新型水驱特征曲线在低渗透油藏的应用

Application of New Type of Water Drive Characteristic Curve to Low Permeability Reservoirs

在油田开发过程中,采出程度、可采储量和含水率变化的预测是评价油田开发效果的重要指标,现有的计算方法大多适用于中、高渗透油藏,在低渗透油藏指标预测过程中存在较大差异。针对该类问题,以吴起油田低渗透油藏为研究对象,运用了一种新型水驱特征曲线公式,该公式综合了纳扎洛夫和西帕切夫水驱特征曲线特点,利用理论推导与数理统计的方法,得出了适用于吴起油田的含水率和采出程度关系图版。研究结果表明:新型水驱特征曲线能够有效反映低渗透油藏含水变化规律,通过数据拟合确定出待定参数,从而确定出低渗透油藏含水率与累计产量的关系式,通过关系式建立的曲线与生产数据曲线符合度高,低渗透油藏含水上升率变化呈先上升后下降的规律。该研究对低渗透油藏的开发部署方案编制中的开发指标预测具有一定指导意义。

In the process of oilfield development,the prediction of recovery degree,recoverable reserves and water cut is an important index to evaluate the effect of oilfield development.Most of the existing calculation methods are suitable for the medium and high permeability reservoirs,and there are great differences in the process of index prediction for the low-permeability reservoirs.In view of such problems,a new type of water drive characteristic curve formula is used taking the low permeability reservoirs in Wuqi Oilfield as the research object,which integrates the characteristics of Nazarov and Sipachev water drive characteristic curves.The relation chart of water cut and recovery degree suitable for Wuqi Oilfield is obtained by theoretical derivation and mathematical statistics.The results show that:the new type of water drive characteristic curve can effectively reflect the rule of water cut change in the low permeability reservoirs,and the undetermined parameters are determined through data fitting,so as to determine the relationship between water cut and cumulative production of the low permeability reservoirs.The curve established by the relation has a high consistency with the production data curve,and the water cut rise rate of the low permeability reservoirs shows a law of first rising and then falling.This study has certain guiding significance for the prediction of development indicators in the development and deployment plan programming for the low permeability reservoirs.