Research on ASP System Displacement Efifciency in Beilei Core
|School||Northeast University of Petroleum|
|Course||Oil and Gas Field Development Project|
|Keywords||ASP system Microscopic pore structure Capillary pressure Interfacial tension Recovery|
ASP flooding is a quickly developed oil technique, but it is a mature techniqueon displacement mechanism. Field application of Daqing indicated that ASP floodingcould enhance oil recovery over20%.This paper aiming at the characteristics of microscopic pore structure in Beilei,natural and artificial core, combined with the requirements of the period of highwater-cut further development to enhance oil recovery. The oil displacement effectevaluation of ASP flooding system was done in laboratory experiments. And thereasonable injection parameters and oil displacement effect were researched.Through comparing with the capillary Pressure Curve, it is found out that theCapillary Pressure Curve of Beilei core is similar with the natural core. No matterfrom the entry pressure, middle pressure in value, sorting coefficient, the ejectionefficiency of rocks, flexure of parameters, Beilei core and the natural core all havegreat similarities, Beilei core and the natural core pore structure were closed butartificial core and the natural core have a lot of difference. Beilei core and the naturalcore pore structure have great similarity. So the Beilei core is choose to evaluate thedisplacement effect of different system.Different ASP system interfacial tension evaluation experiment have done byusing the interface tension instruments. The experimental results show that theinterfacial tension of all ASP system up to10-3mN/m orders of magnitude low value,ASP system shows good ability of decreasing interfacial tension.Through the contrast of ordinary and high concentrations of polymer floodingexperiment found, with the concentration and viscosity of polymer increased, sweepvolume was expanded. High concentrations of polymer can increase oil recovery by5%compared with the conventional polymer.Laboratory experiments indicated that different oil displacement formula hasmuch effect on displacement efficiency. The order of enhanced oil recovery from highto low is the system of strong base and petroleum sulfonate(27.00%), weak base andpetroleum sulfonate(26.45%), strong base and alkyl benzene sulfonate(25.70%), weakbase and alkyl benzene sulfonate(25.15%), drop volume strong base and petroleumsulfonate(22.38%), drop volume strong base and drop volume petroleumsulfonate(19.02%), high concentration polymer(12.43%), ordinary polymer(7.35%).The best oil displacement effect is the system of strong base and petroleum sulfonate. But the system of weak base and petroleum sulfonate has little different from it. Wechoose the system of weak base and petroleum sulfonate from the point of view of thedamage to the formation.