potential oil and/or gas seeps, and of those, we cored approximately 1500 for hydrocarbon geochemical analysis. The sea bottom features best related to hydrocarbon seepage in the GoM are high backscatter circular features with or without bathymetric expression, high backscatter features with “flow” appearance, mud volcanoes, pock marks, brine pools, “popcorn” texture, faults, and anticlinal crests. We also tracked gas plumes in the water column back to the sea bottom to provide an additional criterion for hydrocarbon seepage. Cores from sea bottom targets recovered liquid oil, tar, and gas hydrates. Oil extract and gas analyses of samples from most target types produced values substantially higher than background in oil and gas.

Supernormal fluid pressures in sedimentary rocks of southern Ontario – western New York State

1992 ◽  
Vol 29 (1) ◽  
pp. 80-93 ◽  
Author(s):  
K. G. Raven ◽  
K. S. Novakowski ◽  
R. M. Yager ◽  
R. J. Heystee
Keyword(s):  
New York ◽  
Sedimentary Rock ◽  
New York State ◽  
Sedimentary Rocks ◽  
Fluid Pressure ◽  
Gas Migration ◽  
Southern Ontario ◽  
York State ◽  
Monitoring Wells ◽  
Pressure Transducers

Fluid pressures up to 1.7 times greater than hydrostatic have been measured in argillaceous Paleozoic rocks of low permeability in southern Ontario and western New York State. These supernormal formation fluid pressures were measured at depths of 50–310 m using submersible pressure transducers with straddle packers and multiple-packer casings isolating the test intervals. Measurements were obtained over periods of 7–46 months following casing installations. The pressure measurements from 11 monitoring wells are compiled and supporting hydrogeologic data for 5 selected wells are used as examples to illustrate the occurrence of supernormal fluid pressures in the Ordovician, Silurian, and Devonian sedimentary sequence of southern Ontario and western New York State. Possible explanations for the occurrence of supernormal fluid pressures in sedimentary rock are evaluated considering the available geologic and hydrogeologic information obtained from the monitoring wells. Based on this review, it is hypothesized that gas migration and accumulation from deeper distant sources via permeable vertical pathways is the most plausible explanation for the observed fluid pressures, although secondary contributions from local neotectonic activity are also possible. The implications of such supernormal fluid pressures on regional groundwater flow in sedimentary rocks and related activities such as waste disposal in sedimentary rock are briefly discussed. Key words : supernormal fluid pressure, sedimentary rocks, gas migration.

scholarly journals Thermobaric depth settings of sedimentary rock basins and their fluid dynamics: Communication 3. Superhigh pressures in the stratisphere and salt diapirs

2019 ◽  
pp. 130-148
Author(s):  
V. N. Kholodov
Keyword(s):  
Fluid Dynamics ◽  
Phase Transformations ◽  
Sedimentary Rock ◽  
Sedimentary Cover ◽  
Mud Volcanoes

The article discusses the patterns of location and the conditions for the formation of salt diapirs. Their formation is associated with thick salt cjmpleses in which phase transformations within closed physicochemical systems form ultrahigh pressures. The latter are the cause of the flow of salts and their penetration through tectonic cracks and fractures to the earth's surface. The similarity of the formation of salt diapirs and mud volcanoes is emphasized. The possibility of the influence of ultrahigh pressures on the autonomous folding of the sedimentary cover is assumed.

scholarly journals Proposal for a mechanical model of mobile shales

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan I. Soto ◽  
Mahdi Heidari ◽  
Michael R. Hudec
Keyword(s):  
Critical State ◽  
Mechanical Model ◽  
Sedimentary Rock ◽  
Structural Systems ◽  
Continental Margins ◽  
Subsurface Structure ◽  
Mud Volcanoes ◽  
The Poor ◽  
Poor Understanding

AbstractStructural systems involving mobile shale represent one of the most difficult challenges for geoscientists dedicated to exploring the subsurface structure of continental margins. Mobile-shale structures range from surficial mud volcanoes to deeply buried shale diapirs and shale-cored folds. Where mobile shales occur, seismic imaging is typically poor, drilling is hazardous, and established principles to guide interpretation are few. The central problem leading to these issues is the poor understanding of the mechanical behaviour of mobile shales. Here we propose that mobile shales are at critical state, thus we define mobile shales as “bodies of clay-rich sediment or sedimentary rock undergoing penetrative, (visco-) plastic deformation at the critical state”. We discuss how this proposition can explain key observations associated with mobile shales. The critical-state model can explain the occurrence of both fluidized (no grain contact) shales (e.g., in mud volcanoes) and more viscous shales flowing with grain-to-grain contact (e.g., in shale diapirs), mobilization of cemented and compacted shales, and the role of overpressure in shale mobility. Our model offers new avenues for understanding complex and fascinating mobile-shale structures.

scholarly journals Turbulent flow dynamics and mass transport processes in a natural surface storage zone using field data and numerical simulations

2018 ◽  
Vol 40 ◽  
pp. 05064 ◽  
Author(s):  
Jorge Sandoval ◽  
Cristián Escauriaza ◽  
Emmanuel Mignot ◽  
Luca Mao
Keyword(s):  
Mass Transport ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Field Data ◽  
Large Scale ◽  
Transport Model ◽  
Transport Processes ◽  
Flow Dynamics ◽  
Surface Velocity ◽  
Mean Flow

In this work, the turbulent flow dynamics and mass transport mechanisms in a natural SSZis analyzed. The study site is a river reach of the Lluta River, located in northern Chile in a high-altitude Andean environment known as the Altiplano (~ 4,000 masl) The large-scale turbulent coherent structures are characterized using field measurements and 3D numerical simulations. The detailed topography was measured through DGPS and digital image processing while the surface velocity field, through the LSPIV technique. Regarding the field data, numerical simulations were performed using a DES turbulence model coupled with a 3D passive scalar transport model for Re = 45,800. The coherent structure dynamics in the shear layer was identified as the main mechanism that drives the mass and momentum transport processes between the SSZ and the main channel. Also, the 2D vortical structures of the mean flow are analyzed within the lateral cavity, since they have a strong influence in mass transport, increasing mean residence times due to their lower velocities and longer exchange timescales. Finally, the performance of two simplified transport models is analyzed to represent the mass transport dynamics at larger scales.

Methane emission from natural gas seeps and mud volcanoes in Transylvania (Romania)

Geofluids ◽  
2010 ◽  
Vol 10 (4) ◽  
pp. 463-475 ◽  
Author(s):  
L. SPULBER ◽  
G. ETIOPE ◽  
C. BACIU ◽  
C. MALOŞ ◽  
Ş.N. VLAD
Keyword(s):  
Natural Gas ◽  
Methane Emission ◽  
Mud Volcanoes ◽  
Gas Seeps

scholarly journals The Study of Flow Resulting from Wave on Lhonga Beach, Aceh Besar

Omni-Akuatika ◽  
2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Muhammad Irham ◽  
Ichsan Setiawan
Keyword(s):  
Field Data ◽  
High Tide ◽  
Dynamic Interaction ◽  
Flow Dynamics ◽  
Marine Resources ◽  
Wave Flow ◽  
Average Depth ◽  
Approach Method ◽  
Explicit Finite Difference ◽  
Dominant Direction

Dynamic interaction between waves and topographic generate flow dynamics that affect Lhonga coast, Aceh Besar. To analyze the dynamics, the numerical model of currents induced by wave was developed with the explicit finite difference approach method. The model in this study was tested by verifying the result directly with the field data obtained previously. The model is applied in Lhoknga coast of Aceh Besar district with the aim to study how the dynamics of hydro-oceanography as one of the elements to support the preservation of the marine resources of the area. Based on the simulation, the results obtained that the wave occurred in Lhoknga beach relatively small with the dominant direction to the northwest and the maximum of wave height occurs during the high tide condition. The result also informed that the distribution of longshore currents is generally moving from west to east along the coast. The direction of dominant current occurs in the area of 10-15 meters from the shore with an average depth of 6 meters. Keywords: wave flow, flow dynamics, beach, hydro-oceanography

Empirical Assessment of a Markovian Traffic Flow Model

1997 ◽  
Vol 1591 (1) ◽  
pp. 31-37 ◽  
Author(s):  
Chang-Jen Lan ◽  
Gary A. Davis
Keyword(s):  
Traffic Flow ◽  
Traffic Control ◽  
Field Data ◽  
High Order ◽  
Flow Dynamics ◽  
Model Parameters ◽  
Flow Models ◽  
Real Time Traffic ◽  
Flow Parameters ◽  
Traffic Flow Models

Previous research efforts on developing traffic flow models to account for traffic flow dynamics over transportation networks have centered on macroscopic high-order models. It is unclear whether traffic flow dynamics can be well described using a high-order model formulation, but for real-time traffic control, it is important to have tractable yet accurate models. Described here is a set of tractable traffic flow models based on the Markovian compartment concept. The basic models can be further modified to produce effects analogous to high-order models in capturing unstable traffic behavior during congestion. Special treatments are also made to account for the effects of conflicting flow on the predicted turning exit flow at intersection approaches. The proposed models are evaluated using field data. The results indicate that all the model parameters, including traffic flow parameters and gap acceptance parameters, are reasonably estimated, and the underlying models provide good fits to the field data.

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