Analysing the relationship between skin and formation damage of an oil well (time depended)

Abstract

The concept of skin and formation damage play a vital role in productivity of an oil well. The objective of this study is to introduce the effect of skin into the well flowing equation in transient state. The effect of formation damage zone on the well flowing pressure was introduced to the original solution of diffusivity equation by considering three scenarios. In the first scenario it was assumed that oil is flowing through the reservoir with average (effective) permeability. In the second scenario it was assumed that the oil is flowing with the permeability of reservoir till the boundary of formation damage zone and within the altered zone, oil is flowing with the permeability of damage zone. The third scenario is similar to the second scenario, however it was assumed that the oil is flowing within the altered zone with an average permeability. By considering the difference between calculated reservoir permeability for all three scenarios and assumed values, scenario three was selected as the most suitable way to introduce the effect of skin in to the well flowing equation in transient condition.