陶粒压裂支撑剂发展现状及未来展望

随着水力压裂技术的快速发展,陶粒压裂支撑剂研制到现在,在生产上已经规范化。目前市场上有各种规格的陶粒支撑剂,满足不同油气井的开采需要。油气井深度的增加导致开采环境更加复杂,因此,研制性能更好、适合特殊环境的陶粒压裂支撑剂迫在眉睫。文章介绍了陶粒支撑剂的背景及现状,总结了目前陶粒压裂支撑剂制备工艺和存在的问题,重点分析了制备陶粒的影响因素,简要介绍几种新型陶粒压裂支撑剂,最后探讨了陶粒压裂支撑剂发展前景及方向。     

致密砂岩中浅层低成本压裂支撑剂组合实验研究

由于致密砂岩储层渗透率低,一般未经储层改造,自然产能低,难于达到经济开采的要求。国内目前小于1500m的储层压裂一般都采用石英砂作为支撑剂,大于1500m则采用陶粒,为了进一步降低单井投资成本、提高开发效益,考虑对中浅层储层采用石英砂尾追陶粒的组合方式进行压裂。本文考虑不同闭合压力下的压裂液伤害、支撑剂嵌入等因素的影响,运用长期裂缝导流仪系统,模拟地层闭合压力、温度等环境,对油气田常用的石英砂及陶粒进行了长期导流能力评价,对石英砂尾追陶粒组合的比例进行优化,优化出了适合中浅层油气田的最佳支撑剂组合比例（石英砂：陶粒=70：30）,为国内中浅层储层压裂提高经济效益、降低单井成本提供了参考依据。     

支撑剂嵌入对致密砂岩储层裂缝导流能力的影响

致密砂岩储层经过水力压裂施工后,支撑剂通常会嵌入裂缝壁面导致有效缝宽减小,进而导致裂缝导流能力的降低,影响压裂施工的效果。以鄂尔多斯盆地某致密砂岩油藏储层段岩样为研究对象,评价了不同类型支撑剂、支撑剂粒径以及铺砂浓度条件下支撑剂嵌入对裂缝缝宽和导流能力的影响,结果表明：在相同的试验条件下,石英砂在致密砂岩板上的嵌入对缝宽和裂缝导流能力的影响要大于陶粒;支撑剂粒径和铺砂浓度越小,有效缝宽越小,支撑剂嵌入导致裂缝导流能力的下降幅度越大。在致密砂岩储层压裂施工过程中,应根据现场实际情况优化压裂施工设计,选择合适的压裂施工参数,尽可能地降低支撑剂嵌入对裂缝导流能力的影响。     

高强度压裂支撑剂室内评价研究

阐述了石英砂、低密度陶粒与高强度陶粒的物理综合性能评价情况;对导流能力进行了全方面评价：使用裂缝导流评价系统（FCS-842型）对以上三种压裂支撑剂在不同闭合压力下的短期导流能力进行对比,针对高强度陶粒在50M Pa下基本性能对长期导流能力的影响程度及随时间变化的幅度进行实验分析。研究结果对今后深井压裂选择高强度支撑剂和现场应用具有指导意义。     

陶粒支撑剂的研究及应用进展

深层、低渗透、高闭合压力储层将是未来油气田水力压裂的主要区域,陶粒支撑剂因在水力压裂作业中起到支撑裂缝、提高导流率、增加油气产量的作用而备受关注。随着高品位铝矾土资源日渐枯竭,低铝质原料成为制备陶粒支撑剂的主要原料,目前主要包括低品位铝矾土、硅铝质固体废弃物以及其他材料。本文在总结大量文献的基础上,阐述了低铝质原料制备陶粒支撑剂所具有的优势以及存在强度不足的缺陷。之后针对这一问题,文章提出了覆膜增强和添加剂增强两种增强方式,系统讨论了预固化覆膜增强、可固化覆膜增强、液相助熔增强和畸化晶格增强对陶粒支撑剂强度的影响,总结出针对于不同原料制备、不同应用环境下的陶粒支撑剂最佳的增强方式。最后对陶粒支撑剂未来潜在发展方向进行了展望。     

压裂用支撑剂应用现状和研究进展

水力压裂是石油、天然气开采中应用较广的一门技术,支撑剂是压裂施工的一种关键材料.支撑剂由压裂液带入到地下裂缝中并直接影响着压裂效果.目前市面上使用的支撑剂主要是石英砂、陶粒、树脂覆膜支撑剂,随着支撑剂技术的日臻成熟,许多新的支撑剂也被研发出来.简要地总结了现在的支撑剂的优缺点,主要介绍了三种新型支撑剂,包括低密度支撑剂、表面改性支撑剂和液体支撑剂等,讨论了发展趋势,对压裂支撑剂研究和相关行业具有一定的指导意义..     

疏松砂岩地层组合陶粒岩心嵌入影响实验研究

针对川西高庙子沙溪庙组疏松砂岩储层,开展了支撑剂嵌入对岩心壁面的剥落实验研究以及壁面剥落碎屑对组合支撑剂导流能力的影响实验研究。结果表明,支撑剂的嵌入所造成的裂缝壁面剥落程度随粒径的增大而增大,剥落的岩屑在压裂施工返排过程中存在明显的运移现象,对长期导流能力存在一定的损害。经过实验验证,80%的30/50目陶粒+20%的40/70目混合陶粒在嵌入所造成的裂缝壁面剥落程度方面相对于100%的30/50目陶粒降低39%,12 h长期导流能力相对于80%的30/50目陶粒+20%的岩屑混合物高54%。     

覆膜砂压裂改造技术现场应用效果浅析

油井压裂是储层改造和增产的重要工艺手段,压裂的目的是形成一条用支撑剂支撑的人工裂缝,从而达到使低渗储层获得较高产能的目的。目前压裂常用的支撑剂为普通石英砂和陶粒,但是他们最大的缺点是在地层条件下都会发生破碎,并且破碎的微粒在压裂液返排或油气生产过程中会发生运移.从而堵塞渗流通道,使裂缝的导流能力降低,甚至在压裂液返排过程中出现吐砂现象。本文主要阐述了树脂覆膜砂的性能及防砂、增产和稳产机理。     

水力压裂支撑剂的研究进展

水力压裂工艺技术的核心是形成导流能力强的裂缝.支撑剂是水力压裂过程中能够进入被压开的裂缝并使其不再重新闭合的一种固体颗粒.它能够帮助裂缝处于开启状态,提供油气由地层到井筒的渗流通道,是水力压裂施工中的关键材料.本文概述了近年来国内外水力压裂用支撑剂的发展历程,几种常规支撑剂的类型及特点,重点对几类新型支撑剂进行了综述,最后,针对目前支撑剂技术面临的挑战提出了其今后发展趋势.     

水力压裂支撑剂应用现状与研究进展

水力压裂支撑剂是在储层压裂改造中用来支撑水力裂缝的一种关键材料,是压裂作业中必不可少的元素.在系统调研了国内外压裂支撑剂相关研究的基础上,简要介绍了传统支撑剂的应用现状和优缺点,重点对四种新型支撑剂进行了详细综述,发现新型支撑剂凭借其独特的物理化学性质可以有效提高裂缝导流能力和压裂改造效果,在油气田开发中表现出良好的应...     

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.     

Novel polyurethane coating technology through glycidyl carbamate chemistry

Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

Highly moisture-proof polysilsesquioxane coating prepared via facile sol-gel process

A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by ¹H MAS NMR. For direct comparison purposes, an SiO₂ coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N₂ absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.