Publisher's Synopsis
It is widely accepted today that oil and natural gas originate from microbial and/or thermal degradation of organisms (plants and animals) deposited together with inorganic clastic (clay and sand) or chemical (limestone) sediments on the bottom of the oceans, lagoons or lakes. The amount of these organisms per unit volume of rock depends on environmental conditions existing at the time of sedimentation. The highest concentrations of organic matter occurs in shallow, calm and warm waters, that is, in general, along the continental slope, a short distance from the shore. In these conditions clayey clastic sediments are predominant: consequently, the source rocks are very often composed almost entirely. During the evolution of petroliferous sedimentary basin, the clay minerals contained in the rocks undergo a series of changes in composition and crystal structure in response to tectonics and sedimentation. The amount and type of clay minerals are a function of the provenance of clastic minerals and of diagenetic reactions at shallow and greater depth in different tectonic and sedimentary settings. This 1st volume of Encyclopaedia of Physics of Petroleum Reservoirs covers the up-to-date information on the physical properties of reservoir rocks, reservoir fluids, determination method and engineering application. This volume is intended to offer the practicing engineer and engineering student these new cutting-edge techniques for prediction and forecasting in petroleum engineering and environmental management. As for gaseous hydrocarbon it is fairly certain that the migration takes place in the form of water solution; as for liquid ones is not yet clear whether the migration occurs by means of micro-emulsion in water or solution. For oil and gas exploration, we need at least to confirm the exploration area has potential source that generates the oil and gas. This drives geologists to study the potential source rocks to understand if the organic matter in the source rock can generate hydrocarbons at a given depth in a specific geologic time and when the generated hydrocarbons reach the expulsion peak. Once the hydrocarbon fluids reach the permeable layers (sand, sandstone, limestone and dolomite) in contact with the source rock, oil and water move inside the same, in the direction of the local gradient of the hydraulic potential (secondary migration). Hydrocarbons, lighter than water, separate by gravity inside the porous and permeable.