Fault migration

Hippler, S. j. 1997. Microstructures and Diagenesis in North Sea Fault Zones, Implications for Fault-Seal Potential and Fault-Migration Rates. In Surdam, R. C. (ed.) Seals, Traps and the Petroleum System. American Association of Petroleum Geologists Memoir, 67, 85-101. 

Even if all of the elements described so far have been present within a sedimentary basin an accumulation will not necessarily be encountered. One of the crucial questions in prospect evaluation is about the timing of events. The deformation of strata into a suitable trap has to precede the maturation and migration of petroleum. The reservoir seal must have been intact throughout geologic time. If a leak occurred sometime in the past, the exploration well will only encounter small amounts of residual hydrocarbons. Conversely, a seal such as a fault may have developed early on in the field s history and prevented the migration of hydrocarbons into the structure. 

Fault traps—involve the movement of the reservoir rock formation to a position where the formation across the fault plane provides a seal preventing further migration of hydrocarbons (see Figure 2-48). 

Combination tra/ s—sedimentary trap features that result from both stratigraphic and structural mechanisms. There can be many combinations for stratigraphic and structural traps. An example of such a trap would be a reef feature overlaying a porous and permeable sandstone, but in which the sequence has been faulted (see Figure 2-54). Without the fault, which has provided an impregnable barrier, the hydrocarbons would have migrated further up dip within the sandstone. 

Migration of oil over a long period in a dry expansion circuit should be treated as a design fault, and some action taken to put it right. 

Monosulphonated dyes of lower Mr (300-500) and slightly higher wet fastness that migrate more readily and cover dyeing faults (such as carbonising damage) more effectively. 

Molecular reorientations at Bjerrum fault sites are responsible for the dielectric properties of ice. A second type of fault (proton jumps from one molecule to a neighbor) accounts for the electrical conductivity of ice, but cannot account for the high dielectric constant of ice. Further discussion of such ice faults is provided by Franks (1973), Franks and Reid (1973), Onsager and Runnels (1969), and Geil et al. (2005), who note that interstitial migration is a likely self-diffusion mechanism. 

Site 997 with a strong BSR on the ridge crest. Site 996 was drilled some distance away from the BSR, to investigate migration in a fault zone where methane was leaking from the rise. 

The cold seeps of methane migration along the geologic faults or permeable stratigraphic horizons provide concentrations in excess of... 

Migration (secondary) the movement of the hydrocarbons as a single, continuous fluid phase through water-saturated rocks, fractures, or faults followed by accumulation of the oil and gas in sediments (traps, q.v.) from which further migration is prevented. 

The volcanoes of the Roman Province developed in a region characterised by Late Miocene-Quaternary extensional tectonics related to the eastward migration of Apennine mountain range and to the contemporaneous opening of the Tyrrhenian Sea. The volcanic zone is characterised by a system of Upper Miocene to Pleistocene NW-SE basins, developed along normal faults and intersected by strike-slip NE-SW faults (Bartolini et al. 1982). Both fault systems represent zones of crustal weakness along which Roman potassic magmas were intruded. 

The use of traditional and new techniques to elucidate the structure of synthetic faujasites with different silica alumina ratios, dealuminated by steaming and chemical treatment, and with and without faulting will be described. The migration and fixation of cations and the role of aluminum in the dealumination of the zeolite will be discussed. 

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