Abstract:

Abstract: Based on available geochemical data such as pyrolysis and total organic carbon (TOC), we studied the hydrocarbon expulsion characteristics of the deep source rocks by using the hydrocarbongeneration potential method，which is based on geological threshold theory. Three types of hydrocarbon expulsion models were established in this paper, with the typeI source rock expelling hydrocarbons earlier and more efficiently than the typeⅡand typeⅢ. The Es³ source rocks, the main source rocks in Liaodong Bay, started expelling hydrocarbons (dominated by oil) at the end of Shahejie Formation and the total amount of hydrocarbons expelled is 4.33 billion tons. In comparison, the Es¹⁺² source rocks started expelling hydrocarbons during the deposition of the Dongying Formation, with a total expulsion amount of 2.26 billion tons. The total amount of hydrocarbons expelled from the deep source rocks is 6.59 billion tons. The resource volume is estimated to be 2.106 billion tons, of which oil is 1.712 billion tons. The study results indicate that the resource potential of the deep layers in Liaodong Bay is very huge and dominated by oil. The Liaoxi salient located between the Liaoxi and Liaozhong troughs both of which are hydrocarbon kitchens is very favorable for hydrocarbon accumulation.