世界白云岩油气田勘探综述
- 收稿日期:
1900-01-01
- 修回日期:
1900-01-01
- 刊出日期:
2011-10-10
摘要: 利用C&C数据库的“数字化类比知识系统”,对世界上137个白云岩油气藏勘探数据进行统计研究,分析全球白云岩油气田分布规律、形成的构造背景、发育的盆地类型、赋存的沉积环境及主要产层的时代,并进而分析全球已发现白云岩油气田的油气产量与它们的关系;白云岩油气田以陆上为主,主要分布在北美洲,构造背景以缝合带边缘的前陆盆地为主,其产层主要分布在古生代和中生代,在萨布哈潮坪环境下,更容易发现白云岩气田,而在前缘斜坡和深水盆地环境下,以白云岩油田为主,高能碳酸盐砂和生物建造环境下以凝析气田为主。通过对这些油气田白云岩储集层储集空间的分析及孔、渗数据的研究,揭示白云岩优质储层主要受白云石化作用、溶蚀作用和裂缝化作用控制,沉积环境控制了白云石化作用和溶蚀作用的发生,而构造背景则与裂缝的发育相关;其盖层受白云石化环境的控制,主要以海相页岩和蒸发岩为主。
The Summary on Exploration of the Dolomite Oilfields in the World
- Research Institute of Petroleum Exploration and Development, PetroChina, Beijing 100083
- Received Date:
1900-01-01
- Rev Recd Date:
1900-01-01
- Publish Date:
2011-10-10
Abstract: By analyzing the data of the 137 dolomite reservoirs in the world with the C&C digital analogs knowledge system, the location of the oilfields, the structural setting, the type of basin, the depositional environment and the age of the dolomite strata were all investigated researched. The target is to find the relation between the production and these elements mentioned above. The geographical distribution of the dolomite fields are not evenly. Most of the dolomite fields were onshore oilfield, mainly distribute on the North America, Asia and Europe. The plate tectonics controlled these distribution: most of them have been discovered in compressional basins, especially in the suture belt, such as foreland basin and so on, but few dolomite fields can be found in the rift basin or the passive continental margin. The oil and gas accumulated in the Mesozoic and Paleozoic, mainly from the Cretaceous and Triassic. The next major development potential region are the lower Ordovician and the Cambrian. From the statistics analysis, the reservoirs are the sandy clastic current deposition in the low energy tidal flat lagoon environment and the turbidity current deposition from the foreslope to deepwater basin. The dolomitization and the cap rock can be formed likely in these conditions. If the carbonate platform margin reefs were dolomitized, its' porosity and permeability is not always enhanced. The high quality of the dolomite reservoirs maybe require the postcorrosion. The oilfields were discovered easily in the Sabkha sedimentary environment, but at the slope and the deepwater basin, the highenergy carbonate sand and the reefrimmed skeletal bank, the gas fields were found.The porosity and permeability of the dolomite reservoirs were gathered to indicate that high quality dolomite reservoirs were controlled by the dolomitization, the dissolution and the fracture density. The dolomitization and the dissolution provide the reservoir space and the fracture generated by the fracturing action can improve the permeable capacity of the reservoir. The main types of the reservoir structure are fracturepore, followed by the fracture and the main pore types are the intercrystalline pore,moldic pore and intergranular pore, followed by the fractures and caverns. The fracture action and the corrosion are the key point forming the high quality reservoirs.The sedimentary environment controlled the dolomitization and dissolution. The tectonic setting impact the degree of fracture development in the dolomite reservoir.The seal of the reservoirs were limited by the dolomitization environment composed by the marine shale and evaporates.