Relational expression between TOC and resistivity and interval transit time for the source rocks in western Qaidam basin is established by the correlation analysis of measured data and logging data.Using this relational expression

calculations are performed in 125 wells in western Qaidam basin and large amount of appraisal data are achieved in the four sets of source rocks in the Upper and Lower Ganchaigou Fms.These data are used to compile the areal distribution map of source rocks.The comprehensive study of the distribution area

thickness and maturity of source rocks indicates that the Lower Ganchaigou Fm is the major hydrocarbon kitchen and the Upper Ganchaigou Fm is the less important hydrocarbon kitchen.The accumulation of hydrocarbons in western Qaidam basin is controlled by distribution of hydrocarbon kitchen

and most of oil and gas accumulations so far discovered are distributed near or around the major hydrocarbon kitchens.Based on this pattern

the western and eastern sides of Nanwus

the western side of Youquanzi

the Honggouzi structural zone and Dafengshan region can be considered to be the future exploration targets.