南海西部低渗油田注入水源选择配伍性研究

Study on Compatibility of Injection Water to Low Permeability Oilfield in Western South China Sea

宋吉锋 谢思宇 郑华安 李彦闯 梁玉凯

SONG Jifeng XIE Siyu ZHENG Huaan LI Yanchuang LiangYukai

中海石油(中国) 有限公司湛江分公司, 广东湛江 524057

CNOOC China Limited, Zhanjiang Branch 524057, China

南海西部RX-1油田因衰竭开发导致压力系数下降，急需注水补充地层能量。此文在RX-1油田地层水分析基础上，通过静态配伍性实验、动态配伍性试验及岩心配伍性实验，对4种拟注入水源配伍性进行研究。实验结果表明：地层水自身具有结垢趋势；地层水与海水、生产污水及水源井水配伍性差，混合比例7∶3结垢量最大；纳滤水与地层水混合后几乎无沉淀，岩心驱替100 PV渗透率下降20%以内，能够有效降低结垢风险。

The pressure coefficient of RX-1 oilfield in western South China Sea decreased severely due to the development and depletion, the formation energy was badly in need of supplement by injection water. Based on the analysis of formation water in RX-1, together with the experiment of static compatibility, dynamic compatibility and core compatibility, the authors chosen four types of water to be injected to conduct the study of compatibility. The experimental results show that formation water itself has the tendency of scaling; the compatibility of formation water with seawater, production sewage and well water is poor, the amount of scaling reaches the maximum when the mixture ratio is 7:3. There is little precipitation when the nanofiltration water is mixed with the formation water, and can effectively reduce the risk of scaling as demonstrated by the fact that the permeability decreased is less than 20% when the core displacement reaches 100 PV.

“十三五”国家科技重大专项课题：南海西部海域低渗油藏勘探开发关键技术（课题编号：2016ZX05024-006）部分研究成果。

https://doi.org/10.3969/j.issn.1008-2336.2018.03.027