It is estimated that over the next few decades, EOR will be used for the more than 50% of oil production in the US and worldwide. From these, in reservoir with viscositites ranging between 10 – 150 mPa.s, polymer flooding is suggsted as the EOR method. Therefore, there is an upper limit to the recommended range of reservoir oil viscosities for polymer flooding. To address the issue of this limitation of polymer injectivity and pumping efficiency, we propose a novel method. The method involves the use of Supramolecular Systems, which are composed of long-chain aminoacids and maleic acids post complexation. Their unique feature of resersible viscosities allows the operator to overcome injectivity limitations posed by conventional polymer flooding.
Viscosity of supramolecular systems, prior to contact with oil, can be lowered to ease the injection process and improve pumping efficiency. On contact with oil, an external pH stimulus can be introduced that will reverse its viscosity to higher values. Lab-scale studies conducted on supramolecular systems have validated this property of reversibly adjusting viscosity through pH stimulus. These systems also have high salinity and temperature tolerance.
Conventional polymers, on introduction to extreme shear stress and temperature, have a tendency to breakdown. Supramolecular systems, on the other hand, act as "healable polymers" or undergo dis-assembling and re-assembling when subjected to similar conditions. Therefore, due to these molecular scission processes, these systems are considered to be durable in confining environment. In reservoirs where thermal EOR methods are not suitable candidates, supramolecular system can have significant use due to its high temperature tolerance.
The objective of this work is to futher develop these novel supramolecular systems by studying its cost-effectiveness and feasibility through a reservoir simulation model (stratified reservoir). In this study, we will be focusing on the economics of polymer injection.