羊三木油田三断块馆Ⅱ油组复合碱水驱油室内研究

LABORATORY STUDY ON COMBINED CAUSTIC FLOODING SYSTEMS FOR GUANTAO GROUP Ⅱ, FAULT BLOCK No3, YANGSANMU OIL FIELD, DAGANG

针对羊三木油田三断块馆Ⅱ油组原油粘度高、酸值高的特点,结合早期获得的碱水驱油试验结果,进行了复合碱水驱油试验研究。结果表明,在碱水中加入适量的醇、盐、聚合物组成复合碱水,可改善油水界面性质,降低碱耗,提高驱油效率。在所研究的复合碱水中。碱-聚合物体系的驱油效果最佳,可使碱水驱油效率提高13％左右。

The crude oil from titled reservior is of high viscosity and acid value. For this reservior simple caustic (NaOH) solution flood as a reasonable way of EOR was investigated. In this work some binary systems are studied. It is found that introducing appropriate amount of NaCl (0.1%, w/w) , ethanol (0.5%) and PAM (DH30%, MW10×10~6, 0.1%) leads to significantly broadening concentration range of caustic solution for emulsification and creation of low interracial tension with crude oil, to a shift of optimum caustic requirement from 0.5% to 0.05%, and to lowering minimum interracial tension to values of order 10^(-4)mN/m. The caustic consumption of binary solutions (with 0.5% ethanol or 0.03% PAM) by oily sands is notably decreased (by ～20%) in comparison with simple caustic solution. 15 different floodinq systems including simple caustic, binary caustic-NaCl, caustic-ethanol, and caustic-PAM solutions of varying concentrations and 96 artificial cores are used in simulating flooding tests. The cores are heterogeneous, of similar mineral composition as the reservior rock. The test results show that all binary, combined caustic, systems give much higher ORs than simple caustic systems; of the binary systems caustic-polymer (PAM) flooding solutions are the best ones; residue oil satuation in the reservior with more viscous crude is higher, therefor ORs by caustic systems are higher in such reservior. For field tests a formulation of 0.5% NaOH+0.1% polymer PAM AT-430, MCY co., Japan, is recommended.