Shengtuo Oilfield Es2 Reservoir, Polymer Flooding After Polymer And Surfactant Flooding Technology Research

In the most domestic oil fields with high water cut period, the continuous development of enhanced oil recovery technology has become the dominant technology in a sustained and stable development of high water cut stage oilfield. In the two major oilfield Daqing, Shengli, polymer flooding as the representative of EOR technology has been industrialized. Especially in Shengtuo Oilfield, with the continuous polymer flooding, Production decline of25%to30%after the effective period and the moisture content is rising, which is extremely detrimental to the sustained and stable EOR of the oil field. To some extent, field tests show that the polymer flooding expands the displacement fluid swept volumeand and improves inter-layer heterogeneity, But some continuous oil not affected by displacement fluid and the crude oil still stacked in the pores of the affected area are amounted to about50%.Therefore, the study of the oil recovery technology of further improving the remaining after polymer flooding has a certain economic value and theoretical significance. Polymer surfactant compound flooding is a new type of chemical flooding technology which combined two displacing agent-the polymer and active agent together, based on the advantage of a single chemical flooding. Such flooding technology achieves the requirements of enhanced oil recovery by increasing the swept volume and improving the efficiency of the oil wash, and avoids the various problems in the ASP flooding technology.This article Based on moisture content rising reservoir of Shengtuo Oilfield Shaerduan after polymer flooding, A optimum synergistic surfactant is elected polymer by testing performance of five polyacrylamide modified polymer (viscosity increasing capacity, temperature resistance, salt resistance, anti-dilution resistance, shear resistance, the ability of establishment resistance and residual resistance factor) and the basic performance of7kinds of oilfield commonly used surfactants HD, OP-10, AEC-10, Tween-80of SDBS, YND, and NNR (surface/interfacial tension, wettability) and compounding the selected optimum performance polymer SW-1and surfactant HD, OP-10, AEC-10, YND; The amount of SW-1and surfactant impacting surfactant and apparent viscosity of the binary system have been discussed, Further optimizing the optimum polymer surfactant binary compound flooding formulation. And, Polymer surfactant compound flooding oil displacement efficiency have been evaluated, through the one-dimensional heterogeneous model, the parallel one-dimensional heterogeneous model and "heterogeneous model".The experimental results show that:the surfactant HD, OP-10and the polymer SW-1have more synergy; The HD binary composite system is able to maintain excellent surface/interfacial activity and viscoelastic after compound, and binary system of formulation1500mg/LSW-1+2000mg/LHD have been selected. Flooding tests show that the polymer surfactant compound flooding system could improve residual oil recovery by10percentage points after polymer flooding in different permeability, penetration range and non-homogeneous conditions, which has excellent oil displacement efficiency.