The Application Of Seismic Sedimentology In The Study Of The Fan Delta Sedimentary System In The Mahu Sag

Junggar basin is the main oil producing area in Xinjiang oilfield, the exploration direction and the reserve development area is the key point. Nearly 3 years of exploration shows that the Mahu depression slope area of Baikouquan reservoir has a massive accumulation, reservoir thickness, wide distribution area,and the major area of Xinjiang Oilfield. However, the implementation of the favorable facies belt of fan delta front has become the main problem of the oil and gas discovery. Through a lot of literature research and practice analysis, that the ideas and methods of seismic sedimentology can better help us solve the practical problem faced in the research.on the basis of a detailed analysis of the basic methods in the cons of seismic sedimentology, through practical work experience and combination of methods to further improve and extend, find the one suitable for the fan delta depositional system characterization of effective methods and technology process. Through longitudinal fine analysis implementation of sequence stratigraphic framework and change, plane macro to control deposition is the main source of the distribution and changing trend, under the guidance of the formation of the seismic fine interpretation of the formation of the palaeogeomorphology, the establishment of a reasonable well seismic phase with the corresponding template. The fan delta-plain showed weak amplitude near random reflection, fan delta-front showed moderate amplitude continuous reflection characteristics.the seismic data is processed by 90° phase, the corresponding relationship between reservoir section and seismic reflection is better. Seismic facies prediction by geophysical method, Finally, the prediction of sedimentary system was formed based on the comprehensive analysis of seismic facies and sedimentary facies. The overall performance of Mahu Baikouquan formation depositional system for fan-delta depositional palaeogeomorphology under control, mainly developed in Karamay, Huangyangquan, Xiazijie, Yanbei and Xiayan 5 provenances, delta-front extensive development front overlapped. Through the method of practice, effective prediction of facies and lake Baikouquan formation inside the layers, to guide the scientific research and production, and lake slope of Baikouquan oil and gas discoveries contributed.