scholarly journals Potential hydrocarbon reservoirs of Albian–Paleocene age in the Nuussuaq Basin, West Greenland

Author(s):  
Morten L. Hjuler ◽  
Niels H. Schovsbo ◽  
Gunver K. Pedersen ◽  
John R. Hopper

The onshore Nuussuaq Basin in West Greenland is important for hydrocarbon exploration since many of the key petroleum systems components are well exposed and accessible for study. The basin has thus long served as an analogue for offshore exploration. The discovery of oil seeps on Disko, Nuussuaq, Ubekendt Ejland, and Svartenhuk Halvø (Fig. 1) in the early 1990s resulted in exploration onshore as well. In several wells, oil stains were observed in both the siliciclastic sandstone and in the volcanic series. An important aspect of any petroleum system is a high quality reservoir rock. The aim of this paper is to review petrophysical aspects of the reservoir potential of key stratigraphic intervals within the Nuussuaq and West Greenland Basalt groups. Reservoir parameters and porosity–permeability trends for potential siliciclastic and volcanic reservoirs within the relevant formations of the Nuussuaq Basin are discussed below.

2020 ◽  
pp. SP504-2019-241 ◽  
Author(s):  
Paul Mann ◽  
Stephen Pierce

AbstractOil seeps and small-production oilfields in south-central Hispaniola are regionally isolated from much larger hydrocarbon provinces in the circum-Gulf of Mexico and northern South America. In this study, we evaluate the tectonic, stratigraphic and structural setting of these hydrocarbon occurrences. The zone of late Miocene to Recent oblique convergence includes the Bahamas Platform, Cretaceous and Paleogene arc rocks in Hispaniola, and the Cretaceous Caribbean oceanic plateau. Twentieth-century hydrocarbon exploration in Hispaniola has been concentrated on the elongate, NW- to WNW-trending, thrust- and strike-slip fault-bounded Cibao, San Juan–Azua and Enriquillo basins. Analyses of Cretaceous to Neogene rocks in the Dominican Republic have revealed that most rocks contain poor to marginal total organic carbon values. In the Azua Basin, a shallow marine, basin-edge facies of the middle Miocene Sombrerito Formation underlies the area of natural oil seeps and limited historical oil production and exhibits good to excellent total organic carbon values greater than 1%. Structural traps for oil at the Maleno and Higuerito oilfields of the Dominican Republic are large anticlines formed in post-late Miocene time. Reservoir rock for oil at the Maleno and Higuerito oilfields of the Dominican Republic is submarine fan-deposited sandstone of the late Miocene Trinchera Formation.


2007 ◽  
Vol 13 ◽  
pp. 25-28 ◽  
Author(s):  
Ulrik Gregersen ◽  
Torben Bidstrup ◽  
Jørgen A. Bojesen-Koefoed ◽  
Flemming G. Christiansen ◽  
Finn Dalhoff ◽  
...  

A detailed geophysical mapping project has been carried out by the Geological Survey of Denmark and Greenland (GEUS) in the offshore region south-west and west of Disko and Nuussuaq, central West Greenland as part of the preparations for the Disko West Licensing Round in 2006 (Fig. 1). The main purpose of the study was to evaluate the prospectivity of this almost 100 000 km2 large region, and to increase knowledge of basin evolution and the structural development. Results of the work, including a new structural elements map of the region and highlights of particular interest for hydrocarbon exploration of this area, are summarised below. Evidence of live petroleum systems has been recognised in the onshore areas since the beginning of the 1990s when seeps of five different oil types were demonstrated (BojesenKoefoed et al. 1999). Oil seeps suggesting widely distributed marine source rocks of Mesozoic age are particularly promising for the exploration potential (Bojesen-Koefoed et al. 2004, 2007). Furthermore, possible DHIs (Direct Hydro carbon Indicators) such as gas-clouds, pock marks, bright spots and flat events have been interpreted in the offshore region (Skaarup et al. 2000; Gregersen & Bidstrup in press). The evaluation of the region (Fig. 1) is based on all public and proprietary seismic data together with public domainmag- netic and gravity data. The seismic data (a total of c. 28 000 line km) are tied to the two existing offshore exploration wells in the region (Hellefisk-1 and Ikermiut-1). The study also incorporates information on sediments and volcanic rocks from onshore Disko and Nuussuaq (Fig. 2). Ten seismic horizons ranging from ‘mid-Cretaceous’ to ‘Base Quaternary’ (Fig. 2) have been interpreted regionally. Large correlation distances to wells, varying data quality and a thick cover of basalt in the north-eastern part of the region, add uncertainty in the regional interpretation, especially for the deeper horizons such as the ‘mid-Cretaceous’ equivalent to Santonian sandstone interval drilled in Qulleq-1 far south. Based on the seismic interpretation (Fig. 3) structural elements maps, horizon-depth maps and isopach maps have been produced; these maps, together with general stratigraphic knowledge on potential reservoirs, seals and source rocks (Fig. 2), provide important information for discussions of critical play elements including kitchens and structures.The existence of many large structures combined with the evidence of live petroleum systems has spurred the recent major interest for hydrocarbon exploration in the region.


Author(s):  
Thorkild M. Rasmussen

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article. Rasmussen, T. M. (1). Aeromagnetic survey in central West Greenland: project Aeromag 2001. Geology of Greenland Survey Bulletin, 191, 67-72. https://doi.org/10.34194/ggub.v191.5130 The series of government-funded geophysical surveys in Greenland was continued during the spring and summer of 2001 with a regional aeromagnetic survey north of Uummannaq, project Aeromag 2001 (Fig. 1). The survey added about 70 000 line kilometres of high-quality magnetic measurements to the existing database of modern airborne geophysical data from Greenland. This database includes both regional high-resolution aeromagnetic surveys and detailed surveys with combined electromagnetic and magnetic airborne measurements.


2020 ◽  
Vol 8 ◽  
Author(s):  
John I. Ejembi ◽  
Eric C. Ferré ◽  
Sara Satolli ◽  
Sarah A. Friedman

The anisotropy of magnetic susceptibility (AMS) in sedimentary rocks results from depositional, diagenetic, syn- and post-sedimentary processes that affect magnetic grains. Some studies have also shown the potential role played by post-depositional fluid flow in detrital and carbonate formations. Here we present a new case study of Middle-Upper Jurassic sandstones where secondary iron oxides, precipitated from fluids that migrated through pores, give rise to the AMS. These sandstones are well exposed in the Uncompahgre Uplift region of the Central Colorado Trough, Colorado. The magnetic foliation of these undeformed, subhorizontal strata consistently strike NE-SW over a large distance with an average 45° dip to the SE. This steep AMS fabric is oblique with respect to the regional subhorizontal bedding and therefore does not reflect the primary sedimentary fabric. Also, outcrop-scale and microscopic observations show a lack of post-depositional plastic (undulose extinction) or pressure-solution (stylolites) deformation microstructures in these sandstones, hence precluding a tectonic origin. The combination of magnetic hysteresis, isothermal remanent magnetization, and thermal demagnetization of the natural remanent magnetization indicate that these rocks carry a chemical remanent magnetization born primarily by hematite and goethite. High-field magnetic hysteresis and electron microscopy indicate that detrital magnetite and authigenic hematite are the main contributors to the AMS. These results show that post-depositional iron remobilization through these porous sandstones took place due to the action of percolating fluids which may have started as early as Late Cretaceous along with the Uncompahgre Uplift. The AMS fabric of porous sandstones does not systematically represent depositional or deformation processes, and caution is urged in the interpretation of magnetic fabrics in these types of reservoir rock. Conversely, understanding these fabrics may advance our knowledge of fluid flow in porous sandstones and may have applications in hydrocarbon exploration.


Author(s):  
Mahmoud Leila ◽  
Ali Eslam ◽  
Asmaa Abu El-Magd ◽  
Lobna Alwaan ◽  
Ahmed Elgendy

Abstract The Messinian Abu Madi Formation represents the most prospective reservoir target in the Nile Delta. Hydrocarbon exploration endeavors in Nile Delta over the last few decades highlighted some uncertainties related to the predictability and distribution of the Abu Madi best reservoir quality facies. Therefore, this study aims at delineating the factors controlling the petrophysical heterogeneity of the Abu Madi reservoir facies in Faraskour Field, northeastern onshore part of the Nile Delta. This work provides the very first investigation on the reservoir properties of Abu Madi succession outside the main canyon system. In the study area, Abu Madi reservoir is subdivided into two sandstone units (lower fluvial and upper estuarine). Compositionally, quartzose sandstones (quartz > 65%) are more common in the fluvial unit, whereas the estuarine sandstones are often argillaceous (clays > 15%) and glauconitic (glauconite > 10%). The sandstones were classified into four reservoir rock types (RRTI, RRTII, RRTIII, and RRTIV) having different petrophysical characteristics and fluid flow properties. RRTI hosts the quartzose sandstones characterized by mega pore spaces (R35 > 45 µm) and a very well-connected, isotropic pore system. On the other side, RRTIV constitutes the lowest reservoir quality argillaceous sandstones containing meso- and micro-sized pores (R35 > 5 µm) and a pore system dominated by dead ends. Irreducible water saturation increases steadily from RRTI (Swir ~ 5%) to RRTIV (Swir > 20%). Additionally, the gas–water two-phase co-flowing characteristics decrease significantly from RRTI to RRTIV facies. The gaseous hydrocarbons will be able to flow in RRTI facies even at water saturation values exceeding 90%. On the other side, the gas will not be able to displace water in RRTIV sandstones even at water saturation values as low as 40%. Similarly, the influence of confining pressure on porosity and permeability destruction significantly increases from RRTI to RRTIV. Accordingly, RRTI facies are the best reservoir targets and have high potentiality for primary porosity preservation.


2013 ◽  
Vol 868 ◽  
pp. 142-145
Author(s):  
Zai Qiang Wang

The research on Putaohua oil layer in Taidong,Songliao Basin using core,logging and seisimic information shows that oil is divided into belts from east to west influenced by faults striking from south to north and oil potential is getting poorer from east to west, oil is mainly distributed in the middle of Putaohua oil layer showing double peaks, and the main reservoir type is fault-lithology reservoir formd by NStrending faults and NW trending channel sandbody on the slope dipping to the southeast. According to the match type between fault and sandbody in single trap ,we draw the accumulation law that oil accumulation area is controlled by single fault-terrace belt; the high-quality reservoir is composed of underwater distributary channel and river sheet sand; vertical oil accumulation height is influenced by fault lateral sealing ability; and oil accumulation horizon is controlled by the match type between fault and sandbody.


2018 ◽  
Vol 6 (2) ◽  
pp. T431-T447 ◽  
Author(s):  
Xiaoming Sun ◽  
Siyuan Cao ◽  
Xiao Pan ◽  
Xiangyang Hou ◽  
Hui Gao ◽  
...  

Volcanic reservoirs have been overlooked for hydrocarbon exploration for a long time. Carboniferous volcanic rocks of the Zhongguai paleouplift contain proven reserves of [Formula: see text]. We have investigated the volcanic reservoirs integrating cores, well, and seismic data, and the proposed volcanic reservoir distribution is controlled by the weathering function, fractures, and lithology. The weathering process makes the originally tight igneous rocks become good-quality reservoirs, and fractures play an important role in connecting different types of pores and act as reservoir space. Isolated and ineffective pores become effective ones due to connection among fractures. Only volcanic breccia can be good-quality reservoirs without any weathering function. The nonlinear chaos inversion controlled by weathered layers shows that the good-quality reservoirs are distributed in the top of the weathering crust and the structural high. Furthermore, fluid-detection attributes and background information prove that oil and gas are distributed along the paleostructural high. The objectives of this study were to (1) describe the characteristics of volcanic reservoirs and determine the controlled rules for reservoir distribution, (2) characterize the distribution of reservoirs and hydrocarbon, and (3) propose an effective workflow for hydrocarbon exploration in volcanic rocks combining geologic and geophysical methods.


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