Petroleum Reservoir Evaluation and Development ›› 2024, Vol. 14 ›› Issue (3): 425-434.doi: 10.13809/j.cnki.cn32-1825/te.2024.03.012

• Field Application • Previous Articles     Next Articles

Geological conditions for shale oil formation in the fourth member of Funing Formation of Eocene series in Jintan Basin

ZANG Suhua(),JING Xiaoming,LIU Zhihua,YIN Yanling   

  1. Research Institute of Exploration and Development, Sinopec East China Oil & Gas Company, Nanjing, Jiangsu 210000, China
  • Received:2023-05-22 Online:2024-06-26 Published:2024-07-10

Abstract:

This study evaluates the unconventional oil and gas exploration potential of the Cenozoic residual basins in southern Jiangsu, focusing on Jintan Basin. Utilizing a range of data sources, including drilling records, core analyses, logging data, and laboratory tests from Well-J9, we extensively analyzed the geological features of the fourth member of Funing Formation. These analyses encompass rock mineral composition, sedimentary characteristics, organic geochemical properties, and reservoir qualities. Findings indicate that the fourth member of Funing Formation was deposited in a semi-closed to closed saline sedimentary environment, predominantly characterized by shallow to semi-deep lakes. This member is marked by substantial mud shale thickness(exceeding 250 m in deep concave zones), low organic matter abundance(average total organic carbon(TOC)of 1.02%), and a moderate degree of thermal evolution(vitrinite reflectance(Ro)ranging from 0.81% to 0.85%), providing a fundamental basis for shale oil hydrocarbon generation. Additionally, the presence of fractures and porous shale reservoir spaces, coupled with a high content of brittle minerals, suggests favorable conditions for the development of complex fracture networks during subsequent fracturing interventions. Considering the oil and gas shows in existing boreholes, it is posited that the fourth member of Funing Formation, particularly near the Maoshan tectonic push-over zone, holds medium to low maturity shale oil exploration potential in southern Jiangsu.

Key words: Jintan Basin, the fourth member of Funing Formation, shale oil, geological conditions, low-medium maturity

CLC Number: 

  • TE122