阿尔泰南缘北塔山组火山岩锆石U-Pb定年及地质意义

新疆阿尔泰南缘北塔山组火山岩较为发育。本文对新疆阿尔泰南缘默色克奥依一带北塔山组火山岩进行地球化学分析和年代学研究。研究表明：U-Pb锆石年龄为（384.3±4.0Ma）Ma，为中泥盆世；该组火山岩属于钾质钙碱性系列，全碱（Na2O+K2O=2.07%-6.49%）和YiO2（0.24%-0.64%）含量较低，K2O含量（1.11%-4.04%）变化较大，稀土元素含量（∑REE）较低。稀土元素显示其轻稀土富集且分馏不明显；δEu值均大于1，为Eu富集型；δCe值均小于1，为Ce亏损型。该组火山岩微量元素P明显富集，K、Rb、Ba等大离子亲石元素（LILE）略富集，亏损Ta、Zr、Hf、Ti等高场强元素（HISF）。结合前人研究，本文认为默色克奥依一带北塔山组火山岩形成于岛弧及与俯冲过程有关的活动大陆边缘造山带环境，为泥盆纪古大洋俯冲消减过程中，俯冲板片脱水产生的流体交代上覆地幔楔部分熔融的产物。     

Enhanced oil recovery from carbonate reservoirs by spontaneous imbibition of low salinity water

An experimental study was performed to investigate the impact of low salinity water on wettability alteration in carbonate core samples from southern Iranian reservoirs by spontaneous imbibition. In this paper, the effect of temperature, salinity, permeability and connate water were investigated by comparing the produced hydrocarbon curves. Contact angle measurements were taken to confirm the alteration of surface wettability of porous media. Oil recovery was enhanced by increasing the dilution ratio of sea water, and there existed an optimum dilution ratio at which the highest oil recovery was achieved. In addition, temperature had a very significant impact on oil recovery from carbonate rocks. Furthermore, oil recovery from a spontaneous imbibition process was directly proportional to the permeability of the core samples. The presence of connate water saturation inside the porous media facilitated oil production significantly. Also, the oil recovery from porous media was highly dependent on ion repulsion/attraction activity of the rock surface which directly impacts on the wettability conditions. Finally, the highest ion attraction percentage was measured for sodium while there was no significant change in pH for all experiments.     

渤中凹陷西南部烃源岩TOC含量预测

烃源岩总有机碳（TOC）含量是评价有机质丰度的主要指标。地球化学方法的岩心测试仅能获得离散的TOC含量数据，难以实现烃源岩的三维定量评价。结合地球物理测井方法和地震叠前反演方法，针对渤中凹陷西南部陆相深层烃源岩，通过岩石物理交会分析优选对TOC含量敏感的弹性参数，建立TOC含量与纵波速度、密度的地震反演模型；使用拓展ΔlogR方法和地震叠前反演方法分层计算渤中凹陷西南部东营组和沙河街组烃源岩TOC含量，获得TOC含量曲线和TOC含量三维反演体，进而计算东二下段、东三段、沙一二段、沙三段烃源岩TOC含量地震预测平面图。结果表明预测误差较小，证明了该方法的可靠性。研究区烃源岩非均质性较强，总体呈现“层系多、分布广”的特征。东营组烃源岩北部优于南部，且东三段TOC含量值总体高于东二下段；沙河街组TOC含量值整体较高，为研究区的主力烃源岩层，TOC含量呈现自沉积中心向外逐渐降低的趋势，尤以沙一二段A、B、C、E井区及其附近区域、沙三段A、C井区及其西部、南部部分地区TOC含量值最高，具有良好的生烃潜力。     

巨厚煤层开采覆岩含水层破坏模拟——以准东大井矿区为例

本文针对准东矿区巨厚煤层典型赋存特征,以大井矿区为研究对象,通过识别覆岩关键层及含水层,采用UDEC数值模拟方法,建立大井矿区巨厚煤层开采覆岩力学模型,对不同开采方法覆岩含水层破坏进行了模拟研究。结果表明:研究区覆岩关键层分为4层、覆岩含水层共2层;开采厚度相同时,大采高开采覆岩下沉量、裂隙带发育高度及开采对含水层的扰动影响均大于放顶煤开采;采高24m,推进长度为300m时,导水裂隙已发育至含水层Ⅱ;主关键层对覆岩位移、裂隙分布及开采对含水层的扰动影响起关键作用。     

Geochemical characteristics and accumulation of hydrocarbon in Lower Jurassic tight sandstone in Wenjisang area,Turpan Basin,NW China

In order to investigate the geochemical characteristics, sources and accumulation process of Lower-Jurassic Sangonghe Formation tight sandstone oil, multiple geochemical analyses were performed on source rocks, oil samples and sandstone particles from Wenjisang area in Turpan Basin. The results show that coal-measure source rocks have relatively higher organic matter abundance and type-II organic matter for Xishanyao and Badaowan Formations, with the potential of liquid hydrocarbon generation. Oil samples of Sangonghe Formation have the characteristics of coal-measure-formed oil. Higher maturity indicate the oil may be mainly generated by Lower-Jurassic Badaowan Formation source rocks. Quantitative fluorescence parameters also reflect that hydrocarbons charged into Sangonghe Formation through continuous migration from the bottom of sand body to the top gradually. In down dip direction of Wenjisang area may develope continuous tight oil and gas reservoirs in Lower Jurassic.     

鄂尔多斯盆地下寺湾地区长7储层特征研究

鄂尔多斯盆地下寺湾地区油气资源丰富,而三叠系长7油层组发育大段烃源岩,有利于页岩气成藏。以地质学理论为指导,通过对下寺湾地区岩心资料、测井资料及文献调查,对鄂尔多斯盆地下寺湾地区长7段储层的地化特征、岩石学特征和孔隙特征进行研究。结果表明:研究区长7段泥页岩有机成熟度较高、空隙结构以粒间孔,粒内孔为主,且孔隙度较低。研究结果为鄂尔多斯盆地下寺湾地区长7段储层勘探开发提供依据。     

THE OLIGOCENE–MIOCENE MENILITE FORMATION IN THE UKRAINIAN CARPATHIANS: A WORLD‐CLASS SOURCE ROCK

This study investigates the hydrocarbon potential of Oligocene–Miocene shales in the Menilite Formation, the main source rock in the Ukrainian Carpathians. The study is based on the analysis of 233 samples collected from outcrops along the Chechva River in western Ukraine in order to analyse bulk parameters (TOC, Rock‐Eval), biomarkers and maceral composition. In Ukraine, the Menilite Formation is conventionally divided into Lower (Lower Oligocene), Middle (Upper Oligocene) and Upper (Lower Miocene) Members. The Early Oligocene and Early Miocene ages of the lower and upper members are confirmed by new nannoplankton data. The Lower Menilite Member is approximately 330 m thick in the study area and contains numerous chert beds and turbidite sandstones in its lower part together with organic‐rich black shales. The shales have a high content of silica which was probably derived from siliceous micro‐organisms. The TOC content of the shales frequently exceeds 20 wt.% and averages 9.76 wt.%. HI values range between 600 and 300 mgHC/gTOC (max. 800 mgHC/gTOC). The Middle Member contains thin black shale intervals but was not studied in detail. The Upper Member is about 1300 m thick in the study area and is composed mainly of organic‐rich shales. Chert layers are present near the base of the Member, and a prominent tuff horizon in the upper part represents a volcanic phase during shale deposition. The member grades into overlying molasse sediments. The average TOC content of the Upper Menilite succession is 5.17 wt.% but exceeds 20 wt.% near its base. Low T_max and vitrinite reflectance measurements for the Lower (419°C and 0.24–0.34 %R_r, respectively) and Upper (425°C and 0.26–0.32 %R_r, respectively) Menilite Member successions indicate thermal immaturity. Biomarker and maceral data suggest a dominantly marine (Type II) organic matter input mixed with varying amounts of land‐plant derived material, and indicate varying redox and salinity conditions during deposition. Determination of the Source Potential Index (SPI) shows that the Menilite Formation in the study area has the potential to generate up to 74.5 tons of hydrocarbons per m². The Chechva River outcrops therefore appear to have a significantly higher generation potential than other source rocks in the Paratethys realm. These very high SPI values for the Menilite Formation may explain why a relatively small area in Ukraine hosts about 70% of the known hydrocarbon reserves in the northern and eastern Carpathian fold‐thrust belt.     

柴达木盆地阿尔金东段基岩气藏盖层特征及控藏机制

基于对阿尔金山前东段古近系岩心相、测井相、地震相等分析，发现该地区古近系沉积早期发育一套区域性含膏盐岩盖层。该套含膏盐岩盖层岩性主要为膏质泥岩、含膏泥岩等，纯膏盐发育较少。含膏盐岩盖层发育特征表现为纵向主要分布于路乐河组底部，横向主要发育于尖北、坪西、东坪、牛中等4个局部厚度较大区，且含膏盐岩盖层整体厚度自尖北斜坡区向牛东方向具有逐渐减薄趋势。该地区多类型含膏盐岩的形成及分布特征主要受古近系沉积前的古地貌条件及路乐河组沉积时期的古物源条件、古气候条件联合控制。经综合研究发现该套含膏盐岩盖层的发育程度与油气分布具有良好的匹配关系：含膏盐岩盖层累计厚度较大时，下伏基岩地层油气藏富集，形成构造、岩性、地层油气藏；盖层累计厚度较小时，含膏盐岩盖层相对缺乏，油气向浅层逸散，形成古近系局部盖层和构造控制的多层系构造油气藏。该研究提出阿尔金东段路乐河组含膏盐岩盖层发育特征有效控制气藏纵横向富集规律，并为柴达木盆地下步煤型气有利区预测指明方向。     

松辽盆地南部孤店断陷火石岭组烃源岩评价及预测

烃源岩识别是油气有利目标预测的基础，对致密砂岩油气藏的钻探部署具有重要的指导作用。通过对松辽盆地南部孤店断陷深层烃源岩的有机质丰度、有机质类型和有机质成熟度进行评价，认为孤店断陷火石岭组烃源岩在有机地球化学特征上总体属于好烃源岩。生烃演化分析认为，火石岭组烃源岩处于生烃演化的过成熟阶段，主要生成以甲烷为主的天然气。结合岭深1井热演化史分析，火石岭组烃源岩属于有效烃源岩，是孤店断陷深层重要的天然气来源。对比单一利用三维地震资料、地震属性和波阻抗反演等方法进行烃源岩层识别的优缺点，提出运用波阻抗和瞬时相位相叠合的方法对烃源岩层进行识别更准确。运用此方法对孤店地区烃源岩层进行了精细解释和分析，预测了火石岭组烃源岩的分布范围。     

塔里木盆地哈拉哈塘地区二叠系火成岩体对下伏地层地震成像影响

塔里木盆地哈拉哈塘地区二叠系发育大规模火山活动，为准确了解厚层火山岩对下伏地层地震成像的影响，在实际钻测井资料及三维地震资料的基础上，建立寒武系—白垩系简化地质模型，并采用有限差分法求解弹性波波动方程，开展波动方程正演模拟，真实还原地震成像过程，明确二叠系火成岩体对下伏地层地震成像的影响，以期对哈拉哈塘地区古生界油气勘探开发起到一定的借鉴作用。结果表明：高速、高密度的二叠系英安岩对下伏地层地震成像有屏蔽作用，下伏地层反射波振幅强度相对于覆盖区外围明显减弱；由于岩性的横向突变，致使其下伏地层的地震成像形态发生明显变形及构造异常，而并非断裂带或火山通道的地震响应；杂乱反射带及火成岩下伏区域奥陶系大型缝洞集合体波场复杂，成像速度较难准确求取，存在偏移假象，“串珠状”地震反射难以收敛。