The Research on Optimizing the Plan of New Unary Polymer Surfactant Improving the Effect of Development in Thick Oil Pay

Abstract

Polymer surfactant is a unitary flooding system which be developed in recent years. It has dual characteristics of polymer and surfactant. It has strong solvency even at a lower concentration. It has low molecular weight, counter-mass, high viscosity, anti-shearing force, anti-biodegradation, anti-oxidation degradation, temperature-resistance and salt resistance, and it fits different permeability reservoir. It is also be used to under different mineral degree condition reservoir and be injected with waste water directly. For the situation which not only has the serious invalid injection and production, but also has the oil layer of remaining oil enrichment, the test area carried out comprehensive research on polymer surfactants’ profile modification to improve the development effect of thick oil pay. In this paper, the viscosity increasing property, stability, viscoelatic property, absorption characteristic, interfacial tension, flow characteristic and molecular coil size of the polymer surfactants is studied through laboratory test. The mathematical model of active constituent qualitative change of polymer surfactants flooding is established. The oil displacement scheme of polymer surfactants flooding in test area is optimized. The latest site implementation shows that polymer surfactants has a good suitability for tap potential in thick oil layer, the cumulative oil has increased 5978.5t, and predicting the enhanced oil rate is 1.7 points.

Numerical Simulation of CO2 Diffusion in a Multiliquid-Phase System Using Moving Mesh Technology

“…Global warming and insufficient energy supply have aroused interest in enhanced oil recovery (EOR) with CO 2 and CO 2 capture, utilization and storage (CCUS). − Injection of CO 2 into oil reservoirs known as CO 2 -enhanced oil recovery (EOR) can not only help to store the CO 2 but also improve the recovery of crude oil. − Hence, this process is considered to be the most cost-effective CCUS technique and has been widely used in the development of oilfields. , In CO 2 injection EOR projects, CO 2 diffuses into the formation and helps improve oil recovery by reducing the crude oil viscosity, supplementing the formation energy, swelling oil volume, and reducing the interfacial tension. , Studies have shown that the in situ mass transfer between CO 2 and heavy oil under reservoir conditions is dominated by molecular diffusion and dispersion. , The magnitude of molecular-diffusion coefficients affects the time for the heavy oil to achieve desirable viscosity reduction and swelling effect, thus influencing the oil-production response. , Therefore, the determination of CO 2 diffusion coefficient has extremely important guidance on CO 2 -EOR risk assessment, engineering design, and economic evaluation. , …”

“…9,10 In CO 2 injection EOR projects, CO 2 diffuses into the formation and helps improve oil recovery by reducing the crude oil viscosity, supplementing the formation energy, swelling oil volume, and reducing the interfacial tension. 11,12 Studies have shown that the in situ mass transfer between CO 2 and heavy oil under reservoir conditions is dominated by molecular diffusion and dispersion. 13,14 The magnitude of molecular-diffusion coefficients affects the time for the heavy oil to achieve desirable viscosity reduction and swelling effect, thus influencing the oil-production response.…”