【作者】 周会强；

【导师】 曾英； 李华斌；

【作者基本信息】 成都理工大学 ， 应用化学， 2011， 硕士

【摘要】 二连油田哈76断块油藏属于中低温（74℃）、低渗透率(平均渗透率25.3×10^-3μm²)油藏。二连油田哈76断块油藏存在着断块物性差异大,开发效果差;井网适应性差;断块纵向上产吸差异大,层间矛盾突出等问题,从而其采出程度不高,截止2004年12月,采出程度仅5.76%。目前二连油田哈76断块日产液117.7t,日产油9.3t,综合含水92.1%;采油速度0.15%,累积产油18.7821×10⁴t,累计产水27.0990×10⁴m³。自断块1995年6月正式投入开发以来相继采取过酸化、压裂、调剖及长周期注水等措施来改变油田低效开发的状况,在一定程度上取得了一定的效果,也起到了减缓油田递减的作用,但其开发效果不理想。在二连油田条件下,通过研究弱凝胶深部调驱体系组成及成胶机理、驱油机理等,模拟二连油田哈76断块油藏条件,结合已经筛选出的适合二连油田的弱凝胶深部调驱体系,评价该体系性能,并进行室内模拟驱油实验,从而提出弱凝胶深部调驱方案,并在方案施工后进行初步调驱效果分析。取得的认识和成果主要有:1、弱凝胶是由低浓度的聚合物和交联剂形成的以分子间交联为主分子内交联为辅的具有三维网络结构的弱交联体系。弱凝胶具有深部调剖和驱油的双重作用,能够大幅提高采收率,已成为油田三次采油的一项重要技术。2、天然高分子改性聚合物具有热、剪切稳定性、耐盐性、易溶解性、可增粘性及注入性能控制的综合性能。通过长期的室内实验、论证,可以发现天然高分子改性聚合物可以用于渗透率、低孔隙度的二连油田哈76断块聚合物调驱（剖）矿场试验。3、室内实验筛选出的适合二连油田哈76断块油藏的弱凝胶体系:天然高分子改性聚合物1250mg/L～2000mg/L+间苯二酚交联剂300mg/L～500mg/L+乌洛托品交联剂300mg/L～500mg/L+草酸900mg/L。该体系在二连油田哈76断块油藏条件下,具有良好的成胶性能,而且体系的配方浓度越大,成胶粘度越高。4.研究了弱凝胶体系的溶解性、抗盐性、稳定性等,并结合二连油田哈76断块油藏地质条件进行了驱油模拟实验,实验结果表明:弱凝胶在岩心内部候凝成胶后,对高渗层产生了明显的封堵效果,起到了调剖的作用,提高采收率较高,较水驱采收率增幅为10.28%,因此能满足二连油田调驱（剖）的要求。5.对二连油田哈76断块油藏天然高分子改性聚合物凝胶深部调驱方案设计及效果初期评价结果进行分析,天然高分子改性聚合物凝胶深部调驱作业施工后与调驱前对比结果表明: 11口对应连通油井产液量由104.77t/d上升至148t/d,产油量由7.55t/d上升至13.28t/d,综合含水率由90.7%下降到81.3%,通过实施调驱试验,对应生产井高峰增油达5.5t/d,平均单井增油0.7t¹.2t,含水率降低约9.4%,且表现出注水井注水利用率增高、水驱波及体积扩大的效果。更多还原

【Abstract】 The Ha-76 faulted-block reservoir of Er’lian Oilfield belongs to medium temperature （74℃）, low-permeability (the average permeability is 25.3×10^-3μm²) oil reservoir. There are many problems existing in Er’lian Oilfield H-76 faulted-block reservoir, such as the difference of physical properties are evident., poor development effect, poor well pattern adaptability, large vertical production and injection of fault block, the inconsistencies between formations are obvious and so on, thereby the degree of reserve recovery is not so high, by December 2004, the degree of reserve recovery was only 5.76%. Now, for H-76 faulted-block reservoir of Er’lian Oilfield, the daily fluid output is 117.7t, oil production per day is 9.3t, oil recovery rate is 0.15%, cumulative oil production is 18.7821×10⁴t, cumulative water production is 27.0990×10⁴m³. Sine the fault block has been put into development officially in June 1995, acidizing, sand fracturing, profile control, long cyclic water flooding and other measures have been adopted in succession to change the low level efficiency development condition of oil field, which not only achieved a certain effect to a certain degree, but also played the function of slowing down field decline, yet it can’t change the low efficient production condition of oil field.In er’lian oilfield condition, According to acquiring the system composition of weak gel of deep profile control, gelling mechanism and mechanism of oil displacement etc, it is selected that weak gel profile control system of temperature resistance, salt resistance and organic crosslinking, thus it gives weak gel deep profile control and flooding plan, the scheme will be given after the construction for preliminary analysis. in this paper, the main recognition can be concluded as follows:1、Weak gel, a kind of weak gelation system with three-dimensional structure, is composed with low concentration polymer and cross-lingking agent, in which the intermolecular cross lingking is mostly and the intramolecular cross linking is secondary. It is an important technique in EOR, because it has dual effects that are profile control and oil displacement.2、The modified-natural-macromolecular starch, which has many advantages, such as temperature resistance, salt resistance and good resistant to shear. It is hardness and softness ,and it’s structure make it hard to undergo thermo-oxidative degradation. All of its advantages make it can be used to deep profile control and flooding in H76 faulted-block oil reservoir.3、The weak gel system is choosed out for er’lian oilfield: polymer 1250 mg/L～2000mg/L, resorcinol 300mg/L～500mg/L and urotropine300mg/L～500mg/L. The system has good gelling performances, and the greater the system concentration is, the higher the gelling viscosity is.4、It has also researched the saline and thermal stability, injection property, ageing stability, resistance factor, residual resistance factor, and so on. The injectivity, plugging performance and sweep efficiency of the gel system is evaluated through core experiments. Lab Experiment results indicate that weak gel has caused apparent sealing effect on high permeability core after gelling, which finally indicates the purpose of profile control. So it can meet requires of er’lian oilfield.5、Modified-natural-macromolecular starch can be use to gel deep profile control and flooding plan in H76 fault-block oil reservoir ,After the effect evaluation result analysis, the results show that 11 corresponding connected oil well’fluid production by rise 148t/d original gradually 104.77t/d , and oil producing capacity by rise 13.28d/t original gradually 7.55t/d. the integral water content is down to 81.3% by 90.7%. According to gel deep profile control and flooding ,oil-generating peaks reaches to 5.5 t/d, the average single well potential is up by 0.7t¹20t, water rates were reduced about 9.4%, improving intake capacity between the layers and expanding swept volume effectively to improve water drive recovery factor.更多还原