柴西狮子沟地区渐新统下干柴沟组上段膏盐岩沉积演化特征

发布时间：2018-04-11 12:27

  本文选题：柴达木盆地西部 + 狮子沟地区　； 参考：《天然气工业》2017年05期

【摘要】：经过多年的油气勘探,已在柴达木盆地的多个层位发现了油气藏。其中,该盆地西部(柴西)狮子沟地区古近系渐新统下干柴沟组上段是油气勘探的重要目的层,膏盐岩是该区油气藏得以保存的优质盖层。为了预测柴西下一步油气勘探的方向和目标、指导区域油气勘探部署,在岩心观察的基础上,综合薄片鉴定,粒度,敏感参数Sr/Cu、Fe/Mn、(Fe+Al)/(Ca+Mg)、V/(V+Ni)、Pr/Ph比值以及黄铁矿含量,包裹体等分析结果,研究了该区膏盐岩发育的沉积演化特征和沉积环境。结果表明:(1)膏盐岩主要分布在湖盆的沉积中心,往盆地边缘方向变薄,横向上相变为碳酸盐岩或陆源碎屑岩,平面分布呈不规则的椭圆形;(2)膏盐岩纵向上主要发育在下干柴沟组上段的中部和上部,与碳酸盐岩或陆源碎屑岩相间发育,单层厚度变化大、层数多、连续性较好;(3)下干柴沟组上段Ⅲ砂组—Ⅰ砂组(盐间)地层沉积时气候干旱炎热,为半深湖—深湖还原性水体环境。结论认为:(1)该区下干柴沟组上段膏盐岩分布面积较广,累计厚度较大;(2)膏盐岩是在干旱炎热气候条件和深水背景下湖水蒸发浓缩结晶而成的,非热液成因。
[Abstract]:After many years of oil and gas exploration, oil and gas reservoirs have been discovered in many layers of Qaidam Basin.The upper member of Lower Ganchaigou formation in the Paleogene Lower Ganchaigou formation in the Shizigou area of the western part of the basin (Chaixi) is an important target layer for oil and gas exploration, and gypsum salt rock is the high quality caprock for the preservation of oil and gas reservoirs in this area.In order to predict the direction and target of the next oil and gas exploration in the west of Qaixi, and to guide the regional oil and gas exploration deployment, based on the core observation, the thin slice identification, particle size, sensitive parameter Sr / Cu-Fe / Fe / mn / Fe Al)/(Ca / MgN / V / V / V / V / Ni / P / P ratio and the content of pyrite are synthesized.The sedimentary evolution characteristics and sedimentary environment of gypsum salt rock in this area are studied.The results show that the gypsum salt rocks are mainly distributed in the sedimentary center of the lake basin, thinning towards the margin of the basin, and the lateral facies become carbonate rocks or continental clastic rocks.The plaster salt rock is mainly developed in the middle and upper part of the upper part of the Lower Ganchaigou formation in the longitudinal direction, and developed with carbonate rock or terrigenous clastic rock. The thickness of single layer changes greatly and the number of layers is many.The upper member of Xiaganchaigou formation 鈪，

本文编号：1736042