【摘要】：大慶油田從二十世紀(jì)八十年代至今,著重對(duì)三元復(fù)合驅(qū)以及驅(qū)油效果開展了大量的研究工作,已完成4個(gè)主力油層強(qiáng)堿三元復(fù)合驅(qū)礦場(chǎng)試驗(yàn),隨著三元復(fù)合驅(qū)驅(qū)油技術(shù)在二類油層的開展,驅(qū)替對(duì)象的滲透率更低、層間差異更大,由于存在著層間矛盾大、層段多和儲(chǔ)層結(jié)構(gòu)復(fù)雜等的問題,需要通過(guò)注入能力測(cè)試和三元復(fù)合驅(qū)段塞的優(yōu)選以及色譜分離動(dòng)滯留實(shí)驗(yàn)進(jìn)行確定。以大慶油田二三類油層為依托,通過(guò)開展了聚合物分子量、濃度和巖心滲透率匹配關(guān)系的室內(nèi)實(shí)驗(yàn)研究,計(jì)算三元體系的阻力系數(shù)、殘余阻力系數(shù)等參數(shù)。通過(guò)物理模擬實(shí)驗(yàn)對(duì)三元復(fù)合驅(qū)主、副段塞大小及段塞中各化學(xué)劑濃度進(jìn)行優(yōu)選,以確定最佳主、副段塞大小及段塞濃度。通過(guò)應(yīng)使用足夠長(zhǎng)的天然巖心巖在盡量接近油藏條件下進(jìn)行物理模擬驅(qū)替實(shí)驗(yàn)觀察色譜現(xiàn)象,確定三元組分的無(wú)因次等濃聚等參數(shù)。結(jié)果表明,三元體系的黏度降解程度影響最高注入壓力,滲透率相同時(shí),降解程度越大,最高注入壓力越低;滲透率影響三元體系的最高注入壓力,在三元體系的黏度降解程度相同時(shí),滲透率越低,注入壓力越高;在等黏條件下,低分子量聚合物用量較多,且在巖心中降低水相滲透率的能力較弱,而過(guò)高的聚合物分子量會(huì)導(dǎo)致巖心堵塞,故考慮二類油層滲透率的具體情況,建議采用1600萬(wàn)分子量聚合物三元體系進(jìn)行注入,黏度采用剪切前50m Pa·s三元復(fù)合體系;運(yùn)用制備的與實(shí)際儲(chǔ)層孔滲特點(diǎn)等對(duì)應(yīng)的巖心進(jìn)行段塞大小與濃度優(yōu)選驅(qū)油實(shí)驗(yàn),確定最佳注入段塞為主段塞濃度為[1.2wt%碳酸鈉+0.3wt%表面活性劑+2200mg/L聚合物溶液]0.35PV,副段塞濃度為[1.0wt%碳酸鈉+0.1wt%表面活性劑+2200mg/L聚合物溶液]0.15PV;通過(guò)天然澆筑巖心三元體系動(dòng)滯留實(shí)驗(yàn),確定堿的滯留量為0.31mg/g,表面活性劑的滯留量為0.1 mg/g,聚合物的滯留量為0.051 mg/g,堿的滯留量最大,結(jié)合測(cè)量結(jié)果得到了三元體系各組分的無(wú)因次等濃聚,得出弱堿三元復(fù)合體系在注入時(shí)有色譜分離現(xiàn)象;三元復(fù)合體系在流經(jīng)模型時(shí),聚合物與堿以及表面活性劑之間都發(fā)生了色譜分離,聚合物最先突破,堿和表面活性劑隨后一起突破。二類油層復(fù)雜的孔隙結(jié)構(gòu)可能加劇了色譜分離的程度。
[Abstract]:From the 1980s to the present, Daqing Oilfield has carried out a lot of research work on ASP flooding and its effect, and has completed the field tests of 4 main reservoirs with strong alkali ASP flooding. With the development of ASP flooding technology in the second class reservoir, the permeability of displacement object is lower and the difference between layers is greater. It needs to be determined by injection capability test, optimization of ASP flooding slug and chromatographic separation and retention test. Based on the second and third types of oil layers in Daqing Oilfield, the parameters of resistance coefficient and residual resistance coefficient of ternary system are calculated by laboratory experimental study on the matching relationship among polymer molecular weight, concentration and core permeability. Through the physical simulation experiment, the size of ASP flooding, the size of secondary slug and the concentration of each chemical agent in the slug are selected to determine the optimum size of main and secondary slug and the concentration of slug. The chromatographic phenomena of natural core rock with long enough length should be observed by physical simulation and displacement experiments under the condition of being as close to the reservoir as possible, and the parameters such as dimensionless secondary concentration accumulation of ternary components are determined. The results show that the maximum injection pressure is affected by the viscosity degradation degree of the ternary system, the maximum injection pressure is lower with the same permeability, and the maximum injection pressure is affected by the permeability of the ternary system. When the viscosity degradation degree of the ternary system is the same, the lower the permeability is, the higher the injection pressure is, and the lower the amount of low molecular weight polymer is, the lower the permeability of water phase is in the core of rock. However, too high molecular weight of polymer will lead to core blockage, so considering the specific situation of permeability of the second class reservoir, it is suggested that 16 million molecular weight polymer ternary system be used for injection, and the viscosity is 50 MPA s ternary composite system before shear. By using the prepared core corresponding to the pore and permeability characteristics of the actual reservoir, the slug size and concentration are optimized for oil displacement experiments. The optimum concentration of main slug for injection slug is [1.2wt% sodium carbonate 0.3wt% surfactant 2200mg/L polymer solution] 0.35PV.The secondary slug concentration is [1.0wt% sodium carbonate 0.1wt% surfactant 2200mg/L polymer solution] 0.15PV.The dynamic retention experiment of natural core ternary system is carried out. It is determined that the retention of base is 0.31 mg / g, that of surfactant is 0.1 mg / g, that of polymer is 0.051 mg / g, and that of alkali is the largest. It is concluded that the weak base ternary system has chromatographic separation phenomenon at the time of injection. When the ASP system passes through the model, the chromatographic separation occurs between polymer, alkali and surfactant, and the polymer breaks through first. The base and surfactant then broke through. The complex pore structure of the second class reservoir may aggravate the degree of chromatographic separation.
【學(xué)位授予單位】：東北石油大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2017
【分類號(hào)】：TE357.46
，

本文編號(hào)：2172753