Abstract:

It is one of the main questions in the calculation and evaluation of oil and gas resources to determine the phase demarcation line of oil，gas, water-soluble etc. phases during the first migration in source rock. In this paper，the authors have first cited the coal series formation in Upper Triassic in Northwest Sichuan basin as an example, obtained a total component data of the products of "theoretical lignite" in several stages of hydrocarbon-generating heat simulation of lignite，and calculated their phase maps by PR state equation. After that，considering the solution of porous water，the authors have calculated the phases of hydrocarbon-generating products in coal and mudstone formations respectively. The calculation shows that the originally generated products in the case of III type organic matter are gas phase. Because of a large amount of porous water in coal series mudstone，the generated products are oil phase when Ro values are less than 1.14%，and the products are gas phase when Ro greater than 1.14%.But in coal formation，the oil products are difficult to occur. In 5%of the sections of coal-bearing formation，when Ro values are less than 0.95%，only oil phase occurs, and gas phase comes up only when Ro greater than 0.95 0/. In addition, the authors have roughly divided the phase demarcation line of originally generated products according to oil-gas ratio from heat simulation data of I type organic matter.

Key words: Resources evaluation, First migration, Heat simulation, phase

CLC Number: 

• TE112.12