Shibata oilfield is located about 15 miles east of Niigata City. The subsurface Neogene sediments of the oilfield were studied to discover foraminiferal zonules. The Shibata Well No. 2 was investigated as the so-called "control well". The following four zonules are recognized in the oilfield, namely, (1) Rotalia 2-Nonion 5, (2) Cassidulina 1-Eponides 5, (3) Uvigerina 1, and (4) Cyclammina1 Zonules. The correlation is based on the foraminiferal zonules, since electric Logs are not useful owing to the lapid facies change of rocks.
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.
Kaji oil field is noteworthy as the first recovered oil deposits of the stratigraphical trap type in Japan. The main oil reservoirs are developed in the lower zone of the Nishiyama formation (Uvigerina I Zonule), and it is seem that its sands are thinning out in the transgressive facies. The investigation of the regional stratigraphy for the Kita-Kambara Plain is expected to get the information of the oil development and to advance its exploration of the plain.
Here tke author explaines the woking data of R. 7. W (Flowing well). Fromthe result of the experience, the author states the wells must be completed "straightly and quickly" in the low reservoir pressure field and in thin pay thickness.