N_(12)E二类油层弱碱三元复合驱效果影响因素分析

Analysis of influencing factors on weak alkali ASP flooding effect in N_(12)E secondary reservoir

N_(12)E二类油层弱碱三元复合驱虽然取得增油降水效果,但与数值模拟及其他区块三元复合驱相比效果较差,因此开展了N_(12)E区块三元复合驱效果影响因素分析。通过对N_(12)E区块概况的了解,综合考虑了井网、剩余油、注入体系黏度和储层非均质性等因素对三元复合驱的影响。研究结果表明,N_(12)E区块基础井网水驱末采出程度较高,大部分采出井受效方向少,目的层被聚合物驱动用过,注入黏度未达到设计要求,老井利用效果差,长关采出井开井后效果差和储层非均质严重;综合上述影响因素,使N_(12)E区块三元复合驱效果较差。该研究成果和认识对今后提高类似区块三元复合驱效果具有一定指导和借鉴作用。

Although the weak alkali ASP flooding in N_(12)E secondary reservoir has achieved some effect of increasing oil and reducing water,the effect is still poor compared with that of the numerical simulation and ASP flooding in other blocks.Therefore,the influencing factors on ASP flooding effect in block N_(12)E were analyzed.Through understanding the general situation of block N_(12)E,the effects of well pattern,residual oil,injection system viscosity and reservoir heterogeneity on ASP flooding were comprehensively considered.The research results showed that the recovery degree of basic well network was high at the end of water flooding period in block N_(12)E;,most of the production wells had less effective directional displacement;the target payzones had been flooded by the polymer;the injection viscosity didn’t meet the design requirements;the old well had poor utilization effect;the production effect was not satisfied when reopen the producers after the long-term shut in,and the reservoir heterogeneity was serious.The displacement effect of the ASP flooding in the block N_(12)E was poor due to the influencing factors mentioned above.The research results and understanding have certain guidance and reference for improving the effect of ASP flooding in similar blocks in the future.