Experimental Investigation of a Mechanically Stable and Temperature/Salinity Tolerant Biopolymer toward Enhanced Oil Recovery Application in Harsh Condition Reservoirs

Chunming Xiong,Dianlin Wang,Jing Lv,Song Zhang,Falin Wei,Liming Shao,Cheng Cai

doi:10.3390/en15051601

Abstract

In search of robust polymers for enhanced oil recovery (EOR) application in reservoirs with harsh conditions, a water-soluble biopolymer was thoroughly investigated in this work to evaluate its applicability in such reservoirs. The experimental data revealed that compared to the commonly used EOR polymer, HPAM, the biopolymer was more efficient in thickening a brine solution as a result of its peculiar conformation. The presence of an electrolyte has almost no effect on the rheology of the biopolymer solution, even at an extremely high salt concentration (20 wt% NaCl). The relation between viscosity and the concentration curve was well fitted to the power-law model. Moreover, the rigid polymer chains rendered the polymer solution superior tolerance to elevated temperatures and salinity, but also led to considerable retention within tight porous media. The adsorption behavior was characterized by the average thickness of the hydrodynamic adsorbed layer on sand grains. The mechanical degradation was assessed by forcing the polymer solutions to flow through an abrupt geometry at ultra-high shear rates. The slight viscosity loss compared to HPAM proved the high mechanical stability of this polymer. These properties made it a promising alternative to HPAM in polymer flooding in the near future for high permeability oil reservoirs with harsh conditions.

Highlights

The use of polymers and polymer-based materials in the petrochemical industry is becoming increasingly important and covers many application areas, such as oilfield produced water treatment [1], oil-in-water separation [2], and wax inhibition coatings [3]
Polymer flooding is considered the simplest chemical enhanced oil recovery (EOR) process, which has been extensively used in oilfields, such as Daqing (China) [4,5] and Pelican Lake (Canada) [6]
It is believed that the enhanced oil recovery performance of a polymer is closely related to three factors: (1) viscosity, (2) elasticity, and (3) permeability reduction capacity

Summary

Introduction

The use of polymers and polymer-based materials in the petrochemical industry is becoming increasingly important and covers many application areas, such as oilfield produced water treatment [1], oil-in-water separation [2], and wax inhibition coatings [3]. Polymer flooding is considered the simplest chemical EOR process, which has been extensively used in oilfields, such as Daqing (China) [4,5] and Pelican Lake (Canada) [6]. The advantage of this technique is that more oil can be produced than all other chemical EOR processes in combination [7]. It is believed that the enhanced oil recovery performance of a polymer is closely related to three factors: (1) viscosity, (2) elasticity, and (3) permeability reduction capacity. In addition to viscosity increase, a more favorable mobility ratio can be reached by decreasing the permeability of porous media

Objectives

Methods

Conclusion