基于流体势约束的潜山油气二次运移优势方向选择--以胜利油田桩海地区古生界潜山为例

结合胜利油田桩海地区古生界潜山的油气勘探成果及勘探中存在的问题,定量模拟了其流体势场,并结合输导体系的发育特征,分析了潜山油气二次运移的优势方向.研究表明,油气的二次运移始于排烃后的油汇位置,运移方向宏观上主要受流体势场特征(流体势高低和流体势平面等值线形态等因素)的控制,同时受输导体系的影响,在平面上呈现出有限几个优势方向.对于不整合面发育的潜山,对不整合面分布特征(区域性和局部性)的分析是输导体系研究的前提,在区域不整合面发育的潜山中,输导体系的影响主要体现在断层和碳酸盐岩输导层两个方面,而局部不整合面的存在可以较强地影响优势运移方向.     

Accumulation Mechanisms and Evolution History of the Giant Puguang Gas Field, Sichuan Basin, China

Solid bitumens were found throughout the carbonate reservoirs in the Puguang gas field,the largest gas field SO far found in marine carbonates in China,confirming that the Puguang gas field evolved from a paleo-oil reservoir.The fluid conduit system at the time of intensive oil accumulation in the field Was reconstructed,and petroleum migration pathways were modeled using a 3-D model and traced by geochemical parameters.The forward modeling and inversion tracing coincided with each other and both indicated that oils accumulated in the Puguang-Dongyuezhai structure originated from a generative kitchen to the northwest of the Puguang gas field.The deposition of organic-rich Upper Permian source rocks dominated by sapropelic organic matter in the Northeast Sichuan Basin, the development of fluid conduit system that was vertically near-source rock and laterally near-generative kitchen,and the focusing of oils originated from a large area of the generative kitchen,were the three requirements for the formation of the giant paleo-oil reservoir from which the giant Puguang gas field evolved.The Puguang gas field had experienced a three-stage evolution.The post-accumulation processes,especially the organic-inorganic interaction in the hydrocarbon-water-rock system,had not only profoundly altered the composition and characteristics of the petroleum fluids,but also obviously changed the physicochemical conditions in the reservoir and resulted in complicated precipitation and solution of carbonate minerals.     

阿拉善高原荒漠植被组成分布特征及其环境解释 Ⅲ.植物功能群多样性对环境因素的响应

采用水分生态型(包括旱生植物、旱中生植物、中生植物和湿生植物)、生活型(灌木、半灌木、多年生草本和一二年生草本)和植物主要光合途径(C3和C4)等方法将研究区的植物种类进行了功能群(functional groups/types)划分,为进一步认知荒漠生态系统的结构、功能和过程提供了分析基础。植物功能类群相对集中是阿拉善荒漠植被组成的一个重要特点,这主要和植物趋于旱化、生态型相对简单密切相关。按优势功能群依次为:PFTs1(旱生C3一二年生草本)、PFTs2(旱生C3多年生草本)、PFTs3(旱生C3灌木)、PFTs4(旱生C3半灌木)、PFTs5(旱生C4一二年生草本)、PFTs7(旱生C4灌木)和PFTs8(旱生C4半灌木)。气候、土壤理化指标决定着植物功能类群的分布。其中年均降水量、湿润系数决定着植物的生态型、生活型在水平地带上的分布特征,同时,也影响C3和C4植物(海拔梯度上)的分布。土壤容重、砂粒、粉粒含量决定着植物生活型特征,而土壤pH值、Cl-、SO42-和Ca2+决定着植物水分生态类型的空间分布。这些结果揭示了极端干旱区植物对胁迫环境响应的多样性,是对极端环境条件下如何理解生物多样性维持机制和可持续发展的较好生态学解释。     

Self-Organizing Maps for identification of zeolitic diagenesis patterns in closed hydrologic systems on the Earth and its implications for Mars

We have conducted a survey of zeolite occurrences in saline-alkaline paleolake deposits on Earth to identify the most prominent zeolite alteration patterns and to characterize the most common authigenic minerals and their paragenetic relationships. We collected the bulk mineral assemblages (from previous and our studies) as identified by X-ray diffraction from zeolitic tuff beds and associated sedimentary beds from thirteen paleolake deposits from the USA, Mexico, Greece, and Tanzania. We applied the Kohonen Self-Organizing Maps (SOM) to look for interesting patterns in the tuff bed mineral assemblages without prescribing any specific interpretation, and for information reduction and classification. Decision Tree (DT) method was applied to characterize these clusters. We were able to define clear class boundaries between fresh glass, non-analcime zeolites, analcime, and K feldspar. The non-analcime zeolites were further grouped into several classes based on mineral type. We also discuss the potential implications for Mars, showing that the mineral assemblages of diagenetic facies identified by SOM and DT can be used to test or validate the orbital, in situ, or modeling results, while the trained SOM provides a robust generalized ability to classify the new mineral assemblage data into the most common diagenetic facies identified in saline-alkaline paleoenvironments that contain zeolites. The study concludes that generalizing the complex geochemical behaviors using unsupervised statistical learning methods can help to identify the most prominent geochemical behaviors.     

川西须家河组储层成岩演化

通过对川西须家河组储层砂岩中成岩矿物内流体包裹体均一温度、盐度和组分的分析,结合碳氧同位素、镜质体反射率、粘土矿X-射线衍射等特征,论证了须家河组储层砂岩成岩作用过程。本文认为须家河组随着成岩流体温度的变化以及盐度和有机组分增加,相继发生了早期碳酸盐沉淀（局限于个别夹层）,石英一期加大边生成、绿泥石薄膜生成、长石岩屑溶解、石英二期加大边生成、以及含铁碳酸盐的沉淀。由于喜山期区域性构造运动,川西须家河组发生断裂活动,深部流体进入,部分裂缝中沉积了石英和方解石等。喜山期产生的裂缝对须家河组砂岩储层油气的运移起决定性作用,形成了现今次生孔-裂缝型油气藏。     

青藏高原及其邻近区域穿越对流层顶质量通量的时空演变特征

利用1958~2001年ECMWF资料, 根据Wei公式估算了青藏高原及其邻近区域穿越对流层顶的质量通量 (CTF), 分析了CTF的时空分布特征。分析结果表明: (1) CTF分布呈现纬向型, 在副热带西风急流北侧即对流层顶断裂带中存在东西向的TST (对流层向平流层输送)[CD*2]STT (平流层向对流层输送)[CD*2]TST的波列结构 (水平输送项决定), 而南侧分布决定于垂直输送项。 (2) 在80°E~105°E范围内, 冬春季节, 青藏高原南部及其以南区域为TST, 北部为STT; 夏秋季节, 整个区域几乎由TST所控制。西风急流南侧的CTF主要决定于垂直项, 而北侧主要决定于水平项, 再往北, 垂直项与水平项贡献相当。 (3) 青藏高原与孟加拉湾区域平均CTF在所有季节均为TST, 即有从对流层到平流层净的向上输送, 2月强度最大, 7月为另一个极大值; 两个极大值有不同的产生机制, 后者决定于垂直项, 而前者由水平项决定。 (4) 青藏高原 (及孟加拉湾) 区域年平均CTF在1958~2001年之间的变化趋势在1982年左右出现一个转折: 1982年之前, CTF为递减过程; 而之后CTF为相对较强的增长。上述结果表明: 尽管冬季高原上空为下沉气流, 但高原上空的水平输送项有很强的向上贡献, 这与丛春华等 (2003) 得出的STT不一致。但需要指出的是, 根据Wei公式计算的CTF, 〖JP2〗尤其在急流附近, 对资料中存在的误差十分敏感 (Gettleman等, 2000), 因此青藏高原主体上空在冬季是STT还是TST, 有待于进一步的分析研究。     

Fluid–rock interactions during continuous diagenesis of sandstone reservoirs and their effects on reservoir porosity

The Cretaceous sandstone reservoir in the Kuche Depression, Tarim Basin, western China, was investigated with reference to its reservoir property evolution during diagenesis. Six general diagenetic stages were recognized through petrographic, mineralogical and geochemical analyses. Fluid–rock interaction experiments were conducted under these six continuous diagenetic conditions, that is with a simulation sequence of compaction → early diagenesis → organic acid incursion I → elevated temperature/pressure → organic acid incursion II → late diagenesis. Corresponding to these six experimental stages, a total of six models were constructed. Finally, an extended model of fluid–rock interaction during diagenesis at a geological timescale (from 30 Ma to present) was constructed after various parameters had been validated. Results demonstrate that the diagenetic stages from both the experimental and numerical simulations generally matched findings obtained from the petrographic and geochemical analyses: (i) With compaction becoming weakened, cementation by various minerals was gradually increased. (ii) Quartz overgrowth occurred because the contemporaneous sedimentary water was alkaline. (iii) Most minerals (for example, calcite and feldspar minerals) displayed dissolution owing to the first organic acid incursion, resulting in the visual porosity increasing to 29·26%. (iv) Increases in temperature and pressure caused a minor fluctuation of the porosity change. (v) The cement that formed during earlier stages largely dissolved with the second organic acid incursion. (vi) During the last stage, the reservoir fluid was diluted by sedimentary alkaline water and most minerals precipitated under an alkalic environment. The present porosity simulated is about 11·4%, comparable with the actually measured data. This study demonstrates that the combination of petrographic observations, laboratory experiments and numerical simulations can not only reconstruct the diagenetic process, but also provide a quantitative evaluation and prediction of reservoir petrophysical properties.     

周边气象条件对南京城区大气污染物浓度的影响

针对2014年8月南京国际青年奥林匹克运动会期间周边地区污染源的减排控制研究,本文将2010-2012年8月的NCEP/NCAR 的6 h再分析资料作为驱动场,利用WRF模式处理得到时空尺度更为精细的风场资料,结合南京奥体中心观测点的颗粒物及气体污染物浓度资料,通过相关分析以及合成分析,诊断得到了8月影响南京地区主要污染物的周边源区及其关键输送通道。结果表明：尽管8月青奥会时段南京地区主导风为海洋吹向大陆的东南风,但影响南京地区主要污染物（SO₂,NO₂,PM₁₀）浓度的外源及其主要输送路径各有不同。来自于南京西南部江西、湖南、湖北等地区的较远距离输送是对南京地区SO₂浓度影响的关键通道;来自于南京正南方向（安徽、浙江一带）的近距离输送是对南京地区NO₂浓度影响的关键通道;来自于南京西南部（湖北一带）的中远距离输送是对南京地区PM₁₀浓度影响的关键通道。     

南海北部陆坡高饱和度天然气水合物气源运聚通道控藏作用

气源运聚通道与天然气水合物富集成藏关系密切。利用准三维地震资料并结合钻探成果,深入研究了神狐海域GMGS3钻探区高饱和度水合物站位气源运移疏导通道地质地球物理特征及其控藏作用。结果表明:高饱和度水合物产出站位发育多种类型运移疏导通道,且与BSR空间耦合关系较好;紧邻BSR之下为强振幅反射,强振幅下部游离气体充注现象明显,表明水合物稳定域下部存在气体运移的通道,且深部气体向浅层发生了运移。深大断裂、底辟及气烟囱构成了沟通深部热解气及浅层生物气与浅层温压稳定域的垂向通道,在这些通道上方可以直接形成水合物;浅部滑塌面、水道砂及海底扇构成的高孔渗连续性砂体为浅层生物气及深部运移而来的部分热成因气横向运移通道,气体的侧向运移扩大了气体供给范围,增加了矿体横向展布规模。文章认为,天然气运移疏导系统与其他成藏要素匹配良好的构造和区域是勘探高饱和度水合物的有利目标。     

松辽盆地滨北地区扶杨储层油气优势运移通道

松辽盆地滨北地区具有一定的油气资源潜力,但勘探方向和目标不明,亟需开展油气运移方向的研究。通过对滨北地区影响油气运移方向的地质因素的分析,确定了盖层底面构造形态、砂体、断裂及水动力4种主控因素。通过对每种主控因素与油气运移方向相互关系的系统分析,采用单因素叠加和多信息叠合的方法分别定性和定量地预测了滨北地区扶杨储层的油气优势运移通道。结果表明,滨北地区扶杨储层主要发育两个优势通道方向,分别为自三肇凹陷北端沿绥棱背斜带向东北方向和自克山-依龙背斜带南部向其东北方向。这两个优势运移通道方向所指示的区域是油气勘探的有利区域,而通道上的圈闭则是有利的勘探目标。