The Evaluation On Carbonate Reservoir Of Dengying Formation In Gaoshi 16-Gaoshi 21 Well Area In Central Sichuan Basin

Study block is located in the east of the platform margin of high Shiti Sinian system in the Sichuan Basin.The multi reservoir cap assemblages in marine carbonate field are vertically stacked,which has the advantages of three-dimensional exploration,and is in the favorable gas bearing range of-5230 m at the top of Sinian system as a whole,and has great exploration potential.Study block is deposited in the Dengying Formation of Sinian system far away from the platform margin zone,and the overall reservoir physical properties become poor.It is difficult to predict the distribution law of reservoirs in each group and section.At present,the seismic interpretation of Dengying Formation in three-dimensional area needs to be studied carefully.Based on the field data of drilling,core,logging,logging and earthquake,this paper comprehensively applies the technology methods of well earthquake combination sequence stratigraphy contrast,seismic facies analysis,reservoir analysis and comprehensive evaluation,and conducts in-depth and systematic research on the Dengying Formation reservoir.The following are the following understandings:(1)Based on the analysis of regional structural characteristics and evolution process,the structural characteristics of the Dengying Formation and the fault development were defined by the detailed explanation of the structure of Hechuan Tongnan block;(2)Through the identification and division of sequence boundary marks,the Dengying Formation is divided into two third-order sequences and six fourth-order sequences.The high-precision sequence stratigraphic framework of the second and fourth member of Dengying Formation is further established,and the development characteristics of sequence stratigraphy are clarified;(3)Through the analysis of sedimentary characteristics of Dengying Formation,petrology and spatial characteristics of reservoir,reservoir performance and diagenesis analysis,the reservoir is classified and evaluated,and the formation and main control factors of the second and fourth member of Dengying Formation are summarized.In the process of this study,we can fully draw lessons from and refer to the research methods,research ideas and previous research results of the Dengying Formation of Gaoshiti Moxi.The conclusions and understanding can provide a powerful theoretical and technical guidance for natural gas exploration and production.