Research On Depositional Systems And Prediction On Favorable Sandstone Body Of Lower Member Of Lower Ganchaigou Group In Southwestern Area Of Qaidam Basin

The evaluation of petroleum resource indicates that there is a wider exploration prospect in southwestern area of Qaidam basin, and where the lower member of lower Ganchaigou of Tertiary is one of the most favorable petroleum bed sets. In company with deeply exploration, applying new technologies and methods will become important to research depositional systems and prediction on favorable sandstone body.This paper on basis of studying outcomes in the past, using the drilling, logging, seismic and assaying in the lab data, apply theory of high resolution sequence stratigraphy and technology of exquisite stratigraphic correlation and classification in order to establish stratigraphic correlation framework of high resolution. Combination and stable coefficient of heavy minerals, characteristics and distribution of conglomerate are applied to ascertain source area. Through careful study on sedimentary facies markers of important wells to ascertain the types of sedimentary facies, corresponding relation of conversion between well-logging, logging and sedimentary facies, construct sedimentary facies patter. Favorable sandstone body is predicted through applying facies patter and reservoir inversion technology of 3D-seismic, in the light of outcome of multi-well analysis of profile, studies on relation between reservoir properties of matter and sedimentary facies.In conclusion, ascertained the sedimentary facies are several and close source areas. There are alluvial fans, river, delta, and lacus deposition systems, there are different distribution characteristics of sedimentary facies during the lower member of lower Ganchaigou of Tertiary.In this thesis construct consolidated stratigraphic framework between well and seismic for the first time, and predict distribution of sandstone body through the control of isochronal stratigraphic framework. Finally, combine of analysis to source rock, cap formation, trap and condition of conservation, Pointed out the distribution confines of favorable sandstone body in the area of Qigequan, Yuejinyihao and Hongliuquan on basis.