松辽盆地德惠断陷华家构造带深层储层油气成藏期次——来自流体包裹体证据

Hydrocarbon accumulation stages of deep reservoir in Huajia tectonic zone of Dehui depression of Songliao basin based on evidence of fluid inclusions

松辽盆地德惠断陷具有多期油气充注的特征,受复杂构造运动的影响,原生油气藏发生调整改造。运用流体包裹体分析技术,根据烃类包裹体岩相特征及其伴生盐水包裹体均一温度,结合埋藏史和热史模拟,研究德惠断陷华家构造带深层储层成藏期次和时间。结果表明,德惠断陷华家构造带深层储层油气共经历三期油气充注过程和二次调整改造,第一期油充注发生在沙河子组沉积末期(141.5~135.0 Ma);第二期油气充注发生在登娄库组沉积末期—青山口沉积时期(116.0~91.5 Ma);第三期油气充注发生在嫩江组沉积时期(81.0~72.5 Ma)。第一次原油调整改造发生在营城组沉积晚期到登娄库组沉积早期(128.1~121.0 Ma);第二次原油调整改造和第一次天然气调整改造发生在新近纪(4.0~1.0 Ma)。德惠断陷经历较为复杂的油气成藏过程。

There are characteristics of multi-period hydrocarbon charging in Dehui depression of Songliao basin.Because of complex tectonic movement,the primary reservoirs are adjusted and reconstructed.By the way of fluid inclusion analysis technique,combining with burial-thermal history and analyzing the lithofacies features of hydrocarbon inclusion and the homogeneous temperature of aqueous inclusion associating with hydrocarbon inclusion,conclusions have been reached that deep reservoirs have three stages of hydrocarbon charging and two stages of adjusting and reconstructing:The first charging event took place at the end of Shahezi group deposition period(141.5~135.0Ma).The second charging event happened during the end of Denglouku group deposition period to Qingshankou group deposition period(116.0~91.5 Ma).The third charging event occurred during Nenjiang group deposition period(81.0~72.5 Ma).The first time of adjustment and reconstruction about oil happened from the end of Yingcheng group deposition to the early of Denglouku group deposition period.The second time of adjustment and reconstruction about oil and the first time of adjustment and reconstruction about gas were adjusted and reconstructed during neogene period.Therefore,Dehui depression has experienced complex process of hydrocarbon accumulation.