幂律稠油砂岩油田单井探测半径计算

Calculation of the Investigation Radius of Producing Well Through Power Law Heavy Oil Sand Reservoir

谢明英 刘国涛 闫正和 施征南 孙晓娜

XIE Mingying LIU Guotao YAN Zhenghe SHI Zhengnan SUN Xiaona

中海石油(中国)有限公司深圳分公司, 广东 深圳 518000

CNOOC China Limited, Shenzhen Branch, Shenzhen, Guangdong 518000, China

探测半径是油田开发过程中的一个重要参数，然而传统的探测半径计算公式基于牛顿流体线性渗流理论研究得到，这类探测半径计算公式不再适用于幂律型非牛顿流体。针对南海东部地区近年发现的幂律稠油砂岩油田，提出了一种新的计算方法来研究幂律稠油的探测半径，这种新方法避免了常规方法中试图获得探测半径的解析式的问题，具有更广泛的适用性。另外，传统计算公式并没有考虑井筒储集效应和表皮效应的影响。借助探测半径的相对判断准则，采用了Laplace变换、Stehfest数值反演方法，研究了流性指数、井筒储集效应、表皮效应对探测半径的影响；提出了流性指数在0.80~1.00的探测半径计算公式的统一形式；同时，为了直观地与生产实际联系起来，文中还探索了探测半径与井底压降的关系。研究成果已用于指导南海东部地区幂律稠油砂岩油田井网部署和注采井网优化设计，获得了很好的应用效果。

The investigation radius is an important parameter in oilfield development. However, the well-known formula of the investigation radius is based on the linear fluid flowing in porous medium, so the formula is out of place for nonlinear fluid, such as power-law fluid. Recently the sand oilfields with power law fluid are discovered in the eastern South China Sea. Based on this, a new numerical method is proposed for studying the investigation radius of power-law heavy oil. This new method avoids the problem of trying to obtain the analytical formula of the investigation radius, and it has wider applicability. On the other hand, the well-known formula does not consider the influence of wellbore storage effect and skin effect. With the help of the relative criterion of investigation radius, using Laplace transform and Stehfest numerical inversion, the influence of power-law index, wellbore storage effect and skin effect on investigation radius is studied by a new method here. A formula for calculating the investigation radius with power-law index between 0.80 and 1.00 is proposed, and the unified form of the formula is formed. At the same time, the relationship between investigation radius and bottom hole pressure drop is also explored. The research results have been used for guiding the optimization design well pattern and injection-production well pattern, and good application results are obtained.

10.11885/j.issn.1674-5086.2021.02.08.08