基于定量荧光技术的库车拗陷英买7构造带古近系油气成藏过程分析

Analysis of hydrocarbon accumulation process of Yingmai 7 Structural belt in Kuche Depression based on quantitative fluorescence techniques

利用定量颗粒荧光技术,研究塔里木盆地库车拗陷英买7构造带油气调整特征.英买19古近系储层砂岩样品定量荧光光谱响应及流体包裹体观测、储层沥青镜下分析结果表明：英买19有残余油层存在且古油柱厚度大于现今油层厚度,古油藏发育并发生原油泄漏;英买1 9现今油水界面在4 706 m处;英买7构造带油气藏早期吉迪克期～康村期以油充注为主,并形成古油藏,晚期库车期开始以气充注为主,天然气经过阶段性充注、气洗改造原有油气藏,古油水界面多次向下调整,后受构造抬升运动影响,最终形成现今凝析气藏.该研究成果为英买7构造带古近系油气成藏过程研究提供依据.

In this paper,Quantitative Grain Fluorescence(QGF)techniques were applied to research hydrocarbon adjustment characteristics of Yingmai 7structural belt in the Kuche depression,Tarim basin.Combined with the observation of fluid inclusion,microscopic analysis of reservoir bitumen and analysis of regional tectonic evolution history,this study provides valid evidence for Yingmai 7structural belt's hydrocarbon accumulation process during Paleogene.We concluded that Yingmai 19 had residual oil by analyzing the fluid inclusions,reservoir bitumen and the quantitative fluorescence spectral which response to the samples of Yingmai 19 Paleogene sandstone reservoir.Since the thickness of old oil column is greater than that of current oil,ancient oil reservoir was developed in this area,resulting in oil spill.By analyzing grain fluorescence spectrum,we speculate that the current oil water interface of Yingmai 19 is at 4 706 m.Combined with the analysis of regional tectonic evolution history of southern slope area,we consider that during the early stage(from Jidike period to Kangcun period),the hydrocarbon reservoir of Yingmai 7structural belt was mainly formed by oil charging.Old oil reservoir was formed in this stage.During the late stage(since Kuche period),gas charging is the main way.Original oil and gas reservoir was modified by periodic charging and washing of gas.Old oil water interfaces was adjusted downward many times.Affected by tectonic uplift movement,current gas condensate reservoirs were ultimately formed.