Migration and plugging characteristics of polymer microsphere and EOR potential in produced-water reinjection of offshore heavy oil reservoirs

Temperature- and Salt-Tolerant 2-Acrylamide-2-methylpropanesulfonic Acid/AM@SiO2 Microgel Particles: Synthesis and Enhanced Oil Recovery Performance Evaluation

“…The AMPS/AM microgel particles could effectively block the high permeability area by swelling in the pore, improving the sweep efficiency of the injection of water, and increasing the oil displacement efficiency of the low permeability area by the fluid diversion. 18,28 As can be seen from Figure 12, under the permeabilities of 3259.5 and 354.6 mD, the oil recovery factor of the highpermeability tube was 50% and about 10 times higher than that of the low-permeability tube (5.8%), and the total oil recovery factor was 30.1%. After the injection of the 0.5 PV AMPS/ AM@SiO 2 microgel particles with a mass fraction of 0.2 wt %, the oil recovery factors of high-and low-permeability sandpacked tubes were 70.2 and 31.9%, respectively, which increase by 20.2 and 26.1%, respectively, and the total oil recovery factor was 52.9%, which is increased by 22.8%.…”

“…The concise review shows that the complex microgel particles using nano-SiO 2 for effectively improving the stability of gel particles, making the gel network structure densified, and enhancing the gel skeleton strength have been rarely reported. The reservoir of X block in Bohai Oilfield has strong heterogeneity and serious water breakthrough, and some well groups have entered the high water-cut region, which thus significantly reduces the sweep efficiency of water injection . Therefore, it is very important and urgent to explore effective technologies to remedy excessive water production and stabilize oil production. , To solve this problem, we managed to synthesize the temperature-and salt-tolerant AMPS/AM@SiO 2 microgel particles that have a small size for easy transportation and injection, high temperature and salinity resistance, and strong deformability for long-distance migration for in-depth profile control treatment in high temperature and high salinity offshore oilfields.…”

A Systematic Method to Investigate the EOR Mechanism of Nanospheres: Laboratory Experiments from Core to Micro Perspective

“…12 After that, the polymer microspheres gradually spread to the low-permeability region and expand, which can adsorb on a rock surface or plug by agglomeration and prevent water invasion. 13 The expansion property of polymer microspheres is of great significance for increasing the plugging area and improving the microscopic plugging efficiency. However, polymer microspheres have some limitations.…”

“…Due to the injection pressure difference, injected polymer microspheres can migrate to the depth of the formation and preferentially enter the pores with large radius and good connectivity . After that, the polymer microspheres gradually spread to the low-permeability region and expand, which can adsorb on a rock surface or plug by agglomeration and prevent water invasion . The expansion property of polymer microspheres is of great significance for increasing the plugging area and improving the microscopic plugging efficiency.…”

Using starch graft copolymer gel to assist the CO2huff-n-puff process for enhanced oil recovery in a water channeling reservoir

“…32,33 However, when applying the polymer gel treatment, its plugging performance would also be negatively affected by the acidic environment created by the CO 2 injection, chromatographic separation of the chemical reagents and irreversible formation damage caused by the polymer injection. 34,35 Therefore, it is necessary to nd a novel gel with stable properties to assist with the CO 2 huff-n-puff.…”