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.
