塔河风化壳储层典型单元注水方式优化研究

Optimization Research on Water Injection Mode in Typical Units of Weathering Crust Reservoir of Tahe Oidfield

风化壳古岩溶作用形成的缝洞型油藏是塔河油田奥陶系油藏的主要储层类型,其由于缝洞发育,非均质性极强。目前在注水开发过程中,部分缝洞单元注水效果变差。为强化注水效果,利用数值模拟方法研究了塔河某油藏典型生产单元的最佳注水方式组合。根据注水见效期、稳定期以及调整期的含水率特点,通过对注水方式的组合优化模拟,论证了最佳注水组合的模式及注采参数。模拟结果显示,最佳注水组合为先温和持续注水,后周期注水,最终转为脉冲注水的模式。基于该油藏参数,三种注水方式的参数的优化结果为持续注水强度200 m3/d,常规周期注水采用长注短停注60 d停15 d的方式,脉冲注水为（100~200）m3/d间隔30 d的方式间歇注入。

The fractured-cavity reservoir formed by weathered crust karstification is the main type of Tahe Ordovician reservoir. Because these reservoirs mature plentiful fractures and cavity,they own strong heterogeneity. The current water flooding situation indicates that part of the fracture-cavity unit water flooding efficiency has been decreasing. In order to improve the water flooding efficiency in these reservoirs,the optimized injection combination of one typical fractured-cavity unit in Tahe Ordovician reservoir was investignted by numerical simulation. According to the water cut characters of the water injection efficient period,steady period and modification period,the injection method combination is simulated and the optimizing injection parameter is demonstrated. The simulation result shows the optimized water injection combination is first mild continuous water injection,then the cyclic water flooding and finally impulse water flooding. Due to the reservoir condition,the optimized three injection modes parameters are that the continuous water injection intensity is 200 m3/ d; the conventional cyclic injection period is 75 days including 60 days injection and 15 days well shutting up and the impulse injection is（ 100 ~ 200） m3/ d for every30 days and shut well up for the same period.