Structural controls on fractured coal reservoirs in the southern Appalachian Black Warrior foreland basin

Coal is a nearly impermeable rock type for which the production of fluids requires the presence of open fractures. Basin-wide controls on the fractured coal reservoirs of the Black Warrior foreland basin are demonstrated by the variability of maximum production rates from coalbed methane wells. Reservoir behavior depends on distance from the thrust front. Far from the thrust front, normal faults are barriers to fluid migration and compartmentalize the reservoirs. Close to the thrust front, rates are enhanced along some normal faults, and a new trend is developed. The two trends have the geometry of conjugate strike-slip faults with the same σ₁ direction as the Appalachian fold-thrust belt and are inferred to be the result of late pure-shear deformation of the foreland. Face cleat causes significant permeability anisotropy in some shallow coal seams but does not produce a map-scale production trend.     

准噶尔盆地天然气成藏体系和成藏过程分析

准噶尔盆地目前已发现的天然气以中—小型的中浅层晚期次生气藏为主。研究表明,以区域盖层上三叠统白碱滩组泥岩为界可划分为下部近源原生天然气成藏体系和上部远源次生天然气成藏体系,前者一般具有异常高压的特征,后者则具有正常的压力系统。通过对盆地东部地区、腹部地区、西北缘地区、莫索湾凸起天然气成藏过程的解剖获得了比较一致的认识,即上部次生天然气是在下部原生天然气的改造和调整的基础上形成的,下部天然气成藏体系的原生大—中型天然气藏是未来准噶尔盆地天然气的勘探方向。值得注意的是南缘冲断带的上部成藏体系既有源自侏罗系煤系烃源岩的原生天然气聚集,又伴随有次生天然气藏的形成。     

大型凹陷向斜区油气倒灌式成藏——以松辽盆地三肇凹陷扶杨油层为例

三肇凹陷扶杨油层为典型大型凹陷向斜区油气倒灌式成藏,利用300条地震剖面、825口井曲线、11口井岩芯和探评井试油资料对扶杨油层断层特征及运动期次、油气下排深度、储层沉积特征等油气成藏主控因素综合研究表明：T2断层受控于基底断层、下部火山口、斜向拉张和伸展量差异四种因素具有平面密集成带、剖面“似花状”组合特征,且油气成藏期活动的油源断层多数为断层密集带边界断层;理论计算超压驱动油气下排深度和实际油底包络面统计扶杨油层含油厚度约为200m;重矿物分析扶杨油层主要受北部拜泉—青冈和西南保康物源影响,两物源在徐家围子地区交汇后向东流出;沉积微相揭示扶杨油层发育向上逐渐退积的河控浅水三角洲沉积体系,顶部为三角洲前缘亚相,中—下部为三角洲分流平原亚相,其中扶Ⅰ7—扶Ⅱ1小层为水退最大期,是油气富集主要层位。明水组末期青山口组源岩达到生油高峰,油气在超压作用下沿开启的断层密集带边界断层幕式下排后沿两侧上升盘河道砂体做短距离侧向运移,即断层密集带两侧地垒或断阶块为油气富集区,而断层密集带内多为地堑式组合,不利于油气聚集,在成藏模式指导下刻画出47个油气富集目标区,为松辽盆地北部扶杨油层下一步的勘探与开发指明了方向。     

吐哈盆地低熟气评价的化学动力学方法及其应用

针对目前尚无公认的有效方法评价低熟气生成量的难题,本文从低熟气的（低温）热成因机理出发,认为被广泛、成功应用于成熟的热成因天然气生成量评价的化学动力学理论仍然应该是评价低熟气生成量的有效方法。在此基础上,建立并标定了吐哈盆地代表性泥岩、煤岩干酪根成气的化学动力学模型,与可能部分成为低熟气先质的非烃、沥青质的化学动力学模型一起,构成了评价低熟气生成量的方法。标定结果表明,盆地内有机质成气的平均活化能低于其成油的活化能,而且成气过程中低活化能组分的含量也高于成油过程。这可能正是吐哈盆地的有机质在大量生油之前的低成熟阶段,能开始规模性地生成低熟气、从而导致工业性的低熟气聚集的内因所在。应用表明,吐哈盆地低熟气的总生成量可观,达到632．15×10^11 m^3,而且生气强度较高,最高达到100×10^8m^3／km^2以上。吐哈盆地低熟气资源量约为3．16×10^11～12．62×10^11 m^3。可见,盆地内低熟气具有可观的勘探潜力。本文所建立的方法应该可被推广应用到其他含低熟气盆地的低熟气的评价当中。     

松辽盆地徐家围子断陷火山岩气藏天然气成因类型和气源对比

松辽盆地徐家围子断陷发育营城组火山岩气藏.钻井统计、地球化学特征及天然气组份分析和碳同位素研究表明徐中和徐东地区天然气源岩有机质偏腐泥型,生气潜力更大.对主力源岩层沙河子组和次要源岩层营城组源岩分布有了新的认识.对营城组天然气的烃类气体和CO₂气的来源进行对比和探讨,认为烃类气受气源的控制,CO₂气藏受深大断裂的控制,与火山岩分布关系不大.连通地幔的气藏中,也没有发现无机烃类气体聚集.徐家围子断陷营城组天然气以烃类气占绝对优势,而且主要为甲烷,二氧化碳成藏并不普遍.天然气甲烷成因类型以煤型气为主,甲烷碳同位素变化范围较小.乙烷、丙烷和丁烷碳同位素均有较大的变化范围,而且具有较好的相关性,说明母质类型多样,乙烷、丙烷和丁烷具有相同的来源.含量大于50%的二氧化碳来源于地幔,属无机成因.含量小于50%的二氧化碳既有无机成因,也有有机成因.     

复杂储层识别的地震反演方法及其在塔木察格盆地的应用

随着油气藏勘探开发程度的加深,准确识别复杂储层变得愈发重要,地震反演已成为储层预测的核心技术.本文对蒙占国塔木察格盆地南部凹陷1 800 km²地震资料进行波阻抗反演研究,研究工作包括测井曲线的标准化校正、地质框架模型的准确建立及其它反演参数的正确选取.波阻抗反演结果为研究沉积相划分、砂体空问展布的认识提供了可靠依据,在一定程度上解决了该区主要日的层南屯组沉积物源多、相变快和在地震剖面上无法追踪的问题.     

南海北部台西南盆地973-4岩芯碳的地球化学特征

对南海北部台西南盆地天然气水合物潜在区(973-4岩芯)碳的形态、含量和稳定同位素组成进行了分析,并探讨了成岩环境因素和细菌种群与碳地球化学行为的关系。结果显示:(1)TOC含量为0.4%~1.3%,δ~(13)CTOC为–26.7‰~–23.9‰,说明973-4岩芯主要为陆源有机质,能够满足微生物产甲烷的需要;DIC和δ~(13)CIC的垂向变异及其显著负相关,指示:973-4岩芯560~890 cm深度段有SO42–驱动的AOM反应。(2)p H、Eh、沉积物粒径等成岩环境参数与TOC、IC、δ~(13)CTOC、δ~(13)CIC等碳地化参数显著相关。(3)细菌种群与DIC、δ~(13)CIC显著相关。结论认为:(1)973-4岩芯碳的地化行为与天然气水合物成藏存在明显响应关系。(2)成岩环境参数的垂向变异与碳的地球化学特征密切相关。(3)细菌种群对碳的地化参数变异有着显著影响。     

数字矿山与煤矿瓦斯监测及预警

围绕煤矿瓦斯监测监控系统的开发与运用,介绍了基于数字矿山技术体系进行煤矿瓦斯监测、分析、显示、智能预警及救灾等方面的主要思路、关键技术、系统功能及应用效果。实践表明,瓦斯涌出量及突出动力现象的发生,受地质、地应力和开采条件等多种因素的影响,瓦斯突出预测所涉及的数据具有多源性、时空性、强变化等特征,GIS技术、虚拟现实技术等空间信息技术在煤矿瓦斯监测与预警中具有很大的应用潜力,能对煤矿瓦斯监测与智能预警研究产生重大变革,构建数字矿山对煤矿安全生产具有巨大的推动作用,效益十分显著。     

Brazilian vs. Paraguayan streams: Differences in water quality in a cross-border subtropical region

Monitoring programs are among the first steps to develop robust management strategies, especially in international transboundary waters. Understanding how water quality parameters are impacted by different types of land use promotes a baseline for stakeholders to define the best governance for the management of water resources. Seeking to provide this type of information, we sampled 24 streams – 12 in Brazil and 12 in Paraguay – in February, April, July, September, and November 2019. We determined water quality parameters, grouped into three categories: morphometric, physical and chemical, and nutrients. We explored differences in water quality parameters between countries, and over a one-year sampling. We also tested whether Brazilian and Paraguayan streams are impacted by agriculture, urbanization, and forest cover. Finally, we performed a partial RDA to test the influence of land use on water quality parameters and controlled spatial autocorrelation by including spatial variables (dbMEM) as a condition. Most of the water quality parameters showed significant differences between countries; only turbidity, and pH, presented significant differences between countries and sampling periods, and only water temperature varied significantly along the year. We did not find evidence that different types of land use are causing physical and chemical variance in Brazilian and Paraguayan streams (R² = 0.06, p = 0.68). In conclusion, the results evidenced that the main differences in the water quality parameters occur between countries. Based on the results, transboundary governance can use these data to implement integrated water resources management cooperation.     

Role of reservoir regulation and groundwater feedback in a simulated ground-soil-vegetation continuum: A long-term regional scale analysis

The regional terrestrial water cycle is strongly altered by human activities. Among them, reservoir regulation is a way to spatially and temporally allocate water resources in a basin for multi-purposes. However, it is still not sufficiently understood how reservoir regulation modifies the regional terrestrial- and subsequently, the atmospheric water cycle. To address this question, the representation of reservoir regulation into the terrestrial component of fully coupled regional Earth system models is required. In this study, an existing process-based reservoir network module is implemented into NOAH-HMS, that is, the terrestrial component of an atmospheric–hydrologic modelling system, namely, the WRF-HMS. It allows to quantitatively differentiate role of reservoir regulation and of groundwater feedback in a simulated ground-soil-vegetation continuum. Our study focuses on the Poyang Lake basin, where the largest freshwater lake of China and reservoirs of different sizes are located. As compared to streamflow observations, the newly extended NOAH-HMS slightly improves the streamflow and streamflow duration curves simulation for the Poyang Lake basin for the period 1979–1986. The inclusion of reservoir regulation leads to major changes in the simulated groundwater recharges and evaporation from reservoirs at local scale, but has minor effects on the simulated soil moisture and surface runoff at basin scale. The performed groundwater feedback sensitivity analysis shows that the strength of the groundwater feedback is not altered by the consideration of reservoir regulation. Furthermore, both reservoir regulation and groundwater feedback modify the partitioning of the simulated evapotranspiration, thus affecting the atmospheric water cycle in the Poyang Lake region. This finding motivates future research with our extended fully coupled atmospheric–hydrologic modelling system by the community.