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151.
Advances in photogrammetry have eased the acquisition of high-resolution digital information from outcrops, enabling faster, non-destructive data capturing and improved reservoir modeling. Geocellular models for flow dynamics with in the virtual outcrop in siliciclastic deposits at different sets of sandstone facies architecture remain, however, a challenge. Digital maps of bedding, lithological contrast, spatial-temporal variations of bedding and permeability characteristics make it more easy to understand flow tortuosity in a particular architecture. An ability to precisely model these properties can improve reservoir characterization and flow modeling at different scales. Here we demonstrate the construction of realistic 2 D sandstone facies based models for a pragmatic simulation of flow dynamics using a combination of digital point clouds dataset acquired from LiDAR and field investigation of the Sandakan Formation, Sabah, Borneo.Additionally, we present methods for enhancing the accuracy of outcrop digital datasets for producing high resolution flow simulation. A well-exposed outcrop from the Sandakan Formation, Sabah, northwest Borneo having a lateral extent of 750 m was chosen in order to implement our research approach. Sandstone facies and its connectivity are well constrained by outcrop observations, data from air-permeability measurements, bilinear interpolation of permeability, grid construction and water vector analysis for flow dynamics.These proportions were then enumerated in terms of static digital outcrop model(DOM) and facies model based on sandstone facies bedding characteristics. Flow simulation of water vector analysis through each of the four sandstone facies types show persistent spatial correlation of permeability that align with either cross-bedded orientation or straight with more dispersion high quality sandstone(porosity 21.25%-41.2%and permeability 1265.20-5986.25 mD) and moderate quality sandstone(porosity 10.44%-28.75% and permeability 21.44-1023.33 mD). Whereas, in more heterolithic sandstone(wavy-to flaser-bedded and bioturbated sandstone), lateral variations in permeability show spatially non-correlated patterns over centimeters to tens of meters with mostly of low quality sandstone(porosity 3.4%-12.31% and permeability < 1 mD to 3.21 mD). These variations reflect the lateral juxtaposition in flow dynamics. It has also been resulted that the vertical connectivity and heterogeneities in terms of flow are mostly pragmatic due to the interconnected sandstone rather than the quality of sandstone.  相似文献   
152.
正20140890 Bai Ru(National Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China);Zhang Jingong Characteristics of Pore Character and Its Controls of Chang 6Reservoir of Zhiluo Oilfield(Journal of Northwest University,ISSN1000-274X,CN61-1072/N,  相似文献   
153.
应用录井、测井、地质和地震资料,研究了松辽盆地南部月亮泡地区上白垩统姚家组萨尔图油层Ⅰ砂组的沉积微相,并采用沿层地震属性分析技术,分析了河道砂体的展布特征,利用拟合分析进行验证,结果表明萨尔图油层Ⅰ砂组沉积相为三角洲前缘亚相,其微相类型有水下分流河道、河口坝和分流间湾,已有的勘探成果也证实水下分流河道砂体是油气的有利聚集区,结合构造发育情况,预测了松辽盆地南部月亮泡地区构造岩性油气藏勘探的有利区带  相似文献   
154.
鄂尔多斯盆地镇北地区长3储层微观非均质性的实验分析   总被引:10,自引:0,他引:10  
刘林玉  张龙  王震亮  高潮 《沉积学报》2007,25(2):224-229
油气储层的微观非均质性特征是储层地质学研究的重要内容之一。本文的目的是研究鄂尔多斯盆地镇北地区长3储层微观非均质性特征,研究方法是利用真实砂岩微观模型实验。通过实验发现鄂尔多斯盆地镇北地区长3和储层为致密型砂岩,真实砂岩微观模型实验直观地显示出鄂尔多斯盆地镇北地区长3储层具有很强的微观非均质性,砂岩的成岩作用和孔隙结构是影响本区长3储层微观非均质性的主要原因。在低渗透砂岩中,溶蚀作用引起砂岩产生强烈的非均质性,而这些砂岩则形成长3储层的高渗带。  相似文献   
155.
地洼盆地砂岩铜矿床的构造-流体-成矿体系及演化   总被引:2,自引:0,他引:2  
我国南方地洼盆地构造演化、流体演化和砂岩铜矿成矿作用三者之间具有密切的关系,处于一个统一的系统之中。盆地早中期的裂陷、坳陷作用及热构造活动导致了富铜矿源层的形成、大气降水的深循环和水/岩相互作用、并形成中高温、压、高盐度的热卤水含铜流体。在构造-流体-砂岩铜矿成矿体系的演化中,构造演化制约了含铜流体的演化和砂岩铜矿的成矿作用,而主要发生于盆地演化的晚期。  相似文献   
156.
塔里木盆地志留系沥青砂岩的特性及其成因   总被引:20,自引:0,他引:20  
刘大锰  金奎励 《现代地质》1999,13(2):169-175
采用有机岩石学和有机地球化学相结合的方法,详细研究了塔里木盆地志留系沥青砂岩的特征及其成因。色质分析表明,志留系沥青砂岩含高的三环二萜烷且以C23为主峰,与石炭系源岩不同,γ 蜡烷含量不高,代表藻类生源的β 胡萝卜烷含量较高,且具高孕甾烷、高重排甾烷的特征,反映沥青砂岩油源来自下古生界。有机岩石学研究表明,由于沥青砂岩含可溶性物质甚高,其油浸反射率(Rb为027%~036%)不能反映其真实成熟度,水浸反射率(Rw为135%~153%)与上下地层成熟度相吻合,排除了沥青砂岩“新生古储”的可能性。碳同位素分析结果进一步证实沥青砂岩源自下古生界的生油岩,是早古生代古油藏遭受后期构造破坏的结果。  相似文献   
157.
运用岩石高压三轴加载装置和渗透压加载装置,对砂岩进行固定应力变渗透水压力试验,同时借助SOMATOMPLUS螺旋CT扫描机进行实时观测。通过试验结果分析,推出了基于CT数的岩石空隙率公式,从CT尺度上分析了岩石空隙率、渗透速度、渗流速度、微孔隙直径、渗透率等随渗透水压力的变化规律。结果表明:岩石的渗透参数随渗透压力的增加而增大,渗透参数随渗透压力的变化呈对数关系,这是由于渗透水压力使岩石内部空隙发生变形,这一变形为弹性变形;而渗流速度与渗透水压力呈线性关系,符合宏观尺度渗流的达西定律。   相似文献   
158.
致密砂岩普遍具有低孔、低渗及微裂缝发育的地质特征,并且呈现出很强的非均匀性.致密砂岩储层与常规砂岩储层比较,具有明显的岩石物理性质、渗流力学性质方面的差异.致密砂岩内部的非均匀性对弹性波频散、衰减有显著影响,其中包括孔隙结构的非均匀性,即岩石内部孔隙参数的不均一性,以及孔隙内部不相混溶流体的非均匀分布;此外,非均匀性的尺度也决定了波出现显著频散与衰减的频段.综合考虑致密砂岩孔隙结构非均匀性及流体斑块状饱和的非均匀性,本文采用双双重孔隙介质结构模拟了致密砂岩的弹性波响应,分析了同时具备两类非均质性岩石中的波传播特征.调查分析了两组分别来自中国鄂尔多斯盆地苏里格气田及四川盆地广安气田的不同类型致密砂岩储层的岩芯超声波实验数据,给出了岩石样本的弹性波速度频散与衰减曲线.结果显示理论模型预测结果与完全饱和、部分饱和岩石的实验数据吻合良好.对两个地区致密砂岩岩芯数据进行对比分析,苏里格致密砂岩样本总体上比广安致密砂岩渗透率高,在各孔隙度范围内,特征模拟显示苏里格样本的裂隙尺寸明显大于广安样本.广安致密砂岩在低孔隙度范围内发育了更多、更小的颗粒裂隙/接触.致密砂岩的速度频散与衰减结果受流体黏度、晶体破裂及流体斑块状饱和的共同影响.此外,孔隙度越大,部分饱和岩石中斑块状饱和机制对总衰减的贡献越低,与之相对,结构非均质性所占的比重则有所增强.  相似文献   
159.
We present a comprehensive characterisation of the physical, mineralogical, geomechanical, geophysical, and hydrodynamic properties of Corvio sandstone. This information, together with a detailed assessment of anisotropy, is needed to establish Corvio sandstone as a useful laboratory rock‐testing standard for well‐constrained studies of thermo–hydro–mechanical–chemical coupled phenomena associated with CO2 storage practices and for geological reservoir studies in general. More than 200 core plugs of Corvio sandstone (38.1 and 50 mm diameters, 2:1 length‐to‐diameter ratio) were used in this characterisation study, with a rock porosity of 21.7 ± 1.2%, dry density 2036 ± 32 kg m?3, and unconfined compressive and tensile strengths of 41 ± 3.28 and 2.3 ± 0.14 MPa, respectively. Geomechanical tests show that the rock behaves elastically between ~10 and ~18 MPa under unconfined conditions with associated Young's modulus and Poisson's ratio of 11.8 ± 2.8 GPa and 0.34 ± 0.01 GPa, respectively. Permeability abruptly decreases with confining pressure up to ~10 MPa and then stabilises at ~1 mD. Ultrasonic P‐ and S‐wave velocities vary from about 2.8–3.8 km s?1 and 1.5–2.4 km s?1, respectively, over confining and differential pressures between 0.1 and 35 MPa, allowing derivation of associated dynamic elastic moduli. Anisotropy was investigated using oriented core plugs for electrical resistivity, elastic wave velocity and attenuation, permeability, and tracer injection tests. Corvio sandstone shows weak transverse isotropy (symmetry axis normal to bedding) of <10% for velocity and <20% for attenuation.  相似文献   
160.
To better understand the effect of fluid distribution on the electric response of rocks saturated with oil and brine, we conducted experimental studies on the complex electrical impedance in a Berea sandstone, together with in situ acquisitions of oil distribution images employing a high‐resolution medical X‐ray computed tomography. We performed two tests of brine displacement by oil under high (10 MPa) and low (5 MPa) pressures, which were accompanied by fingering and stable displacement patterns, respectively. The measured complex impedance data were fitted to the Cole model to obtain the resistance, capacitance, peak frequency of the imaginary impedance, and the exponent α of the rock–fluid system. With increasing oil saturation, the resistance showed an increasing trend, whereas the other three parameters decreased. The fingering displacement exhibited lower resistance and capacitance than the stable displacement. The analysis of the resistance changes using a simple parallel connection model indicates that there are more components of residual brine in parallel connections in the fingering pattern than in the stable displacement pattern at the same saturation. We also interpreted the normalised changes in the capacitance (or apparent dielectric constant) with respect to the oil saturation via an analysis of the shape factor of fluid distribution based on the Maxwell–Wagner–Brugermann–Hanai model. The changes in the shape factor suggest that the pinch‐off of the brine in parallel connection by the oil is a dominant mechanism reducing the capacitance. In the stable displacement, most of the connections in the brine phase are immediately pinched off by oil displacement front at a local oil saturation of 65%. Conversely, in the fingering displacement, there is a transition from the bulk or layered brine to the pinched‐off at a local oil saturation below 60%. The analyses indicate that the difference in the fluid distribution under different fluid conditions is responsible for the non‐Archie behaviour.  相似文献   
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