An Origin Study on Lava Reservoir in Oubei-Dawan Area

There are two kinds of lavas in the east depression of Liaohe oilfield. One is trachyte, the main lava reservoir in the area, and the other is basalt. By researching the extension, composition and cause of formation, the paper verifies the reason why the trachyte becomes good reservoir. By contrast, it also gives the reason for which the basalt doesn't contain oil and gas. It concludes that because of its high silicon contents, the trachyte is difficult to flow, and is easy to pile up at the top of structure. Therefore, its main body is beyond the surface. Good crystal brings about its perfect reserve characters. At the same time, the trachyte has lots of cracks. All the facts make the trachyte an excellent reservoir. In the end, the paper presents a pattern of forming reservoir for lava. It points out that its style of oil supply is a side-product and its style of forming reservoir is self-produced, self-reserved and self-sealed.