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.

Simulation of Naturally Fractured Reservoirs

Abstract: A three-dimensional, three-phase reservoir simulator was developed to study the behavior of fully or partially fractured reservoirs It is also demonstrated, that when a fractured reservoir is subject to a relatively large rate of pressure drop and/or it composed of relatively large blocks, the pseudo steady-state pressure concept gives large errors as compared with transient fromulation In addition, when gravity drainage and imbibitum processes, which is the most important mechanism in the fractured reservoirs, are represented by a ''lumped parameter'' even larger errors can be produced in exchange flow between matrix and fractures For these reasons, the matrix blocks are gridded and the transfer between matrix and fractures are calculated using pressure and diffusion transient concept In this way the gravity drainage is also calculated accurately As the matrix-fracture exchange flow depends on the location of each matrix grid relative to the GOC and/or WOC in fracture, the exchange flow equation are derived and given for each possible case The differential equation describing the flow of water, oil, and gas within the matrix and fracture system, each of which may contain six unknowns, are presented The two sets of equations are solved implicitly for pressure water, and gas stauration inmore » both matrix and fractures The first twenty two years of the history of Haft Kel field was successfully matched with this model and the results are included« less

Quantitative fracture study; sanish pool, McKenzie County, North Dakota

Abstract: The Devonian Sanish pool of the Antelope field has several unusual characteristics which make it almost unique in the Williston basin. Some of these are: (1) high productivity of several wells from a nebulous, ill-defined reservoir; (2) association with the steepest dip in the central part of the basin; (3) very high initial reservoir pressure; and (4) almost complete absence of water production. Analysis of these factors indicates that Sanish productivity is a function of tension fracturing associated with the relatively sharp Antelope structure. Fracture porosity and fracture permeability can be related mathematically to bed thickness and structural curvature (the second derivative of structure). It is found that fracture porosity varies directly as the product of bed thickness times curvature and that fracture permeability varies as the third power of this product. A map of structural curvature in the Sanish pool shows good coincidence between areas of maximum curvature and areas of best productivity. Volumetric considerations show that the quantities of oil being produced cannot be coming from the Sanish zone. It is concluded that the overlying, very petroliferous Bakken Shale is the immediate, as well as the ultimate, source of this oil. The role of the Sanish fracture system is primarily that of a gathering system for many increments of production from the Bakken. The extremely high initial reservoir pressure indicates that the Sanish-Bakken accumulation is in an isolated, completely oil-saturated reservoir and, hence, is independent of structure in the normal sense. Similar accumulations should be present anywhere in the Williston basin where a permeable bed, of limited areal extent, is in direct contact with either of the two Bakken shale beds.

Petroleum geology and potential hydrocarbon plays in the Gulf of Suez rift basin, Egypt

Abstract: The Gulf of Suez in Egypt has a north-northwest–south-southeast orientation and is located at the junction of the African and Arabian plates where it separates the northeast African continent from the Sinai Peninsula. It has excellent hydrocarbon potential, with the prospective sedimentary basin area measuring approximately 19,000 km 2 , and it is considered as the most prolific oil province rift basin in Africa and the Middle East. This basin contains more than 80 oil fields, with reserves ranging from 1350 to less than 1 million bbl, in reservoirs of Precambrian to Quaternary age. The lithostratigraphic units in the Gulf of Suez can be subdivided into three megasequences: a prerift succession (pre-Miocene or Paleozoic–Eocene), a synrift succession (Oligocene–Miocene), and a postrift succession (post-Miocene or Pliocene–Holocene). These units vary in lithology, thickness, areal distribution, depositional environment, and hydrocarbon importance. Geological and geophysical data show that the northern and central Gulf of Suez consist of several narrow, elongated depositional troughs, whereas the southern part is dominated by a tilt-block terrane, containing numerous offset linear highs. Major prerift and synrift source rocks have potential to yield oil and/or gas and are mature enough in the deep kitchens to generate hydrocarbons. Geochemical parameters, sterane distribution, and biomarker correlations are consistent with oils generated from marine source rocks. Oils in the Gulf of Suez were sourced from potential source rock intervals in the prerift succession that are typically oil prone (type I), and in places oil and gas prone (type II), or are composites of more than one type (multiple types I, II, or III for oil prone, oil and gas prone, or gas prone, respectively). The reservoirs can be classified into prerift reservoirs, such as the Precambrian granitic rocks, Paleozoic–Cretaceous Nubian sandstones, Upper Cretaceous Nezzazat sandstones and the fractured Eocene Thebes limestone; and synrift reservoirs, such the Miocene sandstones and carbonates of the Nukhul, Rudeis, Kareem, and Belayim formations and the sandstones of South Gharib, Zeit, and

Organic-rich Marcellus Shale lithofacies modeling and distribution pattern analysis in the Appalachian Basin

Abstract: The Marcellus Shale is considered to be the largest unconventional shale-gas resource in the United States. Two critical factors for unconventional shale reservoirs are the response of a unit to hydraulic fracture stimulation and gas content. The fracture attributes reflect the geomechanical properties of the rocks, which are partly related to rock mineralogy. The natural gas content of a shale reservoir rock is strongly linked to organic matter content, measured by total organic carbon (TOC). A mudstone lithofacies is a vertically and laterally continuous zone with similar mineral composition, rock geomechanical properties, and TOC content. Core, log, and seismic data were used to build a three-dimensional (3-D) mudrock lithofacies model from core to wells and, finally, to regional scale. An artificial neural network was used for lithofacies prediction. Eight petrophysical parameters derived from conventional logs were determined as critical inputs. Advanced logs, such as pulsed neutron spectroscopy, with log-determined mineral composition and TOC data were used to improve and confirm the quantitative relationship between conventional logs and lithofacies. Sequential indicator simulation performed well for 3-D modeling of Marcellus Shale lithofacies. The interplay of dilution by terrigenous detritus, organic matter productivity, and organic matter preservation and decomposition affected the distribution of Marcellus Shale lithofacies distribution, which may be attributed to water depth and the distance to shoreline. The trend of normalized average gas production rate from horizontal wells supported our approach to modeling Marcellus Shale lithofacies. The proposed 3-D modeling approach may be helpful for optimizing the design of horizontal well trajectories and hydraulic fracture stimulation strategies.

Influence of Common Sedimentary Structures on Fluid Flow in Reservoir Models

Abstract: This study summarizes the state of the art of deriving detailed permeability-distribution models on the basis of cores, sidewall samples, and logs. Reservoir heterogeneities such as clay drapes and intercalations, cross-bedding, sand laminations, slumping and burrowing in various major depositional environments are examined. 30 refs.