The Geoscience Frontier of Gulong Shale Oil: Revealing the Role of Continental Shale from Oil Generation to Production
Wenyuan He,
Rukai Zhu,
Baowen Cui,
Shuichang Zhang,
Qian Meng,
Bin Bai,
Zihui Feng,
Zhengdong Lei,
Songtao Wu,
Kun He,
He Liu,
Longde Sun
Affiliations
Wenyuan He
China National Oil and Gas Exploration and Development Company Ltd., Beijing 100027, China; Key Laboratory of Shale Oil Accumulation of Heilongjiang Province, Daqing 163712, China
Rukai Zhu
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Baowen Cui
Key Laboratory of Shale Oil Accumulation of Heilongjiang Province, Daqing 163712, China; Daqing Oilfield Company Ltd., PetroChina, Daqing 163712, China
Shuichang Zhang
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Qian Meng
Key Laboratory of Shale Oil Accumulation of Heilongjiang Province, Daqing 163712, China; Daqing Oilfield Company Ltd., PetroChina, Daqing 163712, China
Bin Bai
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Zihui Feng
Key Laboratory of Shale Oil Accumulation of Heilongjiang Province, Daqing 163712, China; Daqing Oilfield Company Ltd., PetroChina, Daqing 163712, China
Zhengdong Lei
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Songtao Wu
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
Kun He
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China
He Liu
Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083, China; Key Laboratory of Shale Oil Accumulation of Heilongjiang Province, Daqing 163712, China
Longde Sun
Key Laboratory of Shale Oil Accumulation of Heilongjiang Province, Daqing 163712, China; China National Petroleum Corporation, Beijing 100007, China; Corresponding author.
The clay mineral content of Daqing Gulong shale is in the range of about 35%–45%, with particle sizes less than 0.0039 mm. The horizontal fluidity of oil in Gulong shale is poor, with near-zero vertical flowability. As a result, Gulong shale has been considered to lack commercial value. In recent years, however, interdisciplinary research in geoscience, percolation mechanics, thermodynamics, and surface mechanics has demonstrated that Gulong shale oil has a high degree of maturity and a high residual hydrocarbon content. The expulsion efficiency of Gulong shale in the high mature stage is 32%–48%. Favorable storage spaces in Gulong shale include connecting pores and lamellar fractures developed between and within organic matter and clay mineral complexes. The shale oil mainly occurs in micro- and nano-pores, bedding fractures, and lamellar fractures, with a high gas–oil ratio and medium–high movable oil saturation. Gulong shale has the characteristics of high hardness, a high elastic modulus, and high fracture toughness. This study achieves breakthroughs in the exploration and development of Gulong shale, including the theories of hydrocarbon generation and accumulation, the technologies of mobility and fracturing, and recoverability. It confirms the major transition of Gulong shale from oil generation to oil production, which has extremely significant scientific value and application potential for China’s petroleum industry.
