VARIATION OF SATURATION PRESSURE VALUES IN MISHRIF AND ZUBAIR RESERVOIRS IN RUMAILA OILFIELD, SOUTHERN IRAQ

Nada Shaker

doi:10.46717/igj.53.1e.2ry-2020-07-02

Abstract

Reservoir fluid, pressure volume temperature properties such as bubble point pressure, gas solubility, oil and gas formation volume factors, and viscosities are important elements in the reservoir management and field development. Therefore, this study aims to distribute the bubble point pressure on the main oil reservoirs in the Rumaila oilfield, laboratories tests results from 103 pressure volume temperature reports were used, these tests were obtained from the Mishrif, Upper Shale and Main pay reservoirs. Pressure gradient in the study area was defined using Surfer14 software, and in order to avoid the variation of low-pressure areas in the future drilling wells plan, continuous monitoring and focus on these areas, pressure maps were drawn then reading graduation of pressure on these maps to obtain final formula to adopt a specific range of saturation pressures values and distribute them among Rumaila oilfield. The study also compares between the main sub-units of the Main pay reservoir and Mishrif reservoir in the North Rumaila and other reservoirs in the South Rumaila oilfield as well as to define other factors in pressure volume temperature reports such as gas oil ratio, viscosity and formation volume factor that contribute to the saturation pressure variation.

Highlights

Rumaila is the largest oilfield in Iraq, it is located 50 km west of Basra city, Southern Iraq (Fig. 1)
This study aims to distribute the bubble point pressure on the main oil reservoirs in Rumaila oilfield to avoid the low-pressure areas in future drilling wells plan, continuous monitoring and focus on these areas
Fourteen wells were used to conduct the study in the Mishrif reservoir in North Rumaila oilfield, these thermodynamic studies were collected in the 1970s by South Oil Company, the owner of the field

Summary

Introduction

Rumaila is the largest oilfield in Iraq, it is located 50 km west of Basra city, Southern Iraq (Fig. 1). The field was discovered in 1953 and been operated in 1972, with oil reserves of about 17 billion barrels (Basra oil company 2016). Pressurevolume temperature (PVT) properties (such as bubble point pressure), gas solubility, oil and gas formation volume factors and viscosities are critical in the reservoir engineering management and computations (Vetter and Farone, 1987). Bubble point pressures (Pb) and gas solubility (Rs) are two of the most critical parameters used to characterize an oil reservoir (BP, 2013), as they play a vital role in the reservoir management and reservoir simulation. The accurate determination of these properties is one of the main challenges in reservoir development and management. The oil formation volume factor is important in the primary and subsequent development of any oil field (Karim, 1992)

Objectives

Methods

Results

Conclusion