三塘湖盆地芦草沟组页岩自吸特征  

Spontaneous Imbibition Characteristics of the Shale in Lucaogou Formation in Santanghu Basin

作　　者：万永清[1] 曹欣瑜 刘海涛 马强[1] 白兆阳 王奇 WAN Yongqing;CAO Xinyu;LIU Haitao;MA Qiang;BAI Zhaoyang;WANG Qi(Research Institute of Exploration and Development,Tuha Oilfield Company,PetroChina,Hami,Xinjiang 839009,China;Tuha Branch,Logging Co.Ltd,CNPC,Shanshan,Xinjiang 838202,China)

机构地区：[1]中国石油吐哈油田公司勘探开发研究院,新疆哈密839009 [2]中国石油测井有限公司吐哈分公司,新疆鄯善838202

出　　处：《新疆石油地质》2020年第6期666-676,共11页Xinjiang Petroleum Geology

基　　金：中国石油科技重大专项(2017E-04-04)。

摘　　要：页岩储集层压裂后,存在压裂液返排率低、产能差异大的特点,大量的压裂液长期滞留井下并被储集层自发吸入,对油气开发及有效动用具有很大影响。以页岩油可动性、页岩静态自吸和润湿性等多项实验为基础,通过页岩自吸压裂液驱油实验和恒压水驱油实验,认识到页岩独具的自吸特征。基于静态自吸实验,从页岩基本吸水物理现象入手,通过自吸饱和度和自吸速率2个自吸特征参数来反映页岩的自吸能力,分析现场压裂后生产排液曲线,认为室内实验结果对页岩压裂后生产排液有一定的预测作用。通过液—岩铺展性实验,分析了三塘湖盆地二叠系芦草沟组页岩润湿性特征及其对自吸能力和特征的影响,认识到页岩既有亲油性又具有亲水性的混合润湿特征,结合相关资料综合分析认为,页岩的自吸能力和特征主要受微观孔隙结构和润湿性的共同控制和影响。After fracturing in shale reservoirs,the flowback rate of fracturing fluid is low,and the production capacity varies greatly.A large amount of fracturing fluid stays downhole for a long time and is spontaneously inhaled by the reservoir,which has a great impact on oil⁃gas development and effective production.Based on some related experiments such as shale oil mobility experiment,static spontaneous imbibi⁃tion experiment and wettability experiment of the shale,etc.,the experiment of fracturing fluid displacing oil with the spontaneous imbibi⁃tion and the experiment of water displacing oil under constant⁃pressure in shale were carried out,and the unique spontaneous imbibition characteristics were revealed.On the basis of static spontaneous imbibition experiment,starting from the basic physical phenomenon that shale absorbs water,the spontaneous imbibition capacity of shale was reflected by two characteristic parameters on spontaneous imbibition curve,namely spontaneous imbibition saturation and spontaneous imbibition rate.And the flowback curve for producing fluid was analyzed,which was believed that the results of laboratory experiments had a certain predictive effect on fluid production after shale fracturing.Through the liquid⁃rock spreading experiment,for the shale from Permian Lucaogou formation in the Santanghu basin,the wettability and the influences of the wettability on spontaneous imbibition capacity and on spontaneous imbibition characteristics were analyzed,finding out that the shale had both lipophilicity and hydrophilicity.After analyzing related data comprehensively,it was concluded that the sponta⁃neous imbibition capacity and spontaneous imbibition characteristics of the shale were mainly controlled and influenced by the microscopic pore structure and wettability of the shale.

关 键 词：三塘湖盆地 芦草沟组 页岩 压裂液返排率 自吸实验 自吸饱和度 自吸速率 润湿性 

分 类 号：TE122.8[石油与天然气工程—油气勘探]