Abstract:
Sealed gold tube pyrolysis was carried out for 3 source rock samples from the third (E
2s3) and first (E
3s1) members of Shahejie Formation, and the third (E
3d3) member of Dongying Formation in the Shanan Sag, and 2 source rock samples from the E
2s3 in the Qinnan Sag in Bozhong area. These samples are lacustrine shale with a high organic matter content and low maturity, and contain type I kerogen. Minerals in the source rock samples are mainly clay minerals and contain a significant amount of calcite, quartz and feldspar. The gold tube pyrolysis experiments focus on liquid hydrocarbon generation. The mean hydrocarbon generation kinetics of E
2s3, E
3s1 and E
3d3 source rock samples range between 219 and 222 kJ/mol, and the kinetics of all samples have a concentrated distribution. Samples from same sag but different intervals, and samples from different sags but same interval have no significant difference, but the samples with a relatively low content of clay minerals and a high content of calcite have a relatively higher mean hydrocarbon activation energy. Carbon isotopes of C
14+ liquid products during peak hydrocarbon generation can be 11.3% heavier than extracts from unpyrolyzed samples, and oil-source correlation with extracts from low maturity source rocks must consider this. TOC loss of residual solids can reach up to 48%. It is necessary to restore organic matter abundance and kerogen type when evaluating high maturity source rocks with a high organic abundance and favorable organic type.