Gas generation characteristics of the lower cambrian niutitang shale in qiannan depression, China.

Based on the thermal simulation experiments of shale and crude oil samples, the amount of gas generated from kerogen and oil cracking during each geological period was calculated based on the chemical kinetic method. The results showed that the total amount of gas generated from the Niutitang Shale in Hy1 well is 49.00 m3/t, including gas generated from kerogen (17.76 m3/t) and gas generated from oil cracking (31.24 m3/t). The period of gas generated from kerogen is from the Cambrian to the Carboniferous with amount of gas generated value of 14.77 m3/t, which is mainly from the Lower Ordovician to the Middle Ordovician (510–470 Ma). The period of gas generated from oil cracking is from the Ordovician to the Triassic, and the main period of gas generated from oil cracking is from the Lower Devonian to the Upper Permian (410–250 Ma). The amounts of gas generated from oil cracking are 13.30 m3/t, 9.44 m3/t, and 3.77 m3/t in the Devonian, Carboniferous, and Permian, respectively. [ABSTRACT FROM AUTHOR]