Sedimentary Characteristics Of The Jurassic Reefs On The Right Bank Of The Amu Darya

Located in the long and narrow area between the national boundaries of Turkmenistan and Uzbekistan, the right bank of Amu Darya is an important source of natural gas and the source of Central Asia-China gas pipeline. The research area locates in the northeast part of Amu Darya Basin. Previous researches show that the reef-bank reservoir in Callovian-Oxfordian of upper Jurassic is the most important gas pay and which has a great potential for hydrocarbon. While the Sedimentary Geological research to the area is week. Guided by sedimentology and geophysics, and based on core data, well-logging data, seismic data and related geological data, this article cover stratigraphic correlation, sedimentary facies analysis, reef-bank distribution characteristics analysis and the classification and evaluation to the reef-bank. Finally the favorable areas are pointed out. which provides the basis for exploration and development in research area. This has a practical significance for guaranteeing the source of Central Asia-China gas pipeline.Based on the analysis of formation lithology information of Callovian-Oxfordian in upper Jurassic, referring to previous research and making use of 3D seismic data and well-logging data, the thin layer correlations are confirmed. Gap in mid-eastern part is XVac and XVp in western part, and XVhp in mid-eastern part is XVm an XVhp in western part.Conducting a comprehensive research of core data, thin section authentication, logging response characteristics, seismic data and analysis of regional deposition backgrounds, Callovian-Oxfordian is considered as the sedimentary model of carbonate platform of shelf type. On the basis, the plane distributions of sedimentary facies characteristics of each stages in Callovian-Oxfordian are confirmed and the sedimentary facies model suited to research area is built by analyzing the plane distribution of single well facies, section facies and seismic facies.Multiple types of reef-bank develop in Callovian-Oxfordian in research area. Based on the difference in type, form, scale and diagenesis, the types of reef-bank are classified into reef> mounds bank. On the basis of analyzing for geologic origin and structural characteristics of reef-banks, and the analyzing for the deformation feature of overlying gypsolyte.117 reef-banks with the area of 1987 km2 are recognized by utilizing seismic attributes such as slowness, RMS amplitude, wave impedance, and wave form. The sedimentary characteristics of Amu Darya are confirmed by analyzing sedimentary model of reef-bank and main controlling factors.