摘要
常规排水采气和控水采气技术难以满足致密气藏低孔、低渗及小孔喉的需求。以致密岩样和自制纳米流体为研究对象,采用岩心动态驱替和静态渗吸实验,系统评价了纳米流体在岩样中的迁移能力、对排出水的渗吸以及对气/水两相渗流的影响等,并探讨了纳米流体排水采气作用机理。结果表明:纳米流体在致密储层中的迁移力强,其理论计算最远迁移距离大于300 cm,可实现深部排水采气的目的;纳米流体质量分数为6.25%时,岩样质量从0.614 g下降至0.452 g,再次渗吸水量降低26.38%,延长有效排水期;质量分数为6.25%和25.0%的纳米流体分别降低了1.83%和3.87%的气/水两相等渗点、降低了8.84%和4.47%的束缚水饱和度、增加了63.79%和100%的水相渗透率、降低了9.80%和13.04%的气相相对渗透率,具有明显的排水效果。研究成果为应用纳米流体提高致密气藏产量提供技术支持。
Conventional drainage gas recovery and water‑controlled gas recovery technologies cannot meet the needs of tight gas reservoirs with low porosity,low permeability and small pore throats.Taking tight core samples and selfprepared nanofluid as the research objects,using core dynamic displacement and static imbibition experiments,nanofluid transportability in the core samples,imbibition of discharged water and gas/water two‑phase flow effects are systematically evaluated,and mechanism of nanofluid drainage gas recovery is discussed.The results show that nanofluid has high transportability in tight reservoirs,and the theoretically calculated maximum transport distance exceeds 300 cm,which can achieve the purpose of deep drainage gas recovery.When the mass fraction of nanofluid is 6.25%,core sample mass reduces from 0.614 g to 0.452 g,and water re‑imbibition amount decreases by 26.38%,extending the effective drainage period.Nanofluids with mass fraction of 6.25%and 25.0%reduce the gas/water two‑phase isoperm points by 1.83%and 3.87%respectively,decrease the irreducible water saturation by 8.84%and 4.47%,increase the water relative permeability by 63.79%and 100%,and decrease the gas relative permeability by 9.80%and 13.04%,showing obvious drainage effects.The research results provide technical support for nanofluid to enhance the production of tight gas reservoirs.
作者
秦国伟
孙赛赛
薛云龙
张蓓蕾
许洪星
郑俨钊
秦文龙
白艳明
代旭
QIN Guowei;SUN Saisai;XUE Yunlong;ZHANG Beilei;XU Hongxing;ZHENG Yanzhao;QIN Wenlong;BAI Yanming;DAI Xu(College of Petroleum Engineering,Xi’an Shiyou University,Xi’an 710065,China;E&D Research Institute of PetroChina Changqing Oilfield Company,Xi’an 710018,China;Downhole Technology Operation Company PetroChina Chunqing Drilling Engineering Co Ltd,Xi’an 710000,China;SINOPEC Jianghan Oilfield Branch,Qianjiang 433124,China;Exploration&Development Research Institute of PetroChina Daqing Oilfield Co Ltd,Daqing 163712,China)
出处
《大庆石油地质与开发》
CAS
CSCD
北大核心
2022年第6期159-166,共8页
Petroleum Geology & Oilfield Development in Daqing
基金
国家自然科学基金项目“离子水驱砂岩油藏固/液体系界面调控及残余油启动机制研究”(52174027)
陕西省自然科学基金项目“低渗气藏绿色纳米流体控水采气作用机制研究”(2020JM-534)和“可回收高分子磁纳米材料与VES流体的超分子自组装机理研究”(2019JM-108)
教育部重点实验室开放课题“低渗气/水同层功能型控水剂研制及其作用机制研究”(NEPU-EOR-2019-04)。
关键词
致密气藏
纳米流体
排水采气
迁移能力
动态驱替
tight gas reservoirs
nanofluid
drainage gas recovery
transportability
dynamic displacement
