Exploitation Effect Evaluation And Remaining Oil Forecasting In Ci78 Block

The thesis in view of the low output, the high composite water cut , the more failure wells, the more serious development conflict and so on in Ci 78 block, base on exploitation characteristic, exploitation effect had been evaluated in Ci78 block, through four aspects, final recovery efficiency, exploitation situation of the reserves, fluid productivity index, productivity index, injectivity index, results showed that: In recently the declining rate is high of the block, utilization of waterflooding is relatively high, the producing proportion of oil wells is about 80%, water wells is about 70%, in new area the number of injection and production wells is reasonable, it is necessity to injection well infill or converted production wells in old area, the curve of water flooding predicted that final recovery efficiency is 42.1% in old area and 15.54% in new area, but 28.5% in entire Ci 78 block.On the basis of development evaluation of water flooding, using numerical simulation techniques, after random building the structure and property models that are agreed with the actual situation of the reservoir, the author has done research on the rule of remaining oil distribution by the eclipse software, at the same time proposed with the optimal Ci78 remaining oil tapping latent potentialities plan, history matching indicated that the original geological model which was established is highly consistent with the fact. the actual reserves of S32 is 157×104t,calculated reserves is 162×104t, the error is 3.0%. numerical simulation of the region oil-producing is 54.14×104m3, and the development data is 54.94×104m3, fractional error is only 1.4%; simulation calculated of the composite water cut is 91.0%, and the development data is 90.4%, relative error is only 0.6 percentage points. Remaining oil in every layer exist as remaining oil formed for interlayer interference, remaining oil formed for fault screened hydrocarbon, remaining oil formed for imperfect production and injection and interwell retention.For the remaining oil distribution, desiged four development programmes. Compared results showed that: dependented on the original pattern, as the opening of the original injection-production wells under the premise of saving energy through conversing high water wells, completely penetrating well pattern encryption Wells, design massiveness inject water within the old area and the new area, for the optimal decision, forecasted results of cumulative oil production is 73.3×104m3, the degree of reserve recovery is 38%.