一种碳酸盐岩油藏试井模型研究

针对碳酸盐岩的多孔储层试井解释,建立了三重介质非牛顿-牛顿流体复合油藏渗流模型,得到了Laplace空间的解析解,并通过Stehfest数值反演算法,利用Matlab绘制了各种参数影响下的无因次压力及压力导数的典型曲线,最后分析了各个参数在典型曲线上的压力响应特征.     

缝洞型碳酸盐岩储层渗流特征及试井评价

根据缝洞型碳酸盐岩油藏的储层类型以及油井产能变化情况,建立了3个缝洞型油藏的试井解释模型,即:溶洞与井筒连通的试井解释模型、缝洞与井筒连通的试井解释模型、孔缝洞与井筒连通的试井解释模型,并研究了三种渗流模式下的渗流数学模型的求解方法,通过分析得到了三种渗流模式下的渗流特征。试井模型主要可以分为三大类,分别是:双重介质模型、复合油藏模型和视均质类油藏模型。     

低渗透裂缝性油藏变形双重介质试井解释模型

由于低渗透裂缝性油藏渗透率低,启动压力梯度的影响、应力敏感导致渗透率的变化均不能忽略,且裂缝性储层具有裂缝和基质双重介质,本文考虑二次梯度项和介质变形对渗流方程的影响,推导并建立了低渗透双重变形介质油藏试井解释模型,采用差分方法进行求解,以渤海B油田裂缝性油藏为例,进行试井解释分析。研究结果表明:对于模型的非线性化问题,可采用无因次化和拉普拉斯变换相结合的方法进行线性化处理,再求解。且采用模型绘制的压力动态曲线特征符合低渗透裂缝性油藏渗流特征,对同类油田试井解释具有一定的借鉴意义。     

一种典型缝洞型油藏双重介质试井特征

缝洞型油藏储层特征与常规砂岩储层区别较大,孔洞及裂缝交错发育,大型溶蚀孔洞作为主要的流体储存空间,裂缝作为流体流动通道,由孔洞和裂缝组成的渗流空间形成了典型的双重介质模型。通过实例井分析了该类缝洞型储层试井双对数曲线所反应出的双重介质模型,为类似储层类型试井解释提供经验借鉴。     

低渗油藏压力恢复试井测试实例解释研究

试井压力曲线的相似性导致难以量化分辨储层发育、渗流机理、油水关系、井筒-地层耦合的复杂性及其差异,多解性强,缺少明确的理论指导和普适性好的解释方法。利用现场低渗储层压力恢复试井资料,开展常规试井解释和低渗透油藏试井解释对比分析。通过归纳分析,从解释成果的可靠性和合理性论证了复合模型的适用性和裂缝模型应用的不确定性,提出了在研究的典型超低渗储层中,复合模型是压力恢复试井解释首选模型。低渗透油藏压力恢复试井过程中,即使没有出现压力导数水平段,依然可以得到较可靠的渗透率。     

用数值试井方法确定注采井组压力分布

数值试井是一种全新的试井解释技术。相对解析试井技术而言,具有假设条件比较少,描述范围大,更加符合油气藏开发实际和渗流特征的特点。在解释多相流、开发井网、复杂边界和非均质油藏等复杂性试井资料方面,具有独到的优势。本文从一数值试井应用实例出发,说明了多相流数值试井方法在确定压力分布和剩余油饱和度分布方面的应用。     

双重均质复合油藏压裂井模型研究

为高效开发油藏提供依据,针对双重均质复合油藏进行水力压裂后形成的有限导流垂直裂缝,应用拉普拉斯变换,求得了双重均质复合油藏考虑裂缝储集和裂缝表皮效应的线性流模型井底压力表达式。应用Stefest数值反演,绘制了无因次压力及压力导数对时间的双对数特征曲线,对其动态特征及影响因素进行了分析。研究结果表明,其压力动态最显著的影响因素是裂缝储集系数、裂缝表皮系数和无因次导流能力,其它参数对井底压力动态的影响与其对普通直井油藏的影响相类似。     

各向异性部分压开垂直裂缝压裂井试井模型研究

通过对部分压开压裂井的不稳定试井模型的研究,可以确定在进行油藏动态分析及数值模拟时所需的参数,如地层渗透率、裂缝半长等。在前人研究成果的基础上,利用源函数的思想以及Newman乘积原理,得到了各向异性部分压开垂直裂缝压裂井的压力响应表达式。利用Stefest数值反演对模型进行了求解并绘制了考虑井筒储集系数和表皮系数的压力和压力导数曲线,并对曲线流动阶段进行了分析。通过Z函数的性质以及渐近式分析,获得了一个新的部分压开裂缝早期线性流动方程。研究结果不仅丰富了压裂井的不稳定渗流理论,而且对正确认识此类油井流体流动特征具有一定指导意义。     

串珠状缝洞型碳酸盐岩油藏数值试井分析

缝洞型碳酸盐岩油藏油井压力恢复测试后,受多缝洞地质特征影响,双对数曲线往往呈现串珠状,常规试井解释无法建立该类油藏模型并得到准确地层参数。分析了串珠状油藏模型试井特征,利用有限元数值试井技术,并结合物探、地质研究成果,对井眼位于缝洞内和裂缝通道位置2口井进行拟合分析,并采用全压力史拟合验证,最终准确描述油藏内外边界,得到不同渗流区域储层渗流特征,提高了试井解释精度,为该类型复杂多缝洞体油藏试井解释提供参考。     

无限导流垂直裂缝井试井分析研究

水力压裂是进行人工增产,实现经济开发的一项重要措施,试井分析作为油藏动态描述的一种手段在压裂设计和分析中发挥了重要作用.本文对水力压裂无限导流垂直裂缝井试井分析研究现状及试井理论模型作了简单的介绍,分析了不同的流动阶段特征以及试井理论曲线特征.     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.