Top-Injection and Bottom-Production (Tinbop) Cyclic Steam-Injection MethodEnhances Oil Recovery

摘要

We have developed a novel method to enhance oil productionrnduring cyclic steam injection. In the Top-Injection andrnBottom-Production (TINBOP) method, the well contains twornstrings separated by two packers (a dual and a single packer):rnthe short string (SS) is completed in the top quarter of thernreservoir, while the long string (LS) is completed in thernbottom quarter of the reservoir. The method requires an initialrnwarm-up stage where steam is injected into both strings for 21rndays; then the LS is opened to production while the SSrncontinues to inject steam for 14 days. After the initial warm-up,rnthe following schedule is repeated: the LS closed andrnsteam is injected in the SS for 21 days; then steam injection isrnstopped and the LS is opened to production for 180 days.rnThere is no soak period.rnWe have simulated and compared the performance of thernTINBOP method against that of a conventional cyclic steamrninjector (perforated across the whole reservoir). Threernreservoir types were simulated using 2-D radial, black oilrnmodels: Hamaca (9°API), San Ardo (12°API) and the SPErnfourth comparative solution project (14°API). For the first tworntypes, a 20x1x20 10-acre model was used that incorporatedrntypical rock and fluid properties for these fields.rnSimulation results indicate oil recovery after 10 years arern5.7-27% OIIP with TINBOP, I.e. 57-93% higher thanrnconventional cyclic steam injection (3.3-14% OIIP). Steam-oilrnratios are also decreased with TINBOP (0.8-3.1) comparedrnto conventional (1.2-5.3), resulting from the improvedrnreservoir heating efficiency.