摘要
经过数十年的勘探,地质学家们在湖相碳酸盐岩勘探中取得了丰硕成果。通过对准噶尔盆地二叠系芦草沟组、四川盆地侏罗系大安寨段、银额盆地白垩系和柴达木盆地渐新统(E23)等4个典型的湖相碳酸盐岩案例进行解剖,分析其储集层特征、烃源岩生烃能力和成藏模式。结果表明:①湖相碳酸盐岩储集层普遍较为致密,以纳米—微米级储集空间为主,包括白云石晶间孔、生物体腔孔和堆积孔、微裂缝系统及其溶蚀扩大孔。咸化环境有利于白云石化作用,可改善湖相碳酸盐岩的储集能力,但绝大多数渗透率小于0.1 mD。②湖相碳酸盐岩既有储集能力,又可作为生油岩,有机质丰度不高,且成熟度普遍较低,但源岩中的分散可溶有机质可在低熟阶段大量生排烃,具有较高的液态烃产率。③油气藏多具有"初期产量高—产量大幅下降—长期低产稳产"的产量特征,为典型"裂缝—孔隙型"油气藏。裂缝网络在地质历史时期的油气初次运移和聚集成藏、现今的油气开采过程中均提供运移通道作用。④油气藏为"连续型"非常规油气藏,常与邻区的常规油气藏共同组成区域性油气田群。该研究成果为重新评价湖相碳酸盐岩的勘探潜力奠定了理论基础。
For decades of exploration,geologists have made great achievements in the exploration of lacustrine carbonate rocks.By dissecting four typical cases of lacustrine carbonate rocks,such as Lucaogou Formation of Permian in Junggar Basin,Da’anzhai Section of Jurassic in Sichuan Basin,Cretaceous in Yin’e Basin and Oligocene in Qaidam Basin,the reservoir characteristics,hydrocarbon generating capacity and reservoir forming model of source rocks were analyzed.The results show that:①Lacustrine carbonate reservoirs are generally dense,with nano-micron reservoir space as the main reservoir space,including dolomite intergranular pore,organism cavity and accumulation pore,micro-fracture system and its corrosion expansion pore.Saline environment is beneficial to dolomitization and can improve the reservoir capacity of lacustrine carbonate rocks,but most of the permeability is less than 0.1 mD.②Lacustrine carbonate rocks have not only reservoir capacity,but also can be used as source rocks.The abundance of organic matter is not high and the maturity is generally low.However,dispersed soluble organic matter in source rocks can generate and expel hydrocarbons in large quantities at low maturity stage,which has high liquid hydrocarbon yield.③Oil and gas reservoirs are characterized by"high initial production,large reduction of production and long-term low and stable production",and are typical"fracture-pore"reservoirs.Fracture networks provide migration pathways in the process of primary migration and accumulation of oil and gas in geological history and oil and gas exploitation nowadays.④Oil and gas reservoirs are"continuous"unconventional reservoirs,which often form regional oil and gas field groups together with conventional reservoirs in adjacent areas.The research results lay a theoretical foundation for re-evaluating the exploration potential of lacustrine carbonate rocks.
作者
杜江民
龙鹏宇
杨鹏
丁强
胡秀银
李伟
柏杨
盛军
Du Jiangmin;Long Pengyu;Yang Peng;Ding Qiang;Hu Xiuyin;Li Wei;Bai Yang;Sheng Jun(College of Resources,Hebei GEO University,Shijiazhuang 050031,China;Changqing Oilfieid Company,CNPC,Xi′an 710018,China;Southwest Oil&Gas Field Company,CNPC,Chengdu 610051,China;Qinghai Oilfield Company,CNPC,Gansu Dunhuang 736202,China)
出处
《地球科学进展》
CAS
CSCD
北大核心
2020年第1期52-69,共18页
Advances in Earth Science
基金
国家自然科学基金项目“塔中地区上奥陶统良里塔格组微生物碳酸盐岩沉积特征对多尺度孔隙耦合的影响”(编号:41702163)
河北地质大学博士科研启动基金项目“碳酸盐岩储层白云岩成因机理研究”(编号:BQ2017049)资助.
关键词
湖相碳酸盐岩
白云石晶间孔
可溶有机质
低丰度—低熟
“连续型”非常规油气藏
成藏模式
Lacustrine carbonate rocks
Dolomite intergranular pore
Soluble organic matter
Low abundance-low maturity
"Continuous"unconventional reservoirs
Hydrocarbon accumulation model
作者简介
第一作者:杜江民(1984-),男,河北石家庄人,副教授,主要从事石油地质、沉积学研究.E-mail:jiangmindu@163.com
