Abstract: Reservoir is the principal object of log interpretation and evaluation. With the development of petroleum industry, the reservoir study is getting more important, because the reservoir controls not only the oil and gas reserve but the productivity and recovery as well. The characteristics of the low- resistivity
reservoirs are different from those of the common shaly sandstone reservoirs for their different geological characteristics. Among which related to the log information are chiefly lithology characteristics; Physical property; electrical characteristics, fluid characteristics and so forth. They are the geological basis of fine log interpretation and evaluation, and the degree of influence of these factors on well log response is the physical basis of log evaluation.

Key words: resistivity, recovery, reservoir, log response, log evaluation