共查询到19条相似文献，搜索用时 356 毫秒
1.
NMR技术评价油田高温堵剂调剖效果 总被引：1，自引：0，他引：1
开采稠油的主要方式是注蒸汽，其中包括蒸汽驱和蒸汽吞吐，随着蒸汽吞吐的次数增加，稠油的采出量依次递减。由于油层的非均质性严重，蒸汽首先进入高渗层，高渗透地层的稠油首先被采出，低渗透率地层采出很少，之后的蒸汽都进入高渗低层，即产生汽窜，所谓的低效蒸汽，蒸汽冷凝后形成热水，受到重力作用进入底部油层，降低了蒸汽的利用率；同时，由于蒸汽的重力履和沿高渗透地层窜流，使蒸汽在地层中的波及系数降低。为了克服蒸汽驱中的问题，国内外学者进行了大量的研究。通过注入一种流体－调剖剂，由于它的高粘度高渗透层后，将减少高渗通道的渗透率，消除“汽窜”，封堵高渗透地层，提高中低渗透油层的动用程度，提高原油产量和采收率。本文利用核磁共振成像（NMR）无损检测技术，对蒸汽驱SAD－□型高温调剖剂进行岩心动态评价实验，考察该调剖剂的热稳定性以及堵剂的封堵效果。 相似文献
2.
利用核磁共振技术对致密砂岩储层不同渗透率级别基质岩心和裂缝基质岩心不同驱替压力下CO2驱油特征进行了研究,简述核磁共振原理及实验方法。表明:致密砂岩储层特低、超低渗透基质岩心在初始CO2驱替压力下,岩心毛细孔隙和微毛细孔隙区间的油不同程度被采出,随着CO2驱替压力增大,特低、超低渗透基质岩心毛细孔隙区间油的采出程度不断增加且累积采出程度不同。裂缝致密砂岩储层岩心,裂缝和毛细孔隙区间的油在初始CO2驱替压力下,岩心裂缝中的油及毛细孔隙中的部分油被驱替出来,CO2驱替压力提高毛细孔隙、微毛细区间油的采出程度和累积采收程度较小。致密砂岩储层特低、超低渗透基质岩心和裂缝致密砂岩储层岩心,随着CO2驱替压力增大毛细孔隙区间的部分剩余油成正比增加进入到微毛细孔隙区间改变储层剩余油分布。核磁共振技术能够深入研究致密砂岩储层CO2不同驱替压力阶段,岩心裂缝、毛细孔隙区间、微毛细孔隙区间油的采出程度和剩余油分布情况,对于研究致密砂岩储层微观驱油机理具有较重要的价值。 相似文献
3.
新疆油田砾岩油藏储量规模大,其岩性变化迅速,非均质性强、孔隙结构复杂,开采难度较大.目前,砂砾岩油藏经过几十年的注水开发,已处于高含水开采阶段.聚合物驱油技术对于砂砾岩油藏的进一步开发意义重大.本研究基于计算流体力学方法和数字岩心技术建立了一套模拟聚合物驱油的方法,实现了包含油驱水、水驱油、聚合物驱油和后续水驱四个过程的聚合物驱全过程模拟.利用该模拟方法,直观地展示出了油、水、聚合物在驱替过程中的变化,给出了压力、速度等物理场的动态变化,分析了水驱油及聚合物驱油过程中的流动规律.利用该方法可以方便地模拟多种条件下的聚合物驱油过程,进而优化聚合物驱的开发方案.该研究在砾岩油藏的聚合物驱开发中具有重要的应用意义. 相似文献
4.
利用X—CT研究大庆油田双重介质裂缝和砂岩孔隙度 总被引：1，自引：0，他引：1
采用Ｘ－ＣＴ图象分析技术以研究双重介质的砂岩裂缝和孔隙度，对于稳产开采石油是很有价值的。Ｘ－ＣＴ法测量双重介质也隙度的优越性在于利用图象分析技术可以分别给出裂缝和砂岩的孔隙度，它同移重方法和核孔隙计测量的数据对比，是一种精度高，直观，无损伤的实验技术，Ｘ－ＣＴ测量双重介质孔隙度可给出孔隙度的分布，这有利于了解和预测残余油的分布。 相似文献
5.
本文应用核磁共振成像技术,在均值、非均值模型中研究了复合剂驱油动态实验过程。观察及分析了复合剂驱油特征和效果,对复合剂驱油段塞前缘进行了实时跟踪,得到了复合剂驱油段塞前缘油墙的形成及剩余油分布与运移的二维图像,给出了复合剂驱油后,剩余油的饱和度分布曲线。实验表明:在层状非均值地层中,若渗透率差异大,复合剂段塞主要进入高渗层,而波及不到低渗层,即复合剂波及效率低。若渗透率差异小,复合剂段塞大部分进入高渗层,有少部分进入低渗层,即复合剂波及效率较高。 相似文献
6.
温度对聚合物的粘度和稳定性有很大影响。注聚合物井的井下温度分布影响因素分析对改善注聚合物方案和研究注聚合物驱油效果具有重要意义。假定聚合物溶液为非牛顿幂律流体,在柱坐标系中构建了包含井筒、注入层和围岩等3部分介质的二维温度场模型,将模型离散化生成有限差分方程并求解。在对经不同注入时间和停注时间后的二维温度分布模拟计算的基础上,分析了注入聚合物溶液的密度、导热系数、比热容、井筒半径等因素对井下温度分布的影响。分析表明,这些因素对井下温度分布均有不同程度的影响,应注意综合考虑。 相似文献
7.
利用核磁共振二维谱、在线测试技术,建立了扩散-弛豫二维谱技术分析岩心含油饱和度的方法;对不同井的不同层段岩心进行了不同驱替速度水驱油的核磁共振在线测试,通过对比不同时刻测试的核磁共振T2图谱的面积值和分布特征,计算不同孔隙区间油的采出程度,分析评价不同孔隙对整体采出程度的贡献率、水驱油效果以及剩余油状况。实验结果表明,TK150井油层段实验岩心水驱大、中孔隙对采出程度的贡献较大,弱水淹段实验岩心水驱大、中、小孔隙对采出程度的贡献较大。但大孔隙所占总孔隙比例小,所以采出程度相比油层段岩心较低。TK960井油层段实验岩心水驱大、中孔隙对采出程度的贡献较大,中水淹段实验岩心水驱中、小孔隙对采出程度的贡献较大,强水淹段实验岩心水驱大、中孔隙对采出程度的贡献较大。不同井的不同层段岩心水驱油后所有尺度的孔隙中都有剩余油分布。 相似文献
8.
针对胜利油田罗家地区以构造裂缝为主、与断层关系密切的特点,本文采用地震资料相干分析和方差分析技术,力求精细而准确地确定该区目的层的断裂系统;提出了地震吸收系数分析技术,期望为确定目的层段的裂缝发育分布提供重要的证据;利用全方位地震信息进行AVA、VVA方法的研究,可望定量地得到目的层段的裂缝方位和密度分布情况;针对AVA和VVA技术的不足,采用了不同方位角阻抗的变化来检测裂缝发育情况的IPVA方法.实例分析表明,该套泥岩裂缝储层勘探方法取得了良好的效果,在泥岩裂缝油气藏定量检测方面获得了重要进展. 相似文献
9.
《地球物理学进展》2017,(2)
致密油储层历经多重地质作用,储集体类型多样、尺度不一、分布离散、岩性混杂,常规建模不能有效刻画其内部复杂性.针对其发育不同尺度孔隙、复杂天然/人工缝网的特点,本文提出以致密砂岩储层微观孔隙结构表征、天然/人工裂缝的识别与描述技术为基础,集不同尺度孔隙、不同尺度天然/人工裂缝于一体的地质建模方法,即基于压汞资料,将孔隙型基质储层分级,相控随机模拟储层分布模型;以地震资料为主,结合蚂蚁体等技术,人机交互、确定性模拟大-中尺度天然裂缝;以测井解释小尺度、薄片鉴定微尺度天然裂缝为基础,地震参与随机模拟裂缝发育密度体,采用示性点过程法随机模拟小尺度与微尺度天然裂缝;以微地震资料为主,确定性加随机性综合模拟不同尺度人工压裂缝.以新疆吉木萨尔凹陷某油田开发先导试验区芦二段上甜点为例,按上述方法建立致密油藏模型,突出致密油藏特点,为数值模拟提供了高精度的多重介质油藏模拟静态模型. 相似文献
10.
《应用地球物理》2016,(1)
裂缝预测在致密油气、煤层气、页岩气等非常规油气勘探中起着十分重要的作用。本文将裂缝分成大(大于1/4波长)、中(1/4~1/100波长)、小(远小于1/100波长)三种尺度类型开展综合预测研究。基于多尺度岩石物理正演模拟技术,分析区分中等尺度裂缝的叠前方位各向异性敏感属性,结合地质、测井和地震属性大尺度裂缝预测方法和岩心薄片观测小尺度裂缝预测,形成了一套综合地质岩心信息、成像测井解释和地震信息的多尺度裂缝综合预测方法。该方法通过岩心裂缝描述和成像测井解释,分析得到裂缝发育控制因素,再通过应力场构造模拟,完成区域性大尺度裂缝发育控制因素研究。利用叠后几何类属性进行大尺度裂缝预测,结合叠前衰减属性进行中等尺度裂缝预测,以及岩性统计学反演和断层叠合结果,验证中等尺度裂缝与岩性、断层的对应关系,明确了中尺度裂缝成因。通过岩心电镜扫描,分析小裂缝发育状况,最后综合三类裂缝研究成果分析储层裂缝发育状况。通过对某实际工区灰岩储层的裂缝发育情况进行综合预测研究,结果表明文中提出的多尺度裂缝预测基础理论方法和多尺度裂缝预测技术流程,能够较好地解决裂缝预测的强非均质性、多尺度问题,综合地质、测井和地震多信息裂缝多尺度预测技术能够实现裂缝性油气藏的储层描述和甜点预测。 相似文献
11.
首次将先进的无损检测NMRI成像技术引入煤层中气水两相运移的研究领域,将自主设计研制的、可同时改变围压、轴压和孔隙压的、非磁性聚碳酸酯材料制成的三轴渗透仪置于NMRI成像仪磁体腔中,通过气驱水和水驱气NMRI试验 实时观测了气水流动规律.主要以水驱气NMRI试验为例,详细介绍了核磁共振三轴渗透仪和型煤试件的研制,并重点阐述了水驱气试验过程和相关参数,利用NMRI技术实时观测得到了不同时间沿驱替方向型煤试件水平剖面的NMRI成像图,最后对试验结果进行了比较分析,揭示了一些新的规律认识：(1)水驱替前缘具有不一致性,从NMRI试验角度验证了前人甲烷类气体赋存形式主要以吸附在孔隙内表面为主的重要结论;(2)煤试件存在优势驱替路径,且这种优势路径在驱替过程中基本保持不变,水驱气的优势驱替路径易产生在煤试件边缘,即煤孔隙裂隙发育区;(3)水驱流量变化决定了水驱前缘的运移速度,且对水驱气效果具有滞后效应;(4)水驱气初次驱替效果好于二次驱替效果;(5)水驱替气的顺序为：主要大裂隙—周边裂隙—周边孔隙. 相似文献
12.
针对鄂尔多斯盆地陕北斜坡长6特低渗透储层受聚合物泥浆伤害,微电极电阻率曲线在渗透层上的正幅度差异不明显,直观指示油气层和水层的深、中,浅探测电阻率在常规储层的有序排列基本消失.通过注聚合物泥浆驱替前后岩石电阻率与孔隙度及含水饱和度实验关系分析,驱替后岩样电阻率显著增大,岩样电阻率随含水饱和度增大而减小的基本规律不复存在.归纳其岩性系数a、电阻率系数b比驱替前大得多,饱和度指数n由正变负,反映出注聚合物泥浆驱替破坏了储层孔隙结构及其基本特征,测井中造成了范围较小的高侵和特高侵地层电阻率带.从而提出在较为致密的低渗砂、致密砂聚合物泥浆伤害储层中,利用微电极负差异及其电阻率曲线不规则增高变化划分特低渗透油层有效厚度,并以实例阐明了利用岩电实验参数变化评价特低渗透储层的方法. 相似文献
13.
长江下游仪征河段处于枯季潮流界的上边界,揭示其汊道分流属性及滩槽联动演变机制,对河势控制工程及深水航道工程实践具有重要意义.本研究收集了1955—2021年水文泥沙及地形等资料,在汊道分流关系及调整成因上:世业洲右汊的分流属性为枯水倾向型汊道,即低流量时期分流比大于高流量时期;1959—2021年期间,世业洲右汊分流比经历了“稳定-下降-上升”的调整过程,上游河段滩槽格局调整及流域来沙减少引起的汊道间不均衡冲刷是分流关系调整的主因;流域流量过程调整、河道崩岸等综合影响引起1959—2017年期间世业洲右汊分流比为减小态势,航道工程实施起到了调控汊道关系的功能,世业洲右汊分流比为增加态势.在滩槽联动演变关系上:仪征河段进口段以展宽为主,世业洲左汊展宽程度大于右汊,左汊河床形态变化与进口段滩槽形态的一致性关系优于右汊,即上游进口段滩槽演变、流域来沙量减少等综合作用会加速了左汊发展;2015年南京以下12.5 m深水航道二期工程建设以来,工程区域淤积且洲体完整性增强,且深槽冲刷及河槽容积增大,表明航道工程已实现汊道分流关系及滩槽调控的功能. 相似文献
14.
Mohamed I.M. Darwish John E. McCray Peter K. Currie Pacelli L.J. Zitha 《Ground Water Monitoring & Remediation》2003,23(2):92-101
Remediation of dense nonaqueous phase liquids (DNAPLs) is recognized as one of the most difficult problems associated with ground water pollution. The pump-and-treat technique, usually consisting of a continuous operation of extraction-injection wells, is widely used for ground water remediation. In a stratified or otherwise heterogeneous aquifer, however, this technique suffers from tailing and rebound problems, which limit its cleanup efficiency and result in higher operation costs. The tailing and rebound is usually due to slow diffusion of contaminants out of lower- permeability heterogeneities into the flow regime of the higher-permeability zone. In this study, we conduct bench-scale experiments to investigate a novel polymer system and injection method to improve the pump-and-treat technique for DNAPL trapped in a layer of porous media that has a relatively low permeability compared to the surrounding media. This technique might be useful, for example, to remove DNAPL from these low-permeability zones after removal of DNAPL from the higher-permeability zones by a more traditional remediation method. The polymer system consists of a mixture of anionic and cationic polyacrylamides in solution and the injection method is based on flow-induced polymer adsorption, called bridging adsorption. The study includes single and parallel-column experiments. The measured polymer penetration depths were compared with values predicted from a numerical simulation, which was developed previously by the authors of this paper. The experiments and simulations show that the polymer injection leads to a modification of the permeability contrast that favors a more efficient pump-and-treat process. These results suggest that additional research to upscale the technology to pilot scales is warranted. 相似文献
15.
Xiaorong Luo 《Earth and Planetary Science Letters》2002,201(2):431-446
Natural hydrofracturing caused by overpressure plays an important role in geopressure evolution and hydrocarbon migration in petroliferous basins. Its mechanism is quite well understood in the case of artificial hydraulic fracturing triggered by high-pressure fluid injection in a well. This is not so for natural hydraulic fracturing which is assumed to initiate as micro-cracks with large influence on the permeability of the medium. The mechanism of natural hydraulic cracking, triggered by increasing pore pressure during geological periods, is studied using a fracturing model coupled to the physical processes occurring during basin evolution. In this model, the hydraulic cracking threshold is assumed to lie between the classical failure limit and the beginning of dilatancy. Fluid pressure evolution is calculated iteratively in order to allow dynamic adjustment of permeability so that the fracturing limit is always preserved. The increase of permeability is interpreted on the basis of equivalent fractures. It is found that fracturing is very efficient to keep a stress level at the rock’s hydraulic cracking limit: a fracture permeability one order of magnitude larger than the intrinsic permeability of the rock would be enough. Observations reported from actual basins and model results strongly suggest that natural hydraulic cracking occurs continuously to keep the pressure at the fracturing limit under relaxed stress conditions. 相似文献
16.
Timo Christian Kessler Alessandro Comunian Fabio Oriani Philippe Renard Bertel Nilsson Knud Erik Klint Poul Løgstrup Bjerg 《Ground water》2013,51(5):692-705
Sand lenses at various spatial scales are recognized to add heterogeneity to glacial sediments. They have high hydraulic conductivities relative to the surrounding till matrix and may affect the advective transport of water and contaminants in clayey till settings. Sand lenses were investigated on till outcrops producing binary images of geological cross‐sections capturing the size, shape and distribution of individual features. Sand lenses occur as elongated, anisotropic geobodies that vary in size and extent. Besides, sand lenses show strong non‐stationary patterns on section images that hamper subsequent simulation. Transition probability (TP) and multiple‐point statistics (MPS) were employed to simulate sand lens heterogeneity. We used one cross‐section to parameterize the spatial correlation and a second, parallel section as a reference: it allowed testing the quality of the simulations as a function of the amount of conditioning data under realistic conditions. The performance of the simulations was evaluated on the faithful reproduction of the specific geological structure caused by sand lenses. Multiple‐point statistics offer a better reproduction of sand lens geometry. However, two‐dimensional training images acquired by outcrop mapping are of limited use to generate three‐dimensional realizations with MPS. One can use a technique that consists in splitting the 3D domain into a set of slices in various directions that are sequentially simulated and reassembled into a 3D block. The identification of flow paths through a network of elongated sand lenses and the impact on the equivalent permeability in tills are essential to perform solute transport modeling in the low‐permeability sediments. 相似文献
17.
提出了纵向非均匀、饱含液体多孔介质孕震动力学方程组的数值解法。为了考虑非弹性效应，对该方程组采用增量形式求解。提供了当存在垂直力源和纵向非均匀时，定量分析研究垂直剖面上的地震孕育过程及其前兆变化机制的方法和软件。选用了一个饱含液体的双层地壳模型，运用所研制的软件计算分析了介质孔隙度、渗透率等地壳水动力学性质对前兆场的影响。研究发现，孕震介质孔隙度的大小对前兆场的分布可以产生显著影响。孔隙度较大时，非弹性体积膨胀（前兆）的出现和变化一开始仅局限于断层附近区域，同时非弹性膨胀（前兆）持续的时间（前兆持时）占总孕震时间的比率较大；孔隙度较小时，非弹性体积膨胀除在紧靠断层的区域内孕震早期会出现非弹性膨胀（前兆）外，在离断层较远的区域内早期也会出现前兆异常。介质渗透率对前兆场的影响主要表现在：当其它条件完全相同，仅介质渗透率不同时，较低的渗透率会推迟前兆异常的发生，同时使前兆异常首先在断层附近出现，然后向外扩展，并且使孕震过程变长；而当渗透率较高时，前兆异常一开始便会展布在断层周围及其远离断层的较大范围内。 相似文献
18.
Porosity, permeability, and fluid flow in the Yellowstone geothermal system, Wyoming 总被引：3，自引：0，他引：3
Patrick F. Dobson Timothy J. Kneafsey Jeffrey Hulen Ardyth Simmons 《Journal of Volcanology and Geothermal Research》2003,123(3-4):313-324
Cores from two of 13 U.S. Geological Survey research holes at Yellowstone National Park (Y-5 and Y-8) were evaluated to characterize lithology, texture, alteration, and the degree and nature of fracturing and veining. Porosity and matrix permeability measurements and petrographic examination of the cores were used to evaluate the effects of lithology and hydrothermal alteration on porosity and permeability. The intervals studied in these two core holes span the conductive zone and the upper portion of the convective geothermal reservoir. Variations in porosity and matrix permeability observed in the Y-5 and Y-8 cores are primarily controlled by lithology. Y-8 intersects three distinct lithologies: volcaniclastic sandstone, perlitic rhyolitic lava, and non-welded pumiceous ash-flow tuff. The sandstone typically has high permeability and porosity, and the tuff has very high porosity and moderate permeability, while the perlitic lava has very low porosity and is essentially impermeable. Hydrothermal self-sealing appears to have generated localized permeability barriers within the reservoir. Changes in pressure and temperature in Y-8 correspond to a zone of silicification in the volcaniclastic sandstone just above the contact with the perlitic rhyolite; this silicification has significantly reduced porosity and permeability. In rocks with inherently low matrix permeability (such as densely welded ash-flow tuff), fluid flow is controlled by the fracture network. The Y-5 core hole penetrates a thick intracaldera section of the 0.6-Ma Lava Creek ash-flow tuff. In this core, the degree of welding appears to be responsible for most of the variations in porosity, matrix permeability, and the frequency of fractures and veins. Fractures are most abundant within the more densely welded sections of the tuff. However, the most prominent zones of fracturing and mineralization are associated with hydrothermal breccias within densely welded portions of the tuff. These breccia zones represent transient conduits of high fluid flow that formed by the explosive release of overpressure in the underlying geothermal reservoir and that were subsequently sealed by supersaturated geothermal fluids. In addition to this fracture sealing, hydrothermal alteration at Yellowstone appears generally to reduce matrix permeability and focus flow along fractures, where multiple pulses of fluid flow and self-sealing have occurred. 相似文献
19.
K. E. Martel R. Martel R. Lefebvre P. J. Gélinas 《Ground Water Monitoring & Remediation》1998,18(3):103-113
The use of surfactant solutions for the in situ recovery of residual NAPL in aquifers is increasingly considered as a viable remediation technique. The injection of a few pore volumes of high concentration surfactant solutions can mobilize most of the residual NAPL contacted by the solutions. However, the washing solutions'physico-chemical properties (low density and high viscosity), combined with the natural porous media heterogeneity, can prevent a good sweep of the entire contaminated volume. From the petroleum industry, it is well-known that polymer solutions can be injected following a surfactant solution slug to act as a mobility buffer and increase the overall sweep efficiency. The objective of our laboratory study is first to select and characterize polymers that would be suitable for aquifer restoration. Our experiments showed that among several polymers, xanthan gum solution rheology was made in order to predict shear rates, xanthan gum concentrations, salinity, and temperature effects on solution viscosity. The second set of experiments were made with a sand box which was designed to reproduce a simple heterogeneous media consisting of layers of sand with different permeability. These tests illustrate the xanthan gum solution's ability to increase surfactant solution's sweep efficiency and limit viscous fingering. The tests established that: (1) the injection of xanthan solution behind a surfactant solution slug decreases fluid velocity in high permeability layers and increases it in low-permeability ones, thus increasing the sweep efficiency (2) xanthan solutions eliminate viscous fingering at the polymer/surfactant solution front; (3) a xanthan solution preflush is desirable to limit surfactant solution mobility and prevent surfactant adsorption on solids; and (4) depending on site heterogeneity injection strategies should be applied to limit overriding by low-density surfactant solution. 相似文献