页岩气含气量及其影响因素综述

页岩气为源岩区油气聚集,以游离和吸附状态为主存在。富有机质页岩含气量是页岩气资源评价和有利区优选的关键参数。页岩有机质含量和地层的压力、温度、深度等因素影响页岩的含气量,开展页岩气含气量参数地质评价,还要研究岩石的矿物成分、裂缝影响等其它参数。     

渤南洼陷沙四段地层特征及其成藏规律

一直以来红层是渤南洼陷沙四上、下段地层划分标准。本文运用构造运动和沉积环境的对应关系,通过构造运动、地震相位追踪、沉积特征对沙四上、下段进行论述,明确了该洼陷沙四上、下段地层特征,进而提出了该洼陷沙四段的成藏模式。     

河125地区储层及油气富集规律研究

河125大断层是牛庄洼陷和中央背斜带的分界断层，河125断层下降盘的中带地区已开发部分沙三段油藏区块，通过对该区油源条件、地层压力、储层物性3个关键因素对滑塌浊积砂体形成岩性油气藏进行研究，根据区域沉积规律及相邻区块的含油气情况分析认为该区沙三段有利含油地区。     

中美页岩气成藏条件、分布特征差异研究与启示

美国页岩气大多为海相热成因型,产气页岩主要分布在前陆和克拉通盆地的泥盆—石炭系,埋藏深度一般为1 500～3 500 m。我国页岩分为海相、海陆过渡相与煤系、湖相三类,其中海相页岩主要发育在坳拉槽和克拉通盆地的下古生界,富有机质集中段分布稳定,热成熟度偏高,有较高的含气量,勘探前景最好;海陆过渡相与煤系页岩主要发育在大型坳陷和前陆盆地,层系以石炭系—侏罗系为主,没有明显的富有机质集中段,含气量差别较大,勘探潜力有待落实;湖相页岩主要发育在中、新生代陆相盆地,富有机质集中段厚度大,成熟度较高的凹陷中心区可能具有一定资源前景。预测我国页岩气勘探将经历较长的探索期,未来年产量可达500亿～600亿m3规模。     

渤南油田隐蔽油藏储层规律研究

渤南油嗣沙三段水道砂岩油藏的形成主要是受古地形的控制，另外还与水动力强弱、物源供给能力等因素有关，呈连续或不连续的展布形态，储层相变快。由于储层分布规律不清，受控因素不明，影响下一步的勘探开发。加强地质综备研究，利用相控储量技术，精细油藏描述，对储层分布进行研究，滚动扩大渤南浊积砂体的含油面积，为新区产能建设提供新的阵地。     

有机地球化学分析技术在油田勘探中的应用

利用有机质中镜质组反射率测定、干酪根显微组分及类型划分、棒薄层色谱等地球化学分析手段,对兴隆镇中生界生油层及附近新生代生油层的生油能力、有机质特征进行了分析归纳.评价目标区不同洼陷原油物理化学特征,通过油源对比技术解决了辽河油田西部凹陷西斜坡南段油气来源问题,为该区进行下一步勘探指明了有利方向.     

基于富有机质页岩层系的电阻率变化研究

页岩气作为一种非常规油气资源，是以“自生自储”的方式赋存于页岩层中的天然气。页岩气具有含气面积广、资源量大和开采周期长等诸多优点，引起国内外专家学者的关注。近年来国内外岩石物理特征和电学特性方面的研究成果，为本课题的研究提供了宝贵的资料。通过研究发现，地下物质的整体电阻率主要由孔隙、裂痕和断层破碎带内的水溶液电解导电控制，因此对岩石电阻率变化起主导作用的是温度、压力、有机质含量、水饱和度以及束缚水的含量。     

页岩气主要富集因素与核心区选择及评价

影响页岩气规模开发的因素很多,最核心的因素是首先要通过建立地质评价标准,选出页岩气核心区。核心区的确定关系到在页岩气勘探初期,是否能找准页岩气最富集的目标,选择最有利地区进行勘探,突破出气关,进而实现大规模经济开发。从页岩气成藏特征、页岩气富集因素分析入手,重点探讨我国富有机质页岩的丰度、成熟度、脆性矿物含量、含气性以及盖层等关键参数及其作用。借鉴北美页岩气勘探开发和研究成果,结合我国页岩气勘探开发和研究新进展,初步建立我国页岩气核心区地质评价标准,并优选出我国南方海相页岩气的核心区,指出四川盆地南部是我国最现实的页岩气开发区。     

富林洼陷沙河街组成藏模式研究

富林洼陷是渤海湾盆地济阳坳陷沾化凹陷的一个重要次级洼陷，长期勘探工作一直未有较大的突破。本文以富林洼陷烃源岩特征研究、油源对比为重点，结合地质构造研究，得出三点最新认识：（1）提高了对富林洼陷，特别是中次洼和东次洼的生烃潜能的评价；（2）将富林洼陷的原油成熟度划分为中次洼、东次洼及孤南洼陷三种成因类型；（3）综合分析构造、储盖组合及油源等控制因素，提出富林洼陷的油气具有三种成藏模式。     

页岩气储层矿物组成成分分析方法浅析

页岩气指储集在富含有机质的细粒碎屑岩中的天然气。页岩气储层岩石矿物组分分析是储层评价的基础,可为后续的储层物性、岩石力学等的评价提供必的参数。本研究采用了岩心实验分析、最优化计算以及元素俘获能谱测井三种方法对页岩层储层矿物组分进行了分析。我国页岩气资源的勘探开发刚刚起步,希望通过页岩气储层矿物组成成分的分析,能够对我国页岩气的资源开发有所帮助。     

中国南方页岩气勘探评价的几点思考

中国南方广泛发育下寒武统、下志留统、上二叠统三套海相区域性富有机质泥页岩,同时在四川盆地、江汉盆地和苏北盆地发育陆相富有机质泥页岩,具备形成页岩气的地质条件。但是,与美国页岩气相比,南方海相页岩气具有多期构造运动叠加改造、热演化程度高、保存条件复杂的特点,而陆相泥页岩有机碳含量、孔隙度相对较低,因此南方页岩气勘探面临诸多挑战,不能盲目乐观。笔者等对比研究认为,四川盆地海相、陆相是实现页岩气规模勘探开发的现实领域,江汉盆地、苏北盆地陆相可作为南方页岩气勘探的后备领域。     

页岩储层网络压裂技术研究与试验

页岩储层压裂技术是页岩油气高效勘探开发的关键技术和核心技术。与常规低渗油气储层压裂单一长缝改善压裂效果不同,低孔极低渗的页岩压裂主要目标是形成具有有效导流能力的网络裂缝,确保压裂改造体积足够大,且经济有效。提出了页岩网络压裂有效改造体积（ESRV）的概念。在借鉴北美页岩气压裂的经验和前期国内页岩气压裂实践的基础上,针对我国页岩储层的具体特点,在压前进行评价方法、射孔参数优化、诱导复合测试压裂、网络压裂对策和排采技术等方面进行了探索性的研究,初步形成了页岩网络压裂技术,现场试验效果明显,解决了裂缝性脆性页岩压裂易砂堵、成功率低的难题。     

Varying-scale shale gas flow: Discrete fracture networks (DFN) based numerical simulation

ABSTRACT

The development of unconventional gas reservoirs represents totally distinctive characteristics as compared with its conventional counterparts. The prevailing commercial strategy of stimulating fractures to connect the matrix to wellbores results in an even more complicated shale gas flow behavior, in which matrix flow is fairly coupled with fracture flow. Numerous works have been contributed to unveil the underground shale gas production mechanisms. And some impressive progresses have been made in describing the complex subterranean shale gas flow, such as the introduction of discrete fracture network (DFN) from National Energy Technology Laboratory (NETL). However, none of them captures the varying-scale nature of the in-place gas flow in shale sediments. In this work, we try to fill this gap. Following the concept of DFN, we set up mathematical models for shale gas flow in matrix and fracture networks, and also for their mass transfer in between without neglecting its varying-scale nature. In addition, we also investigate comprehensively the impact of various effects and phenomena occurred in pore spaces during production course, such as adsorption and desorption on rock surfaces, gas slippage and Knudsen diffusion, and diffusion in bulk kerogen, on the overall shale gas production using our new model for a specific shale gas reservoir case study.     

The Fast Road of Shale Gas Development in China——Reflections on Building a Special Test Areas for National Shale Gas Development

China's shale gas development has had a good start. It is necessary that the developers take advantage of the opportunity to make further efforts to promote shale gas development in China, in particular by rolling out a comprehensive plan on a national level. The author makes a proposal to establish a special shale gas test area in and adjacent to the Sichuan Basin as the most important way to promote the rapid development of shale gas in China. For this purpose, the author analyzes the current situation and problems of shale gas development in China, addresses the necessity and feasibility of establishing a special test area for shale gas development, and draws up the scope of this shale gas special test area of about 450 thousand square kilometers, covering Sichuan, Chongqing, Guizhou, and part of Yunnan, Hunan, Hubei provinces, and proposes the establishment of a shale gas test area in China. This consists of an overall plan, targets, and contents in 10 aspects, along with organization and implementation modes. The shale gas exploration and development in the shale gas zones is promoted vigorously by introducing special policies and innovating exploration, development and utilization model. While at the same time, the shale gas zones of continental facies in the Ordos Basin and marineterrigenous facies in South Hubei Basin will be established.The experiences of the reform in the shale gas zones will be the good practice for the reform of petroleum organization system.     

Numerical simulation study of shale gas reservoir with stress-dependent fracture conductivity using multiscale discrete fracture network model

The exploitation of shale gas has increasingly become the focus of worldwide energy industry. Due to the existence of natural/hydraulic fractures, most of the shale gas reservoirs exhibit high degree of heterogeneity and complexity which leads to the stress-dependent fracture conductivity of shale gas reservoir. Discrete fracture network (DFN) model is adopted in this research since the conventional continuum model cannot meet the numerical simulation requirements of fractured shale gas reservoir. A series of experiments about the fracture properties stress-dependent have been conducted on some shale core samples, the stress-dependent fracture conductivity correlation is selected and incorporated into the mathematical model to characterize the reduction of fracture conductivity potential with the reservoir pressure drop. The DFN model is applied to a shale gas reservoir with fracture network to study the effect of the stress-dependent fracture conductivity on the shale gas well performance. The results show that the effect of fracture conductivity reduction with pressure drop on the shale gas well performance depends on both the initial fracture conductivity and matrix permeability. The complex interactions between the fracture and matrix permeability should be considered when select the appropriate size of proppants for fracturing.     

全球页岩气发展启示与中国未来发展前景展望

中国页岩气勘探开发已开展了大量露头地质调研、前期研究与勘探开发先导试验等工作,尤其是在中国南方海相页岩气区,完钻了页岩气井40余口,获气10余口,多口井经压裂初期日产量超过了1万m3。实践表明,中国页岩气资源发展前景较好,但也具有明显的特殊性,许多地质与开发难题亟待解决,随着页岩气勘探开发理论与关键技术的突破、经济条件的改善和国家政策的支持,未来中国页岩气资源发展前景广阔。     

Preparation and characterization of silica aerogels from oil shale ash

The silica aerogels were successfully synthesized using oil shale ash which is a by-product of oil shale processing via ambient pressure drying. The physical and textural properties of the silica aerogels have been investigated and discussed. The results showed that the organic modification of hydrogels was a crucial step during the processing which preserved mesopores in ambient pressure drying. The unmodified hydrogel underwent tremendous shrinkage during the drying and yielded microporous silica aerogel. Using this novel route, it could produce silica aerogel with low tapping density of 0.074 g/cm³, high specific surface (909 m²/g) and cumulative pore volume of 2.54 cm³/g. From the industrial point of view, the present process is quite suitable for a large scale production of powdered silica aerogel. Furthermore, it provides a new way to solve the problem of oil shale ash pollution.     

美国Eagle Ford页岩气开发对我国页岩气勘探开发的启示

据估计,我国的页岩气可采储量高达20万亿～36万亿m3,虽然我国页岩气储量评估处于初级阶段,但仍然可以肯定我国是页岩气资源丰富的国家之一,如果都能开发,按当前的天然气年产量计算,可以开发200多年。目前国内外多家企业聚焦中国,逐鹿页岩气,页岩气有望成为我国常规能源替代品,页岩气的勘探开发必将对我国乃至世界能源格局产生重大影响。但是由于页岩气储层致密,渗透率低至纳达西级,若不采取特殊的增产措施难以实现商业开发。美国是目前唯一实现页岩气商业开采的国家,技术和商业模式都相当成熟,中海石油斥资10多亿美元收购了美国页岩气主产区Eagle Ford 33.3%的股份,该地区页岩气地质储量高达6 000亿m3,开发前景广阔。为提升我国页岩气总体水平,笔者率领技术专家深入考察了美国Eagle Ford页岩气项目,增进了对水平钻井与分段压裂等关键技术的了解,同时分析了相应扶持政策,对中国页岩气的勘探开发具有重要的参考价值。