Petroleum reservoir

About: Petroleum reservoir is a research topic. Over the lifetime, 5403 publications have been published within this topic receiving 83535 citations. The topic is also known as: petroleum deposit.

Sills in Sedimentary Basins and Petroleum Systems

Abstract: Our knowledge of igneous emplacement in sedimentary basins has been revolutionised by studies of offshore 3D seismic reflection data, where large scale structures and relationships are realised. These offshore data sets require detailed information from onshore analogues to fully understand subsurface structure of such intrusions and their potential effect on petroleum systems. The Inner Hebrides of Western Scotland, which contains an onshore record of the extensive Palaeogene magmatic activity that affected much of the North Atlantic, allows us to examine some of the classic sill geometries on a seismic to sub-seismic (outcrop) scale. As hydrocarbon exploration moves to more challenging basins, it is clear the need exists for us to fully understand the role in which intrusive volcanism plays in active hydrocarbon systems. Intrusions in general can have major effects on prospective sedimentary basins by forming interconnected low-permeability zones which can compartmentalise significant volumes of source and reservoir rock. We present a series of outcrop case studies which allow the potential influences of sills on what would represent potential source and reservoir rock intervals to be addressed and discuss the wider implications for sill emplacement in such basins.

Upper Jurassic updip stratigraphic trap and associated Smackover microbial and nearshore carbonate facies, eastern Gulf coastal plain

Abstract: The development of Little Cedar Creek field in the eastern Gulf coastal plain of the United States has shown that the current exploration strategy used to find hydrocarbon-productive microbial and high-energy, nearshore carbonate facies in the Upper Jurassic Smackover Formation requires refinement to increase the probability of identifying and delineating these potential reservoir facies. In this field, the petroleum trap is a stratigraphic trap characterized by microbial boundstone and packstone and nearshore grainstone and packstone reservoirs that are underlain and overlain by lime mudstone and dolomudstone to wackestone and that grade into lime mudstone and dolomudstone near the depositional updip limit of the Smackover Formation. Reservoir rocks trend from southwest to northeast in the field area. The grainstone and packstone reservoir is thickest in the central part of the field. The boundstone reservoir is thickest in local buildups that are composed of thrombolites in the southern part of the field and is absent along the northern margin. These reservoir facies are interpreted to have accumulated in water depths of approximately 3 m (10 ft) and in 5 km (3 mi) of the paleoshoreline. In contrast to most other thrombolites identified in the Gulf coastal plain, these buildups did not grow directly on paleohighs associated with Paleozoic crystalline rocks. The characterization and modeling of the petroleum trap and reservoirs at Little Cedar Creek field provide new information for use in the formulation of strategies for exploration of other Upper Jurassic hydrocarbon productive microbial and related facies associated with stratigraphic traps in the Gulf coastal plain.

Sedimentology and Sandstone Diagenesis of Hibernia Formation in Hibernia Oil Field, Grand Banks of Newfoundland

Abstract: The Hibernia oil field is the largest discovery off the east coast of North America. The most important reservoir unit in the field is the Upper Jurassic-Lower Cretaceous Hibernia formation, which averages 200 m in thickness and occurs at depths between 3,475 and 4,200 m. On the basis of sedimentological descriptions of cores and downhole log responses, five lithofacies have been defined, and the formation has been subdivided into two lithostratigraphic units. The "Main Hibernia zone" is dominated by thick medium to very coarse-grained quartzarenites, interpreted as distributary channel deposits of a deltaic plain environment. The "Upper Hibernia zone" consists of relatively thin very fine to medium-grained quartzarenites interbedded with mudstones and siltstones. This zo e is interpreted as deposits of a shallow marine delta-front environment. Porosities observed in thin section and provided by core analysis in the Hibernia sandstones range from 1 to 22%. Many sandstones with high porosities show evidence of dissolution of carbonate cement and some framework grains. This late enhancement of porosity by decarbonatization preceded main hydrocarbon migration and is a major factor in both the accumulation of large reserves and the potential producibility of the field. Lower porosities are associated mainly with well-compacted sandstones or those retaining abundant unleached carbonate cements. Time-temperature index modeling constrains the interpreted time and depth of hydrocarbon generation and accumulation in the sandstone reservoirs.