Investigating Productivity of Vertical and Horizontal Wells in One of the Persian Oil Fields

Abstract

First horizontal well in Iran was drilled in July 1992 in Marun oil field. Since then, most of the Persian giant oil fields have experienced horizontal drilling. This can be considered as a step towards improved recovery. In this paper we try to compare the productivity of vertical and horizontal wells in a particular field. This field is located in the Southern part of Iran, with two separate carbonate reservoirs, R1 and R2. R1 is on the top and R2 in the bottom. An impermeable layer separates the two reservoirs. In this field about 50% of drilled wells are horizontal. Production results from horizontal wells are not satisfactory, and in most cases productivity index of horizontal wells is equal or even less than vertical wells, therefore the reasons should be investigated.