Analysis of Cretaceous Reservoir Differences between Suohan Outcrop and Dabei Gas Field in Kuqa Depression

Key words: 
• reservoir study /
• difference analysis /
• Bashijiqike Formation 3rd /
• Suohan outcrop /
• Dabei gas field

Abstract: The analysis of Cretaceous Bashijiqike Formation 3rd member reservoir finds the similarities and differences between Suohan outcrop and Dabei gas field in Kuqa depression of Tarim Basin. They both have the similar depositional environment and characteristics: both of them mainly deposited  fan delta frontal surfaces. Their petrological characteristics are of slightly different. But obvious difference exists in the reservoir property and reservoir space. The physical properties of outcrop are  much better with the porosity of 13%~18% and the permeability of  1×10³~100×10³ m²while the data of Dabei gas field are 2%~7% and 0.01×10³~1×10³  m². Meanwhile the reservoir space types are drastically disparate. The reasons of the differences lay in that Bashijiqike formation 3rd member of Suohan outcrop has ever experienced from shallow burial, low compaction, weak exposure and modern weathering and leaching reformation which Dabei gas field has not. It has important significance to realize reservoir property and reservoir evaluation on tight sandstone and fractured reservoir in Kuqa depression.