梯度多凝水泥浆在长封固井段固井中的应用

对于封固段较长的固井作业,采用梯度多凝水泥浆体系,在一定程度上可以代替双级固井,具有很强的优越性。根据不同的井下条件采用有针对性的不同密度、稠度梯度的水泥浆配方,可以防气窜,防漏失,防套管腐蚀,防施工高压,降低固井及钻井成本,缩短建井周期,并能高效地保护油气层,提高固井质量。现场2口井的应用表明,应用该体系水泥浆,固井质量优良。

多凝水泥浆体系在LD气田的应用

采用多凝水泥固井技术,在一定程度上可以代替双级固井,具有极大的优势。根据不同的井下条件采用针对性的水泥浆配方,可以防气窜、防漏失、防套管腐蚀、防施工高压、降低固井成本,并能高效地保护油气层,提高固井质量。

双基多凝水泥浆体系的室内研究

本文通过研究双基多凝水泥浆,具有良好的API性能,上下段稠化时间差合理,高密度尾浆短速凝且过渡时间短,减少水泥浆失重带来的影响,解决了临盘地区井深4000m以内、长封固段、易窜、易漏井的固井难题,提高了固井质量。

浅层气井防气窜固井技术

浅层气井固井防窜是国内外固井作业不断探索研究的技术难题之一。结合多年来在不同地区的气井固井作业经历对浅层气固井技术进行了分析,归纳得出一系列浅层气固井的防窜技术措施。

影响固井质量的因素和预防措施研究

固井质量是关系油田开发的重要环节,关系到油田开发效益成效。但是在老油田开发过程中,由于受到长期注水的影响,改变了原来地层的压力系统,同一口井的不同层系会存在多种压力体系,直接影响固井质量。分析了固井施工的难点和影响固井质量的主要因素,在固井工程中使用多凝水泥体系可以满足不同压力体系,适应不同地温条件和不同稠化时间的需要,提高固井质量。

Effect of melt superheat on structural uniformity of lotus-type porous metals prepared by unidirectional solidification

Structural uniformity is an important parameter influencing physical and mechanical properties of lotus-type porous metals prepared by directional solidification of metal-gas eutectic (Gasar). The effect of superheat on structural uniformity as well as average porosity, pore morphology of porous metals was studied. The experimental results show that, when the superheat is higher than a critical value (ΔTc), the bubbling or boiling phenomenon will occur and the gas bubbles will form in the melt and float out of the melt. As a result, the final porosity will decrease. In addition, a higher superheat will simultaneously cause a non-uniform porous structure due to the pores coalescence and bubbling phenomenon. Finally, a theoretical model was developed to predict the critical superheat for the hydrogen to escape from the melt and the corresponding escapement ratio of hydrogen content. Considering the escapement of hydrogen, the predicted porosities are in good agreement with the experimental results.

大跨度易窜井固井技术及现场应用

商河油田商25区块的地质因素和开发因素共同导致普通水泥浆体系及工艺无法满足商25区块调整井固井质量要求,严重制约商河油田勘探开发和经济效益提升。针对商25区块调整井固井面临难题展开深入研究,结合梯度多凝水泥浆技术、前置液防污染技术、提高顶替效率技术和浆量设计等工艺措施共同构成商25区块调整井防窜固井技术,并进行了多次现场试验。结果表明,新型低密度水泥浆体系和防窜固井技术效果明显,解决了商25区块调整井固井防窜的问题,初步形成了一套具有较强理论基础和实践指导意义的调整井防窜固井工艺技术与配套措施,为临盘地区固井作业奠定了较好理论和实践基础,有效提高了临盘地区油田采收率和开发水平。

Influence of solidification mode on pore structure of directionally solidified porous Cu-Mn alloy

By the directional solidification of metal-gas eutectic method（GASAR）,porous Cu-Mn alloy with oriented pores was fabricated successfully.The variation of pore structure was studied by experiments.The results show that the pore structure is primarily dependent on the solidification mode（planar,columnar cellular,columnar dendritic,equiaxed dendritic）,which is controlled by the solidification process.By numerical simulation,it is noted that along with solidification,the solidification mode of the alloy transforms from cellular to columnar dendritic and finally to equiaxed dendritic.Through increasing melt temperature and mold preheating,the range of equiaxed dendrite could be decreased,which helps to extend the region of oriented pore structure.

Structural Analysis and Anticoagulant Activity of Polysaccharides from Opuntia milpa alta

[Objective] To analyze the components and structure of Opuntia milpa alta polysaccharides, and to study its anticoagulant activity. [Method] The crude polysaccharides （CP） were prepared from Opuntia milpa alta using hot water extraction and ethanol precipitation method, purified by anion-exchange chromatography and gel filtration chromatography to study its monosaccharide composition, weight-average molecular weight distribution and main chain structure. And a preliminary study was conducted on the anticoagulant activity of polysaccharide components. [Result] The polysaccharide components WSP1, WSP2a and WSP3 were obtained from CP by the anion-exchange chromatography and gel filtration chromatography. WSP1 was mainly composed of galactose with a weight-average molecular weight of 2.32×106. WSP2a consisted of rhamnose, arabinose, xylose, mannose, glucose, galactose, glucuronic acid and galacturonic acid, the contents were 6.3%, 32.3%, 12.9%, 1.5%, 4.8%, 37.1%, 0.64% and 4.4%, respectively. WSP3 mainly composed of arabinose, xylose, rhamnose and trace of glucose, mannose, uronic acid. The weight-average molecular weight of WSP2a and WSP3 was 1.24×106 and 7.92×106, respectively. WSP2 prolonged the activated partial thromboplatin time （APTT） and thrombin time （TT）, while had no significant effect on the prothrombin time （PT） in vitro, indicating that anticoagulant activity of WSP2 functions by affecting the intrinsic coagulation system. The test of inhibition to the conversion of fibrinogen into thrombin showed that WSP2a and WSP3 had obvious anticoagulant activity. Methylation analysis indicated that the main chain of WSP2a was constituted of 1, 4-GalA, 1, 2-Rha and 1, 2, 4-Rha. [Conclusion] This study provided experimental basis for the optimization and development of polysaccharide resources from cactus

胜利油田提高调整井固井质量技术及推广应用

随着胜利油田的勘探开发进入中后期，由于整个调整井区块长期注水开发，有的压力系数甚至上升到1．6以上，且地层中形成了多套压力层系。一次注水泥同时封固多套压力层系时，注水泥具有漏喷的矛盾。采用常规固井技术已无法解决调整井固井质量受高压水窜影响的问题，给油田后期开发造成极大的经济损失。因此，针对调整井区块特点进行固井技术研究，推广成熟的防窜固井技术已迫在眉睫。

复合水泥浆体系在邵549井的应用

在漏涌并存的井眼条件下,采用堵漏承压技术,结合多凝水泥浆和复合水泥浆体系解决活跃油气层的封固质量。

Thrombin-induced microglial activation contributes to the degeneration of nigral dopaminergic neurons in vivo

Objective To evaluate the role of thrombin-activated microglia in the neurodegeneration of nigral dopaminergic neurons in the rat substantia nigra （SN） in vivo. Methods After stereotaxic thrombin injection into unilateral SN of rats, immunostaining, reverse transcription polymerase chain reaction （RT-PCR） and biochemical methods were used to observe tyrosine hydroxylase （TH） irnmunoreactive positive cells, microglia activation, nitric oxide （NO） amount and inducible nitricoxide synthase （iNOS） expression. Results （1） Selective damage to dopaminergic neurons was produced after thrombin injection, which was evidenced by loss of TH imrnunostaining in time-dependent manner; （2） Strong microglial activation was observed in the SN; （3） RT-PCR demonstrated the early and transient expression of neurotoxic factors iNOS mRNA in the SN. Immunofluorescence results found that thrombin induced expression of iNOS in microglia. The NO production in the thrombininjected rats was significantly higher than that of controls （P 〈 0.05）. Conclusion Thrombin intranigral injection can injure the dopaminergic neurons in the SN. Thrombin-induced microglia activation precedes dopaminergic neuron degeneration, which suggest that activation of microglia and release of NO may play important roles in dopaminergic neuronal death in the SN.

Liquid-state fermentation with Bacillus subtilis Bs-07 to enhance anticoagulant function of Auricularia auricula polysaccharide

In order to improve the anticoagulant function of Auricularia auricula, Auricularia auricula polysaccharide （AAP） was converted into its derivatives by the microbial fermentation method and then polysaccharide derivatives with stronger anticoagulant activity were prepared. The optimal conditions for fermenting the polysaccharide from A. auricula were examined and the in vitro anticoagulant activities of transformed and untransformed polysaccharides were compared. Response surface tests and an orthogonal experiment indicated that the best conditions for microbial conversion of AAP3 were an AAP3 concentration of 4.0 mg/ mL, a ratio of substrate （AAP3 ） to donor （p-hydroxybenzoic acid） of 40：1, and a pH of 6.0. Bacillus subtilis Bs-07 was inoculated and then placed on a rotary shaker （ 120 r/min）, followed by fermentation for 48 h at 35 ℃. The conversion rate was found to be greater than 40%. The result of in vitro anticoagulant activity showed that the transformed polysaccharide improved activated partial thromboplastin time, prothrombin time, and thrombin time values and greatly enhanced anticoagulant activity compared to the untransformed polysaccharide.

A Preliminary Study of Rotundine-Polyion Complex Release System

A rotundine-polyion complex(PIC)release system was prepared first by granulation of rotundine containing chitosan acetate solution and then by complexing with carboxymethyl glucomannan(CMGM)solution on the granular surface.The granules have an average diameter of 1.38-1.53 mm and the drug content reaches 62.89％.The external release tests showed T_(50) to be 45 rain and the total release time 4 h in an artificial gastric juice,while no more than 60％ of the drug was released in the same period of time in an ar- tificial intestinal fluid.The various factors affecting the external release were examined.

Effect of gelcasting conditions on quality of porous Al-Cu alloy

The porous A1-Cu alloy was prepared by the gelcasting process. And the effects of gelcasting conditions, such as monomer, the volume ratio of cross-linker and monomer, dispersant and redox initiating system on the height, gelling time and the quality of green body were investigated. （It was found that the dispersant and monomer played significant roles in the height and quality of green bodies, respectively.） The optimal conditions were 10% monomer, 2% cross-linker, 0.2% initiator （volume fraction）, and 1.2 g dispersant, in which the green body exhibited the best quality. The mechanisms of process conditions in eliminating the cracks and forming the pores of in the five stages were proposed. Mercury porosimetry provided a description of pore diameter ranging from 10 to 10000 nm and open porosity of 38.78 %.

新型保温材料在蒸汽管道的应用实践

介绍了新型节能环保材料SC-DN多凝泡沫玻璃在蒸汽管道上的应用,可使蒸汽管道表面温度长期低温有效防止热损失,达到了节能减排的效果。

Optimization of Multiplex PCR and Multiplex Gel Electrophoresis in Sunflower SSR Analysis Using Infrared Fluorescence and Tailed Primers

In an effort to simplify the procedure and to reduce the cost of fluorescence SSR analysis, the conditions of the multiplex PCR and the multiplex gel electrophoresis were optimized in the genetic analysis of sunflower (Helianthus annuus L.) inbred lines. Results indicated that factors for a successful multiplex PCR assay were related to the cycling touchdown annealing temperature, the balance of primer concentration at the various loci, the concentration of PCR buffer and the Taq DNA polymerase. Based on the optimization, a tailed primer strategy was outlined, and the effective ways were proposed to overcome the troubleshootings commonly encountered in the multiplex PCR and the multiplex gel electrophoresis.

Cooling rate dependence of polymorph selection during rapid solidification of liquid metal zinc

The polymorph selection during rapid solidification of zinc melt was investigated by molecular dynamics simulation. Several methods including g（r）, energy, CNS, basic cluster and visualization were used to analyze the results. The results reveal that the cooling rate has no observable effect on the microstructure as TTc（Tc is the onset temperature of crystallization）; and at the first stage of crystallization, although microstructures are different, the morphologies of nucleus are similar, which are composed of HCP and FCC layers; the polymorph selection of cooling rate finally takes place at the second stage of crystallization： at a high cooling rate, the rapid increase of FCC atoms leads to a FCC crystal mixed with less HCP structures; while at a low cooling rate, HCP atoms grow at the expense of FCC atoms, resulting in an almost perfect HCP phase. The results reveal that the cooling rate is one of the important factors for polymorph selection.

A Novel Approach to Synthesizing Porous ZnO Films: Inorganic Chelating Sol-Gel Method

Porous ZnO films are synthesized by inorganic chelating sol-gel method,which is a novel sol-gel technique using zinc nitrate as starting materials and citric acid as the chelating reagent.The crystal structure,surface morphology,porous and optical properties of the deposited films are investigated.X-ray diffraction pattern analysis shows that crystal structure of the ZnO films is hexagonal wurtzite.Scanning electron microscopy (SEM) shows that the ZnO film is porous.The curve of pore size distribution has two peak values at about 2.02nm and 4.97nm and BET surface area of the ZnO film is 27.57m2/g.In addition,the transmittance spectrum gives a high transmittance of 85% in the visible region and optical bandgap of the ZnO film (fired at 500℃) is 3.25eV.