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1.
研究了柠檬酸与重铬酸钠的反应历程、生成螯合物的结构以及Cr^3 -HPAM胶态分散体冻胶的性能。在75℃下用柠檬酸将重铬酸钠中的Cr^6 还原为Cr^ 3 ,同时与Cr^3 发生螯合反应,生成柠檬酸铬螯合物。这种螯合物在一定条件下释放出Cr^3 ,它与HPAM交联形成胶态分散体冻胶。实验表明,柠檬酸铬-HPAM胶态分散体冻胶体系最长的成冻时间为40d,最大强度为0.036 MPa。用平行管岩心模型考察了冻胶的液流转向作用,调剖后高渗透层流量减小,液流转向低渗透层。  相似文献   

2.
冻胶失水导致的体积收缩会缩短油田调剖堵水作业的有效期,因此冻胶失水问题需要引起足够的重视。考察了CaCl_2对部分水解聚丙烯酰胺/铬(HPAM/Cr)冻胶失水规律的影响,研究了CaCl_2对HPAM/Cr冻胶微观形貌、HPAM流体力学半径、黏度的影响;并通过红外光谱技术分析了CaCl_2对HPAM/Cr冻胶失水的作用机理。实验结果表明,高浓度CaCl_2会促进HPAM/Cr冻胶失水,而低浓度CaCl_2具有抑制HPAM/Cr冻胶失水的作用;冻胶容水孔洞减少是高浓度CaCl_2加剧HPAM/Cr冻胶失水的内在原因;HPAM流体力学半径越小,HPAM/Cr冻胶失水越严重,低浓度CaCl_2具有提高HPAM流体力学半径的作用;低浓度CaCl_2能够降低HPAM的黏度损耗速率;Ca~(2+)可与HPAM分子羧基中的C—O发生交联反应,该反应是低浓度CaCl_2能够提高HPAM流体力学半径、降低HPAM黏度损耗速率以及抑制HPAM/Cr冻胶失水的根本原因。明确了CaCl_2对冻胶失水的作用机理,可为今后研制抗盐高稳定性冻胶提供理论参考和支持。  相似文献   

3.
硫化氢对冻胶型堵剂的影响   总被引:2,自引:1,他引:1  
研究了H2S对常规冻胶型堵剂成冻时间和冻胶强度的影响,这些冻胶型堵剂包括交联聚丙烯酰胺形成的铬冻胶和酚醛树脂冻胶.探讨了H2S对冻胶型堵剂影响的作用机理.结果表明:H2S对无机铬交联体系的影响较大,而对有机铬交联体系和酚醛树脂交联体系的影响相对较小;对于无机铬交联体系,H2S能迅速将Cr6+还原为Cr3+,提高交联HPAM的速度,而当H2S含量偏高时,被还原出的Cr3+会与过量的H2S生成Cr2S3沉淀,不能形成整体冻胶;对有机铬和酚醛树脂交联体系的影响主要体现在pH值的变化上.当选择冻胶型堵剂应用于含H2S的油气藏时,最好选用酚醛树脂冻胶.  相似文献   

4.
致密/页岩油气长期压裂开发下优势窜流通道发育,冻胶分散体在流道调控扩大波及方面具有很好的应用效果。冻胶分散体机械强度与其宏观封堵性能间应有密切关系,然而,目前的冻胶分散体机械强度缺乏有效表征手段。以铬冻胶分散体为例,通过原子力显微镜直接测量了微纳尺度铬冻胶分散体杨氏模量,并通过对其宏观封堵性能进行评价,从而建立了二者间映射关系。研究表明,控制聚合物质量分数为0.3%,SD-107质量分数由0.4%增大到0.7%,本体冻胶强度随之增大,相应冻胶分散体杨氏模量也随之增加。当杨氏模量自159 Pa上升至633 Pa时,封堵率由93.23%上升至98.08%。通过调控微纳尺度冻胶分散体杨氏模量研究其封堵性能差异,为致密/页岩油气储层高效开发提供基础理论指导。  相似文献   

5.
深部调剖是高含水油田控水稳油的重要措施。低油价下深部调剖需要成胶时间长、成胶后强度高的冻胶堵剂。以低质量分数的部分水解聚丙烯酰胺(HPAM)为成胶液,以氨基树脂为交联剂,研究了氨基树脂冻胶的成胶规律及其使用条件。研究结果表明,在乙酸催化下,氨基树脂可和低质量分数HPAM交联形成冻胶,该冻胶可以在70℃、盐含量为10 174 mg·L~(-1)以下地层使用。成胶时间大于3 d,冻胶强度可达到G级以上,冻胶90 d脱水率小于10%,适合深部调剖。  相似文献   

6.
为了考察壳聚糖(CTS)对重金属离子铬(VI)的螯合性能,利用紫外分光光度法对壳聚糖螯合铬(VI)的机理进行了研究,测定了不同c(Cr6+)/c(-NH3+)浓度比下壳聚糖-铬(Ⅵ)螯合物的紫外吸收光谱,确定了螯合物的配位比并计算了稳定常数。结果表明:壳聚糖对铬(VI)具有螯合作用,在不同壳聚糖氨根配体浓度下,当c(Cr6+)/c(-NH3+)≥0.5时,螯合反应达到平衡;壳聚糖中主要配体-NH2基团与铬(VI)按物质的量比2:1形成螯合物,壳聚糖铬(VI)螯合物的稳定常数为1.212×108。通过实验考察了壳聚糖用量、体系pH值对壳聚糖螯合铬(Ⅵ)离子效果的影响。结果表明:壳聚糖用量为0.15 g·L-1,反应酸碱度为pH=4的弱酸环境时,铬(VI)离子去除率可达到87.5%。  相似文献   

7.
针对过交联造成的冻胶堵剂脱水问题,通过实验建立了一种可以具体表征交联反应过程的方法,即采用分光光度法测定Cr~(3+)浓度以表征Cr~(3+)交联剂的反应速率。考察了交联反应过程中交联剂Cr~(3+)的反应量、冻胶脱水率的变化情况,研究了温度和盐浓度对Cr~(3+)与HPAM交联反应速率及冻胶脱水率的影响,并对交联速率与冻胶脱水的相互关系进行了分析。研究结果表明,温度升高后,Cr和聚合物羧基之间的反应速率加快,交联中间体——Cr多核羟基桥离子的形成速率也会加快;温度越高,Cr多核羟基桥离子的流体力学直径增大速度越快,从而使得Cr的交联反应速率越快。而增大无机盐浓度,有利于Cr多核羟基桥离子的形成,其流体力学直径达到最大值的时间显著缩短。因此,在温度和无机盐的影响下,交联反应过程中冻胶易出现交联速率过快的问题,交联过度会增加交联体系的密度,导致交联体系的保水能力降低,从而使冻胶脱水。本研究对探索抑制冻胶体系脱水的方法具有指导意义。  相似文献   

8.
本文以水溶性酚醛树脂为交联剂,以纳米颗粒为稳定剂,以HPAM以及不同AMPS含量的聚合物为成胶剂,在低盐含量的模拟注入水中制备了稳定的冻胶。研究发现,相同交联剂和聚合物用量下,AM-AMPS共聚物成胶时间比HPAM长,但成胶后强度高。评价了制备的冻胶在不同盐含量模拟水中的脱水情况,结果表明,当模拟水盐含量为10000mg/L、30000mg/L时,冻胶会吸水膨胀、强度降低;但当模拟水盐含量高于50000mg/L时,冻胶则脱水,冻胶强度提高。模拟水盐含量越高,脱水幅度越大。提高冻胶中纳米颗粒的含量或用AMPS含量高的共聚物做成胶剂,可明显降低冻胶在高盐含量中的脱水幅度。研究结果对红河油田裂缝封堵剂的开发有指导意义。  相似文献   

9.
首先研究了HPAM的交联影响因素以及胶态分散凝胶的堵水调剖渗流特征.与同浓度的聚合物(HPAM)相比,胶态分散凝胶的粘度降低,下降幅度与聚合物浓度、水解度、分子量有关;在所选用的交联比、分子量、水解度、浓度条件下,均可生成胶态分散凝胶,并且聚合物浓度越大,生成胶态分散凝胶后其粘度的下降幅度越大.聚合物分子量对胶团粒度的影响较大;胶态分散凝胶具有较好的注入能力,可进行深部调剖,提高水驱的波及体积.  相似文献   

10.
多孔介质剪切下铬冻胶体系成胶行为研究   总被引:2,自引:0,他引:2  
采用安瓿瓶和填砂管考察了铬冻胶体系的静态成胶和动态成胶过程.结果表明:同一配方下铬冻胶在多孔介质中动态成胶的初始成胶时间是其在多孔介质中静态成胶的初始成胶时间的1~3倍,最终成胶时间是其在多孔介质中静态成胶时间的1~3.5倍.铬冻胶在多孔介质中静态成胶的初始成胶时间是其在安瓿瓶内静态成胶的初始成胶时间的1~2倍,最终成胶时间是其在安瓿瓶内静态成胶时间的3~5倍.随着剪切速率的增大,铬冻胶体系受到的剪切作用增强,其初始成胶时间和最终成胶时间均延长,成胶后的封堵能力降低.随着聚合物浓度和交联剂浓度的增大,铬冻胶的初始成胶时间和最终成胶时间均延长,成胶后的强度增大.聚合物分子的吸附和捕集作用不是引起压力增大的主要原因,引起压力变化的主要因素是铬冻胶在多孔介质中的成胶.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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