The Research Of Clastic Rock Sedimentary Micro-facies And Prediction For Favorable Areas In Block Of Ka 1, Tazhong

The oil-bearing properties of the Tarim Basin have attracted more and more attention of Chinese Petroleum Industry, especially exploration of the TaZhong Area which is the most important part of the Tarim Basin. Though miniature structural reservoir in the Siluric-Carboniferous clastic rocks of the TaZhong area has been in recent years, the principles of oil pool distribution patterns in TaZhong area are still quite enigmatic, so the success potential of exploration is low. Previous works thought the main problem for that was it was lacking of research about the subtle and low range structural traps. In addition, it's worth taking a further investigation on how the traps were deformed by the later volcanic activity and tectonism.Through detailed analyses of the 3D structural mapping, sedimentary micro-facies. sand body spatial distribution and the palaeostructural evolution, we mainly discuss the reason for failed well, how the paleo tectonics influenced the reservoir formation, as well as the main factors for this effective reservoir. Based on the research of available source-rock in different times, kokin traps mplementation and the factor of reservoir formation, we discuss the reservoir forming conditions in block of Ka-1, and some conclusions are as follow:1. Two types of sedimentary facies in Ka-1 area were found, coastal and tidal flat which was much more developed. Both of these two sedimentary facies are in the same sedimentary sequence. Because of the paleo tectonics and steep slope near the unconformity surface, the mainly sedimentary facies are littoral-neritic sea, locally displaying as fan delta. Tidal flat is mainly exposed in the gentle slope and middle of the sedimentary sequence. Tidal flat sedimentary facies are variable in different geological period from Siluric to Carboniferous. At the early stage, there was big and mid-tidal range sedimentary, big tidal bar and ebb delta related sands occupy the main sand body, while in the late period, there was small-tidal range sedimentary, lagoon and tidal channel related sand are developed. 2. Kalashayi formation mainly show river and delta sedimentary fades.3. The sands in Tataaiertage and Keziertage are relatively well deveoped, however, as the bad reservoir quality, it cannot to be a good reservoir.4. By detailed analyses of the structural mapping, only fault nose and updip thin out traps in the 3-D seismic area sikian were developed, except the faulted anticline traps in Donghe-sand formation in well Zhong 1 and Zhong 16 respectively.5. Through the analyses on the top of Donghe-sand and Kepingtage formation, the palae-nasal process was the primary path for hydrocarbon migration, and only the trap located in the palae- nasal process can be taken as good oil and gas reservoir.