Research On Distribution Of Remaining Oil Of Block C9in Liao He Oilfield

At present, some of the old oilfields in China exist many aspects of the problemswidely.For example, low formation pressure, fluid supply capability, complex geologicalconditions, narrow band of oil, poor physical properties, complex lithology, strongheterogeneity, and etc. In order to improve the production efficiency, after a lot of survey, andcombined with the practical geological and development characteristics of C9block, Thispaper calculates10indexes in six aspects of the effect of water flooding development. Theresults show that water flooding development effect of this area is in poor situation. Weshould take measures to improve the development effect, such as improving the well pattern,injection production relationship conversion and so on. results of evaluation on well networkadaptability show that the actual well spacing density is less than reasonable well spacingdensity. We should adjust the program of injection and production,and consider playing infillwells to tap the remaining oil at the same time.Based on the static and dynamic datas of the C9block, we established the geologicalmodel accords with the actual reservoir by using Petrel software, do the historical fitting byusing Eclipse software, and discusse the distribution of remaining oil in this block. The resultsshowed that the model is consistent with the actual situation at a high degree. Geologicalreserves of C9block is468×104t, geological reserves of this model is467.02×104t, relativeerror between them is0.26%. The relative error between the cumulative oil production of thenumerical simulation calculation and development data is2.43%, the relative error of watercontent of is3.16%.Analysing the residual oil saturation maps of C9block, we get many results showing that:in the longitudinal direction, distribution of the remaining reserves is uneven distribution,which mainly distributed in the simulation of layer C2, C3and C6. That is the geologicallayer S1II, S1IIIand S1Ⅵlayer. The plane remaining oil exists in four forms: the remainingoil in fault block, injection production faultiness of residual oil, the formation of the sandstoneedge region and remaining oil with uncontrollable well pattern.According to the distribution of remaining oil, based on the existing well pattern, wedesigne5kinds of development schemes. Including patching holes, open the shuting well,converted production and converted injection, injection increasing, respective well patternthickening. Results show that: The comprehensive plan with adjustment and encryptionscheme is the optimal solution, the cumulative oil production is52.45×104t, recovery degree is13.59%, ratio based scheme recovery increased by2.67%.