山东东营凹陷幕式成藏的流体包裹体证据

On fluid inclusion evidence of episodic reservoir accumulation in Dongying depression of Shandong

利用流体包裹体综合分析技术,研究东营凹陷不同构造区带油气成藏方式。结果证明,不同构造区带成藏期古压力及成藏方式具差异性:北部陡坡带沙四段烃源岩上储层油气成藏主要分3期,成藏方式以间歇的幕式充注为主;中央背斜主要分2期,成藏方式以突发式的幕式充注为主;南部缓坡带仅1期,早期成藏方式以持续性充注为主。在凹陷南部缓坡带孔店组的储层中发现沸腾包裹体,分析认为成藏晚期发生过幕式充注,推测在沙四烃源岩下存在新的成藏体系。东营凹陷不同区带成藏模式的确定,可为在高勘探程度地区寻找隐蔽油气藏提供理论依据。

The author studied the episodic reservoir-formation of different tectonic zones in Dongying depression with fluid inclusion technology. The results demonstrated that the accumulation period and ancient pressure accumulation mode were different during differ- ent tectonic zones. The intermittent episodic reservoir-formation was the dominant pattern for lithologic reservoir in northern steep slope in Dongying depression, the burst episodic reservoir-formation was the dominant pattern in the central anticline zone with fault develop- ment, the durative episodic reservoir-formation was the dominant pattern in south slope zone. In addition, the fluid inclusion evidence of episodic reservoir-formation was discovered in early Tertiary. The bubble inclusion was discovered in Kongdian Formation of south slope zone and bubble inclusion was the favorable evidence of episodic reservoir-formation. The high waxy oil of Wangjiagang area was different from the upper source rocks, which indicated that the new accumulation system might exist in underneath source rocks. The re- sult provided a new object for further exploration. The determination of different episodic reservoir-formations in Dongying depression provided theoretic evidence for the search of subtle reservoirs in mature exploration regions.