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Line 1: − The principles of hydrocarbon migration, discussed in this section, can be summarized as follows:+ − • Hydrocarbons migrate as a separate phase, primarily due to buoyancy. This force causes them to move vertically at geologically rapid rates.+ − • Lithologic layers slow or restrict the vertical movement of hydrocarbons. Seals deflect the hydrocarbons laterally up dip through underlying beds to a trap or spill point. Lateral migration is also facilitated by meteoric groundwater flow. Flow rates for compaction-driven water generally are too slow to significantly affect hydrocarbon flow.+ − • The properties of reservoirs and carrier beds (dip, relative permeability, etc.) control the rate of migration and thus the specific direction of the bulk of hydrocarbons under seals.+ + + + + + + + + + + + +
lead - merged another article
'''Migration''' of hydrocarbons is a little-understood but critical process of the [[petroleum system]]. This chapter attempts to address the following questions:
* How does oil escape from the [[source rock]]?
* Does oil migrate out of the trap?
* Why are there marked differences in oil gravity, wax content, and sulfur content in lateral and stratigraphically successive sands?
* Why are there differences in water salinity for multiple sands in one [[structural trap]]?
* What is the role of [[fault]]s in transporting and trapping hydrocarbons?
* Why are there barren sands within sequences of productive sands?
* How is cross-formational flow of hydrocarbons accomplished?
* Does the form change during migration and, if so, which form is dominant under what conditions?
* How can we estimate the timing, volumes, and compositions of transported hydrocarbons?
==Principles of migration==
* Hydrocarbons migrate as a separate phase, primarily due to buoyancy. This force causes them to move vertically at geologically rapid rates.
* Lithologic layers slow or restrict the vertical movement of hydrocarbons. Seals deflect the hydrocarbons laterally up dip through underlying beds to a trap or spill point. Lateral migration is also facilitated by meteoric groundwater flow. Flow rates for compaction-driven water generally are too slow to significantly affect hydrocarbon flow.
* The properties of reservoirs and carrier beds (dip, relative permeability, etc.) control the rate of migration and thus the specific direction of the bulk of hydrocarbons under seals.
Less is known about migration than any other process involved in the accumulation of hydrocarbons in the subsurface. It is generally described as that unknown process or group of processes that enable petroleum to move from a source to a reservoir.
Less is known about migration than any other process involved in the accumulation of hydrocarbons in the subsurface. It is generally described as that unknown process or group of processes that enable petroleum to move from a source to a reservoir.