*The technical challenges and significance on ultra-deep buried hill reservoir exploration in Bohai Bay Basin, China

Zhiwen Deng¹, Xianzheng Zhao², Xuming Bai¹, Wanfu Zhang¹, Feng Yan¹, Chuanzhang Tang¹, and Shenghui Yuan¹

Abstract

ND buried hill zone is located in the downthrown of ND fault in Jizhong Depression, Bohai Bay Basin, China. Under the control of ND boundary fault, a series of unidirectional faults in the downthrown of ND fault construct a propelling structure of basement, which forms fault terrace hills with maximum burial depth of 7000m. Whether the buried hill reservoirs exist in the ND area of Huabei Oil Field has been the research project for more than 30 years. Since 1970s, geologists have carried out extensive investigations, focusing on the ND buried hill zone. However, no substantial progress has been made due to the lack of advanced and appropriate exploration technology and equipment. In the recent 10 years, some new technology have been developed, such as joint nonseismic and seismic; seismic acquisition with high fold, wide azimuth and high density; anisotropic prestack depth migration etc.. By applying these techniques, higher quality seismic data have been acquired, and meanwhile the geometry and structure of the ND buried hill have been recognized.Through the drilling of Well ND1 which is the deepest well to drill into buried hill with more than 5000m in eastern China, excellent highly matured source rocks with more than 2000m thickness are discovered at the Kongdian formation of Es4 and a prolific oil & gas flow was gained in the ultra-deep buried hill. So abundant hydrocarbons may be exist. Reservoirs of the buried hill field possess good petrophysical properties, which are generally not affected by the buried depth. So the ultra-deep buried hill field is a very important exploration domain in the Bohai Bay Basin.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain