Geothermal gradients range between 2.0℃ and 4.5℃ per hundred meters in western Qaidam basin

with an average value of 3.0℃ per hundred meters. Abnormally high pressure can occur at a depth of 2 300 m and over

and the pressure coefficient can be as high as 2.0. Laterally

the temperature-pressure systems in western Qaidam basin can be divided into 9 subareas such as HPHT

according to the formation pressure coefficients and the distribution intervals of the abnormal geotemperatures. Vertically

they can be divided into the upper static pressure type and the lower overpressure type. The upper and lower temperature-pressure systems have quite different fluid energies

thus hydrocarbons are highly capable of migrating vertically and are prone to accumulate around the boundaries of temperature-pressure systems. Laterally

oil and gas pools are basically distributed in the subareas with relatively low fluid energy; there are also oil and gas pools occurring in the sub-areas with high fluid energy

but most of them are primary oil and gas reservoirs with good sealing and preservation conditions

such as lithologic and structural-lithologic reservoirs. Characteristics of present temperature-pressure systems show that the deep temperature-pressure systems of high pressure type have good sealing conditions and contain most of the oil and gas reserves

thus they would be the main targets of future petroleum exploration.