Diagenetic Numerical Modeling And Favorable Reservoirs Prediction In The Deep Zone Of The Xujiaweizi Fault Depression

In order to complete the task of prospecting and choosing the new natural gas area and field in the deep zone of Songliao basin and research the natural gas accumulation law of deep Xujiaweizi,and apply it to the exploration work of other less-exploration fault depression,the paper carefully studied every kind of clastic digenesis under the high temperature and high pressure in the deep zone of Xujiaweizi fault depression.And based on the exploration practice of the deep zone,we completed the current standard of diagenetic stage division and furtherly refined the diagenetic standard of the deep zone.At the same time, appling the diagenetic numerical modeling technology,we simulated the diagentic evolution of the formation of Shahezi,Yingcheng and Denglouku.The results show that the source rocks started generating hydrocarbon at the end of Yingcheng period,the source rocks are in maturity-over maturity and a great deal of natural gas are generated at the end of Denglouku period.At this period,the Yingcheng formation are in the early diagentic stage-mid diagenetic stage A, source rock,reservoir and cap rock are all well developed and natural gas are fromed in large scale.Appling diagenetic numerical modeling technology,we predicted the diagenetic stage and diagenetic facies of the formation of Shahezi,Yingcheng,Denglouku and Quantou in the Xujiaweizi fault depression.Diagenetic framework of Songliao basin is established,and based on the controls of diagenetic facies on hydrocarbon potential of sandstone and cong-lomerate,we predicted the favorable reservoirs of each formation.We organically combined diagenetic numerical modeling and the research results of sequence stratigraphy,founded the methods of reservoir plane classification and evaluation and favorable reservoirs prediction.The distribution of favorable sandstone reservoirs of the the member 3 of the Denglouku formation and the favorable conglomerate reservoirs (porosity>4%) of Yingcheng formation has been predicted.The Industrial gas wells of the member 3 of the Denglouku formation is mainly distributed in the reservoirs of typeâ…¡or typeâ…¢, The Industrial gas wells of the conglomerate reservoirs of the member 4 of Yingcheng formation is mainly distributed in the reservoirs of typeâ… or typeâ…¡.The division project of the diagenetic stage of the deep clastic,the control function of the diagenesis on hydrocarbon potential in every kinds of reservoir and the prediction methods of favorable reservoirs can be used in the deep reservoir research of other fault depressions in Songliao basin.