相渗透率改善剂的研制
摘要
大庆油田是一个陆相沉积的多油层、非均质砂岩油田，注水开发是保证油田高产、稳产的重要措施。但是，随着开发年限的延长，大量的注入水沿水洗强度较高的高渗透带窜流，导致油井过早水淹，产油量下降。2002年底全油田综合含水达87%，基础井网开采的主力油层含水已达到90～95%，致使开采成本逐年增加。在高含水及地层能量逐渐枯竭的情况下，油井过多产水，消耗大量注入水资源，使地面的脱水费用增加，造成极大的浪费，还可能使储层结构破坏，造成油井出砂甚至引发生产事故，另外，油井见水后也会增加液体的相对密度，增大井底油压，产生层间干扰。油井出水还会腐蚀井下设备，严重时可能引发事故。另一方面低水淹部位动用情况较差，地层中出现水圈闭的死油区，注入水绕道而过，从而降低采收率，为油田经济开发带来很大的隐患。
目前，油田常用的降水增油技术很多，最常规的技术是化学堵水技术，简称化堵技术。化学堵水技术是将各组分混合，在地面或注入地下后发生化学反应，生成不溶于水的化合物，通过堵塞岩石的孔隙来达到阻止水从地层被采出的工艺措施。国内外都十分重视油田堵水工作，利用行之有效的堵水技术可以保持地层能量，保障注水开发或三次采油的效果。国外将堵水作为三次采油前地层的预处理措施， 而中国将堵水作为控水稳油的重要手段。但是，常规的堵水技术在堵塞地层水道的同时，也堵塞了油流通道，使油井产油量下降，影响经济效益。
相渗透率改善剂（RPM，Relative Permeability Modifiers），从性能上说属于一种选择性堵剂，即只大幅降低地层水相渗透率，而对油相渗透率降低很少甚至不降低的一种物质。相渗透率改善剂的研究是从上世纪70年代开始，首先采用水溶性聚丙烯酰胺降低油井的产水量和注入井的流度控制。随着研究的深入，人们发现许多水溶性高分子溶液具有这种不等比例降低油水相渗透率（DPR，Disproportionate Permeability Reduction）
的功能，同时，人们还发现，利用一些金属离子交联高分子溶液，可以获得更好的DPR效果。
本文的研究工作是以作者本人承担的《相渗透率改善剂研制》项目为背景，该项目是大庆油田有限责任公司级项目《厚油层压裂控水技术研究》项目的子课题之一。其研究目的是针对油田开发的主力油层—厚油层的地质特点，研制一种适应大庆油田地质条件改善剂，并与其它技术如压裂、水井注入等相结合，达到堵水不堵油的挖潜目的。经过研究，研制一种.铬（Cr3+）交联的相渗透率改善剂体系，主要组分为聚丙烯酰胺溶液，醋酸铬交联剂，稳定剂，桥联剂等，其中，聚合物浓度可根据需要在1000mg/l～6000 mg/l之间选择，体系在温度为45℃左右，矿化度低于10000 mg/l，pH值在7左右，能形成强度较好的胶体。室内岩心实验表明，注入改善剂后，岩心渗透率降低，束缚水饱和度增加，相渗曲线具有特低渗透岩石的相渗特征，注入改善剂后注入压力明显高于注改善剂之前的注入压力，而且随着水饱和度增加，注入压力增加，这表明改善剂对水的阻力比对油的影响更大。与注入改善剂前相比，岩心注入改善剂后，含水率降低，油相对渗透率增加，而水相对渗透率明显降低，残余阻力系数达2.268以上，油饱和度降低10%以上，最多可降低18.8%，而采收率比水驱提高15.25%以上。通过比较水驱含水率达到98.8%、87.5%时注入改善剂的残余阻力系数、油饱和度分别降低幅度、采收率提高幅度及相渗曲线和含水率曲线，含水率为98.8%时注入改善剂比含水率为87.5%时注入的效果更好。在水驱含水率相同条件下，改善剂注入量越多，驱油效果越好。6.相渗透率改善剂技术可提高驱油效率，按提高采收率能10%，1m3改善剂的成本是50元计算，每注入1m3改善剂可获得0.1m3油（价值是130元），其经济效益极为显著，尤其是在油田进入高含水后期开发，应用前景极为广阔。
Daqing Oilfield is a heterogeneous sandstone reservoir of continental origin with multi-layers, and water flood is important method to guarantee stable high oil production. But, as time goes on, great amounts of injected water flows along the high permeable zone, which results in early watered-out producers and declining yield. By the end of 2002, the overall water cut for the oilfield is up to 87%, and water cut for the main pay zone has reached 90~95%. On one hand, this leads to increasing cost, superabundant water production, and possible damage for the formation structure. What’s more, water in producer will also add the density of the liquid, increase the bottom hole pressure, and cause interference between layers; additionally, it can erode the downhole tools. On the other hand, water trapped dead oil zone forms in the low watered out position, and the injected water bypasses here, which leads to lower recovery.
At present, the conventional water plugging technology is chemical water shutoff, which reacts on the surface or in the formation to produce water insoluble matter to plug the hole, thus prevents water producing. Water shutoff is paid great attention in domestic and overseas because effective water shutoff can keep high drive energy and ensure the effect of enhanced oil recovery (abbr. EOR). Water shutoff is regarded as pretreatment before EOR overseas, while China treats it as main method for water control and stable oil production. But the conventional water shutoff technology not only blocks the water channel, but also oil passage, thus decreases the oil production, and affects the economic effect.
Relative permeability modifiers (abbr. RPM) is a kind of selective water plugging agent, namely it only decreases the permeability of water phase, causes little or even no impact on oil phase. The research on RPM can trace
back to 1970s, and water-soluble polyacrylamide to reduce the water production and control the fluidity. Later on, it was found that many kinds of water-soluble polymer had the ability of disproportionate permeability reduction (abbr. DPR), meanwhile, it was also discovered that some metallic ion crosslinked polymer could get better DPR.
The background of the article is the Development of Relative permeability modifiers, which is undertaken by the author and is the sub-project of Daqing Oilfield Company Ltd. project----Research on Thick Layer Fracturing and Water Controlling Technique. The target of the research is to develop modifier that is suitable for Daqing oilfield geological conditions according to the characteristic of main pay zones----thick layers. Further more, the target of water-shutoff instead of oil-shutoff can be achieved by combining other techniques such as fracturing and water injection. After a serious of research work, a kind of chromium-cross-linking phase permeability modifier system, which is mainly consist of polyacrylamide, acetic acid chromium cross linking agent, stabilizer, and bridging agent, was developed. The polymer density ranges from 1000mg/l to 6000mg/l. The temperature of the system is around 45℃. The salinity is lower than 10000mg/l; the PH value is about 7. All the features is helpful for forming a good intensity colloid. The Lab core experiment indicated that core permeability decreased and irreducible water saturation increased after injecting modifier. The phase permeability curve features special lower permeability. The injection pressure after modifier injection was obviously higher than that of before modifier injection. In addition, the injection pressure increased with the water saturation. This indicated that modifier resists water more than resists oil. The water cut of core, when compared with that before modifier injection, decreased. Oil phase permeability increased, while water
phase permeability decreased obviously. Residual resistance factor was more than 2.268. Oil saturation decreased more than 10% and decreased up to 18.8%. The recovery ratio, on the other hand, increased 15.25% more than that of water
目前，油田常用的降水增油技术很多，最常规的技术是化学堵水技术，简称化堵技术。化学堵水技术是将各组分混合，在地面或注入地下后发生化学反应，生成不溶于水的化合物，通过堵塞岩石的孔隙来达到阻止水从地层被采出的工艺措施。国内外都十分重视油田堵水工作，利用行之有效的堵水技术可以保持地层能量，保障注水开发或三次采油的效果。国外将堵水作为三次采油前地层的预处理措施， 而中国将堵水作为控水稳油的重要手段。但是，常规的堵水技术在堵塞地层水道的同时，也堵塞了油流通道，使油井产油量下降，影响经济效益。
相渗透率改善剂（RPM，Relative Permeability Modifiers），从性能上说属于一种选择性堵剂，即只大幅降低地层水相渗透率，而对油相渗透率降低很少甚至不降低的一种物质。相渗透率改善剂的研究是从上世纪70年代开始，首先采用水溶性聚丙烯酰胺降低油井的产水量和注入井的流度控制。随着研究的深入，人们发现许多水溶性高分子溶液具有这种不等比例降低油水相渗透率（DPR，Disproportionate Permeability Reduction）
的功能，同时，人们还发现，利用一些金属离子交联高分子溶液，可以获得更好的DPR效果。
本文的研究工作是以作者本人承担的《相渗透率改善剂研制》项目为背景，该项目是大庆油田有限责任公司级项目《厚油层压裂控水技术研究》项目的子课题之一。其研究目的是针对油田开发的主力油层—厚油层的地质特点，研制一种适应大庆油田地质条件改善剂，并与其它技术如压裂、水井注入等相结合，达到堵水不堵油的挖潜目的。经过研究，研制一种.铬（Cr3+）交联的相渗透率改善剂体系，主要组分为聚丙烯酰胺溶液，醋酸铬交联剂，稳定剂，桥联剂等，其中，聚合物浓度可根据需要在1000mg/l～6000 mg/l之间选择，体系在温度为45℃左右，矿化度低于10000 mg/l，pH值在7左右，能形成强度较好的胶体。室内岩心实验表明，注入改善剂后，岩心渗透率降低，束缚水饱和度增加，相渗曲线具有特低渗透岩石的相渗特征，注入改善剂后注入压力明显高于注改善剂之前的注入压力，而且随着水饱和度增加，注入压力增加，这表明改善剂对水的阻力比对油的影响更大。与注入改善剂前相比，岩心注入改善剂后，含水率降低，油相对渗透率增加，而水相对渗透率明显降低，残余阻力系数达2.268以上，油饱和度降低10%以上，最多可降低18.8%，而采收率比水驱提高15.25%以上。通过比较水驱含水率达到98.8%、87.5%时注入改善剂的残余阻力系数、油饱和度分别降低幅度、采收率提高幅度及相渗曲线和含水率曲线，含水率为98.8%时注入改善剂比含水率为87.5%时注入的效果更好。在水驱含水率相同条件下，改善剂注入量越多，驱油效果越好。6.相渗透率改善剂技术可提高驱油效率，按提高采收率能10%，1m3改善剂的成本是50元计算，每注入1m3改善剂可获得0.1m3油（价值是130元），其经济效益极为显著，尤其是在油田进入高含水后期开发，应用前景极为广阔。
Daqing Oilfield is a heterogeneous sandstone reservoir of continental origin with multi-layers, and water flood is important method to guarantee stable high oil production. But, as time goes on, great amounts of injected water flows along the high permeable zone, which results in early watered-out producers and declining yield. By the end of 2002, the overall water cut for the oilfield is up to 87%, and water cut for the main pay zone has reached 90~95%. On one hand, this leads to increasing cost, superabundant water production, and possible damage for the formation structure. What’s more, water in producer will also add the density of the liquid, increase the bottom hole pressure, and cause interference between layers; additionally, it can erode the downhole tools. On the other hand, water trapped dead oil zone forms in the low watered out position, and the injected water bypasses here, which leads to lower recovery.
At present, the conventional water plugging technology is chemical water shutoff, which reacts on the surface or in the formation to produce water insoluble matter to plug the hole, thus prevents water producing. Water shutoff is paid great attention in domestic and overseas because effective water shutoff can keep high drive energy and ensure the effect of enhanced oil recovery (abbr. EOR). Water shutoff is regarded as pretreatment before EOR overseas, while China treats it as main method for water control and stable oil production. But the conventional water shutoff technology not only blocks the water channel, but also oil passage, thus decreases the oil production, and affects the economic effect.
Relative permeability modifiers (abbr. RPM) is a kind of selective water plugging agent, namely it only decreases the permeability of water phase, causes little or even no impact on oil phase. The research on RPM can trace
back to 1970s, and water-soluble polyacrylamide to reduce the water production and control the fluidity. Later on, it was found that many kinds of water-soluble polymer had the ability of disproportionate permeability reduction (abbr. DPR), meanwhile, it was also discovered that some metallic ion crosslinked polymer could get better DPR.
The background of the article is the Development of Relative permeability modifiers, which is undertaken by the author and is the sub-project of Daqing Oilfield Company Ltd. project----Research on Thick Layer Fracturing and Water Controlling Technique. The target of the research is to develop modifier that is suitable for Daqing oilfield geological conditions according to the characteristic of main pay zones----thick layers. Further more, the target of water-shutoff instead of oil-shutoff can be achieved by combining other techniques such as fracturing and water injection. After a serious of research work, a kind of chromium-cross-linking phase permeability modifier system, which is mainly consist of polyacrylamide, acetic acid chromium cross linking agent, stabilizer, and bridging agent, was developed. The polymer density ranges from 1000mg/l to 6000mg/l. The temperature of the system is around 45℃. The salinity is lower than 10000mg/l; the PH value is about 7. All the features is helpful for forming a good intensity colloid. The Lab core experiment indicated that core permeability decreased and irreducible water saturation increased after injecting modifier. The phase permeability curve features special lower permeability. The injection pressure after modifier injection was obviously higher than that of before modifier injection. In addition, the injection pressure increased with the water saturation. This indicated that modifier resists water more than resists oil. The water cut of core, when compared with that before modifier injection, decreased. Oil phase permeability increased, while water
phase permeability decreased obviously. Residual resistance factor was more than 2.268. Oil saturation decreased more than 10% and decreased up to 18.8%. The recovery ratio, on the other hand, increased 15.25% more than that of water
引文
[1]《化学调剖堵水技术》 刘一江 王香增 石油工业出版社，1999。11 ISBN 7-5021-2740-2 2
[2]《提高石油采收率基础》 张继芬 石油工业出版社 1997
[3]《油田堵水剂及其新发展》 王任芳 李克华 戴彩丽 《钻采工艺》 1998年第21卷第四期 67~69
[4]《粘土双液法调剖剂封堵地层大孔道研究》 赵福麟 张贵才 孙铭勤等 《石油学报》，1994，15（1）；56~65
[5]《波南油田高温低渗透砂岩油藏调剖剂的研究与应用》赵福麟 张贵才 孙铭勤等 《石油学报》，1998，19（2）；67~72
[6]《油田堵水剂》 王任芳 李克华 《钻采工艺》 1999年第21卷第四期 63~66
[7]《萨莫特洛尔油田的新型堵水工艺》 译 张洪 《国外油田工程》 2001.5 VoL.17 No.5 7~9.
[8]《堵压综合采油技术研究与应用》 郭大立 赵金洲 吴刚等 《石油钻采工艺》 1999年（第21卷）第6期.
[9]《高强度复合凝胶选堵剂CY-98结构与性能研究》 梁兵 代华 张熙等 《油田化学》 2001.3 VoL.18 No.1 27~30.
[10]《利用廉价堵剂封堵产水大孔道》译 赵炜 《国外油田工程》 2000.4 8~9
[11]《微生物调剖的实验设计和矿场应用》译 李蔚 伍晓林 韩培慧 《国外油田工程》 2000.10 9~14
[12]《凝胶实现选择性堵水的机理探讨》译 范建芳 《国外油田工程》 2000.12 13~15
[13]《新型稠油选择性堵水剂的研究与应用》 马青庄 温淑新 曲小东 《油气地质与采收率》 2002.4（第9卷）第2期 74~75..
[14]《弱凝胶对油水相对渗透率的影响》 朱怀江 刘玉章 绳德强等 《石油学报》 2002.5（第23卷）第3期 17~25..
[15]《两性聚合物水溶液选择性堵剂的探索研究》 苗和平 刘淑芳 王香增 《油田化学》 1998.9（第15卷）第2期 257~260.
[16] Aniello Mennella,Luisa Chiappa,Thomas P.Lockhart,Giovanni Burrafato:Candidate and Chemical Selection Rules for Water Shutoff Polymer Treatments, paper SPE 59344 presented at the 1999 SPE European Formation Damage Conference held in The Hague,The Netherlands,31 May-1 June 1999
[17] C.G.Zhang,B.L.Gall,H.Gao,A.E.Miller,R.S.Bryant:聚合物吸附和流动性质对孔隙
介质中两相流的影响，SPE39632,第十一届国际改善石油采收率会议译文集
[18] Liang,J., Seright,R.S.：Wall-Effect/Gel-Droplet Model Of Disproportionate Permeability Reduction, paper SPE 59344 presented at the SPE J V 6, NO 3, PP 268-272, SEPT 2001 （ISSN 1086055X, SPE-74137, REVISED SPE-59344, 15 REFS）
[19] Liang,J., Sun,H., Seright,R.S.：Why Do Gels Reduce Water Permeability More Than OIL Permeability, paper SPE 27829 presented at the
[20] Seright,R.S.：Impact Of Permeability and Lithology on Gel Perfoeance，paper SPE 24190
[21] Nilsson,S., Stavland,A., Jonsbraten,H.C.：Mechanistic Study of Disproportionate Permeability Reduction,paper SPE39635 presentation at the 1998 SPE/DOE Improved Oil Recovery Symposium held in Tulsa, Oklahoma, 19-22 April 1998.
[22]J. Liang, H.Sun, and R.S Seright.：Reduction of Qil and Water Permeabilities Using Gels,paper SPE/DOE 24195 presentation at the SPE/DOE Eighth Symposium on Enhanced Oil Recovery held in Tulsa, Oklahoma, April 22-24, 1992
[23] Zaitoun,A., bertin ,H.：Two-Phase Flow Property Modifications by Polymer Adsorption, paper SPE 39631 presented at the 1998 SPE/DOE Improved Oil Recovery Symposium Held in Tulsa Oklahoma,19-22 April 1998
[2]《提高石油采收率基础》 张继芬 石油工业出版社 1997
[3]《油田堵水剂及其新发展》 王任芳 李克华 戴彩丽 《钻采工艺》 1998年第21卷第四期 67~69
[4]《粘土双液法调剖剂封堵地层大孔道研究》 赵福麟 张贵才 孙铭勤等 《石油学报》，1994，15（1）；56~65
[5]《波南油田高温低渗透砂岩油藏调剖剂的研究与应用》赵福麟 张贵才 孙铭勤等 《石油学报》，1998，19（2）；67~72
[6]《油田堵水剂》 王任芳 李克华 《钻采工艺》 1999年第21卷第四期 63~66
[7]《萨莫特洛尔油田的新型堵水工艺》 译 张洪 《国外油田工程》 2001.5 VoL.17 No.5 7~9.
[8]《堵压综合采油技术研究与应用》 郭大立 赵金洲 吴刚等 《石油钻采工艺》 1999年（第21卷）第6期.
[9]《高强度复合凝胶选堵剂CY-98结构与性能研究》 梁兵 代华 张熙等 《油田化学》 2001.3 VoL.18 No.1 27~30.
[10]《利用廉价堵剂封堵产水大孔道》译 赵炜 《国外油田工程》 2000.4 8~9
[11]《微生物调剖的实验设计和矿场应用》译 李蔚 伍晓林 韩培慧 《国外油田工程》 2000.10 9~14
[12]《凝胶实现选择性堵水的机理探讨》译 范建芳 《国外油田工程》 2000.12 13~15
[13]《新型稠油选择性堵水剂的研究与应用》 马青庄 温淑新 曲小东 《油气地质与采收率》 2002.4（第9卷）第2期 74~75..
[14]《弱凝胶对油水相对渗透率的影响》 朱怀江 刘玉章 绳德强等 《石油学报》 2002.5（第23卷）第3期 17~25..
[15]《两性聚合物水溶液选择性堵剂的探索研究》 苗和平 刘淑芳 王香增 《油田化学》 1998.9（第15卷）第2期 257~260.
[16] Aniello Mennella,Luisa Chiappa,Thomas P.Lockhart,Giovanni Burrafato:Candidate and Chemical Selection Rules for Water Shutoff Polymer Treatments, paper SPE 59344 presented at the 1999 SPE European Formation Damage Conference held in The Hague,The Netherlands,31 May-1 June 1999
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介质中两相流的影响，SPE39632,第十一届国际改善石油采收率会议译文集
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