Advances in Earth Science ›› 2020, Vol. 35 ›› Issue (1): 52-69. doi: 10.11867/j.issn.1001-8166.2020.006.
Previous Articles Next Articles
Jiangmin Du 1( ),Pengyu Long 1,Peng Yang 2,Qiang Ding 2,Xiuyin Hu 3,Wei Li 1,Yang Bai 1,Jun Sheng 4
Received:
Revised:
Online:
Published:
About author:
Supported by:
Jiangmin Du,Pengyu Long,Peng Yang,Qiang Ding,Xiuyin Hu,Wei Li,Yang Bai,Jun Sheng. Characteristics of Carbonate Reservoir and Its Forming Conditions in Continental Lake Basin of China[J]. Advances in Earth Science, 2020, 35(1): 52-69.
For decades of exploration, geologists have made great achievements in the exploration of lacustrine carbonate rocks. By dissecting four typical cases of lacustrine carbonate rocks, such as Lucaogou Formation of Permian in Junggar Basin, Da'anzhai Section of Jurassic in Sichuan Basin, Cretaceous in Yin'e Basin and Oligocene in Qaidam Basin, the reservoir characteristics, hydrocarbon generating capacity and reservoir forming model of source rocks were analyzed. The results show that: ① Lacustrine carbonate reservoirs are generally dense, with nano-micron reservoir space as the main reservoir space, including dolomite intergranular pore, organism cavity and accumulation pore, micro-fracture system and its corrosion expansion pore. Saline environment is beneficial to dolomitization and can improve the reservoir capacity of lacustrine carbonate rocks, but most of the permeability is less than 0.1 mD. ② Lacustrine carbonate rocks have not only reservoir capacity, but also can be used as source rocks. The abundance of organic matter is not high and the maturity is generally low. However, dispersed soluble organic matter in source rocks can generate and expel hydrocarbons in large quantities at low maturity stage, which has high liquid hydrocarbon yield. ③ Oil and gas reservoirs are characterized by "high initial production, large reduction of production and long-term low and stable production", and are typical "fracture-pore" reservoirs. Fracture networks provide migration pathways in the process of primary migration and accumulation of oil and gas in geological history and oil and gas exploitation nowadays. ④ Oil and gas reservoirs are "continuous" unconventional reservoirs, which often form regional oil and gas field groups together with conventional reservoirs in adjacent areas. The research results lay a theoretical foundation for re-evaluating the exploration potential of lacustrine carbonate rocks.