高浓度聚合物注入时机及段塞组合对驱油效果的影响  

Oil Displacement Efficiency of High Concentrated Polymer Solutions:Effects of Moment of Injection and Slug Ensemble

作　　者：吴文祥[1] 张涛[1] 胡锦强[1] 

机构地区：[1]大庆石油学院石油工程学院,黑龙江大庆163318

出　　处：《油田化学》2005年第4期332-335,共4页Oilfield Chemistry

摘　　要：在大庆油田聚合物驱条件下(45℃,原油粘度～10 mPa·s,清水配制聚合物溶液),取聚合物总用量2020 PV*mg/L,在人造岩心上实验研究了水驱之后不同段塞组合的'普浓聚合物'(浓度1000 mg/L、粘度8.6 mPa·s、分子量1.7×107的HPAM溶液)+'高浓聚合物'(浓度最高达3000 mg/L、粘度最高达369 mPa·s、分子量2.5×107的抗盐聚合物溶液)的驱油效果.在普浓聚合物驱的5个不同时机转注浓度2500 mg/L、粘度315 mPa·s的高浓聚合物,转注时机越早则聚驱采收率越高,前期(不注普浓聚合物)转注为45.1%,中前期(含水降至80%时)转注为44.0%,后期(含水升至98%时)转注为41.0%.注入0.350 PV普浓聚合物后再分别注入浓度在1000～3000 mg/L的抗盐聚合物,随浓度增大,聚驱采收率由35.7%增至41.5%,但增幅迅速减小(4.8%～0.1%).注入0.350 PV普浓聚合物段塞之后依次注入浓度2500 mg/L、分子量递减(2.5×107,2.1×107,1.7×107)、尺寸递减(0.450,0.118,0.100 PV)的3个聚合物段塞,聚驱采收率最高,为48.2%;普浓聚合物段之后注入2500 mg/L的高浓聚合物单段塞或浓度递减(2500～1000 mg/L)的4个抗盐聚合物段塞,聚驱采收值相近但大大降低(41.1%或41.0%).在讨论高浓高粘高分子量聚合物驱油机理时,强调了高粘弹性聚合物溶液提高微观驱油效率的作用.图1表4参4.The oil displacement efficiency of ＂standard concentration polymer＂ （SCP） and ＂high concentration polymer＂ （HCP） in different combinations is studied experimentally on artificial cores after water flood finished at total polymer use level 2020 PV-mg/L under typical conditions of polymer flood in Daqing： temperature 45℃, crude oil viscosity - 10 mPa· s, and preparing polymer solution with fresh water. SCP denotes polymer HPAM of M^- = 1.7 × 10^7 in solution of concentration 1000 mg/L and viscosity 8.6 mPa·s and HCP-salts tolerant Am copolymer （STAmCP） of M^-= 2.5 × 10^7 in solutions of concentration up to 3000 mPa·s and viscosity up to 369 mPa·s. In a set of core flow experiments, the injection of HCP of concentration 2500 mg/L and viscosity 315 mPa · s is started in 5 different phase of SCP flooding and it is shown that the earlier the HCP injection starts the higher the enhancement inoil recovery, η, can be obtained： η is of 45.1%, 44.0%, and 41.0% in cases of the pre-early phase （no SCP having been injected）, the early phase （water cut decreased to 80% ）, and the late phase （water cut increased to 98% ）, respectively. The value η by polymer flood increases from 35.7 % to 41.5 % with increment fast dereased from 4.8 % to 0.1% when 0. 350 PV of SCP has been injected and followed by an STAmCP slug of increasing concentration from 1000 to 3000 mg/L. A highest value η by polymer flood, 48.2%, is observed when polymer slugs injected have structure： 0.350 PV of SCP＋ successive 3 slugs of equal concentration 2500 mPa·s, decreasing molar mass, 2.5 × 10^7, 2.1 × 10^7, and 1.7 × 10^7, and seize, 0.450, 0.118, and 0.100 PV; much lower ηvalues by polymer flood, 41.4% or 41.0%, are obtained when HCP of concentration 2500 mg/L single slug or 4 STAmCP slugs of decreasing concentration from 2500 to 1000 rag/L are injected as successive slugs after SCP slug. A stress on improvements in microscopic oil displacement efficiency by high viscoelasticity of polymer solutions is

关 键 词：高浓度聚合物溶液 段塞结构 聚合物驱 提高采收率 驱油机理 微观驱油效率 高分子量聚合物 丙烯酰胺共聚物 大庆油田 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程] TE39