Whether oil and gas fields can be found in basins or depressions depends on whether there are oil-bearing layers that can produce a large amount of oil and gas. As the saying goes, "a clever wife can't cook without rice" means that no matter how clever a wife is, she can't cook without rice. Many things in nature are similar to this. If various exploration methods, especially high-precision seismic, drilling, logging and other methods are adopted, it is proved that there are no good source rocks and a large number of kerogen, which is the parent material of oil and gas generation, and can be rejected by one vote. No matter how good the reservoir and caprock are, it is useless. The exploration work in Yili basin and Wulungu depression in Junggar basin was rejected by this vote.
The Middle East is rich in oil because it has source rocks as thick as 200 ~ 650 meters. Daqing is rich in oil because it has nearly 300 meters thick source rocks and contains a lot of kerogen. There are many oil fields near Karamay, which rely on thick source rocks in Mahu sag to generate a large amount of oil and gas and migrate here continuously. In addition, there are many reservoirs and caprocks near Karamay, so it can be said that Karamay Oilfield has become a famous geomantic treasure house at home and abroad.