[en] Radioisotope microball tracer which was produced by new process is applicable to injection profiling in low injection rate wells. Five-parameter combo logging tools were developed, which enhance accuracy and reliability of log by integrating interpreting flowrates inside tubing, shut-in and flowing well temperatures and tracing results. Reliable impulse oxygen-activation logging tools and a tracer logging method with correlation arithmetic were developed to meet the need of profiling polymer injectors. These new techniques are widely used in injection profile logging at Daqing oilfield. (authors)