二氧化碳水合物的形成、预测及防治方法

在二氧化碳试气过程中,经常会在井筒上部和地面流程形成水合物,形成的水合物严重地影响正常试气,甚至会危及人、井与设备的安全。为了避免形成水合物,需要知道二氧化碳形成水合物的压力及温度条件,及时采取相应措施。本文介绍了二氧化碳形成水合物的原因及条件,绘制了二氧化碳形成水合物预测图版,介绍了二氧化碳水合物的防治方法。     

二氧化碳水合物浆在空调蓄冷技术中的研究进展

介绍了近几年国内外气体水合物空调蓄冷技术的研究进展。分析了气体水合物作为新型蓄冷工质在空调蓄冷应用中的重要性。二氧化碳水合物浆是一定浓度的二氧化碳水合物固体颗粒悬浮于水溶液中的浆状流体,其生成条件相对容易,具有很好的流动性。本文分别从生成方法、分解焓、流动特性、添加剂的影响等方面详细阐述了二氧化碳水合物浆在空调蓄冷应用中的可行性。为气体水合物浆蓄冷技术特别是二氧化碳水合物浆技术尽快走向实用化提出了研究方向,并对其应用作了相关展望。     

不同结构二氧化碳水合物热物性的分子动力学模拟

二氧化碳水合物在空调蓄冷、海水淡化、烟气捕集以及置换法开采天然气水合物等领域均有重要应用,热物性是气体水合物技术发展和应用的基础.以I型二氧化碳水合物、II型二氧化碳水合物、II型二氧化碳和环戊烷二元水合物为对象,采用平衡分子动力学模拟手段,研究了20MPa、50-200K条件下二氧化碳水合物的热物性,包括密度、等温压...     

吉林油田凝析气井水合物冻堵防治技术与应用评价

针对英台气田凝析气井开发过程中出现的水合物冻堵问题,以其气体实际组分为依据,通过理论计算和软件模拟,预测了该凝析区块水合物冻堵的临界温度和临界压力,并通过现场试验,明确了英台气田气井井口压力在7.5～22.5MPa时,保持井口温度在19℃～25℃以上时,井筒将不生成水合物。同时也对其水合物防治工艺进行了论述和探讨,提出了针对英台气田的水合物冻堵防治对策,经现场试验验证,采取水合物防治措施后,大大减少了冻堵情况的发生,有效保证了试、采气工作的顺利进行,取得了明显的效果。     

水合物分解的噪声研究

海洋中水合物在分解后会形成大量气泡并向外辐射噪声信号。基于水合物分解的特点,建立了适用于描述水合物分解的非理想气泡的振动模型,并通过数值方法分别对辐射噪声的频率和辐射声压做了仿真模拟。结合测量二氧化碳水解噪声的实验数据,对分解得到的不同半径气泡辐射噪声频率和声压做了统计分析。结果表明,理论模型与实验结果吻合较好,该研究对监测水合物的泄漏分解等具有重要的意义。     

含二氧化碳天然气藏开发和二氧化碳驱标准体系建立方法

目前,含二氧化碳气藏的开发与利用给油气田开采带来了较大的难度,为安全、规范地进行油气田的开发与利用工作必须要依据一套可行的标准。因此,含二氧化碳天然气技术标准体系的建立对气田安全高效开发、二氧化碳驱油形成最佳生产秩序具有现实意义。本文根据含二氧化碳气田和低渗透油田的特点对这类油田标准体系的建立进行了体系定位,制定了体系的5个建立原则,形成了4个层次标准体系结构;该标准体系使现场操作可以做到有标可依、规范有序,为二氧化碳气藏合理开发利用提供保障。     

专利技术

一种储存和捕集二氧化碳气体的混合物 摘要：本发明属于二氧化碳储存与捕集领域,具体涉及一种促进二氧化碳水合物形成的混合物。所述混合物包括水,其特征在于,所述混合物还包括：3％～20％的环戊烷、1％～10％的碳纤维、0．3％～8％表面活性剂、1％～6％的助表面活性剂,所述百分数表示质量分数,     

CO2/N2分离中水合物膜形成的影响因素研究

温室效应是如今人类所面临的一个重大问题,而二氧化碳对温室效应的"贡献"最大,因此发展研究捕集CO2的新型高效节能技术及相关理论,对避免温室效应,保护环境具有极其重要的意义.本文提出了将膜分离法和水合物法结合起来即水合物膜法,并利用自行组建的水合物膜法分离二氧化碳实验系统初步探索了多孔陶瓷管的孔径,体系的压力、温度、气体...     

气体水合物分解与生成技术应用研究进展

水合物技术应用可归纳为分解应用和生成应用,本文就这两大应用方向对水合物进行了分类综述。从水合物分解角度,阐述了天然气水合物资源勘探开发、管道水合物解堵、水合物抑制防控等技术应用的研究进展;从水合物分解的逆过程(生成)角度,阐述了水合物储气、二氧化碳捕获与封存、海水淡化、溶液提浓、污水处理、混合气体分离、蓄冷等应用技术。同时论文结合气体水合物发展历程,概括了气体水合物技术在诸多领域的应用,指出了水合物技术发展取得的诸多成果,也提出了新形势下水合物发展所面临的问题,希望能为今后水合物技术的发展带来一定指导。     

酸性气田钻具常见失效形式

近些年来,随着酸性气田的不断勘探开发,钻具失效事故时有发生,阻碍了天然气的安全高效开发。在全面分析了酸性气田开发中存在的各种腐蚀环境后,对酸性气田中普遍存在的氧腐蚀、二氧化碳腐蚀和硫化氢腐蚀三种腐蚀失效机理进行了分析;并通过具体的酸性气田开发中出现的钻具失效案例,分析了钻具在氧气、二氧化碳和硫化氢三种不同的酸性腐蚀环境下的裂纹萌生与扩展特点以及失效形式;最后提出了预防钻具腐蚀失效的措施,对预防和减少酸性气田开发中钻具失效事故的发生具有指导意义。     

Hydrates in the ocean and evidence for the location of hydrate formation

There is substantial evidence that the oceans of the world will pose the most important challenges in the area of hydrate formation. This work indicates three areas of concern for hydrate formation in the ocean: (1) deposits of natural gas in ocean hydrates, which will serve as an energy resource and environmental concern in the next tnillenium, (2) a recent proposal for the ocean storage of carbon dioxide in the form of hydrates, and (3) the prevention of hydrate formation in ocean pipelines. To address such applications, fundamental knowledge on the site of hydrate formation was determined. Results are presented for quiescent, high-pressure experiments done in a sapphire tube to determine the site of hydrate formation in deionized water and in mixtures with amorphous silica and sodium dodecyl sulfate. Visual (microscope aided) results are presented for formation with a typical gas mixture and with carbon dioxide.Invited paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, USA.     

The clathrate hydrate process for post and pre-combustion capture of carbon dioxide

One of the new approaches for capturing carbon dioxide from treated flue gases (post-combustion capture) is based on gas hydrate crystallization. The basis for the separation or capture of the CO(2) is the fact that the carbon dioxide content of gas hydrate crystals is different than that of the flue gas. When a gas mixture of CO(2) and H(2) forms gas hydrates the CO(2) prefers to partition in the hydrate phase. This provides the basis for the separation of CO(2) (pre-combustion capture) from a fuel gas (CO(2)/H(2)) mixture. The present study illustrates the concept and provides basic thermodynamic and kinetic data for conceptual process design. In addition, hybrid conceptual processes for pre and post-combustion capture based on hydrate formation coupled with membrane separation are presented.     

表面活性剂促进气体水合物生成的研究

天然气水合物被公认为21世纪的重要后续能源,其生成与压力、温度、气水接触面积以及添加剂等因素有关。文章概述了表面活性剂的基本性质,并从改变反应液的表面张力、形成胶束、改变水合物形貌等方面总结了表面活性剂对促进水合物生成的影响,提出了其促进水合物生成的机理。对于未来的研究,我们不仅要观察水合物的形态,也要从水合物膜的内部结构分析表面活性剂对水合物的生成影响,为水合物生成机理形成统一的认识和气体水合物进一步发展提供参考。     

Preparation of gas hydrates by nonequilibrium condensation of molecular beams

Layers of amorphous ice saturated with carbon dioxide were prepared by the deposition of molecular beams of water and gas onto a substrate cooled with liquid nitrogen. Their heating is accompanied by glass transition (softening) and subsequent spontaneous crystallization. The glass transition and crystallization temperatures were determined from the change in dielectric properties during heating. The heat effects of the transformations were detected using differential thermal analysis. The crystallization of amorphous layers under conditions of deep metastability leads to the formation of crystalline hydrates. The avalanche nucleation of crystallization sites captures the gas molecules; therefore, they are not displaced by the movement of the crystallization front.     

天然气水合物合成实验

为提高天然气水合物的生产效率及储气密度,在专门设计的水合物合成实验装置上,进行了纯甲烷水合物的合成实验。实验结果表明:对于纯净甲烷水合物,压力越高,合成速率越大;但当压力大于5 MPa时,压力的提高对生成速率的影响不大。水合物合成前抽真空时间越长,生成的水合物吸收的气体量越大,表明抽真空可以排出水中溶解的气体,提高水合物的储气密度。     

Optimization of cryogenic carbon dioxide capture from natural gas

Cryogenic carbon dioxide removal from natural gas requires accurate thermodynamic phase study of the natural gas mixture and individual components. Thermodynamic data generation of carbon dioxide‐methane mixture having 90 % carbon dioxide for cryogenic carbon dioxide capture from natural gas using Peng Robinson equation of state is discussed in this research work. Golden section search technique along with Eureqa optimizing tool is then used to optimize the pressure‐temperature conditions for the cryogenic carbon dioxide capture in the solid‐vapour two‐phase region. Cost optimization is done for the carbon dioxide capture system at atmospheric pressure and 20 bar. Temperature ranges for optimization were obtained from the predicted thermodynamic data for the mixture. The optimum temperatures obtained in this research work for the cryogenic carbon dioxide capture at atmospheric pressure and the 20 bar are ?103.8 °C and ?60.90 °C respectively. For atmospheric pressure at ?103.8 °C the worth of methane, carbon dioxide, and energy is 114 $/h, 9 $/h, and 53 $/h respectively, while at 20 bar and ?60.9 °C the worth of carbon dioxide, methane, and the energy are found to be 129 $/h, 46 $/h, 52 $/h, respectively.     

Catalytic conversion of Kraft lignin to bio-multilayer graphene materials under different atmospheres

Kraft lignin was catalytic graphitized by iron at 1000 °C in argon, hydrogen, CO₂, methane, and natural gas atmospheres, respectively. The effect of atmospheric agent types on product distribution (gas, liquid, and solid carbon yields) was analyzed. The solid products were characterized by scanning electron microscopy, Raman, high-resolution transmission electron microscopy, and X-ray diffraction. Experimental results have shown that the degree of graphitization of Kraft lignin depends not only on the highest temperature, but also the type of ambient gas phase during heat treatment. Methane and natural gas in the ambient gas phase seem to accelerate the formation of multilayer graphene materials with a range of 2–30 layers, and hydrogen and carbon dioxide have an etching effect on solid carbon species during the catalytic graphitization process, while multilayer graphene-encapsulated iron nanoparticles were the main products in the case of argon.     

A Perspective on Rheological Studies of Gas Hydrate Slurry Properties

Gas hydrates are solid inclusion compounds that are composed of a three-dimensional hydrogen-bonded network of water cages that can trap small gas molecules, such as methane and carbon dioxide. Understanding the rheological properties of gas hydrate crystals in solution can be critical in a number of energy applications, including the transportation of natural gas in subsea and onshore operations, as well as technological applications for gas separation, desalination, or sequestration. A number of experimental and modeling studies have been done on hydrate slurry rheology; however, the link between theory and experiment is not well-defined. This article provides a review on the current state of the art of hydrate slurry viscosity measurements from high- and low-pressure rheometer studies and high-pressure flowloops over a range of different sub-cooling (ΔT_sub = T_equil − T_exp) and fluid conditions, including for water and oil continuous systems. The theoretical models that have been developed to describe the gas hydrate slurry relative viscosity are also reviewed. Perspectives’ linkage between the experiments and theory is also discussed.     

Mathematical model of natural gas flow in pipelines with allowance for the dissociation of gas hydrates

On the basis of the methods and equations of mechanics of multiphase systems a system of ordinary differential equations describing the hydrodynamics and thermal physics of a flow in the gas main in the presence of deposits of gas hydrates on the duct walls has been obtained. Some methods for preventing and controlling the formation of hydrates in the process of natural gas transport in a pipeline have been considered. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 81, No. 2, pp. 271–279, March–April, 2008.