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.

Geological mode and hydrocarbon accumulation mode in Muglad passive rift basin of Sudan

Abstract: Muglad Basin in Sudan is a passive rift basin.It was resulted from the extensional tectonics of the dextral shear stress field in the shear zone of middle Africa.It is different from the active rift basin formed by the uplift of mantle convection.The multi-phase rifting and sagging cycles are obvious in the basin.In the vertical direction,there are three phases of rifts with the strong-weak-strong pattern,respectively.The geothermal gradient in Muglad Basin is lower than that in active rift basin and higher than that in cratonic basin.The main structure stale is half graben.In generally,the basin (mainly in Block 1/2/4) can be characterized by an uplift,two depressions and two slopes.The depressions and uplifts arranged in alternative pattern and have different characteristics in the east and the west parts.There developed many sets of oil source rocks.The Abu Gabra Formation generated in the first rift phase is the principle oil source bed in the basin.The assemblage of Bentiu reservoir rock and Aradeiba regional cap rock formed the chief oil-bearing beds.The tilted antithetic normal fault blocks are the main traps,where the enclose ability of the reservoir and the height of oil column were decided by the throw of the fault and lithology in both sides of the fault.The Muglad Basin has predominant hydrocarbon forming conditions and a great exploration potential.

Petroleum system analysis of the Khatatba Formation in the Shoushan Basin, north Western Desert, Egypt

Abstract: The Middle Jurassic Khatatba Formation is an attractive petroleum exploration target in the Shoushan Basin, north Western Desert, Egypt. However, the Khatatba petroleum system with its essential elements and processes has not been assigned yet. This study throws the lights on the complete Khatatba petroleum system in the Shoushan Basin which has been evaluated and collectively named the Khatatba-Khatatba (!) petroleum system. To evaluate the remaining hydrocarbon potential of the Khatatba system, its essential elements were studied, in order to determine the timing of hydrocarbon generation, migration and accumulation. Systematic analysis of the petroleum system of the Khatatba Formation has identified that coaly shales and organic-rich shales are the most important source rocks. These sediments are characterised by high total organic matter content and have good to excellent hydrocarbon generative potential. Kerogen is predominantly types II–III with type III kerogen. The Khatatba source rocks are mature and, at the present time, are within the peak of the oil window with vitrinite reflectance values in the range of 0.81 to 1.08 % Ro. The remaining hydrocarbon potential is anticipated to exist mainly in stratigraphic traps in the Khatatba sandstones which are characterised by fine to coarse grain size, moderate to well sorted. It has good quality reservoir with relatively high porosity and permeability values ranging from 1 to 17 % and 0.05–1,000 mD, respectively. Modelling results indicated that hydrocarbon generation from the Khatatba source rocks began in the Late Cretaceous time and peak of hydrocarbon generation occurred during the end Tertiary time (Neogene). Hydrocarbon primarily migrated from the source rock via fractured pathways created by abnormally high pore pressures resulting from hydrocarbon generation. Hydrocarbon secondarily migrated from active Khatatba source rocks to traps side via vertical migration pathways through faults resulting from Tertiary tectonics during period from end Oligocene to Middle Miocene times.

Petroleum systems framework of significant new oil discoveries in a giant Cretaceous (Aptian–Cenomanian) clinothem in Arctic Alaska

Abstract: Recent oil discoveries in an Aptian–Cenomanian clinothem in Arctic Alaska demonstrate the potential for hundred-million- to billion-barrel oil accumulations in Nanushuk Formation topsets and Torok Formation foresets–bottomsets. Oil-prone source rocks and the clinothem are draped across the Barrow arch, a structural hinge between the Colville foreland basin and Beaufort Sea rifted margin. Stratigraphic traps lie in a favorable thermal maturity domain along multiple migration pathways across more than 30,000 km2 (10,000 mi2). Sediment from the Chukotkan orogen (Russia) filled the western Colville basin and spilled over the Beaufort rift shoulder, forming east- and north-facing shelf margins. Progradational shelf margin trajectories change abruptly to “sawtooth” trajectories at midclinothem, the result of reduction in sediment influx. Two stratigraphic trap types are inferred in Nanushuk basal topsets in the eastern part of the clinothem: (1) lowstand systems tracts, inferred to reflect forced regression, include a narrow, thick progradational stacking pattern perched on a sequence boundary on the upper slope; and (2) highstand-progradational systems tracts include a broad, thin wedge of shingled parasequences above a toplap surface. Both include stratigraphically isolated sandstone sealed by mudstone. Trap geometries in Torok foreset and bottomset facies in the same area include basin-floor fan, slope-apron, and slope-channel deposits that pinch out upslope and are sealed by mudstone. Significant potential exists for the discovery of additional oil accumulations in these stratigraphic trap types in the eastern part of the clinothem. Less potential may exist in the western part because reservoir–seal pairs may not be well developed.

Primär och sekundär migration av hydrokarboner

Abstract: The purpose of this literature study is to explain the primary and secondary migration of hydrocarbons. Primary migration is the process when hydrocarbons, after their maturation in the source rock, are migrating to the reservoir rock. The main reason for primary migration is supposed to be cracking within the source rock or transportation with subsurface waterflows acting to a depth of about 2000 m. In the reservoir rock the secondary migration takes place where the hydrocarbons under favourable conditions may get trapped. The movement of hydrocarbons in the reservoir is due to density differences, float-force and capillary pressure. Some cases in the North Sea, Norwegian Sea and Baltic Sea have also been examined and their evolution described. The study has shown there are differences in the basin history.