人工压裂低渗透油藏二氧化碳吞吐因素敏感性分析  

Analysis of the sensitivity of carbon dioxide huff 'n' puff for fractured reservoirs with low permeability

作　　者：钟立国[1,2,3] 韩大匡[2] 李莉[3] 

机构地区：[1]大庆石油学院提高采收率教育部重点实验室,黑龙江大庆163318 [2]中国石油勘探开发研究院博士后科研流动站,北京100083 [3]大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《大庆石油学院学报》2009年第4期125-129,共5页Journal of Daqing Petroleum Institute

基　　金：中国博士后基金项目(20080440924)

摘　　要：根据大庆外围油田人工压裂低渗透油藏的一般地质特征，开展二氧化碳吞吐的主要油藏参数和注采参数的敏感性分析，结果表明，人造裂缝半长、注入强度、开井压力、油层厚度和压力因数对人工压裂低渗透油藏CO2吞吐的换油率和采油强度具有显著的影响；人工压裂低渗透油藏CO2吞吐的选井要求是人工压裂规模适中（人造裂缝半长为30～40m）、油层厚度大，原油黏度低，含油饱和度高，分层性强，但对油藏基质和天然微裂缝渗透率要求不高；CO2吞吐工程设计时，必须考虑人造裂缝半长来确定合理的注入强度、注入速度、焖井时间和开井压力；建议焖井时间为10～40d，开井压力为0．5～1MPa，不宜高于2MPa．According to the typically geological characteristics of reservoirs with low permeability in Daqing Oilfields,numerical simulation cases are obtained by orthogonal design of main reservoir parameters and injection and production parameters,then sensitivity analysis by Eclipse compositional model are carried out for CO2 huff 'n' puff.It shows that semi length of artificial fracture,injection intensity of CO2,production pressure,thickness of reservoir and formation pressure coefficient have greater effect on ratio of oil to CO2 and periodical oil production for CO2 huff 'n' puff.The well selection requirements of CO2 huff 'n' puff applied to fracture reservoir with low permeability include proper semi artificial fracture length(30~40 m),larger formation thickness,lower viscosity of crude oil,higher oil saturation and more layers,and it is applicable to low permeable reservoirs with matrix and natural fracture at different permeability grades.It is noted that semi length of artificial fracture should be involved to design rational CO2 injection intensity,injection rate,shut-off time and production pressure in CO2 huff 'n' puff process.It is recommended that the shut-off time is confined to 10~40 d,production pressure 0.5-1 MPa,undesirable to produce over 2 MPa.

关 键 词：低渗透油藏 压裂 二氧化碳 吞吐 敏感性分析 换油率 采油强度 

分 类 号：TE345[石油与天然气工程—油气田开发工程]