Institute of Shaanxi Yanchang Petroleum(Group) Corporation, Xi'an, 710075, China

Based on testing methods of ICP-AES and stable isotope mass spectrometry, the authors we analyzed the compositions of trace elements, carbon and oxygen isotopes of Permian carbonate rocks in Khorat Basin. Studies were also carried out on the palaeo-sedimentary environment and its significance for the development of carbonate source rocks in the studied area. The comprehensive examination of δ¹³C/δ¹⁸O, Sr/Ba, V/Ni, V/(V+Ni) results show that sedimentary environment in shallower slope sub-facies of the studied area is typically characterized by fresh-brackish water and weak oxidation-weak reduction environment. Deeper slope sub-facies located below the wave base is characterized by brackish-saline water, anoxic and reduction environment, which is favorable for the preservation of organic matter. Deeper slope sub-facies are confirmed to be more favorable for the development of carbonate source rocks in the studied area.