Analysis of Petroleum Geological Characteristics of the Jurassic in Karakul Block, Amu-Darya Basin
详细信息
- 责任者：Zhang Jinhai (Department of Geology ; Northwest University ; Xi’an 710069 ; China) ; Liu Yiqun
- 刊名：Acta Geologica Sinica
- 出版年：2012
- 卷期：86(4)
- 关键词：油气勘探 ; petroleum exploration ; 乌兹别克斯坦 ; Uzbekistan
- 页码：p.651-660
- 图表：6 illus., 1 plate, 18 refs.
- 分类号：1003
- issnNo：ISSN0001-5717
- isbnNo：CN11-1951/P
摘要
Karakul block is located in the Chardzhou terrace of the northern Amu-Darya basin in Uzbekistan.The main exploration target is upper Jurassic Callovian-Oxfordian carbonate rocks.The source rocks are dominated by dark gray mudstone,carbon mudstone and coal deposited in the Lower-Middle Jurassic coastal-delta facies,and medium-high organic matter abundance indicating sapropel-humic and humic organic types suggests good potential to generate hydrocarbon once the rocks enter mature stage.The Chardzhou terrace is located in the direction of the hydrocarbon migration,and this is favorable for accumulation of oil and gas.Oolitic limestone and calcarenite are the major types of reservoir rocks deposited in upper Callovian-Oxfordian terrace facies,and both form main reservoirs in the block.The reservoirs consists of intragranular dissolved pore,mould pore and solution stylolite.The carbonate reservoirs are of low porosity and low permeability,and of good accumulation capability if in company with relatively developed fractures.The formation water in the upper Jurassic carbonate rocks is highly mineralized and the ratios of Na/Cl and Ca/Mg are 0.7 and 3.5,which indicate a weak reduction environment.Moreover,the large thickness,widely distributed gypsum-salt deposited in Kimmeridgian-Tithonian tidal flat-lagoon facies as cap rocks,are favorable for gas accumulation and preservation.Based on structural interpretation of Karakul block,the main trap style is low amplitude anticlinal structure.The forming times of traps rationally matches with generation and migration of hydrocarobon.It is suggested that the potential plays may occur along the anticline belt in the south of Karakul block.