摘要
准噶尔盆地玛湖凹陷下二叠统风城组为盆地西北缘的主力烃源岩,具有较大的页岩油勘探前景。利用场发射电子扫描显微镜以及高压压汞等测试手段,对研究区玛页1井风城组页岩油储层的孔隙结构进行了精细研究和分类评价。研究结果表明:(1)玛湖凹陷风城组页岩油储层以薄层状或块状云质、粉砂质、钙质或硅质泥岩为主,且泥岩中常发育大量白云石、方解石、及硅质条带、团块或斑块。(2)研究区风城组页岩油储层孔隙类型主要有粒间孔、基质溶孔、粒内溶孔、晶间孔、晶内溶孔以及微裂缝等,以基质溶孔和晶间孔最为发育。储层物性差,孔隙度为0.4%~17.7%,大多小于3.0%;渗透率最大值为2.90 m D,大多小于0.03 mD,属于低孔特低渗储层。(3)研究区样品孔隙体积普遍较小,平均为0.25 cm3;均值系数平均为13.95;分选系数平均为2.44;偏态平均为0.97;峰态平均为1.25;变异系数平均为0.17;最大进汞饱和度低,平均为37.23%;退汞效率低,平均仅为25.73%。(4)研究区页岩油储层可分为Ⅰ,Ⅱ,Ⅲ等3类,其中物性好且内部孔隙连通性好的Ⅰ类页岩油储层具有好的油气勘探开发前景。
The Lower Permian Fengcheng Formation in Mahu Sag is the major source rock in the NW Junggar Basin,with great prospects for shale oil exploration.The pore structure of shale oil reservoirs of Fengcheng Formation in well Maye 1 in the study area was studied and classified by means of field emission electron scanning microscope and high-pressure mercury injection.The results show that:(1)The shale oil reservoir of Fengcheng Formation in Mahu Sag is dominated by thin-layer or massive dolomitic,silty,calcareous or siliceous mudstone,and a large amount of dolomite,calcite and siliceous bands,lumps or patches are often developed in the mudstone.(2)The pore types of shale oil reservoirs of Fengcheng Formation in the study area are mainly intergranular pores,matrix dissolved pores,intragranular dissolved pores,intercrystalline pores,intracrystalline dissolved pores and microfractures,among which matrix dissolved pores and intercrystalline pores are the most developed.The physical properties of the shale oil reservoirs are poor,the porosity values range from 0.4%to 17.7%and are mostly less than 3.0%,and the permeability value are mostly less than 0.03 mD,with the maximum of 2.90 mD,belonging to low porosity and extra-low permeability reservoirs.(3)The pore volume of samples in the study area is generally small,with an average of 0.25 cm3.The average values of average coefficient,sorting coefficient,skewness,peakedness and coefficient of variation is 13.95,2.44,0.97,1.25 and 0.17,respectively.The maximum mercury saturation is low,with an average of 37.23%,and the efficiency of mercury-ejection is low,with an average of only 25.73%.(4)The shale oil reservoirs in the study area can be divided into three types:Ⅰ,ⅡandⅢ.Among them,typeⅠshale oil reservoirs with good physical properties and good internal pore connectivity have good prospects for oil and gas exploration and development.
作者
雷海艳
郭佩
孟颖
齐婧
刘金
张娟
刘淼
郑雨
LEI Haiyan;GUO Pei;MENG Ying;QI Jing;LIU Jin;ZHANG Juan;LIU Miao;ZHENG Yu(Xinjiang Key Laboratory of Shale Oil Exploration and Development,Karamay 834000,Xinjiang,China;Research Institute of Experiment and Detection,PetroChina Xinjiang Oilfield Company,Karamay 834000,Xinjiang,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China)
出处
《岩性油气藏》
CSCD
北大核心
2022年第3期142-153,共12页
Lithologic Reservoirs
基金
国家自然科学基金“碱湖油页岩中微晶白云石沉淀-成岩机理研究”(编号:42002116)资助。
