Seismic and sequence stratigraphic analyses are important methodologies for interpreting coastal and shallow-marine deposits. Though both methods are based on objective criteria, terminology for reflection/stratal stacking is widely linked to eustatic cycles, which does not adequately incorporate factors such as differential subsidence, sediment supply, and autogenic effects. To reduce reliance on model-driven interpretations, we developed a Geometrical Breakdown Approach (GBA) that facilitates interpretation of horizon-bound reflection packages by systematically identifying upward-downward and landward-seaward trajectories of clinoform inflection points and stratal ter­minations, respectively. This approach enables a rigorous characterization of stratal surfaces and depositional units. The results are captured in three-letter acronyms that provide an efficient way of recognizing repetitive stacking pat­terns through discriminating reflection packages objectively to the maximum level of resolution provided by the data. Comparison of GBA with selected sequence stratigraphic models that include three and four systems tracts and the accommodation succession approach shows that the GBA allows a greater level of detail to be extracted, identifying key surfaces with more precision and utilizing more effectively the fine-scale resolution provided by the input seismic data. We tested this approach using a synthetic analogue model and field data from the New Jersey margin. The results demonstrate that the geometric criteria constitute a reliable tool for identifying systems tracts and provide an objective and straightforward method for practitioners at all levels of experience.

<p>Heterogeneities within clinoforms, which can be in the form of variations in internal geometry and/or change in sediment distribution, may act as fluid flow barriers or conduits for hydrocarbon or freshwater reservoirs. These heterogeneities can lead to considerable uncertainty in estimating pore-fluid recovery factors by up to 35%. And yet, variations in sediment petrophysical characteristics within clinoforms have been poorly documented. Understanding the rock physics of clinoform heterogeneities along continental margins is a key to reducing the uncertainties in predicting the dynamics and the volume of recoverable pore fluids within these structures.</p><p>The Miocene sedimentary record of the New Jersey continental margin is a prime candidate for studying continental-margin clinoform structures and the variation in their petrophysical properties. The margin has experienced a stable tectonic history, smooth and gradual thermal subsidence, and continuous sediment loading in the Miocene, resulting in deposition of well-developed siliciclastic clinoformal sequences. We use data from three IODP Expedition 313 boreholes and an encompassing high-resolution 3D multichannel seismic volume, collected in 2015 by the <em>R/V M.G. Langseth</em> on the New Jersey continental shelf, to predict shallow-marine sedimentological properties of the Miocene clinoforms at a significantly higher resolution (~5 m laterally) than previously achieved (~100s of m). We identify 76 system tracts and 22 sequences spanning ~8 m.y. of the Miocene. The results of our 3D stratigraphic analysis provide a detailed structural framework for analyses of the Miocene deposits to: 1) define the sedimentary structure in terms of stratal packages and 2) estimate the internal clinoform heterogeneity associated with phases of known mid-Cenozoic sea-level change.</p><p>Our statistical analysis of the estimated elastic properties, including P-wave velocity (Vp), density and clay volume, reveals repeating spatial patterns in the internal rock physics properties of the Miocene clinoforms. We show that diagenesis and sediment compaction within the dipping parts of clinoforms cause a continuous increase of Vp in the seaward direction, with a magnitude that decreases from top to bottom. Our results also suggest that lithofacies change in clinoforms imposes a stronger influence on density, as lateral changes in lithofacies are more pronounced in sediment density than in Vp. In the Miocene sedimentary record, the transgressive system tracts show a seaward coarsening trend in grain size and a 3%-5% increase in density from clinoform topsets to bottomsets. Highstand and lowstand system tracts show a fining trend basinward, with a ~8% and 5% reduction in density, respectively. We further demonstrate that the identified trends can provide a standard model allowing incorporation of clinoforms in reservoir characterization techniques, such as model-based seismic inversion, and enable setting of guidelines on how the petrophysical properties change regionally in shallow-marine siliciclastic environments of continental margins.</p>

<p><span>Over the 6 years of the Transatlantic Ocean System Science and Technology program (TOSST - 2014 – 2019), graduate students participated in a variety of first class research expeditions in the North Atlantic Ocean, contributing to high quality datasets for this region and reaching a total of 380 days at-sea. These research cruises expanded from the Arctic Ocean, Labrador Sea and sub-Polar North Atlantic to the Equatorial North Atlantic, and along the African and Cabo Verdean coasts. A total of 12 long term cruises with collaboration between 18 research institutes, were conducted on board of 10 research vessels of various nationalities (Canada, Germany, Bermuda, Sweden, Ireland and USA). The range of measurements performed during these cruises, which highlights the interdisciplinary nature of the TOSST program, includes: chemical oceanography; biological oceanography; physical oceanography; marine biogeochemistry; microbiology; paleoceanography; geology; marine geophysics; and atmospheric chemistry. In this work, we will showcase the breath of research covered by TOSST graduates in the North Atlantic Ocean and provide details on the overall goals/objectives of each cruise, the teams and research vessels involved, the diverse scientific instrumentation deployed and sampling schemes. We highlight the importance of multi-disciplinary expeditions and at-sea experiences for professional as well as for personal development of early career scientists. Logistic and economic efforts are required to collect samples and to deploy instruments, therefore collaboration between disciplines, research institutes and countries (of which TOSST graduates’ research is an example) are fundamental in order to increase the quality, quantity and variety of observations in the North Atlantic Ocean. </span></p>

Traditional absolute pore space concept considers the whole pore volume within the reservoir rock. Total porosity accounts for the entire pore space, so the maximum fluid saturation in rock related to this value. The structural complexity of pores in rocks especially in carbonates frequently results in isolated pores creation. These stagnant pores contribute to the absolute porosity of the rock, but are not involved in the flow of fluids through the rock. The intercommunicating pore spaces that maintain the flow of fluids make up the effective porosity. As fluid transport in porous media is controlled by the available amount of pores for flow, so this is the effective pore space not absolute one, in which real reservoir flow process occurs. In this study, play based hydrocarbon exploration procedure for an area followed. This region is surrounded by the gas discoveries in different reservoir horizons on the adjacent blocks. Complexity of geological structures and sequence of terrigenous-carbonates facies' change had led to drilling of seventeen dry wildcats. Aiming to reinvestigate the hydrocarbon potential, integrated petrophysical and seismic interpretation designed to identify hydrocarbon accumulation on the basis of regional studies. By analysis of core and well log data, static petrophysical properties calculated, reservoir horizons characterized and afterward the effective porosity was estimated using adaptive well log interpretation. The effective porosity estimations imported as an input for genetic inversion procedure to determine its distribution over the targeted formation. The effective porosity cube presented anomalies in areas where seismic attenuation attribute confirms possibility of gas accumulation. Successful implementation of shared-earth model using close interpretation of seismic and well data led to identifying a stratigraphic prospect with an acceptable probability of success.

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