柴达木盆地致密油形成的地质条件及勘探潜力分析

柴达木盆地具备致密油形成的地质条件。柴达木盆地大面积分布的中下侏罗统（J₁₊₂）半深湖相泥岩、第三系下干柴沟组（E₃）、上干柴沟组（N₁）半深湖及深湖相烃源岩和与其互层或位于其附近的滨浅湖相砂体或碳酸盐岩构成了对致密油形成非常有利的源储共生关系。柴北缘侏罗系湖相烃源岩有机碳平均1.85%,有机质类型以Ⅰ-Ⅱ₂型为主,处于成熟-高成熟阶段,具有较好的生油潜力。柴西第三系烃源岩有机碳一般在0.4%~1.2%,有机质类型以Ⅰ-Ⅱ₁型为主,R_O分布在0.4%~1.2%范围内,处于生油窗内。与国内其它盆地相比,柴西第三系烃源岩具有烃转化率较高的特点。碎屑岩储集空间以残余粒间孔和溶蚀孔隙为主,孔隙度3.8%~10.2%,渗透率0.1~2.0×10-3 μm2,储层具有单层厚度较薄、纵向上多层叠加、累计厚度较大、平面上多油层复合叠置分布的特点。碳酸盐岩储集空间以溶蚀孔和层间收缩缝为主,孔隙度5%~7%,渗透率0.2~0.7×10-3 μm2,储层层数较多,单层厚度薄,多沉积相带控制,具有横向广覆连片分布的特点。古构造斜坡区和生油凹陷中心是致密油分布集中区。致密油可能的成藏组合包括源内包裹组合、源上广覆组合、源下依伏组合和源侧披覆组合等四种。柴达木盆地致密油资源丰富、潜力大,初步估算资源量在8.16~10.46×108 t。通过成藏条件分析,认为柴西扎哈泉-乌南、小梁山-南翼山、七个泉-跃进和柴北缘冷湖等四个有利勘探区带可作为近期致密油勘探的首选目标。     

基于裂缝性致密储层关键渗流参数的逆向渗吸速度计算

在致密油藏水平井体积压裂开采过程中,压裂液通过缝网与基质接触并发生逆向渗吸作用,由于接触面积很大渗吸作用不可忽视;但目前关于表征致密储层的渗吸作用,从而研究渗吸对水平井体积压裂生产过程影响的研究尚未深入.为了解决以上问题,首先利用毛管束模型,通过考虑致密储层中边界层的特征,建立了解析的渗流参数计算表达式,用以计算致密储层的渗透率、毛管力、相渗曲线这3个关键渗流参数;同时,基于以上关键渗流参数和渗吸控制方程建立了适用于致密储层的渗吸速度计算模型;然后,将渗吸项作为源汇项加入到考虑缝网的双孔单渗模型中.最后,在真实水平井体积压裂开采过程中,耦合渗吸作用.研究表明,相比于不考虑边界层特征的致密油藏,边界层的存在将大幅度减弱储层的渗吸能力,同时也说明了在致密储层中,边界层的存在是不可忽视的,如果在渗吸计算中忽视致密储层的边界层特征会严重高估渗吸对致密储层产能的影响.      

南海北部深水区油气勘探关键地质问题

南海北部深水区已经获得了重大的天然气发现,正逐渐成为全球深水油气勘探的热点区之一。通过与相邻陆架区以及世界上典型深水盆地的类比发现,南海北部深水区具有独特的石油地质特征。南海北部大陆边缘经历了从燕山期主动陆缘向新生代边缘海被动陆缘的转变,其演化过程和成盆机制复杂;陆坡深水区具"热盆"特征,凹陷发育超压,其生烃机制不明;深水区距离物源区较远,缺乏世界级大河系的注入,具远源沉积特征,未发现盐层及其相关构造,其油气成藏条件具有特殊性。此外,南海北部深水区海底地形崎岖、多火山,还面临着地震采集、处理等地球物理难题。因此,南海北部深水油气勘探需要在借鉴相邻陆架区和世界其他深水区成功经验的基础上,一方面深入研究其独特的油气地质特征,另一方面研发适应于我国深水环境的地球物理勘探新技术,切实推动深水油气勘探的进程。     

Fine Geological Modeling of the Tight Oil Reservoir

<正>1 Introduction The study area of Northern Honggang is located in the Daan-Honggang terrace in the central depression of the southern Songliao basin,covering an area of 110km2.The oil field is categorized as an ultra-low permeability reservoir and the target horizon is the Fuyu oil layer.The reservoir is characterized as poor physical property,strong     

The Significance of Wettability in Tight Oil Exploration and Development

<正>With the increasing of energy demand and conventional oil and gas resources depletion,unconventional oil and gas resources are getting more and more attention,and have become a major contributor to the global oil and gas production growth over the past five years(Zou et al.,2012;Jia et al.,2014).After shale gas,the tight oil in the     

Geological Prospecting in China Has Achieved New Breakthroughs during 2018

正During 2018, Chinese geoscientists made many breakthroughs in shale gas geological exploration, nonferrous polymetallic ore exploration and non-metallic ore exploration by constantly trying new methods, new technologies and new hypotheses and testing theories in prospecting research. These breakthroughs focus mainly on the following aspects:     

再论中国煤炭地质综合勘查理论与技术新体系

基于近年来大量专题科研成果和勘查工程实践．系统总结形成了适应中国煤田地质特点和煤炭工业要求的煤炭地质综合勘查理论与技术体系。该体系可概括为一个创新思路、两大支撑理论、五大关键技术、一套标准规范：提出了集资源勘查、矿井建设、安全生产、环境保护为一体的”煤炭地质综合勘查”新思路：聚煤规律研究和构造控煤作用研究取得突出进展,为当代煤炭地质综合勘查技术体系提供了强大的理论支撑：建立并完善了由煤炭资源遥感技术、高精度地球物理勘查技术、快速地质钻探技术、煤炭资源信息化技术、煤矿区环境遥感监测技术等五大核心技术构成的地质综合勘查技术体系;编制技术规范与标准14项,为构建中国煤炭地质综合勘查体系提供了政策依据。     

Accumulation Characteristics of Tight Sandstone Oil below Source Rocks and Its Major Controlling Factors：Fuyu Oil Layer in Da’an Area in Songliao Basin, NE China

<正>1 Introduction Tight sandstone oil generally refers to the oil accumulated in tight sandstone reservoir rocks,with insitu permeability less than 0.1×10~(-3)μm~2(or surface permeability lower than 1×10~(-3)μm~2).Under normal conditions,there is no oil natural capacity in the well,or natural capacity is lower than the threshold of industrial     

Formation Conditions and Exploration Potential of Tight Oil in the Kong2 Member, Cangdong Depression

<正>To study the sedimentary environment,source rock,reservoir characteristics and distribution,symbiotic relationship between source and reservoir,the old wells and well area reexamination,experimental data were involved in the analysis,guiding by the theories and methods of petroleum geology,mineralogy,organic geochemistry,geophysics.The potential targets were     

地质灾害勘查的地球物理方法及其发展趋势

地质灾害的勘查是地质灾害评估、灾害治理方案设计、防治工程实施的重要保证,其中物探技术可以发挥重要作用.近年来,物探勘探技术在此方面的实验研究工作发展迅速,本文对这种新的应用技术进行了简要的综述,以利于地质灾害勘查工作的进一步发展.     

中国油页岩富集与地质事件研究

油页岩是一种有机质富集的细粒沉积岩,高古湖泊生产力和稳定的还原环境是油页岩成矿的关键。越来越多的学者研究发现,在含油页岩沉积组合序列中,经常出现火山、热液、大洋缺氧、气候突变、海侵、重力流等地质事件。通过对全国50个盆地、95个含矿区油页岩成因和分布规律的总结和归纳,揭示出火山、热液、大洋缺氧、气候突变、海侵、重力流等事件不同程度地改变古湖泊水体条件,引发湖泊表层高生产力,促进藻类勃发和微生物繁盛,并形成稳定的湖泊分层环境,成为油页岩富集的有利因素。但若过量的火山灰、频繁火山爆发释放大量气体、高温高压的间歇性热液流体以及频繁的重力流作用将不利于油页岩富集。针对这些地质事件研究,目前还只停留在对单个事件的分析,未来需要从地球系统科学整体出发,促进沉积学、地球化学、微生物学等多学科交叉,揭示非常规油气资源沉积富集与重大地质环境突变的生态循环过程,进一步深入加强多种地质事件耦合作用对油页岩成矿影响,丰富非常规油气沉积学理论。     

致密储层油气成藏机理研究现状及其关键科学问题

致密油气是世界上近20年来勘探、开发和研究的热点。在大量文献资料调研的基础上,首先总结了前人对致密储层特征及成因、致密储层油气形成和分布特征以及致密储层油气运移和聚集机理等方面的研究现状;然后分析了目前国内外有关致密储层油气成藏研究的主要特点;最后提出微米—纳米级孔喉网络系统油气充注、运移和聚集机理是致密储层油气成藏机理的核心科学问题,具体体现为油气由烃源岩向致密储层的充注机理、致密储层微米—纳米级孔喉网络系统油气运移的渗流机理以及致密储层微米—纳米级孔喉网络系统油气的赋存和聚集(滞留)机理3个具体的关键科学问题,而这将是致密储层油气成藏机理下一步研究的重点。     

Geological Conditions of Tight Sandstone Gas Accumulation by Diffusion in Sulige Gasfield, Ordos Basin, China

<正>1 Introduction Tight sandstone gas reservoirs have become the focused field in the global unconventional natural gas exploration and tight sandstone gas output accounts for 75%of the unconventional gas output(Zou et al.,2013).In China,tight sandstone gas reserves and output account for a third of the whole country natural gas reserves and output(Zou     

Exploration and Realization of Several Key Problems of Geological Big Data

正With the rapid development of technology,geological big data is increasing explosively,and plays an increasingly important position in the national economy (Zhang and Zhou,2017;Zhou et al.,2018).Governments and agencies attach great importance to the open internet service of geological big data and information at home,and abroad (Yan et al.,2013;Guo et al.,2014).The basic norms of western countries'geological data information services are rich and varied products,efficient and     

Geological and Geochemical Characteristics and Exploration Prospect of Coal‐Derived Tight Sandstone Gas in China: Case Study of the Ordos,Sichuan, and Tarim Basins

This work extensively investigated global tight sandstone gas, and geologically and geochemically analyzed the tight sandstone gas in China's Ordos, Sichuan, and Tarim basins. We compared typical tight sandstone gas in China with that in North America. We proposed six conditions for the formation of China's tight sandstone gas, and illustrated the geological characteristics of tight sandstone gas. In China, gas-bearing tight sandstones were mainly deposited in continental lake deltas and marine-terrigenous facies basin environments, associated with coal-measure strata, and were mostly buried deeper than 2000 m under a formation pressure of 20–30 MPa, with pressure coefficients varying from overpressure to negative pressure. In other countries, tight gas bearing sandstones were dominantly deposited in marine to marine-terrigenous facies environments, occurred in coal-measure strata, and were mostly buried shallower than 2000 m in low-pressure systems. We systematically analyzed tight sandstone gas in the Ordos, Sichuan, and Tarim basins in terms of chemical compositions, geochemical characteristics of carbon isotopes, origins, and sources. Tight sandstone gas in China usually has a hydrocarbon content of 95%, with CH4 content 90%, and a generally higher dry coefficient. In the three above-mentioned large tight sandstone gas regions, δ13 C1 and δ13 C2 mainly ranges from-42‰ to-28‰ and from-28‰ to-21‰, respectively. Type III coal-measure source rocks that closely coexist with tight reservoirs are developed extensively in these gas regions. The organic petrology of source rocks and the carbon isotope compositions of gas indicate that tight sandstone gas in China is dominantly coal-derived gas generated by coal-measure strata. Our analysis of carbon isotope series shows that local isotope reversals are mainly caused by the mixing of gases of different maturities and that were generated at different stages. With increasing maturity, the reversal tendency becomes more apparent. Moreover, natural gas with medium-low maturity(e.g., Xujiahe Formation natural gas in the Sichuan Basin) presents an apparent reversal at a low-maturity stage, a normal series at a medium-maturity stage, and a reversal tendency again at a high-maturity stage. Finally, we proposed four conditions for preferred tight sandstone gas "sweep spots," and illustrated the recoverable reserves, proven reserves, production, and exploration prospects of tight sandstone gas. The geological and geochemical characteristics, origins, sources, and exploration potential of tight sandstone gas in China from our research will be instructive for the future evaluation, prediction, and exploration of tight sandstone gas in China and abroad.     

我国主要含油气盆地油气资源潜力及未来重点勘探领域

油气资源是油气工业的基础,随着油气勘探工作的不断深入,油气勘探形势发生了明显变化,亟需评价落实国内常规与非常规油气资源潜力,明确剩余油气资源的重点勘探领域与有利勘探方向,夯实油气资源家底.中国石油天然气集团公司以近十几年来油气勘探成果、地质认识成果与资料积累成果为基础,攻关形成常规与非常规油气资源评价方法技术体系,系统开展了第四次油气资源评价,评价结果显示我国常规石油地质资源量1 080.31×108 t,技术可采资源量272.50×108 t;常规天然气地质资源量78×1012 m3,技术可采资源量48.45×1012 m3.我国非常规油气资源非常丰富,非常规石油地质资源量672.08×108 t,技术可采资源量151.81×108 t;非常规天然气地质资源量284.95×1012 m3,技术可采资源量89.3×1012 m3.其中,致密油地质资源量125.80×108 t,油砂油地质资源量12.55×108 t,油页岩油地质资源量533.73×108 t;致密砂岩气地质资源量21.86×1012 m3,页岩气地质资源量80.21×1012 m3,煤层气地质资源量29.82×1012 m3,天然气水合物153.06×1012 m3.我国陆上常规剩余油气资源主要分布在岩性-地层（碎屑岩）、复杂构造（碎屑岩）、海相碳酸盐岩、前陆冲断带四大重点领域.其中,陆上剩余石油资源主要分布在岩性-地层（碎屑岩）、复杂构造（碎屑岩）两大领域,陆上剩余天然气资源主要分布在海相碳酸盐岩、前陆冲断带两大领域.海域油气资源主要分布在构造、生物礁、深水岩性3个领域.      

Accumulation Pattern of Jurassic Tight Oil in Sichuan Basin and Its Exploration & Development Prospect

<正>Jurassic tight oil in Sichuan Basin is chiefly distributed over the central basin with an area of about 4.2×104 km2.Since the first drilling in 1953,it has experienced four stages,including the Central Sichuan Basin Brought under Exploration and Development,Progressive Exploration and Development,Setting A Goal of 30×104 t/a,and Adjusting and Keeping A Stable Production.More than sixty-year exploration and development history     

中国煤层气勘探开发技术

中国煤层气资源丰富，近１０年在煤层气勘探开发技术方面形成了包括煤层气钻井取心、试井、完井、强化压裂和排采系统配套的工程工艺技术。介绍了这套煤层气勘探开发工程工艺技术的基本内容、特点及应用情况。     

Geological Controls on High Production of Tight Sandstone Gas in Linxing Block,Eastern Ordos Basin,China

Tight sandstone gas in the Linxing Block, eastern Ordos Basin, has been successfully exploited. The high performance is mainly a result of the special geological conditions. The key geological controls for high production have been discussed on the basis of seismic data, field observation, sample features, mercury porosimetry, mechanical properties, and basin modeling. Firstly, the coal measures have good gas generation potential, not only because of the existence of coalbeds and organic-rich shales, but also because coal laminae and microbial mats in the shales significantly increase their total organic carbon(TOC) contents. Secondly, except for the uplifted zone of the Zijinshan complex and the eastern fault zone, rare large faults develop in the Carboniferous–Permian sequence, ensuing the sealing capacity of cap rock. Small fractures generally concentrated in the sandstones rather than the mudstones. Thirdly, gas accumulation in the Linxing Block was controlled by the tectonic, burial and thermal histories. Gas accumulation in the Linxing Block started in the Late Triassic, followed by three short pauses of thermal maturation caused by relatively small uplifts;the maximum hydrocarbon generation period is the Early Cetaceous as a combined result of regional and magmatic thermal metamorphisms. Field profiles show abundant fractures in sandstone beds but rare fractures in mudstone beds. Mechanical properties, determined by lithostratigraphy, confine the fractures in the sandstones, increasing the permeability of sandstone reservoirs and retaining the sealing capacity of the mudstone cap rocks. The modern ground stress conditions favor the opening of predominant natural fractures in the NNW-SSE and N-S directions. These conclusions are useful for exploring the potential tight sandstone gas field.