GENETIC TYPES OF NATURAL GASES AND THEIR MATURITY DISCRIMINATION IN THE EAST OF TARIM BASIN

A comprehensive study of maturity discrimination, genetic types and ga s sources on lower Paleozoic marine hydrocarbon gases is carried out. AU the lower Paleozoic strata-sourced gases are mainly composed of dry gas (dry coefficient>0.9), belonging to marine sapropelic type of cra cking gases, which are characterized by low delta(13)C(1) and Delta(de lta(13)C(2)-delta(13)C(1)) values due to deficiency of terrestrial sou rce input. According to the thermal simulation data of source rocks fr om upper Proterozoic to lower Paleozoic, a delta(13)C(1)-R(0) regressi on equation is established, so the problem of how to distinguish matur ities and sources of natural gases is resolved. These natural gases ar e divided into four genetic types. In addition, the aspect of multi-so urces and multistages of natural gas generation has also been discusse d.