Seismic Identification Of The Upper Permian Changxing Formation Reef On The East Side Of The Kaijiang-Liangping Trough

Along with all kinds of uncompartmentalized gas fields discoveried like PuGuang in Northeastern part in Sichuan province in recent years,platform margins reef reservoir in the"Kaijiang-Liangping shelf" has become an important part of carbonate oil and gas zone in our country.This area also day by day becomes the hot spot area which is researched by multitudinous domestic and foreign scholars.The Changxin reef oil and gas reservoir which is on the platform margin of west side of "Kaijiang-Liangping shelf" has been a major breakthrough,which directly promote oil and gas field of trillion square construction in platform margins of Sichuan basin.Compared to the west,"Kaijiang-Liang Ping shelf' to the East has a similar sedimentary environment,and shows the huge potential of exploration.Because the predecessors study mainly from the geological perspective features,sedimentary environment of reef reservoir and so on,research method is relatively simple.The characteristics of the subject makes understanding of the reef recognition mode one-sided,which failed to form the reef reservoir seismic identification system of comprehensive seismic geology method,so directly restricts fine prediction of reef reservoir.Based on the understanding of the predecessors and modern carbonate sedimentology,seismic prediction technology as the main method,the main research contents and results are as follows:(1)Based on the sedimentary model of the study area,using the geological and logging data,research area of Changxing group's reef is divided into two developments period.According to a lot of logging and seismic data,it is considered that the level of the ancient landform before the deposition of the Changxing formation determines the development degree of the reef.We could restored the ancient landform during the deposition of Changxing group,and pointed out the favorable position of the distribution of the reef.(2)On the basis of the reef geological development model,we could use seismic practice physiognomy method and seismic attribute analysis technology,as a result we establish recognition model of reef seismic facies,and depict distribution area of the platform marginals in space.At the same time,we could points out the favorable position of reef development.(3)Based on the seismic geomorphology theory,control factors of the reef development are summarized.According to slope steep degree,reef can be divided into different types.We believe that there is an obvious linear relation with the reef foreslope zone steepness and reservoir development thickness(4)In the control of reef seismic geology recognition model,using seismic velocity inversion and porosity inversion carries out reservoir prediction,which ultimately form an amount of technologies applying to reef reservoir prediction of the study area.Based on the establishment of the reef geological identification model,in this paper,integrating of geological,seismic,logging information and so on,a kind of seismic-geology recognition technology system applying to reef reservoir prediction is formed.It is significant that the technology system could finely describe the reef distribution range,predicts favorable exploration area and deepen reef seismic forecasting theory system.