【作者】 倪玉伟；

【导师】 范振忠； 张柏；

【作者基本信息】 大庆石油学院 ， 石油与天然气工程， 2009， 硕士

【摘要】 中深度调剖技术是目前油田开发后期提高原油采收率的有效手段,在稳油控水方面起着越来越重要的作用,由于浅调剖存在着处理半径小、有效期短、注入水绕流等现象,而常规凝胶类、颗粒类等深度调剖技术施工费用较高,对产量较低的低渗透油田来说,存在投入产出比低、成本回收期长等问题,不适于在外围低渗透油田规模应用。因此,针对上述问题,根据大庆外围油田地层特点,本论文采取了结合中深度调剖剂的配方优化与现场应用相结合的方法对中深度调剖技术提出了新的实验设计思路。中深度调剖的弱凝胶配方:以部分水解聚丙烯酰胺为主体、重铬酸钠为交联剂来进行室内实验。在实验过程中,通过改变交联剂,酸度调节剂,还原剂,抗氧剂,等各种添加剂的质量分数,观察了聚丙烯酰胺、重铬酸钠、硫脲、亚硫酸钠和碳酸钠在不同配比条件下的配方优选实验,评价其各在不同的温度下成胶状况、粘度变化等,最终筛选出最佳配比浓度的中深度调剖剂配方,所调剖剂配方为:HPAM1000mg/L+交联剂600 mg/L+调节剂400 mg/L+增强剂500 mg/L+抗氧剂300 mg/L。建立了室内中深度调剖剂的性能评价指标及物理模型,通过室内岩心实验,针对优选的配方进行了实验得出以下结论:随束缚水饱和度的增加,调剖剂的堵水率和堵油率都增加,油层中水的饱和度越低,堵油堵水的能力越低,这是由于在含水饱和度较低的油层,孔隙中大部分的体积被油覆盖,水以分散相的形式存在于油中,调剖剂在油层中的吸附量较低,但由于调剖剂中的阴离子聚合物的水中呈现线状,高分子相互缠绕,在油层孔隙内部形成整体的结构,堵塞了水的流动,而在含油的孔隙中,聚合物的长链不能伸展,无法形成空间连续的网状结构,随后续油的驱入,部分凝胶被驱出,使得油相的渗透率的堵塞率较小。确定了新型中深度弱凝胶调剖的配方的合理性。最后,依据高含水区块调剖选井原则,设计了整套施工方案,并对中深度调剖剂配制和现场注入设计提出了创新:调剖前后对裂缝进行了测试及动态分析。通过现场试验措施效果评价,证实该中深度弱凝胶调剖剂是能够满足外围油层高渗部位进行有效封堵的技术要求的,具有施工时易注入、成胶后耐冲刷性强、有效期长等特点,各项试验参数均能满足现场施工需要的性能指标。更多还原

【Abstract】 At present,medium-deep gel blocking technical is the most effective measures to enhance the recover of the oil during the later stage of field development. It plays more and more important role in stabilizing the production of the oil and reducing the production of water.However,the shadow blocking measures presents the following problems:higher operating expenses, lower production and longer cost recovery cycle for tight formation, which cannot be applied in large scale.Therefore,according the formation character of the Da Qing peripheral oil field and the present problems,this paper combines the optimizing formulas and field application and provides a new experiment measure.The gel formulas as follows:HPAM as the main part,Na2Cr2O7 as crosslinker.During the experiments process,the concentrations of crosslinker,acidity modifier,reductant,antioxidant and other addictives were changed in order to observe the optimizing formulas of HPAM,Na2Cr2O7,thiocarbamide,sodium sulphite and sodium carbonate under different matching conditions. It also evaluates the gel strength and the viscosity under different temperatures.The optimizing formulas as follows:HPAM1000mg/L+crosslinker600 mg/L+modifier 400 mg/L+intensifier 500 mg/L+antioxidant 300 mg/L.The in-house performance index and physical model of the blocking agent were founded.Through the in-house core experiments,we can infer that the more saturation of water irreducible,the more water plugging rate.Most of the pore volume is covered by oil in lower water saturation formation,water dispering in the oil.Although less plugging agent was injected into the reservoir,the plugging agent can still block the flow of the water,the polymer can’t extend in the oil-bearing core,which makes the polymer can’t form net structure.The polymer would be sweepouted by the sequent oil,which would decrease the blocking rate of oil permeability.Finally,according to the principle of high water cut block,the whole construction program was designed. The preparation of blocking agent and field process has been innovated.Dynamic analysis was carried on the fracture before and after installation phase.Field experiments indicated that the blocking agent could meet the technical requirements.All kinds of experimental parameters could meet the performance index required by the field experiments.更多还原