大庆油田某区块酸敏储层的酸化液配方体系优选

Optimization of Acidizing Fluid Formulation System for Acid Sensitive Reservoir in a Block of Daqing Oilfield

大庆油田某区块储层地质资料分析,该油层的特点是储层渗透率低,物性差,温度高,敏感性强,开发过程中储层极易受到伤害,油田开发难度大。针对该区块的地质特点,通过室内岩心流动敏感性实验,评价了该区块储层的酸敏特性,通过天然岩心粉末膨胀率测定,评价筛选了常用粘土稳定剂类型和浓度,通过天然柱状岩心注入粘土稳定剂实验,优化了粘土稳定剂的注入浓度、注入PV数以及段塞组合、针对储层强酸敏特点,通过岩心溶蚀率测定以及岩心模拟注酸实验,以防酸敏为主导思想,确定了酸液主剂、酸敏抑制剂,形成了针对区块强酸敏储层的酸化液配方体系。

Reservoir geological data of a block in Daqing oilfield were analyzed. The results show that characteristics of the reservoir are low permeability, poor physical property, high temperature and strong sensitivity, the reservoir is highly susceptible to damage during development process, and oilfield development is difficult. According to the geological characteristics of the block, through the indoor flow sensitivity experiment of core, acid sensitive features of reservoir in this block were evaluated. Through the inflation rate determination of natural core powder, types and concentrations of common clay stabilizers were screened. Through the experiment of injecting clay stabilizer into natural columnar core, the injection concentration of clay stabilizer was optimized as well as injection PV and slug combination. According to the characteristics of reservoir acid sensitivity, through the measurement of core dissolution rate and core simulation acid injection experiment, in case of acid sensitive as the dominant idea, optimized acidizing fluid formulation system for acid sensitive reservoir in the block was determined.