OIL AND GAS EXPLORATION DIRECTIONS IN THE T₂l₃⁴ OF THE SICHUAN BASIN

In recent years, CNPC and Sinopec have made significant progress in oil and gas exploration in the T₂l₃⁴ of the Sichuan Basin with good prospects. Based on new drilling wells and the latest research results, methods of hydrocarbon sources correlation, burial history, thermal evolutionary history of source rocks, and temperature measurement of inclusions are adopted for analysis of stratigraphy, sedimentary facies, source rocks, reservoirs, and accumulations. The petroleum geological conditions of the T₂l₃⁴ sub-section in the Sichuan Basin is further analyzed, and their hydrocarbon accumulation characteristics summarized. Then favorable exploration zones are proposed to help expand the exploration area of the Leikoupo Formation in the Basin. The research results suggest that the natural gas of the T₂l₃⁴ is dominated by mixed source rocks of the Leikoupo Formation and Xujiahe Formation; the reservoir space is dominated by intergranular and intergranular dissolved pores, which are low in both porosity and permeability; the T₂l₃⁴ subsegment gas reservoir is a two-stage accumulation, and the source rocks have approached the peak of hydrocarbon generation during the middle and late Jurassic. There are two types of gas reservoirs in the T₂l₃⁴ segment: the tectonic and lithologic. The Longmenshan piedmont fault zone is a favorable exploration area for structural type of gas reservoirs. Both the Xinjin-Qionglai slope and the Zhitong-Yanting slope are favorable exploration areas for structural and lithologic type of gas reservoirs.