Research of Clay Minerals Catalysis on the Formation of Transitional Zone Nature Gas

In this paper the existence style of hydrocarbons in the clay minerals has been analysed and the surface acid of clay minerals has been determined. Meanwhile, the simulating experiment has been carried out by mixing low-mature source rock and its kerogen extracts with different clay minerals. Through the experiment of alcohol dehydration reaction catalysed by clay minerals, the clay mineral catalysis of hydrocarbons to produce transitional zone nature gas has been discussed. The chief conclusions are as follows:Montmorillonite is the main catalyst for the formation of transitional zone nature gas because there are large amounts of Al³⁺ replacing Si⁴⁺ in its crystal layers when M→I/M transition occurs during diagenesis.As a result, the electric change balance on the surface of montmorillonite is destroyed to form surface acids such as Bronsted and Lowes acids which cause long chain hydrocarbons broken to produce light hydrocarbons with short chain.