塔中26-24井区良里塔格组储层烃包裹体特征及成藏期次

Characteristics of hydrocarbon inclusions and the timing of the hydrocarbon accumulation in the Lianglitage Fm in Tazhong26-24 wellblock

邢永亮 张鼐 张宝收 赵瑞华 陈延贵 杨晓光

Xing Yongliang Zhang Nai Zhang Baoshou Zhao Ruihua Chen Yangui Yang Xiaoguang

塔中26-24井区奥陶系良里塔格组碳酸盐岩储层发育丰富的烃包裹体。通过对烃包裹体的赋存位置、生长关系、烃包裹体特征和烃包裹体及其伴生盐水包裹体的显微测温分析,认为塔中26-24井区存在Ⅰ,Ⅱ,Ⅲ 3期烃包裹体。第Ⅰ期烃包裹体(Ⅰ:OL+OLG)以浅褐色、无色液烃包裹体为主, 在紫外光下发中等强度的黄白-黄色荧光。第Ⅱ期烃包裹体(Ⅱ:OLG+OG)多为无色、极浅褐色的气、液两相烃包裹体,在紫外光下气、液两相烃包裹体发强的蓝白色-蓝色荧光。第Ⅲ期烃包裹体(Ⅲ:OLG+OG+OA)多为浅褐色、褐色、深褐色的气、液两相烃包裹体,在紫外光下发强的黄-黄褐色荧光。其形成温度范围分别集中在80~90,90~100和97~110℃。结合本区地质背景,认为塔中26-24井区油气藏存在3个成藏期,即晚海西期中质油成藏、早喜马拉雅期轻质-凝析油气成藏和晚喜马拉雅期高成熟油。

Carbonate reservoirs of the Ordovician Lianglitage Formation in Tazhong26-24 wellblock are abundant in hydrocarbon inclusions.Three stages of hydrocarbon inclusions,including Ⅰ,Ⅱ and Ⅲ,are identified in the study area through analyses of occurrence,growth relationship and characteristics of the hydrocarbon inclusions,as well as microthermometric analysis of hydrocarbon inclusions and their coexisting aqueous inclusions.The stage Ⅰ inclusions(Ⅰ:OL+OLG) are dominated by light brown and colorless liquid hydrocarbon inclusions which exhibit moderate yellow to yellowish-white fluorescence under the UV-light.The stage Ⅱ inclusions(Ⅱ:OLG+OG) are mainly colorless and extremely light brown oil & gas inclusions with strong blue white to blue fluorescence under the UV-light.The stage Ⅲ inclusions(Ⅲ:OLG+OG+OA)are mainly light brown,brown and deep brown oil & gas hydrocarbon inclusions which are characterized by strong yellow to tan-colored fluorescence under the UV-light.Moreover,they were formed within temperature ranges of 80~90℃,90~100℃ and 97~110℃ respectively.Finally,in combination with the geological background of the study area,we believe that there are three accumulation periods in the Lianglitage Formation of Tazhong26-24 wellblock:intermedium hydrocarbon accumulation in the Late Hercynian period,light oil-condensates accumulation in the Early Himalayan period and highly mature hydrocarbon accumulation in the Late Himalayan period.

10.11743/ogg20110503