热采稠油证实储量评估中递减率的合理确定方法

递减法是证实储量评估中针对热采稠油的唯一评估方法,该方法的关键是递减率的合理确定。热采稠油经常采用井间、块间接替的开发模式,产量剖面上经常出现相对稳产或多段递减,造成合理递减率难以选取。针对这一难题,把国内计算热采稠油油藏技术可采储量的方法-累积油汽比法引入到证实储量评估中,运用递减法和累积油汽比法计算总可采量相等的理念反推递减率,并以曙光油田杜229块为例,证实了该方法的适用性和可行性,对其它同类油田具有一定的借鉴意义。

Method of Determining Decline Rate of Reserves Evaluation in Thermal Recovery of Heavy Oil

Depreciation is the only proven reserves evaluation method for thermal recovery of heavy oil,and the key of this method is to determine a reasonable lapse rate. Crosswell and inter block replacement development model are often used for thermal recovery of heavy oil. Production profile often appears relatively stable or multi segment decline,causing the decline rate difficult to select reasonably. Aiming at this problem,the method of recoverable reserves of heavy oil reservoir thermal recovery technology of domestic calculation of cumulative oil steam ratio method is introduced to the proven reserves evaluation,which uses the descending method and cumulative oil steam ratio method to calculate the total recoverable amount,which is an equal idea of backstepping decline rate. Taking Shuguang Oilfield Du 229 block as an example,the paper confirms the feasibility and applicability of the method,which has a certain reference significance to other similar oilfields.