薄层稠油水平井蒸汽驱优化设计

Optimization design of steam flooding for horizontal well in thin heavy oil reservoir

辽河油田W块为深层薄层状特超稠油油藏,2005年采用水平井蒸汽吞吐整体开发,目前处于蒸汽吞吐开发中后期,水平井吞吐效果变差,周期产油量低,油汽比低,急需转换开发方式,前期研究表明该块转水平井蒸汽驱可行。文中根据W块油藏埋藏深、油层薄、原油黏度高的特点,建立了三维数值模型,对汽驱开发井网、注汽层段、注采参数等水平井蒸汽驱关键参数进行了优化设计。结果表明,采用75 m井距水平井注采井网、注汽水平井水平段长度为采油水平井的2/3、油层下部1/3处高干度注汽的汽驱方案能够获得较高的油藏采收率。

Block W in Liaohe Oiltield is a deep and thin ultra-heavy oil reservoir, which has been developed by steam stinmlation of horizontal well sim：e 2005. At present, it is drawing the end of producing life under steam stimulation. Because the effect of steam stimulation is poor, the cycle oil production is low and the oil-steam ratio is low, it is in urgent need of changing the development method. Previous researches show that the steam flooding is the best development method in this block. According to the geology characteristics of deep burial, lamellar structure and high chide oil viscosity of this block, the three^timensional numerical model is established and the injection pattern, injection interval and injection-produc, tion parameters are optimized. The results show that nsing the injecqion-production pattern of 75 m, the length of horizontal interval for steam injection horizontal well is two-thirds length of oil production horizontal well. The steam flooding at one-third position of lower oil layer can get high oil recovery.