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.

Altamont-Bluebell--A Major, Naturally Fractured Stratigraphic Trap, Uinta Basin, Utah

Abstract: The Altamont-Bluebell trend is composed of a highly overpressured series of oil accumulations in naturally fractured, low-porosity, Tertiary lacustrine sandstones. It now covers more than 350 sq mi (907 km2) located across the deeper part of the Uinta basin of northeastern Utah. Postdepositional shift of the structural axis of the basin in late Tertiary time produced a regional updip pinchout of northerly derived sandstones into a lacustrine "oil-shale" sequence. Facies shifts during the deposition of more than 15,000 ft (4,570 m) of lacustrine sediments have resulted in a changing pattern of reservoir distribution and hydrocarbon charge at various stratigraphic levels. About 8,000 ft (2,440 m) of stratigraphic section is oil bearing, and up to 2,500 ft (760 m) of section contains overpressured producing zones in the fairway wells. Reservoir performance is significantly enhanced by vertical fractures and initial fluid-pressure gradients, some of which exceed 0.8 psi/ft. The crude has a high paraffin content resulting in pour points above 100°F (37.78°C), gravities of 30-50° API, and an average GOR of 1,000 cu ft/bbl. This unique combination of geologic and hydrocarbon conditions makes it difficult to evaluate the ultimate recovery of the field, which could be more than 250 million bbl.

The Prediction of Permeability From Well Logging Data Based on Reservoir Zoning, Using Artificial Neural Networks in One of an Iranian Heterogeneous Oil Reservoir

Abstract: The distinct characteristics of Iranian oil reservoirs, such as high pressure, heterogeneity and anisotropy, high thickness, carbonation, huge size, and presence of cracks and various rock types, lead to deficiency of present applications of neural network methods. The authors attempt to improve the proficiency of present methods in one of Iranian heterogeneous oil reservoirs for permeability prediction using the well logging data, by zoning the reservoir on the basis of geology characteristics and sorting the data in correspondence. The obtained results from the well logging data using artificial neural networks are compared with the measured permeability in core analysis experiments. The appropriate compatibility of the results confirms the proposed method.

Shuaiba reservoir geological study, Yibal field, Oman

Abstract: The Yibal oil field in west central Oman is a large dome created by deep-seated salt movement. The maximum oil column is 370 ft (112.8 m) and the productive area is about 4.3 x 6.2 mile (7 x 10 km). The structure is complicated by extensive tensional faulting. The main oil accumulation is in the Shuaiba chalk overlain disconformably by the Nahr Umr shale. The Shuaiba reservoir is in pressure communication with the underlying Kharaib formation. It is speculated that early accumulation of oil played a major role in preserving the high porosity and greater crestal reservoir thickness by inhibiting diagenetic processes. This field study provided the reservoir simulation engineer with a viable geological and petrophysical model of the Shuaiba reservoir to aid in understanding observed phenomena.

Fracturing in Spraberry Reservoir, West Texas

Abstract: The Spraberry formation of West Texas is developed in the lower Leonard of middle Permian, restricted in most part to the Midland basin. The main producing structure is a fractured permeability trap on a homoclinal fold. This homogeneous mass is undifferentiated except as to alternate layers of sands, siltstones, shales, and limestones, deposited in a deep basin under stagnant conditions with hydrocarbons formed throughout the 1,000 feet of sedimentary rocks. Fractures were created by tensional forces after induration, probably during post-Leonard time. With storage of the oil reservoir in the sandstone matrix, the fractures serve as "feeder lines" to conduct the oil to the bore hole. Without these fractures commercial production would be from a seemingly "too-tight" reservoir rock. The producing area of the Spraberry formation is a "fairway" 150 miles long and 50 miles wide at an average depth of 6,800 feet. The main area, however, is 50 miles long, with width ranging from a few miles to 48 miles, thus creating a triangle of 488,000 proved and semi-proved productive acres.