极地天然气水合物勘探开发现状及对中国的启示

极地天然气水合物分布于南北极大陆及其毗邻海域的沉积物(岩)中,与广泛分布的永久冻土带密切相关,资源潜力巨大。极地天然气水合物储层类型主要为富砂沉积物储层,能提供天然气水合物高浓度聚集所需的储集渗透性,最可能实现远景勘探和商业利用。随着全球气候变暖,北冰洋海冰加速融化和航道开通,北极地区蕴藏的丰富资源都将从潜在利益变成现实利益,各国的权益纷争也将愈演愈烈。本文综述了极地天然气水合物勘探开发现状和相关国家的水合物开发政策,依据中国海陆域天然气水合物勘查开发现状,提出了中国参与极地天然气水合物研究和开发的思路和途径,为中国极地资源开发利用战略提供参考。     

北极地区盆地群油气地质特征及其资源潜力

北极地区具有超过4 000亿桶油当量的待发现技术可采储量, 是未来全球油气勘探与开发的重要增长点。本文按照地理和地质构造因素将北极地区分为北冰洋海盆区和环北极含油气区（含潜在含油气盆地）,按照板块演化及盆地发育历史将后者划分为北太平洋极地盆地群、俄罗斯极地盆地群和欧洲极地盆地群。根据大量文献和IHS数据, 结合生油层、储层、盖层及圈闭特征方面的研究, 系统对比、分析北极地区石油、天然气分布特征:北太平洋极地盆地群重要烃源岩形成于侏罗纪和白垩纪, 盆地群中重要储层大部分都分布于新生界布鲁克斯层, 油气系统以构造圈闭为主。俄罗斯极地盆地群中多数盆地具有古生代基底, 受斯堪的纳维亚早古生代造山期变形、西伯利亚板块古生代西部造山变形影响, 60%以上的烃源岩产自中生界, 储层以中生界前陆、克拉通盆地沉积物为主,盖层分布较广, 以中生界居多。欧洲极地盆地群受控于北大西洋洋脊的扩张和迁移, 各盆地烃源岩分布于中生界, 大部分储层分布于上白垩统—古新系, 自生自储、古生新储为该区域盆地的主要成藏模式。其中, 俄罗斯极地盆地油气储量最多, 占北极地区总储量45%以上且勘探潜力最大。     

北极阿拉斯加北坡盆地天然气水合物成矿 规律与资源潜力

北极阿拉斯加北坡盆地是全球开展天然气水合物的调查研究最早的地区之一,对全球天然气水合物的研究具有示范作用。在大量文献资料综合分析的基础上,本文系统归纳了阿拉斯加北坡地区天然气水合物的成矿地质条件和成矿规律。认为阿拉斯加北坡的天然气水合物成矿系统是下伏下白垩—第三系含油气系统在浅部的衍生,是由下伏气源、断裂、岩性、北极的特殊环境(永久冻土、地层温压场)等多种因素共同作用的结果。通过模拟计算和分析,将阿拉斯加北坡地区划分了3级远景资源区,估算出整个阿拉斯加地区的天然气水合物资源为6.0×1012m3标准天然气,其中I级远景区主要分布于阿拉斯加北坡的滨岸冻土区和陆架区,资源量为2.83×1012 m3标准天然气。     

南海诸岛的自然环境、资源与开发——纪念中国政府收复南海诸岛70周年(3)

结合近百年几代科学工作者在南海诸岛开展的自然科学调查研究,从区域地质地貌、气候、海洋水文、海洋生物、陆地生物、土壤、自然综合体和自然区划等方面对南海诸岛的自然环境进行了综合阐述;继而从国土资源、渔业资源、旅游资源、油气资源和天然气水合物资源、灰沙岛陆地生物资源和水资源、港口航道资源及海洋―大气能资源等方面对南海诸岛拥有的自然资源进行了详细解释。在此基础上,结合其自身禀赋、战略地位的重要性,提出了科学开发南海诸岛的策略。南海诸岛的开发,除了大力发展旅游业、捕捞业和环礁潟湖养殖业外,应重点推进海洋油气和天然气水合物资源勘探与开发。     

冻土区天然气水合物研究现状与内蒙古多年冻土区地质条件概述

天然气水合物是一种资源量丰富的新型能源。本文概述了国内外冻土区天然气水合物的最新研究进展,简要介绍了内蒙古自治区多年冻土的分布情况和地质概况,认为根河-拉布达林一带多年冻土区具备天然气水合物赋存条件,并提出了内蒙古多年冻土区天然气水合物勘查开发建议。     

辽阳市非常规能源——煤层气资源开发利用的研究

1、国内煤层气(瓦斯)勘探开发现状与进展将煤层气(瓦斯)作为天然气资源进行商业性开采,是世界油气工业史上的一个重要里程碑。中国煤层气(瓦斯)勘探开发已走过     

我国极地航运能力建设和高冰级船队发展对策分析

我国在南极和北极的活动日益增多,参与南北极事务和争取极地资源的利用已经成为国家未来向外扩展的重要举措之一。随着气候变暖,极地冰融速度加快,尤其是北极航运窗口期越来越长,两极资源利用和科考活动的需求量越来越大。而目前我国用于航行两极,尤其是北极的高冰级商业化船队十分缺乏,航运的陆基支持保障能力缺少,这将严重影响我国极地事业和商业航运运营的发展。本文通过对不同冰级船舶的保有量、建造技术能力、船舶运营和极地港口设施等各环节的分析,得出我国缺乏带较高等级冰级符号且可抗浮冰厚度1m及以上的极地航行船舶、相应极地航运能力不足的结论,并提出了我国建设极地航运能力的对策建议,为我国建设一支能在极地航行且带较高等级冰级符号船舶的船队、破冰船队以及建设极地陆基航运支持保障能力等提供决策参考。     

我国极地船舶能力分析与发展建议

"冰上丝绸之路"是"一带一路"倡议的有效延伸,维护我国海外利益以及拓展我国大国地位的重要体现,是贯彻落实海洋强国战略实施的重要路径。建设"冰上丝绸之路",开发利用北极航道,迫切需要极地船舶的装备支撑。本文对比分析国内外极地船舶现状,从极地破冰船、科考船、运输船、邮轮、渔船等船型发展角度,评估我国极地船舶总体能力,凝练我国极地船舶的差距与短板,提出满足未来发展需求的建议措施,为我国提升极地活动能力、治理能力与业务能力提供指导。     

西沙、南沙和中沙群岛进一步开发的设想

论述了西、南、中沙群岛区位的重要性,该区陆地小而海洋国土大,拥有丰富的国土资源、海洋生物与渔业资源、海底矿物资源、海洋一大气能资源和旅游资源;开发历史悠久,但开发程度低,进一步开发大有可为.提出了开发定位:建设一个现代化的具海洋产业的热带海岛花园边境城市.认为应首先发展旅游一休闲度假产业链;其次发展海洋捕捞与养殖业;第三大力开发太阳能、风能和其它海洋能源,以海南岛和华南大陆为后方基地勘探开发海底石油天然气与海底天然气水合物资源,同时建立海水淡化产业;第四,配合军队和海警搞好国防建设,维护国家主权和权益,保境安民.     

水下机器人在极地科学考察中的应用

本文首先介绍了当前极地科学考察的背景与技术现状,重点阐述了水下机器人在极地科学考察中的作用及其应用的必要性。其次调查了国内外水下机器人在极地考察中的研究和应用现状,描述了我国研制的“海极”号水下机器人在“中国第二次北极科学考察”中的作业情况,对极地考察水下机器人的未来发展趋势做了分析。最后,本文针对极地环境和极地科学考察的需求,对极地考察水下机器人的一些关键技术进行了探讨。     

Unconventional Energy Resources: 2007–2008 Review

This paper summarizes five 2007–2008 resource commodity committee reports prepared by the Energy Minerals Division (EMD) of the American Association of Petroleum Geologists. Current United States and global research and development activities related to gas hydrates, gas shales, geothermal resources, oil sands, and uranium resources are included in this review. These commodity reports were written to advise EMD leadership and membership of the current status of research and development of unconventional energy resources. Unconventional energy resources are defined as those resources other than conventional oil and natural gas that typically occur in sandstone and carbonate rocks. Gas hydrate resources are potentially enormous; however, production technologies are still under development. Gas shale, geothermal, oil sand, and uranium resources are now increasing targets of exploration and development, and are rapidly becoming important energy resources that will continue to be developed in the future.

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Natural Gas Hydrate Stability in the East Coast Offshore-Canada

The methane hydrate stability zone beneath the Canadian East Coast oceanic margin has developed to a depth of more than 600 meters beneath the deep water column in the area of the deep shelf and the slope. This zone is continuous spreading from the Labrador continental shelf in the north to the slope of the Nova Scotia shelf in the south. Gas hydrates within the methane hydrate stability zone are detected only in one situation, however, they are numerous in the deeper zone in which type II gas hydrates are present through the whole area at water depths as low as 100-200 m. Well-log indications of gas hydrate situated deeper than the base of the methane hydrate stability zone may be an indication of wetter, compositionally more complicated hydrates that probably are not of bacterial only origin. This could indicate a deep thermogenic source of gas in hydrates. The presence of hydrates in the upper 1000 m of sediments also can be considered as an indicator of deeper hydrocarbon sources.     

Spatial coupling relationships of gas hydrate formation in the Tibetan Plateau

At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.     

Study of the Natural Gas Hydrate “Trap Zone” and the Methane Hydrate Potential in the Sverdrup Basin,Canada

The methane hydrate stability zone beneath Sverdrup Basin has developed to a depth of 2 km underneath the Canadian Arctic Islands and 1 km below sea level under the deepest part of the inter-island sea channels. It is not, however, a continuous zone. Methane hydrates are detected in this zone, but the gas hydrate/free gas contact occurs rarely. Interpretation of well logs indicate that methane hydrate occurs within the methane stability zone in 57 of 150 analyzed wells. Fourteen wells show the methane hydrate/free gas contact. Analysis of the distribution of methane hydrate and hydrate/gas contact occurrences with respect to the present methane hydrate stability zone indicate that, in most instances, the detected methane hydrate occurs well above the base of methane hydrate stability. This relationship suggests that these methane hydrates were formed in shallower strata than expected with respect to the present hydrate stability zone from methane gases which migrated upward into hydrate trap zones. Presently, only a small proportion of gas hydrate occurrences occur in close proximity to the base of predicted methane hydrate stability. The association of the majority of detected hydrates with deeply buried hydrocarbon discoveries, mostly conventional natural gas accumulations, or mapped seismic closures, some of which are dry, located in structures in western and central Sverdrup Basin, indicate the concurring relationship of hydrate occurrence with areas of high heat flow. Either present-day or paleo-high heat flows are relevant. Twenty-three hydrate occurrences coincide directly with underlying conventional hydrocarbon accumulations. Other gas hydrate occurrences are associated with structures filled with water with evidence of precursor hydrocarbons that were lost because of upward leakage.     

Unconventional Energy Resources: 2011 Review

This report contains nine unconventional energy resource commodity summaries prepared by committees of the Energy Minerals Division (EMD) of the American Association of Petroleum Geologists. Unconventional energy resources, as used in this report, are those energy resources that do not occur in discrete oil or gas reservoirs held in structural or stratigraphic traps in sedimentary basins. These resources include coal, coalbed methane, gas hydrates, tight gas sands, gas shale and shale oil, geothermal resources, oil sands, oil shale, and uranium resources. Current U.S. and global research and development activities are summarized for each unconventional energy commodity in the topical sections of this report. Coal and uranium are expected to supply a significant portion of the world’s energy mix in coming years. Coalbed methane continues to supply about 9% of the U.S. gas production and exploration is expanding in other countries. Recently, natural gas produced from shale and low-permeability (tight) sandstone has made a significant contribution to the energy supply of the United States and is an increasing target for exploration around the world. In addition, oil from shale and heavy oil from sandstone are a new exploration focus in many areas (including the Green River area of Wyoming and northern Alberta). In recent years, research in the areas of geothermal energy sources and gas hydrates has continued to advance. Reviews of the current research and the stages of development of these unconventional energy resources are described in the various sections of this report.     

Assessment Methodology and Results From the Canadian Gas Potential Committee 2001 Report

Since 1991 volunteers from the Canadian Gas Potential Committee (CGPC) have conducted assessments of undiscovered gas potential in Canada. Reports were published in 1997 and 2001. The 2001 CGPC report assessed all established and some conceptual exploration plays in Canada and incorporated data from about 29,000 discovered gas pools and gas fields. Mainly year-end 1998 data were used in the analysis of 107 established exploration plays. The CGPC assessed gas in place without using economic cut offs. Estimates of nominal marketable gas were made, based on the ratio between gas in place and marketable gas in discovered pools. Only part of the estimated nominal marketable gas actually will be available, primarily because of restrictions on access to exploration and the small size of many accumulations. Most plays were assessed using the Petrimes program where it could be applied. Arps-Roberts assessments were made on plays where too many discovered pools were present to use the Petrimes program. Arps-Roberts assessments were corrected for economic truncation of the discovered pool sample. Several methods for making such corrections were tried and examples of the results are shown and compared with results from Petrimes. In addition to assessments of established plays, 12 conceptual plays, where no discoveries have been made, were assessed using Petrimes subjective methodology. An additional 65 conceptual plays were recognized, discussed, and ranked without making a quantitative assessment. No nominal marketable gas was attributed to conceptual plays because of the high risk of failure in such plays. Nonconventional gas in the form of coalbed methane, gas hydrates, tight gas, and shale gas are discussed, but no nominal marketable gas is attributed to those sources pending successful completion of pilot study projects designed to demonstrate commercially viable production. Conventional gas resources in Canada include 340 Tcf of gas in place in discovered pools and fields and 252 Tcf of undiscovered gas in place. Remaining nominal marketable gas includes 96 Tcf in discovered pools and fields and 138 Tcf of undiscovered nominal marketable gas. The Western Canada Sedimentary Basin holds 61% of the remaining nominal marketable gas. Future discoveries from that area will be mainly in pools smaller than 2.5 Bcf of marketable gas and increasing levels of exploratory drilling will be required to harvest this undiscovered resource. A pragmatic, geologically focussed approach to the assessment of undiscovered gas potential by the CGPC provides a sound basis for future exploration and development planning. Peer reviewed assessment on a play-by-play basis for entire basins provides both detailed play information and the ability to evaluate new exploration results and their impact on overall potential.     

Stability Zone of Natural Gas Hydrates in a Permafrost-Bearing Region of the Beaufort—Mackenzie Basin: Study of a Feasible Energy Source1 (Geological Survey of Canada Contribution No.1999275)

Analysis of geological and geophysical data from 150 wells in the Beaufort—Mackenzie region(study area between 68°30–70°00N and 131°–39°W) led to reinterpretation of the depth ofmethane hydrate stability and construction of the first contour maps displaying thickness of hydratestability zones as well as hydrate stability zone thicknesses below permafrost. Calculations werebased on construction of temperature-depth profiles incorporating regional heat-flow values, temperatureat the base of ice-bearing permafrost, and models relating thermal conductivity with depth.Data analysis indicates the presence and extent of the methane hydrate stability zone is relatedmainly to the history of permafrost development and less so by the relatively small regionalvariations of temperature gradients. Analysis of well logs and other indicators in conjunction withknowledge of the hydrate stability zone allows reevaluation of the location of possible gas hydrateoccurrences. Log analysis indicates that in the onshore and shallow sea area of theBeaufort—Mackenzie Basin, methane hydrate occurs in 27 wells. Fifteen of these locations coincides withunderlying conventional hydrocarbon occurrences. Previous analyses place some of the hydrateoccurrences at greater depths than proposed for the methane hydrate stability zone described inthis study. Interpretation of geological cross sections reveals that hydratesare related mainly to sandy deltaic and delta-plain deposits in Iperk, Kugmallit, and Reindeer sequences althoughadditional hydrate picks have been inferred in other sequences, such as Richards. Overlyingpermafrost may act as seal for hydrate accumulations; however, the thickness of permafrost andits related hydrate stability zone fluctuated during geological time. It is interpreted that only inthe last tens of thousand of years (i.e., Sangamonian to Holocene), conditions for hydrates changedfrom nonstable to stable. During Early and Late Wisconsinan and Holocene time, conditions werefavorable for generation and trapping of hydrates. However, previously during Sangamonian time,less favorable conditions existed for hydrate stability. Gas release from hydrates may have occurredduring times when hydrate stability was nonexistent because of permafrost melting episodes. It isinterpreted that entrapment of gas in hydrate molecular structures is related to the existence ofconventional structural traps as well as less permeable sediments such as the Mackenzie BayFormation, which act as seal.     

Natural Gas Hydrates in the Offshore Beaufort–Mackenzie Basin—Study of a Feasible Energy Source II

In the offshore part of Beaufort–Mackenzie Basin depth of methane hydrate stability reaches more than 1.5 km. However, there are areas in the western part of the basin where there are no conditions of methane hydrate stability. Construction of the first contour maps displaying thickness of hydrate stability zones as well as hydrate stability zone thicknesses below permafrost in the offshore area, shows that these zones can reach 1200 m and 900 m, respectively. Depth to the base of ice-bearing relict permafrost under the sea (depth of the –1°C isotherm-ice-bearing permafrost base) and regional variations of geothermal gradient are the main controlling factors. Hydrostatic pressures in the upper 1500 m are the rule. History of methane hydrate stability zone is related mainly to the history of permafrost and it reached maximum depth in early Holocene. More recently, the permafrost and hydrate zone is diminishing because of sea transgression. Reevaluation of the location of possible gas hydrate occurrences is done from the analysis of well logs and other indicators in conjunction with knowledge of the hydrate stability zone. In the offshore Beaufort–Mackenzie Basin, methane hydrate occurs in 21 wells. Nine of these locations coincides with underlying conventional hydrocarbon occurrences. Previous analyses place some of the hydrate occurrences at greater depths than proposed for the methane hydrate-stability zone described in this study. Interpretation of geological cross sections and maps of geological sequences reveals that hydrates are occurring in the Iperk–Kugmallit sequence. Hydrate–gas contact zones, however, are possible in numerous situations. As there are no significant geological seals in the deeper part of the offshore basin (all hydrates are within Iperk), it is suggested that overlying permafrost and hydrate stability zone acted as the only trap for upward migrating gas during the last tens of thousand of years (i.e., Sangamonian to Holocene).     

Worldwide Estimates of Deep Natural Gas Resources Based on the U.S. Geological Survey World Petroleum Assessment 2000

The U.S. Geological Survey recently assessed undiscovered conventional gas and oil resources in eight regions of the world outside the U.S. The resources assessed were those estimated to have the potential to be added to reserves within the next thirty years. This study is a worldwide analysis of the estimated volumes and distribution of deep (>4.5 km or about 15,000 ft), undiscovered conventional natural gas resources based on this assessment. Two hundred forty-six assessment units in 128 priority geologic provinces, 96 countries, and two jointly held areas were assessed using a probabilistic Total Petroleum System approach. Priority geologic provinces were selected from a ranking of 937 provinces worldwide. The U.S. Geological Survey World Petroleum Assessment Team did not assess undiscovered petroleum resources in the U.S. For this report, mean estimated volumes of deep conventional undiscovered gas resources in the U.S. are taken from estimates of 101 deep plays (out of a total of 550 conventional plays in the U.S.) from the U.S. Geological Survey's 1995 National Assessment of Oil and Gas Resources. A probabilistic method was designed to subdivide gas resources into depth slices using a median-based triangular probability distribution as a model for drilling depth to estimate the percentages of estimated gas resources below various depths. For both the World Petroleum Assessment 2000 and the 1995 National Assessment of Oil and Gas Resources, minimum, median, and maximum depths were assigned to each assessment unit and play; these depths were used in our analysis. Two-hundred seventy-four deep assessment units and plays in 124 petroleum provinces were identified for the U.S. and the world. These assessment units and plays contain a mean undiscovered conventional gas resource of 844 trillion cubic ft (Tcf) occuring at depths below 4.5 km. The deep undiscovered conventional gas resource (844 Tcf) is about 17% of the total world gas resource (4,928 Tcf) based on the provinces assessed and includes a mean estimate of 259 Tcf of U.S. gas from the U.S. 1995 National Assessment. Of the eight regions, the Former Soviet Union (Region 1) contains the largest estimated volume of undiscovered deep gas with a mean resource of343 Tcf.     

极地海洋石油烃污染物的生物降解研究进展

随着南极考察活动的发展和北极地区的开发利用,极地海洋中的石油烃污染逐渐增多。由于这些地区常年处于低温状态,石油烃的自然降解非常缓慢。生物降解是修复污染的一个主要机制,具有经济、高效的特点。极地海洋环境中存在着大量烃降解菌,它们在清除当地石油烃污染中发挥了很大作用,并显现出了低温修复的潜力。本文从极地海洋环境中的石油烃降解菌、影响低温降解的因素、降解基因和低温生物修复四个方面介绍了国外对该领域的研究成果。