深部地热和天然气水合物组合利用可行性研究

近年来的研究表明,海洋中天然气水合物的成藏和分布受温度的影响较大,一些海域中的天然气水合物资源与地热资源同时存在,且有一定的分布规律。文章提出在利用地热开采天然气水合物基础上把两种资源结合起来利用,并对天然气水合物和地热资源的组合评价进行了相关的方法研究;参考组合评价相关经验公式,建立了组合评价的模型,并应用在实例中。通过实例应用,丰富了该开采方法的可行性论证,并对圈定的两种资源的综合利用的远景区进行了评价。     

海洋天然气水合物分解过程中其上部地层稳定性分析

在有覆盖层的海洋天然气水合物开采过程中,由于水合物分解引起上部地层应力重新分布可能导致上部地层蠕变、坍塌、滑坡、套管变形及井口安全等事故.以海洋天然气水合物沉积层具有覆盖地层为例,利用静力学理论建立了采用控压法开采海洋天然气水合物时上部地层物性参数、井筒压力及天然气水合物分解后地层剩余支撑力之间的力学稳定性模型.从理论上讲:当K＞1时,上部地层稳定;当K＜1时,上部地层失稳.该力学模型可对海洋天然气水合物开采井设计及安全开采具有一定的借鉴意义.     

全球能源发展的战略制高点——《天然气水合物:21世纪的新能源》书评

正《天然气水合物:21世纪的新能源》一书近日由海洋出版社出版发行。本书有助于读者全面了解天然气水合物的相关基础理论、资源分布、成矿机制以及矿床勘查、评价和开采的技术方法。天然气水合物是一种新型的、清洁的能源矿产,分布广、规模大、能量密度高,目前已成为备受科技界重视的新能源资源。我国相关专家学者和技术人员经过长期的不懈努力,在紧跟世界发展脚步和广泛进行国际交流合作的同时,对天然气水合物的勘查开发理论、技术、工程、装备等方面积极开     

极地天然气水合物资源利用前景CSCD

极地天然气水合物资源潜力巨大,储层类型主要为富砂沉积物储层,最可能实现远景勘探和商业利用,是一种重要的战略能源。综述了天然气水合物在极地的分布情况、极地主要地区天然气水合物矿藏资源量以及水合物开发利用的资源金字塔。结合美国、加拿大和俄罗斯在北极冻土区天然气水合物勘探开发的案例进行了4种开采技术优缺点对比,并对极地区和非极地区5次天然气水合物试采效能进行对比评价。根据目前国际油气价格、能源结构、各国水合物研究目标和我国天然气水合物勘查开发现状等,提出了我国参与极地天然气水合物研究和开发的思路。     

极地天然气水合物资源利用前景

极地天然气水合物资源潜力巨大,储层类型主要为富砂沉积物储层,最可能实现远景勘探和商业利用,是一种重要的战略能源。综述了天然气水合物在极地的分布情况、极地主要地区天然气水合物矿藏资源量以及水合物开发利用的资源金字塔。结合美国、加拿大和俄罗斯在北极冻土区天然气水合物勘探开发的案例进行了4种开采技术优缺点对比,并对极地区和非极地区5次天然气水合物试采效能进行对比评价。根据目前国际油气价格、能源结构、各国水合物研究目标和我国天然气水合物勘查开发现状等,提出了我国参与极地天然气水合物研究和开发的思路。     

海域天然气水合物开采的地质控制因素和科学挑战

目前,国际上对天然气水合物产状、分布和特征的认识已取得显著进展,开展了一系列陆地多年冻土区和海域天然气水合物试采,但天然气水合物开采仍面临科学挑战。本文在综述全球天然气水合物勘探开发现状的基础上,阐述了天然气水合物储层分类及其开采的地质控制因素,提出了海域天然气水合物有效经济开采面临的资源评价、开采技术方法、储层地质参数和工程地质风险等4方面的科学挑战。要实现海域天然气水合物的有效经济开采,资源评价是基础,开采技术方法是关键。判定天然气水合物储层是否可采需要精确的储层地质参数,能否实现有效开采取决于工程地质风险的控制。     

海洋天然气水合物开采方法及产量分析

海洋天然气水合物的巨大储量刺激了世界各国能源部门努力研究如何从天然气水合物储层生产天然气。根据水合物形成的条件，只有当水合物处在其相平衡条件以外，水合物才能分解。因此，水合物的开采方法只能为热熔法、抑制剂刺激法、减压法和地面分解法。为了对天然气水合物储层中气体的生产有个定量的评估，本文以水合物开采井为例，运用数学方法推导了水合物井中气体的产生量。结果表明，在天然气水合物储层中，天然气释放量是井内水合物分解温度、压力及水合物层气体渗透性的敏感函数。该函数可以用于天然气水合物井气体开采量的计算及对水合物储层可开采性评价。     

水力输送法开采海底浅层天然气水合物技术理论分析

天然气水合物被誉为洁净的潜在能源.海洋天然气水合物约占水合物总量的99%,绝大部分海洋水合物没有良好的覆盖层,不能用开采传统油气资源的方法进行开采.分析了利用海底采矿技术开采海底浅层水合物的方法,设计出水合物采矿车开采量与高压水泵输送的水力输送设备参数.根据水合物分解热及输送量,建立水合物输送系统与分解速度之间的理论关...     

全球天然气水合物勘查试采研究现状及发展趋势

天然气水合物是一种规模巨大且高效的新型清洁能源,其资源量是全球石油天然气和煤炭等化石能源资源量总和的2倍。日益增长的能源需求和对气候的重大影响,使人们对天然气水合物巨大资源潜力的兴趣倍增,因此,天然气水合物亦被科学家称为"未来全球能源发展的战略制高点"。近10多年来,美国、加拿大、日本、中国等均先后开展了陆地和海洋天然气水合物勘查与试采实验,印度和韩国亦准备近期开展海洋天然气水合物试采。总之,全球天然气水合物勘查试采的高潮正在蓬勃掀起。笔者分析阐述了世界天然气水合物研究的4个发展阶段,剖析了全球天然气水合物资源分布及主要国家天然气水合物资源潜力,并在此基础上,重点分析阐明了国内外天然气水合物勘查试采进展以及未来发展趋势,以期对我国天然气水合物勘查试采与研究工作有所裨益。     

测井技术在水合物储层识别中的应用前景

海洋天然气水合物是一种潜在的巨大能源。地球物理测井在天然气水合物探测与储量评价领域发挥了重要作用,并且随着以勘探天然气水合物为目的的钻井数量的增多日益受到重视。主要介绍了常规测井方法、成像测井和核磁测井在识别天然气水合物储层中的应用,发展海洋天然气水合物的识别技术,准确了解天然气水合物的分布与蕴藏量,对我国海洋天然气水合物产业的建立具有关键作用。     

南海北部大陆边缘天然气水合物稳定带厚度的地热学研究

The exploration of unconventional and/or new energy resources has become the focus of energy research worldwide,given the shortage of fossil fuels.As a potential energy resource,gas hydrate exists only in the environment of high pressure and low temperature,mainly distributing in the sediments of the seafloor in the continental margins and the permafrost zones in land.The accurate determination of the thickness of gas hydrate stability zone is essential yet challenging in the assessment of the exploitation potential.The majority of previous studies obtain this thickness by detecting the bottom simulating reflectors(BSRs) layer on the seismic profiles.The phase equilibrium between gas hydrate stable state with its temperature and pressure provides an opportunity to derive the thickness with the geothermal method.Based on the latest geothermal dataset,we calculated the thickness of the gas hydrate stability zone(GHSZ) in the north continental margin of the South China Sea.Our results indicate that the thicknesses of gas hydrate stability zone vary greatly in different areas of the northern margin of the South China Sea.The thickness mainly concentrates on 200–300 m and distributes in the southwestern and eastern areas with belt-like shape.We further confirmed a certain relationship between the GHSZ thickness and factors such as heat flow and water depth.The thickness of gas hydrate stability zone is found to be large where the heat flow is relatively low.The GHSZ thickness increases with the increase of the water depth,but it tends to stay steady when the water depth deeper than 3 000 m.The findings would improve the assessment of gas hydrate resource potential in the South China Sea.     

国外天然气水合物调查研究综述

天然气水合物是21世纪的一种具有巨大潜在开发价值的海洋新型能源矿产。截至2002年底，全球范围内共有23处水合物矿点直接获取水合物岩心样品。我们在收集国外天然气水合物调查研究方面的文献资料基础上，介绍了国外的研究进展，供我国天然气水合物研究者在开展调查研究时参考。     

Permafrost-associated natural gas hydrate occurrences on the Alaska North Slope

In the 1960s Russian scientists made what was then a bold assertion that gas hydrates should occur in abundance in nature. Since this early start, the scientific foundation has been built for the realization that gas hydrates are a global phenomenon, occurring in permafrost regions of the arctic and in deep water portions of most continental margins worldwide. In 1995, the U.S. Geological Survey made the first systematic assessment of the in-place natural gas hydrate resources of the United States. That study suggested that the amount of gas in the gas hydrate accumulations of northern Alaska probably exceeds the volume of known conventional gas resources on the North Slope. Researchers have long speculated that gas hydrates could eventually become a producible energy resource, yet technical and economic hurdles have historically made gas hydrate development a distant goal. This view began to change in recent years with the realization that this unconventional resource could be developed with existing conventional oil and gas production technology. One of the most significant developments was the completion of the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well on the Alaska North Slope, which along with the Mallik project in Canada, have for the first time allowed the rational assessment of gas hydrate production technology and concepts. Almost 40 years of gas hydrate research in northern Alaska has confirmed the occurrence of at least two large gas hydrate accumulations on the North Slope. We have also seen in Alaska the first ever assessment of how much gas could be technically recovered from gas hydrates. However, significant technical concerns need to be further resolved in order to assess the ultimate impact of gas hydrate energy resource development in northern Alaska.     

Potential map of gas hydrate formation in Caspian Sea based on physicochemical stability evaluation of methane hydrate

Preliminary studies of Caspian Sea have shown the possibility of gas hydrate accumulations, because of suitable physicochemical conditions, existence of clayey deposits, and high concentrations of organic matter. Studies have indicated that gas hydrates are mainly composed of methane. Therefore, based on physicochemical equations for methane hydrate stability in different pressure, temperature, and salinity, this study was designed to calculate the potential of gas hydrate formation in the Caspian Sea basin. For this, data of more than 600 locations were analyzed and in each location, upper and lower limits of methane hydrate formation zone were calculated. Then, the zoning maps of upper and lower limits were prepared which can be useful for exploring the gas hydrate as an energy source or predicting gas hydrate hazards. According to the calculations and maps, methane hydrate formation in Caspian Sea, theoretically, can take place from near the seabed to 4000 and 2500 m beneath the sea surface when low and high geothermal gradient are supposed, respectively. By comparing the results with gas hydrate zones revealed in geophysical profiles, it has been shown that, in Caspian Sea, gas hydrates probably accumulate near the lower limit when a high geothermal gradient is assumed.     

海底天然气水合物开发的前景研究——基于经济可行性的视角

海底天然气水合物的开发利用对于国家能源安全与环境保护具有重要意义。然而,作为一种新型深海能源,海底天然气水合物至今仍未实现商业化生产。除开发技术等因素外,天然气水合物开发投入、产出的成本问题也是制约海底天然气水合物大规模开发的另一关键因素。文章从经济可行性的视角分析海底天然气水合物目前开采成本、未来开采成本的变化以及未来的价格优势,从而对天然气水合物开发的前景进行相关研究。研究结果显示,虽然目前天然气水合物的开采成本要高于常规天然气,但随着今后开采技术的改进,天然气水合物开采的总成本、边际成本和平均成本都会相应降低,当天然气水合物的价格低于常规天然气价格时,天然气水合物的商业化生产便可能实现。     

甲烷水合物CO2置换开采研究现状与展望

天然气水合物广泛存在于海底沉积物和大陆永冻区,是一种潜在的能源资源。CO2置换法开采天然气水合物,不仅可以从水合物藏中开采出天然气,还能够使空气中的CO2以水合物的形式长期埋存于地下。本文从可行性、微观机理及影响因素等方面,总结了甲烷水合物CO2置换法开采的研究现状,论述了目前研究中存在的问题及不足,并对以后的研究工作提出了一些展望和建议。     

2-D Numerical Simulation of Natural Gas Hydrate Decomposition Through Depressurization by Fully Implicit Method

Natural gas hydrate, as a potential energy resource, deposits in permafrost and marine sediment with large quantities. The current exploitation methods include depressurization, thermal stimulation, and inhibitor injection. However, many issues have to be resolved before the commercial production. In the present study, a 2-D axisymmetric simulator for gas production from hydrate reservoirs is developed. The simulator includes equations of conductive and convective heat transfer, kinetic of hydrate decomposi...     

2-D Numerical Simulation of Natural Gas Hydrate Decomposition Through Depressurization by Fully Implicit Method

Natural gas hydrate, as a potential energy resource, deposits in permafrost and marine sediment with large quantities. The current exploitation methods include depressurization, thermal stimulation, and inhibitor injection. However, many issues have to be resolved before the commercial production. In the present study, a 2-D axisymmetric simulator for gas production from hydrate reservoirs is developed. The simulator includes equations of conductive and convective heat transfer, kinetic of hydrate decomposition, and multiphase flow. These equations are discretized based on the finite difference method and are solved with the fully implicit simultaneous solution method. The process of laboratory-scale hydrate decomposition by depressurization is simulated. For different surrounding temperatures and outlet pressures, time evolutions of gas and water generations during hydrate dissociation are evaluated, and variations of temperature, pressure, and multiphase fluid flow conditions are analyzed. The results suggest that the rate of heat transfer plays an important role in the process. Furthermore, high surrounding temperature and low outlet valve pressure may increase the rate of hydrate dissociation with insignificant impact on final cumulative gas volume.     

利用地热开采南海天然气水合物的技术研究

近年的研究表明南海北部陆坡区发育有底辟构造、海底滑坡以及活动断层带等有利于天然气水合物形成的地质构造环境.受深部地幔上隆的影响,南海整个海区热流背景值偏高,地热资源十分丰富,由此提出了利用地热加热海水,用热激发法分解天然气水合物的设想,并设计了初步的生产工艺.用传统热激发方法开采天然气水合物藏本身需要消耗大量能源,而且...     

海底天然气水合物稳定带的特征分析

水合物稳定带（HSZ）控制着海底天然气水合物的成矿作用和分布规律，其厚度及分布范围决定了天然气水合物的蕴藏量，所以水合物稳定带的分析对天然气水合物的成矿与分布规律、成因与演化机制以及资源研究具有重要的指导意义。水合物稳定带本身受海底温度、压力和甲烷量等因素的影响，其变化会影响水合物稳定带的范围、稳定带底界的位置，并制约着天然气水合物的稳定性和甲烷气的释放。