中国水驱砂岩油田含水与采出程度的量化关系

分析了中国砂岩油田的地质特点和含水变化影响因素，在分析含水与可采储量采出程度关系曲线的基础上，利用中国已进入高含水阶段的15个典型注水砂岩油田开发资料，得到了代表全国注水开发水平的含水变化曲线及理论公式。对不同含水阶段下采出程度的定量分析结果表明，中国水驱砂岩油田含水变化整体呈凸型曲线特征，近70%的可采储量要在油田进入高含水阶段(含水率>60%)之后采出，其中高含水期（60%≤含水率<90%）是提高采收率最为关键的时期，约50%的可采储量要在此阶段采出。本研究成果除充分认识中国水驱砂岩含水变化规律并进行定量分析外，还可应用于油田开发指标预测、开发效果评价和开发潜力评估等方面。

A quantization relationship between water cut and degree of reserve recovery for waterflooding sandstone reservoirs in China

The present paper deals with geological characteristics of sandstone reservoirs in China and influential factors of water cut variations.Based on correlation curves normalized by water cut versus percent of recoverable reserves,we obtained varying curves of water cut and their theoretical formulas that represent the current level of waterflooding development in China by means of applying development data of 15 typical large waterflooding sandstone reservoirs in China,which have been at a high water cut stage.The results of quantitative analysis on the degree of reserve recovery at different water cut stages indicate that variations of water cut in waterflooding reservoirs in China are wholly characterized by a convex curve,suggesting nearly 70% of recoverable reserves would be recovered after reservoirs enter into a high water cut stage(water cut >60%),and the high water cut stage(water cut >60% and <90%) is the most important period to enhance oil recovery,during which about 50% of recoverable reserves would be recovered.Besides a help to fully understand regulations of water cut variations of waterflooding sandstone reservoirs in China and to analyze them quantitatively,the present study result can also be applied to the prediction of development indexes and the evaluation of both development potential and development effects.