Sand-lithofacies distributions are a vital component of reservoir characterisation and the generation of successful reservoir models, particularly in thin reservoirs thickness. The integration between seismic attributes and conceptual geologic models is important to identify the sand distributions and reservoir geometries. The aim of this work is illustrating the uses of seismic data in revealing the structural and stratigraphic elements of two main reservoir units. It is important to identify and list the attributes, which can be involved in analysing the reservoirs and their degree of involvement in the characterisation of the hydrocarbon accumulation zones. The study was carried out for the reservoirs: Abu Roash C and Abu Roach E in Sitra oil and gas concession, which is located in the northern part of the Egyptian Western Desert. Four seismic attributes are used: 1- Coherence (Variance) 2- 3D Curvature attributes were used for resolving mainly the structural features and also the stratigraphic features 3- Instantaneous phase 4- Instantaneous frequency attributes were used mainly for resolving the stratigraphic features. Through the integration of selected seismic attributes with post-stack seismic data, reservoir distributions and architectures are accurately delineated for the Upper Cretaceous reservoir (Abu Roash ‘C’ and ‘E’). Five wells were used to match the results of the seismic attributes and establish the regional trends of reservoir parameters. The integration of wells data, conventional seismic interpretation and extracted the relevant seismic attributes help in reaching a robust geologic model for the reservoirs of interest. Stratigraphic and structural interpretation objectives based on extracting the seismic attributes for reservoir characterisation become more dominant, as they go deeper in seismic data, to derive more subsurface geologic data than traditional interpretation. 3D structure model of the concern area was established by interpreting the available seismic data as both reservoirs implicated by two fault trends: NW-SE and ENE-WSW. By the end a 3D geological model was defined based on the results of the conventional interpretation of the seismic and seismic attributes to reflect all structural and stratigraphic elements of the two reservoir units.

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Summary International efforts to decarbonise the global energy sector require the immediate deployment of all available clean energy technologies including a major push to increase energy efficiency and a significant scaling up of renewable energy. Herein, we provide a short overview of the role hydrogen can play in decarbonising the energy sector and on the primary sources of hydrogen. Ireland has significant potential for domestic green hydrogen production because of its considerable offshore and onshore wind potential. Hydrogen can also be used as a temporary energy store and help to address challenges associated with the future ramping up of renewable electricity generation. This will require hydrogen to be stored in high pressure tanks on the surface or in underground (geological) storage. Salt cavern geostorage potential exists within Permian and Triassic basins, and we provisionally estimate a hydrogen working gas capacity of 1.6 TWh for a planned storage facility on Islandmagee in Northern Ireland. Hydrogen geostorage potential also exists in depleted gas fields, and we provisionally estimate hydrogen working gas capacities of 67 TWh and 38 TWh for the Kinsale Head and Corrib gas fields, respectively. Further research is required to properly assess the hydrogen geostorage potential in Ireland.

4D seismic surveys are now routinely used to monitor hydrocarbon reservoirs. Because seismic reflections are sensitive to formation stress and fluid content, repeated seismic surveys are able to detect pressure changes and fluid exchanges that occur during field production. These measurements can help to optimise recovery strategy and identify areas where hydrocarbons have been bypassed. In practice, the seismic signal associated with such changes may be negligible, especially in heterogeneous carbonate reservoirs. However, by applying a 4D seismic co-processing workflow, we were able to detect and quantify a 4D signal even with suboptimal repeated acquisition geometry. Seismic inversion helped to overcome noise, multiple contamination, and differences in dynamic amplitude range between baseline and monitor seismic surveys. Matching the 4D seismic signal to changes in reservoir production characteristics aided in the investigation of the mechanism underlying the observed 4D signal. Detectability of 4D signals was found to be primarily related to changes in reservoir pressure and fluid saturation, which increased from 2010 to 2020 the time-lapse between the base and monitor survey.

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Whilst designing an onshore seismic survey the geophysicist is principally concerned with geophysical parameters, such as the point and line spacing. The survey cost, however, cannot be ignored during this initial stage. In particular, weather can add significant cost to a survey. In this paper we show how the weather-related risk for seismic surveys in the Bowen Basin, Queensland, Australia, can be quantified using historical weather data. As well as allowing quantifiable risk determinations, such analyses can also be used to identify the most appropriate time of the year to acquire data. In the specific example given here we were principally impacted by rain. It is easily conceivable, however, that such analyses could be applied to areas where other weather impacts (e.g., snow) are important.

This work evaluates the hydrocarbon potential of the Orange Basin offshore South Africa by considering key seismic features such as basement, Gravity Slide Systems (GSS), Mass Transport Complexes/Deposits (MTCs/MTDs), contourites, mixed depositional systems, and seafloor morphology. Further, by integrating an updated structural domains classification, we revise the chronostratigraphy of the basin. Two gravity slide systems within the northern and southern parts of the basin are mapped in their entirety and named the Orange-Senqu and Bergoli Deepwater Fold and Thrust Belts (DWFTBs), respectively. In addition to uplift, gravitational collapse, and differential sediment loading, sediment failure is likely also triggered by fluid expulsion from the basement and gas hydrate dissociation. MTCs comprise 70–90% of the Cretaceous succession from the slope seaward. We propose the name ‘crestal deformation surface’(creds) for the top of an MTC. Contourite and mixed depositional systems are described for the first time in the basin. The Sandhaai prospect is a new turbidite-contourite fan play type. Venus and Graff-type analogues, and ‘intra MTC’ plays are also recorded within the basin. Finally, we document a segmented continental slope. Segmentation is attributed to sediment mass failure and deposition, and large-scale erosion driven by bottom currents, giving the slope a graded-to-stepped appearance.

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