关键词: 天然气藏, 成藏期, 成藏史, 库车前陆逆冲带, 塔里木盆地

Abstract: Based on the synthetical analyses of the timing of trap formation,gas maturity and hydrocarbon inclusions,3 periods of the formation and filling history of natural gas reservoirs in Kuqa foreland thrust belts are discerned,i.e.the early-middle Kangcun period(17~10Ma),late Kangcun to early-middle kuqa period(10~3Ma)and late Kuqa to Xiyu period (3~1Ma).Among them the late Kuqa to Xiyu period is the major one for the formation of natural gas pools in the foreland thrust belts,in which the discovered Kela 2,Kela 3,Dabei 1,Yinan 2 and Tuzi 1 gas fields were formed.The Kangcun to early-middle Kuqa period is the critical moment for the formation of original oil and condensate pools.Nerverthless,those early oil and condensate accumulations were generally adjusted and even destroyed by the latter strong tectonic movements and/or the filling of natural gas of high maturity and over-maturity in the late Kuqa to Xiyu period.The remanined oil accumulations are mostly secondary reformed in this period.

Key words: natural gas reservoirs, accumulation timing, filling histoty, Kuqa foreland thrust, Tarim Basin