SEC准则下蒸汽吞吐稠油油藏递减率计算方法

Calculation method of declining rate in steam stimulation of heavy oil reservoirs under SEC rules

SEC准则下,递减法是评估蒸汽吞吐稠油油藏证实储量的唯一方法。针对产量剖面递减规律不明显,递减率难以确定的问题,把中国国内计算经济可采储量的累积汽油比法引入到SEC储量评估中。在SEC准则下确定递减率时,先用累积汽油比法计算出评估单元的经济可采储量,代入指数递减法经济可采储量计算公式中,即可求得评估单元的递减率。以辽河油区DuX块为例,运用该方法计算递减率为11.6%,计算结果符合油田开发实际,证实了该方法的适用性和可行性,对其他同类型油田有一定的借鉴意义。

Under SEC rules,decline method is the only method to evaluate the proved reserves of steam huff and puff heavy oil reservoir.Aiming at the problems that the decline law of production profile is not obvious and the decline rate is difficult to determine,the cumulative gasoline ratio method for calculating economic recoverable reserves in China is introduced into the reserve evaluation of SEC.When determining the decline rate under SEC criteria,the economic recoverable reserves of the evaluation unit are calculated by the cumulative gasoline ratio method firstly.Then substitute the result into the calculation formula of economic recoverable reserves of exponential decline method to obtain the decline rate of the evaluation unit.Taking Dux block in Liaohe oilfield as an example,the decline rate calculated by this method is 11.6%,and the calculation results are in line with the actual development of the Oilfield.The applicability and feasibility of this method are confirmed,which can be used as a reference for other oilfields.