Pilot Field Test of Surfactant Flooding in Thin and Poor Reservoirs

In order to further improve the oil recovery of the middle and low permeability reservoirs, the Institute of Chemistry of the Chinese Academy of Sciences has developed a new type of chemical oil displacement agent-surface poly-surfactant, the surface poly-surfactant combines the advantages of polymer and Surfactant and has high viscosity and Solubility properties. The result of oil displacement experiment in laboratory shows that the effect of polymer flooding is better than that of common polymer flooding with the same molecular weight, and the enhanced oil recovery is over 18% (OOIP). After more than seven years of field test, it is proved that the effect of polymer flooding is obvious, and the actual effect is better than that of laboratory flooding. The injection end can effectively improve the water injection profile of the low permeability reservoir, and the emulsion property of the produced fluid is good. Under the condition that the water cut of the produced well reaches 100% limit water cut after water flooding, the water cut drops 17.5% points and the daily oil increase 6.9 t after polymer flooding, the recovery factor is increased by 25.8% points at the stage of the central well in the test area. The recovery factor of the test area is predicted by the follow-up simulation method. The recovery factor of the test area will reach 27.5% points at the final stage, it provides the technical support for the recovery factor of the second-and third-class reservoirs in Daqing Field.