Calculation of OIIP and Water Influx for Bottom Water Drive Reservoir ( Sarir C-North field in Libya ).

Abstract

This paper is determine water influx using Fekovich method  and the original oil in place of reservoir using  method Havlena,D.,and Odeh  .The material balance method is a powerful technique used to study reservoir performance and describing the important properties of the reservoir , including the estimates of original oil in place and the strength of aquifer.When people calculate water influx using the gas reservoir engineering method, they usually utilize three methods of van Everdingen-Hurst ⁽¹⁾, Carter-Tracy ⁽²⁾ and Fetkovich⁽³⁾. Fetkovich ⁽³⁾ developed a method of describing the approximate water influx behavior of a finite aquifer for radial and linear geometries .The Fetkovich ⁽³⁾ theory is much simpler, and, like the Carter-Tracy ⁽²⁾ technique, this method does not require the use of superposition. Hence, the application is much easier, and this method is also often utilized in numerical simulation models. This approach begins with two simple equations. The first is the productivity index (PI) equation for the aquifer, which is analogous to the PI equation used to describe an oil or gas well. The results show that estimated value of water influx was 36762.86 bbl  for one year and 3092857.415 bbl at the end of seven years and the original oil in place was 310 MMST .