塔里木盆地塔河油田原油中双金刚烷分布特征与油气运移

DISTRIBUTION OF DOUBLE DIAMANTANE HYDROCARBONS IN CRUDE OILS FROM TAHE OILFIELD OF TARIM BASIN AND ITS IMPLICATION FOR OIL AND GAS MIGRATION

研究了塔里木盆地塔河油田原油中双金刚烷的分布特征,探讨了该油田油气的充注期次和运移方向,结果表明,原油中双金刚烷指标值反映了原油的成熟度,并且指示研究区4区和6区原油充注时间较早、9区原油充注时间较晚,其它油区原油充注时间介于上述二者之间;原油中双金刚烷指标值分布特征显示出塔河油田下奥陶统油气存在2个充注方向,一是由南向北,并且油气成熟度相对较低,可能主要代表了早期的油气运移,另一个是由东向西,原油成熟度相对较高,可能主要代表了晚期的油气运移。根据原油成熟度和运移方向特征,认为塔河油田的早期油气起源于满加尔坳陷,晚期油气起源于满加尔坳陷和草湖坳陷,主力烃源岩层为寒武—奥陶系。

In this context, the distribution characteristics of double diamantane hydrocarbons in crude oils from the Tahe oilfield of Tarim basin was discussed, and the period and direction of oil and gas migration were done. Results show that indicator values of double diamantane hydrocarbons in crude oils reflect the crude oil maturity. These indicator values also indicate that an earlier time of oil and gas charge in area 4 and area 6 compared to area 9 in studied regions. In other areas, charging time of oil and gas is between the time of area 4 and 6 and area 9. Distribution characteristics of double diamantane hydrocarbons in crude oils show two charging directions of low Ordovician oil and gas in the Tahe oilfield, one is from south to north, the other is from east to west. Oil and gas charged along the first path have a higher maturity, likely presenting an earlier period of oil and gas migration, in contrast these charged along the second path have a lower maturity, likely presenting a later period of oil and gas migration. According to the characteristics of maturity and charging direction of crude oils, the earlier oil and gas in the Tahe oilfield were derived from the Manjiaer sag, but the later from the Manjiaer sag and Caohu sag. The major source rocks of oil and gas in the Tahe oilfield are Cambrian-Ordovician system.