Green EOR Utilizing Well-Defined Nano-Cellulose Based Nano-Fluids from Flask to Field

摘要

The environmental issues of the traditional oilfield chemistries are challenging the Enhanced Oil Recovery (EOR) industry. Therefore, eco-friendly chemical EOR methods must be quickly developed. In this work, an abundant natural polymer on earth, nano-cellulose, was extracted from the plant-based materials and then introduced to EOR. On the basis of the original nano-cellulose, a series of surface-grafting were performed for the interest to make it more favorable for EOR application, thus generating the well-defined nano- cellulose based nano-fluids. The EOR related properties including morphology, thermal stability, rheology, etc., were first studied. The displacement responses of the nano-fluids were then collected. Thereafter, these nano-fluids were introduced to foam EOR as foam film stabilizers. The results showed that the nano-fluids exhibited superior thermal resistance, salt tolerance and viscoelastic properties after surface-grafting. As a result of the amphiphilic nature, the stabilities of surfactant foam in the absence and presence of crude oil were significantly improved by using the tested nano-fluids and 12% of incremental oil recovery was obtained in this stabilized foam flooding. When this nano-fluid was used alone to displace the oil in place, 6% of incremental oil recovery was produced after 0.4 PV nano-fluid slug was injected. The experimental findings obtained from this work promised the nano-cellulose based nano-fluids as green agents in chemical EOR.