Abstract
In Japanese oil field, wire line coring has been developed in recent several years and has passed beyond experimental stage, and now, is available in practical work. In this paper, the author explaines the outline of this wire line coring and traces the development of this coring in the oil well operation and introduces the record of R. 111 well in INNAI oil field in which the wire line coring indicates the fine ratio of core drilling and then the author states the fucure problems of wire line coring.
