The Research Of Further Improving Oil Recovery Methods In SZ36-1Oil Field Research

SZ36-1oil field is heavy oil fields which is located in the Bohai bay area. Since2005began to inject the polymer, currently in the high water cut stage of the late polymer injection,but there are still a lot of scattered distribution of remaining oil in strata is not out, and thesescattered remaining oil recoverable reserves will be a great contribution to the field. Using theeclipse numerical simulation software analyses SZ36-1oil field after polymer flooding andconclude that the distribution regularity and distribution type of residual oil. Putting forwardthe method of further residual oil after polymer flooding in target field, namely binarycompound flooding and high concentration polymer flooding, high concentration polymerflooding, binary compound flooding and poly alternating injection flooding.On the basis of a large number of research literature at home and abroad, understandingthe three extract methods based on the oil displacement mechanism of different types ofremaining oil, considering the factors of life of offshore oil platform, exploitation of age limit,Using the indoor experiments, optimizing the surfactant concentration is2000mg/L, theconcentration of polymer solution is1750mg/L of binary complex system optimizing, andgetting the optimal solution of the binary composite system, namely injection volume is0.3PV,the interfacial tension is10-3mN/m, the viscosity is26mPa·s. On the basis of the optimalinjection parameters of binary compound flooding through the experiments, using thenumerical simulation software optimizing and getting the Injection speed is0.03PV/a, thevalue of optimization of binary complex flooding to improve oil recovery is6.2%.Furthermore, getting the high concentration polymer flooding increase the polymerconcentration, injection volume and injection rate within a certain range appropriately, usingeclipse numerical simulation software getting the value to improve recovery is4.12%of theoptimal scheme. The optimum parameters of the injection of natural gas and polymeralternately injection as follows, gas injection volume is0.3PV, the injection speed is0.03PV/a,the ration of gas and liquid is1：2, alternating injection cycle is30days. Through contrast theparameter of binary compound flooding, high concentration polymer flooding and gas andpolymer alternating flooding, and eventually improve recovery efficiency of the whole value,getting that binary compound driving is more in line with the high speed and efficient miningmode for offshore oil field, and it is a new technology which is relatively suitable for SZ36-1oilfield to further improve oil recovery after polymer flooding.