R&D background
The ternary composite flooding has achieved significant oil recovery in China, with an average increase of over 15%. However, ternary composite flooding also encounters many problems, such as high cost of chemical agents, high breakeven point in the form of low crude oil prices, and poor economic benefits; Due to the addition of alkali, environmental pressure is enormous; The injection process is relatively complex, with the injection of several chemical agents, while also preventing scale and corrosion to prevent formation damage; Difficulty in separating oil and water from produced wastewater, resulting in high treatment costs; There is a chromatographic separation phenomenon that affects the effectiveness. For this reason, the oil field urgently needs a displacement agent that combines the efficient viscosity increasing performance of polymers and the emulsification performance of surfactants. It has strong emulsification based stability, high apparent viscosity, appropriate adsorption and plugging control performance, and achieves the goal of "one agent with multiple functions".
Technical approach
Using efficient salt resistant polymers as the main body and introducing an appropriate amount of lipophilic groups to achieve polymer polymer chains. There are two types of hydrophilic and lipophilic groups on the polymer chain, namely the amphiphilic structure, which achieves a certain degree of surface activity. Oil displacement agents have both good viscosity increasing performance and strong emulsification performance, thereby improving oil recovery by improving the oil-water mobility ratio and expanding the injected liquid wave volume, and improving oil displacement efficiency through emulsification dispersion function, thereby comprehensively improving oil recovery.
Technical characteristics
1. Emulsification is one of the main characteristics of active polymers. The emulsification dispersion effect can improve the oil washing efficiency, while the emulsification thickening effect can further increase the viscosity of the polymer solution, improve the profile, and expand the swept volume. This property is determined by the molecular structure, rather than by simply mixing the polymer and surfactant physically. The lipophilic group of the active polymer can be inserted into the oil drop and adsorbed on the oil-water interface as a whole, which can greatly improve the mechanical properties of the interface, reduce the probability of collision and coalescence of oil drops, and thus improve the stability of emulsification. In addition, because the emulsification mechanism of the active polymer is completely different from that of the surfactant, the demulsification process is relatively simple, which has been proved by many field tests.
2. High efficiency tackifying property is also one of the main characteristics of active polymers. The concentration viscosity test under the condition of oilfield simulated sewage shows that the viscosity of active polymer solution is more than 50% higher than that of polyacrylamide under the same conditions, which can significantly save polymer consumption and cost.
