Experimental Study on Water Sensitivity Difference Based on Oiliness of Porous Medium Rock

Jie Li,Wei Li,Li Li

doi:10.1155/2017/5758046

Abstract

This study presents the differences of water sensitivity experiment of porous medium rock between conventional dry core samples and oil-bearing core. The comparison was made to analyze the impact of single-phase fluid and multiphase fluid on the actual sensitivity of rock. The nuclear magnetic resonance (NMR) test was carried out to reveal the distribution of oil in porous medium and the microscopic influence mechanism of oil phase. The study shows that the initial oil in place could isolate the clay from water, and then the expansion and the migration of the clay were prevented to reduce the decrease of degree of damage.

Highlights

Along with the continuous reduction of conventional geological reserves, the discovery of geological reserves becomes more and more difficult
The dry core flooding test method is widely used in recent years to evaluate the water sensitivity in China, which is adopted to diagnose the mechanisms of formation damage
CT scanning technique was used widely for quantitative evaluation of reservoir damage mechanism [11, 12]. While all these sensitivity experiment studies are made by utilization of dry core and the impact of oil-bearing is not considered in the study, it is possible that research cognition exaggerates the impact of sensitivity

Summary

Introduction

Along with the continuous reduction of conventional geological reserves, the discovery of geological reserves becomes more and more difficult. The dry core flooding test method is widely used in recent years to evaluate the water sensitivity in China, which is adopted to diagnose the mechanisms of formation damage. CT scanning technique was used widely for quantitative evaluation of reservoir damage mechanism [11, 12] While all these sensitivity experiment studies are made by utilization of dry core and the impact of oil-bearing is not considered in the study, it is possible that research cognition exaggerates the impact of sensitivity. This paper provides a theoretical and technical basis for prevention of water injection damage in the actual production process of oilfield and quantitatively proposes the impact of water sensitivity on ultimate recovery

Water Sensitivity Experiment

Experimental Porous Medium Rock Samples and Fluids

Experiment and Analysis on Oil-Bearing Core

Oil Saturations Impact on the Water Sensitivity Damage

Findings

Analysis of Microscopic Mechanism for Core Water Sensitivity Damage