Synthesis of a low viscosity amphoteric polyacrylamide and its application in oilfield profile control

Abstract

A low viscosity amphoteric polyacrylamide (LHPAM) was synthesized with Acrylamide and a Cationic etherifying agent. FTIR, SEM, and EDS all suggest that it successfully synthesized a new material. It can be demonstrated from TG and DSC that the temperature resistance of LHPAM is higher than that of partially hydrolyzed polyacrylamide (HPAM) and it can be found from ultraviolet–visible spectrophotometer that the flocculability of LHPAM is stronger than that of HPAM. The viscosity testing shows that the viscosity of LHPAM is greater than that of HPAM at the beginning, but the viscosity of LHPAM has been ultimately lower than that of HPAM after 1d. In addition, LHPAM reacts with Cr3+ to form a gel with an interpenetrating network structure, while HPAM is a gel with a comb‐shaped system, and the gelation time of LHPAM is longer than that of HPAM. However, the final gelation strength is the same. The final flow experiment shows that the plugging rates of LHPAM and HPAM are greater than 95%, but the resistance coefficient of LHPAM is smaller than that of HPAM. This study expands the application of HPAM in profile control and water shutoff, which is of great significance for enhanced oil recovery.

Preparation of hydrophobic nano calcium carbonate and its application in EOR

“…Functional group analysis was performed by using a WQF-520 FTIR. Specific experimental methods: Sample preparation was carried out according to the ratio of sample and KBr 1:100, and the absorption spectrum at 4000-500 cm -1 wavelength was measured with a WQF-520 FTIR [22].…”

“…Then, continued to inject nano oil flooding system into the core at 0.1mL/min, recorded the injection pressure, oil production and water production until the oil cannot be driven out. Finally, calculated oil recovery [22]. In the experiment, the confining pressure was 4MPa and the simulated reservoir temperature is 60℃.…”

Investigation of Polyvinyl Alcohol–Phenolic Aldehyde–Polyacrylamide Gel for the Application in Saline Oil Reservoirs for Profile Modification

“…Due to the special reservoir environment (high temperature and high salinity), the stability of conventional profile control plugging agents is weakened, − and the high permeability layer seriously affects the water flooding operation, which limits the recovery rate. , As one of the most effective methods in the process of reservoir profile control and water plugging and enhanced oil recovery, the polymer gel profile control system is mainly composed of polyacrylamide (PAM), hydrolyzed polyacrylamide (HPAM), acrylamide (AM), and the organic or inorganic cross-linking system; − furthermore, the carboxylic acid groups of PAM hydrolysis are also coordinated with the multivalent cation. − However, the field application of conventional gel profile control agents in Tahe oilfield still has limitations. , In the research process of gel profile control agents with high-temperature resistance and high salt, phenol-formaldehyde gel has been widely used, ,− but the toxicity of formaldehyde limits its application . In addition, EOR technology using profile control agents or oil displacement agents accounts for two-thirds of the initial oil production .…”