... Underwater Vehicle (AUV) technology. Since the area is geohazard prone, with the occurrence of multiple hydrocarbon-fluid migration features (pockmarks, asphalts domes, High Impedance Reflectors (HIR), etc.) at or near seabed, the analysis of the different datasets, following a time-lapse approach...

... a powerful tool to gather and archive all geographical data but one of the major strength of a GIS is its capacity to be used for analyzing the data. The proposed GIS approach is a real added value for seabed geohazards assessment for subsea layout validation. The semi-automatic method of seabed pockmarks...

... to an emission point or vent in the seafloor. The rising speed of the oil in a water column of 1800 m is 10 cm/s, which corresponds to a lateral drift of about 1000 m. Active vents in the seafloor correspond to submarine mounds and clustered pockmarks, whereas unit or single pockmarks are not associated...

... Abstract Natural hydrocarbon (HC) seeps are commonly observed at seabed and at shallow depth below seabed in the deep offshore Angola. They are associated to various types of geological features, such as pockmarks, Methane Derived Authigenic Carbonate (MDAC) crusts, nodules, mounds or more...

... Abstract Pockmarks and related subsurface features are mapped and interpreted inoffshore Sarawak, South China Sea. Data was collected using sidescan sonar, sub-bottom profiler, 2D high-resolution seismic and core samples. Pockmarkdistributions are interpreted and defined on the basis...

... Abstract Pockmarks are crater-like depressions resulting from fluid flows at the seabed. Fluids may be of different types (water, gas, oil) and origins (dewatering, biogenic, thermogenic). In the Eastern Niger Submarine Delta (ENSD), pockmarks are generally circular depressions of variable...

... to discriminate the backscatter response of four seafloor features: a carbonate mound, a hydrate mound, a small mud volcano, and pockmarks in the vicinity of the well- documented Bush Hill seep site. Each of these features are associated with fluid migration though both the geologic structures...

..., including pockmarks and slope instabilities. It must be kept in mind that FG seepages at the seafloor in GH prone areas do not mean that GH are dissociating, as GH bearing sediments do not form an impermeable barrier to FG flows or dissolved CH4. Pockmarks: Pockmarks are the seabed expression of fluid...

... is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of OTC copyright. Abstract Among marine geohazards, pockmarks are the most common features observed in deep-water environments. They are interpreted as the result...

... pockets are present, and the migration into annuli is independent of the presence and quality of cement. The gas migration as a potential hazard for the platform foundation and a possible link with a natural gas flux in the seabed and the formation of pockmarks has been checked. The time scale for gas...

... are presented; the first using commercially available sensors for monitoring methane in the drill shafts of a gravity based platform, and the deployment of passive gas traps to attempt to identify periodic leakage from seabed pockmark features. The equipment and techniques presented have been developed...

... seismic data. The survey methods, seismic processing and results of a UHR 3D seismic survey over a newly forming pockmark on the upper continental slope of Nigeria are explained. Introduction C & C Technologies (C&C) teamed with its Nigerian partner, Multinational Geosurveys Limited, to provide Total...

... target depth reflector instability sediment reservoir characterization offshore technology conference seafloor instability water depth otc 17496 landslide pockmark geohazard chinguetti seafloor development area seismic data shallow gas hydrate tiof upstream oil & gas...

... of conflicting observations that may be made. On one hand the generally crisp nature of the majority of the morphological features, such as the sharp aretes between gullies on the canyon sides, indicates geologically recent erosion. Also, there is distinct evidence of pockmarks along the shelf edge indicating...

... ABSTRACT Two potential geologic hazards, mud volcanoes and pockmarks, have been documented with increasing frequency since worldwide requirements for offshore hazard, environmental and engineering surveys have become more exacting. Terrestrial and marine mud volcanoes, as researched...