Numerical simulation and field application of biological nano-technology in the low- and medium-permeability reservoirs of an offshore oilfield

Abstract

As a result of deep burial depth, small pore throat, poor connectivity between pores, different clay mineral contents in reservoirs, and strong reservoir sensitivity, injection wells often have problems such as rapidly increasing water-injection pressure and insufficient water-injection quantity in the process of water-injection development. The main measures used to solve the difficulties of water injection in low-permeability reservoirs include fracturing, acidizing, and surfactant depressurization and injection increase, all of which have some disadvantages of high cost and environmental damage. In recent years, depressurization and injection-increase environment-safe bio-nano-materials have been introduced into low-permeability reservoirs and have achieved good application results in China. On the other hand, although there have been many researches on EOR (enhanced oil recovery) of nano-materials, the numerical simulation field of nano-depressurization and injection-augmenting technology is still a blank that the wettability mechanism of nano-materials and EOR nano-materials used in bio-nano-depressurization and injection-augmenting technology are almost completely opposite, and the influence of adsorption on formation is almost completely opposite. The adsorption of nanoparticles in other EOR studies will reduce the porosity and make the reservoir more hydrophilic. Nanoparticles used in biological nano-technology will produce hydrophobic film near the well, which will reduce the seepage resistance through the slip of water phase. In this study, a set of water flooding model of numerical simulation technology for depressurization and injection-augmenting of biological nano-materials considering adsorption characteristics and reservoir physical properties was established, the sensitivity analysis of key injection parameters was carried out, and the application effect prediction chart of biological nano-technology was drawn, and the model and prediction chart were verified by real oilfield data. As far as we know, this is the first numerical simulation study on biological nano-technology that has been applied in oil fields.

Laboratory Experiment and Application Evaluation of a Bio-Nano-depressurization and Injection-Increasing Composite System in Medium–Low Permeability Offshore Reservoirs

“…After being injected into the water injection well, it drives away the pore hydration film around the bottom of the well to increase the pore seepage area and form a hydrophobic film of nano-thickness, resulting in water phase slip to reduce the seepage resistance, − thereby reducing the injection pressure of the water injection well. It has achieved very good results in the field pilot experiment in Bohai Oilfield. − …”

Research on Characterization Technology and Field Test of Biological Nano-oil Displacement in Offshore Medium- and Low-Permeability Reservoirs

“…In a recent numerical simulation field, the E-amin research group has done some research on the transfer and mass transfer of nanoparticles in porous media and established a systematic flow coupling equation method of nanoparticles in porous media. − Pryazhnikov and Guzei et al simulated the oil displacement process of nanoparticles from the micropore point of view, studied the flow characteristics of the oil displacement process of nanoparticles, and optimized the influencing factors of oil displacement by nanoparticles. − However, there are still few reports about nanoparticles used in the field, and the numerical simulation of reservoir scale in this area is even rarer. , Therefore, most of these studies are still confined to laboratory tests or theoretical stages, and there is no verification of relevant field information reports.…”

“…37 − 40 However, there are still few reports about nanoparticles used in the field, and the numerical simulation of reservoir scale in this area is even rarer. 41 , 42 Therefore, most of these studies are still confined to laboratory tests or theoretical stages, and there is no verification of relevant field information reports.…”

Mechanism of Nano-depressurization and Injection-Augmenting Technology and Its Application in China’s Oilfields: Recent Advances and Perspectives

“…The result showed that the modified silica nanoparticles are adsorbed on the surface of the core and form a hydrophobic layer, changing the wettability of the sand surface from water wet to oil wet, thereby decreasing the flowing pressure. 18 Gao et al 19 established a set of biological nanomaterial depressurization and injection-augmenting numerical simulation technology water flooding models that consider the adsorption characteristics and reservoir physical properties. They also conducted a sensitivity analysis on the key injection parameters, drew the application effect prediction graph of the biological nanotechnology, and verified the model and prediction graph with actual oilfield data.…”