莫北油田低渗透油藏氮气泡沫调驱技术研究与应用

发布时间：2018-05-06 07:29

本文选题：低渗透油藏 + 氮气泡沫调驱　；参考：《西南石油大学》2017年硕士论文

【摘要】：新疆莫北油田2井区J1s21油藏特点为中-低孔、低-特低渗,平均孔隙度13.57%、平均渗透率3.19mD,该油藏目前正处产量递减阶段,储层非均质性引起了严重的水淹水窜现象,导致部分井组综合含水率超过90%、生产井关井比例高、开发效果差,现阶段水驱采出程度仅为12.8%,亟需开展提高原油采收率工艺技术的研究与应用。由于氮气泡沫调驱技术具有既调又驱、对储层伤害小等优势,能在该类油藏起到较好的控水增油效果,因此根据油藏特征,本文开展了氮气泡沫调驱技术的相关研究,取得了以下认识:(1)开展了泡沫体系配方筛选及油藏适应性评价。筛选出适用于注入水配液的配方为:起泡剂FA-2浓度0.2%,起泡剂FA-3浓度0.4%,稳泡剂FS-3浓度0.05%,起泡体积720mL,泡沫半衰期128min;适用于地层水配液的配方为:起泡剂FA-2浓度0.1%,起泡剂FA-3浓度0.5%,稳泡剂FS-3或FS-4浓度0.03%～0.05%,起泡体积600mL,泡沫半衰期95min,该配方具有较好的耐温性、耐盐性、稳定性和遇油消泡性能;(2)开展了泡沫体系等流度注入参数优选研究。通过并联高、低渗岩心建立三组渗透率级差(设定值分别为:3、6、9),在不同级差下分别优选出具有最佳剖面改善效果的气液比为:2:1、1:1、1:1,注入速度为:0.6mL/min、0.8mL/min、0.6mL/min,段塞尺寸为:0.2PV、0.3PV、0.3PV,注入方式为气液同时注入;并通过制作可视化模型观察到泡沫对非均质多孔介质吸水剖面的改善过程;(3)开展了泡沫体系驱油效果评价研究。泡沫对并联岩心组合的剖面改善效果随高、低渗岩心残余油饱和度差异的增大而变好;水驱后在三组并联岩心组合中采用泡沫调驱,原油采收率分别提高了 20.33%、25.48%、12.81%,提高幅度随渗透率级差的增大呈现先增大后减小的趋势;(4)对典型井组进行了施工方案设计与应用效果分析。矿场先导试验井组取得了良好的控水增油效果:施工井组平均日产油量增加8.4t/d,平均单井产水率降低26.3%。本文基于2井区J1s21油藏开展的氮气泡沫调驱技术相关研究对于莫北油田低渗透油藏提高原油采收率技术的研究与应用具有一定的借鉴意义。
[Abstract]:The J1s21 reservoir in the 2 well area of the Mobei oilfield of Xinjiang is characterized by medium low porosity, low ultra low permeability, average porosity of 13.57%, and average permeability of 3.19mD. The reservoir is currently in the stage of production decline. The reservoir heterogeneity causes serious water flooding phenomenon, resulting in the comprehensive water content of some well groups exceeding 90%, high proportion of well well in production wells, poor development effect and present order. The level of water flooding is only 12.8%, and it is urgent to develop the research and application of the technology of oil recovery. Because of the advantages of adjusting and driving, small damage to the reservoir, the nitrogen foam adjustment and drive technology can improve the effect of water control and increase the oil in this kind of reservoir. Therefore, according to the characteristics of the reservoir, this paper has carried out the correlation of nitrogen foam flooding technology. The following understanding has been obtained: (1) the formulation of the foam system formula and the evaluation of reservoir adaptability were carried out. The formula suitable for injection water distribution was selected: the concentration of foaming agent FA-2 0.2%, the concentration of the foaming agent FA-3 0.4%, the FS-3 concentration of the foam stabilizer 0.05%, the bubble volume 720mL, the half aging 128min of the foam, and the formulation of the formation water mixture as the foaming agent FA-2. The concentration is 0.1%, the concentration of the foaming agent FA-3 is 0.5%, the concentration of foam stabilizer FS-3 or FS-4 is 0.03% ~ 0.05%, the bubble volume 600mL, the half life of the foam 95min. The formula has good temperature resistance, salt resistance, stability and oil defoaming performance. (2) the optimization of the injection parameters of the foam system is studied. Three groups of permeability grades are established by parallel high and low permeability cores. The difference (set value is: 3,6,9), the gas and liquid ratio, which has the best profile improvement effect under the different gradation, is 2:1,1:1,1:1, the injection speed is 0.6mL/min, 0.8mL/min, 0.6mL/min, the size of the slug is 0.2PV, 0.3PV, 0.3PV, and the injection mode is the same time injection of gas and liquid, and the foam is observed by the visualization model. The improvement process of the water absorption section of the medium; (3) the evaluation of the oil displacement effect of the foam system was carried out. The improvement effect of the foam to the parallel core combination was improved with the increase of the difference of the residual oil saturation of the low permeability core. After water flooding, the foam flooding was adopted in the three groups of parallel cores, and the oil recovery rate increased by 20.33%, 25.48%, 12. respectively. 81%, the increasing amplitude increases with the increase of the permeability gradation and then decreases; (4) the construction scheme design and application effect of the typical well group are analyzed. The field pilot test well group has obtained good water control effect: the average daily oil production of the construction well group is increased by 8.4t /d, and the average water production rate of the single well is reduced by 26.3%. based on 2 well The study on the nitrogen foam flooding technology in the J1s21 reservoir in the area has a certain reference for the research and application of the low permeability reservoir in the Mobei oilfield to improve the oil recovery technology.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357.46

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