* Size of the aquifer,
* Permeability of the reservoir and aquifer
* Thickness of the reservoir open water
* If you push back or side is.
If removal of the reservoir is greater than the rate at which water can enter the reservoir pressure decline. On the other hand, excessive extraction rates individual wells or areas of low permeability, causing excessive pressure drop between the reservoir and wells, creating great pressure sinks in these wells.
In a uniform sand, sinks pressure caused by high rates of extraction can result in a cone of water (Coning) towards the completion interval.
In a stratified sand, high extraction rate of fluids may result in the pipeline (Fingering) of water over the sands of high permeability and to the wells, even though the wells are completed on the contact water – oil ( WOC).
When a Fingering or Coning has reached the completion interval, tends to become stable and persist in a continuous water production because the relative permeability to oil has been reduced as a result of increased water saturation.
In some wells, the rock and fluid characteristics are such that the cone subsist even if the rate of production is reduced.
Fingering development or Coning of large-scale water through the reservoir will reduce the ultimate recovery (EUR-Enhanced Ultimate Recovery) because the natural energy of push of water is being used to produce water instead of forcing the oil before the water. In addition, this early water production will reduce the economic benefit to the use of force early artificial lift equipment and requirement of handling water volumes increased for the same amount of oil.