利用磁共振录井技术定量评价水淹层

Quantitative Evaluation of Water-Flooded Zone Using Magnetic Resonance Measurements for Mud Logging(MR-ML) Technology

产水率是划分水淹级别的关键参数,如何通过含水饱和度计算产水率是进行水淹层评价工作要解决的主要问题.通过测定油-水相对渗透率的注水实验制备出不同产水率的岩样,分析并研究不同产水率下的磁共振录井谱图特征和分析参数响应特征,可探讨利用磁共振录井资料评价水淹级别的可行性.该工作根据密闭取心井的试油资料和相渗曲线,提出了利用磁共振含水饱和度计算地层产水率经验公式的方法,并进行了生产应用.结果表明,利用磁共振录井技术评价水淹层的符合率达到了86%,证明了该项技术在快速、定量评价水淹层和划分水淹级别的良好应用前景.

Water production rate is a key parameter for classifying flooding level in water-flooded zone. How to calculate water production rate from water saturation index is a main problem in evaluating water-flooded zone. In this work, rocks with different water production rate were first produced with the water-injection preperation commonly used for evaluating oil/water relative permeability, and then analyzed by steady-state magnetic resonance measurements for mud logging （MR-ML） spectroscopy. Based on the response characterisics of the rocks, an empirical formula to calculate water production rate from the water saturation index was proposed, which takes advantage of the oil production test data and oil/water relative permeability curve from sealed core analysis. The feasibility of using the water production rate derived to evaluate flooding level was investigated. The results from practical applications showed that MR-ML spectroscopy can be used for rapid identification of water flooded layer, classifying water flooding level, with high accuracy.