松辽盆地梨树断陷富有机质页岩古环境演化及发育模式  

Paleo-environmental evolution and development model of organic rich shale in Lishu fault depression,Songliao Basin

作　　者：朱建峰[1] 逄海明 李忠博[1] Zhu Jianfeng;Pang Haiming;Li Zhongbo(Northeast Oil&Gas Branch,SINPOC,Changchun 130022,China)

机构地区：[1]中国石油化工股份有限公司东北油气分公司,吉林长春130022

出　　处：《能源与环保》2025年第2期112-120,130,共10页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：中国石化科技攻关项目(P22084);国家自然科学基金项目(42472182)。

摘　　要：富有机质页岩是页岩油气富集高产的物质基础,勘探证实了松辽盆地南部梨树断陷陆相页岩气资源丰富,亟待深化对富有机质页岩成因机制及发育模式的认识,以指导陆相页岩气资源评价和有利区优选。针对梨树断陷陆相页岩样品开展了总有机碳(TOC)、X射线衍射(XRD)、X射线荧光(XRF)、电感耦合等离子体质谱仪(ICP-MS)实验测试,深化了对古环境及富有机质页岩发育模式的认识。结果表明,梨树断陷营城组早期主要为淡水—半咸水、弱还原水体环境,古气候温暖潮湿;营一Ⅰ亚段底部Ⅲ层组陆源碎屑输入大,发育块状泥岩,中部Ⅱ层组陆源碎屑输入少,湖水盐度升高导致水体分层,同时大量生物死亡提高古生产力,内源沉积作用发育富有机质钙质页岩,顶部Ⅰ层组陆源碎屑输入增加,有机质被稀释,主要发育含有机质页岩硅质页岩。富有机质页岩分布发育(TOC>2%)受到古生产力和有机质保存的控制,陆源输入的营养物质促进了古生产力的提高,叠加缺氧分层水体条件,导致Ⅱ层组富有机质页岩最早发育,是梨树断陷陆相页岩气勘探开发的甜点段。研究成果为梨树断陷及其他地区陆相页岩气勘探开发提供了有益的借鉴。Organic rich shale is the material basis for the enrichment and high yield of shale oil and gas.Exploration has confirmed that the Lishu fault depression in the southern Songliao Basin has abundant terrestrial shale gas resources.It is urgent to deepen the understanding of the genesis mechanism and development mode of organic rich shale to guide the evaluation of terrestrial shale gas resources and the selection of favorable areas.Total organic carbon(TOC),X-ray diffraction(XRD),X-ray fluorescence(XRF),and inductively coupled plasma mass spectrometry(ICP-MS)experiments were conducted on continental shale samples from the Lishu fault depression,deepening our understanding of the Paleo-environmental and the development patterns of organic rich shale.The results indicate that the early stage of the Yingcheng Formation in the Lishu fault depression was mainly composed of freshwater brackish water and weakly reducing water environments,with a warm and humid ancient climate.At the bottom of the YingyiⅠsub section,there is a large input of terrestrial debris in theⅢlayer group,which develops blocky mudstone.In the middle,there is less input of terrestrial debris in theⅡlayer group,and the increase in lake salinity leads to water stratification.At the same time,a large number of biological deaths increase ancient productivity,and endogenous sedimentation develops organic rich calcareous shale.At the top,the input of terrestrial debris in theⅠlayer group increases,and organic matter is diluted,mainly developing organic shale siliceous shale.The distribution and development of organic rich shale(TOC>2%)are controlled by paleoproductivity and organic matter preservation.Nutrients input from terrestrial sources promote the improvement of paleoproductivity,coupled with oxygen deficient stratified water conditions,resulting in the most developed organic rich shale in theⅡlayer,which is the sweet spot segment for the exploration and development of terrestrial shale gas in the Lishu fault depression.The research result

关 键 词：松辽盆地 页岩气 古环境恢复 岩相划分 沉积模式 

分 类 号：P618.13[天文地球—矿床学] TE121[天文地球—地质学]