Japan hunted oil in Manchuria before World War II. In 1927 Japanese geologist found scattered asphalt in vugs of basalt and quaternary gravel deposits on the north western shore of Hulun Nur (lake), NW Manchuria. Geological Survey of China made a check survey of the area, and found the same asphalt in 1931.
After establishment of Manchukuo, geological survey, tortion balance and refraction seismograph survey, and drilling were conducted during 1932-1941. One deep well (1,114 m TD) and 21 core holes were drilled on the northern shore of the lake, but no potential oil were found.
That the core hole drilled in Fuxin coal mine hit oil shows in 1938, led to extensive oil exploration program. Geological field party mapped a broad anticline located on east of Fuxin, and the core hole drilled on the anticline recovered some 30 m thick sandstones (100-200 m in depth) impregnating with oil. To explore this oil called on massive drilling campaign, and 47 or more wells were drilled on this anticline, but the reservoir quality was not good enough to establish commercial production. It is noteworthy to point out that the geologists engaged in Fuxin oil exploration thought that the oil came from Jurassic shales deposited in fresh water lake.
In 1940 oil shows were found in the water wells near Chengde, and a one-month field check survey was conducted, and mapped a small anticline in Jurassic shales, but no further exploration was conducted.
