By comparing and analyzing for testing data, it is found that the polluti on to formation of open hole testing is little, production is high and formation productivity and physical information are gained which have irreplaceable role to work of knowing reservoir and latter testing operation.

By analysis of its difficulties,matching tools and technology of the YD301 well are introduced,and successful experience of drill stem testing in long open hole well is summarized.

To the fact of sampled well structure,long bore hole zone and irregular hole radius,taking example of bore hole test of JN1-1 well,the operation of collar location,adjusting mud and measuring actual bottom has been done to make sure test successful.