共查询到20条相似文献，搜索用时 500 毫秒
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含水合物沉积物孔隙结构特征分析和微观渗流模拟是水合物研究的基础性、关键性工作,对深入理解沉积物中水合物的分解机理、储层渗流机理和开采机理有十分重要的意义。总结了国内外含水合物沉积物的微观孔隙探测方法,对比分析了多种微观探测技术应用在水合物研究中的技术特点;重点分析了计算机断层扫描(CT)、扫描电子显微镜(SEM)和核磁共振成像(MRI)技术在含水合物沉积物孔隙结构研究中的应用现状;简述了利用微观数值模拟方法进行含水合物沉积物渗流分析的研究进展;在此基础上,展望了含水合物沉积物孔隙特征分析和微观渗流模拟研究的未来方向和挑战。 相似文献
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利用X射线计算机断层扫描系统(CT)获得不同饱和度下含水合物石英砂内部气、水、水合物各相态分布特征,通过有限元方法计算了不同水合物饱和度下石英砂液相渗透率变化,并模拟了流体在孔隙内的流动情况,获得了假定边界条件下孔隙流体的三维流速分布。研究结果表明,随着水合物饱和度的降低,渗透率逐渐增大,其中当水合物饱和度从56%下降到39%时,液相渗透率值增速最大;水合物分解末期,液相渗透率并未随着有效孔隙度的增大而快速升高,通过CT扫描图像显示,部分石英砂孔隙和喉道可见甲烷气泡滞留,由于气体的贾敏效应在一定程度上阻碍了液体的流动,从而导致液相渗透率增速降低。本研究建立了一种基于石英砂内部真实孔隙特征的液相渗透率和液体流速计算方法,可为水合物开采过程中储层微观渗流演化机理研究提供参考。 相似文献
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海坨子油田属于特低渗透裂缝性油藏,其开发实践表明:微裂缝为流体渗流的主要通道,能否准确描述储层中裂缝分布形态,直接关系到油藏开发效果。本文以钻井取心资料、成像测井资料及铸体薄片分析资料为基础,对海坨子油田储层中微裂缝的形成机理、形态及产状特征进行了研究,得到了裂缝描述的详细参数,并形成了一套适用于该类型油藏微裂缝系统描述及有效识别的方法。以此为基础,利用随机建模的方法,建立了海坨子油田海21-4试验区微裂缝的分布DFN模型,预测了裂缝的分布密度、分布方位及裂缝大小,为油藏数值模拟双重介质模型的建立提供了基础。 相似文献
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海上吸力锚负压下沉渗流场的特性分析 总被引：4，自引：1，他引：4
采用8结点等参元的有限元方法，对海上吸力锚负压沉贯过程中锚体周围土体的渗流场进行了数值计算与分析，并给出了渗流场相关要素的计算方法，如水头、等势线、渗流力、渗流速度和渗流量等。通过对实例的分析，计算结果和结论令人满意，为吸力锚的设计等现实应用提供了依据。 相似文献
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海洋沉积地质过程模拟:性质与问题及前景 总被引：3，自引：0，他引：3
高抒 《海洋地质与第四纪地质》2011,(5):1-7
探讨了海洋沉积地质数值模拟的功能问题.地球科学研究以正演方法(以数值模拟为代表)和反演方法(以地层记录分析为代表)的结合为特征.数值模拟作为一种重要的研究工具,具有获得过程和机理分析结果、形成工作假说、指导现场观测和采样的作用.与此同时,在正反演交融中模型本身也得到了提高和完善.在海洋沉积地质领域,数值模拟在沉积物输运... 相似文献
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为了研究波浪与抛石潜堤相互作用过程中大自由表面变形和堤内渗流等强非线性紊流运动问题,利用改进的MPS法,建立了模拟波浪与抛石潜堤相互作用的MPS法数值计算模型。模型将抛石潜堤假定为均质多孔介质,采用Drew的二相流运动方程描述多孔介质内外的流体运动;通过在动量方程中增加非线性阻力项,并引入亚粒子尺度紊流模型,模拟波浪与可渗结构物相互作用过程中的紊流运动。选取“U”型管中多孔介质内渗流过程和孤立波与可渗潜堤相互作用两个典型的渗流问题,通过将数值计算结果与理论解和实测值的对比分析,对所提出的MPS法紊流渗流模型的模拟精度进行验证。结果表明:基于改进的MPS法构建的垂向二维紊流渗流模型可以很好地再现“U”型管中多孔介质内渗流以及波浪作用下可渗潜堤内外的复杂流场,显著缓解流-固界面处的压力震荡与粒子分布不均匀问题,实现了较高的模拟精度。 相似文献
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本文应用有限元数值分析方法求解了不规则波作用下抛石基床上圆柱墩底部的渗流力.抛石基床内的渗流阻力采用了非线性的Forchheimer方程,同时还考虑了基床以外海床土内的渗流特性.为了验证所得到的数值解,进行了模型试验,两者吻合良好.应用所编程序,进行了大量计算以研究一些主要参数的影响.文中还对不规则波与规则波作用下渗流力的比值作了较为深入的分析,对此比值得到了一个可供工程实际应用的简化计算模式,从而可以简化不规则波作用下渗流力的计算. 相似文献
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基于管长龙等（１９９５ａ,ｂ）的扩展本征矢方法,提出了可用于入射波和反射波共存浪场能量方向分布的估计方法,并给出了直接计算反射率的公式。数值模拟结果表明,此方法大大改善了原有方法的估计精度,计算得到的反射率在一定范围内与实际符合 相似文献
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储层孔隙结构是影响低渗储层微观孔隙内流体运移与聚集的主要因素,决定了储层的优劣。以w11－7油田流沙港组三段储层为例,应用压汞资料定性与定量研究储层孔隙结构特征。研究结果表明,孔隙结构分为三类,总体上具有“喉道细、分选差、连通性差”的特点,这种较差的孔隙结构发育特征是造成储层呈低渗一特低渗的核心因素。在此基础上应用多元判别方法优选出排驱压力、中值压力、最大孔喉半径、孔喉半径均值、分选系数五类孔隙结构分类评价参数,并结合常规物性将储层分为三类,其中Ⅱ、Ⅲ类是广为发育的储层。 相似文献
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百色盆地东部坳陷中央凹陷带那读组为陆相碎屑岩沉积地层,其储集层具有岩石结构复杂、物性条件差、低孔低渗、非均质性极强等特点,使用传统方法预测其初始产量比较困难。因此从基础资料入手,分析储层特征,并通过研究储层流体性质的响应特征,提出了运用含油指示参数OID与反映孔隙结构的参数m的交会面积方法来预测初始产量。该方法由于综合了影响该地区储层产量的孔隙度、泥质含量、厚度、含油饱和度、渗透率等关键参数,预测精度和直观性有很大的提高,较好实现对那读组致密储层产量的快速预测,实际应用效果十分显著。 相似文献
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Understanding the oil distribution characteristics in unconventional tight reservoirs is crucial for hydrocarbon evaluation and oil/gas extraction from such reservoirs. Previous studies on tight oil distribution characteristics are mostly concerned with the basin scale. Based on Lucaogou core samples, geochemical approaches including Soxhlet extraction, total organic carbon (TOC), and Rock-Eval are combined with reservoir physical approaches including mercury injection capillary pressure (MICP) and porosity-permeability analysis, to quantitatively evaluate oil distribution of tight reservoirs on micro scale. The emphasis is to identify the key geological control factors of micro oil distribution in such tight reservoirs. Dolomicrites and non-detrital mudstones have excellent hydrocarbon generation capacity while detritus-containing dolomites, siltstones, and silty mudstones have higher porosity and oil content, and coarser pore throat radius. Oil content is mainly controlled by porosity, pore throat radius, and hydrocarbon generation capacity. Porosity is positively correlated with oil content in almost all samples including various lithologies, indicating that it is a primary constraint for providing storage space. Pore throat radius is also an important factor, as oil migration is inhibited by the capillary pressure which must be overcome. If the reservoir rock with suitable porosity has no hydrocarbon generation capacity, pore throat radius will be decisive. As tight reservoirs are generally characterized by widely distributed nanoscale pore throats and high capillary pressure, hydrocarbon generation capacity plays an important role in reservoir rocks with suitable porosity and fine pore throats. Because such reservoir rocks cannot be charged completely. The positive correlation between hydrocarbon generation capacity and oil content in three types of high porosity lithologies (detritus-containing dolomites, siltstones, and silty mudstones) supports this assertion. 相似文献
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为了改善注水开发效果差的情况,对无因次等孔隙体积配产配注理论改善注水开发效果的方法进行了研究。针对高30断块油藏,分别使用无因次等孔隙体积法和传统的kh值计算其合理配产配注量,接着采用油藏数值模拟进行了无因次等孔隙体积配产配注法和传统的kh法在该断块油藏注水开发的对比预测。结果表明,相比kh法,无因次等孔隙体积法使油田有效开发时间延长27年,采出程度由22．46％提高到27．94％,提高5．48％,增产原油19．88×10^4t。所以采用无因次等孔隙体积配产配注法比传统kh配产配注法更加符合油藏实际,使有效开发年限更长,最终水驱采收率更高。该方法可以为同类注水开发油藏的合理配产配注提供参考。 相似文献
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为研究海上稠油砂岩油藏水驱开发储层物性变化规律,以渤海海域Z油田为目标,利用多口密闭取心井资料,结合油田生产实际,从储层的黏土矿物、孔隙结构、储集孔渗及渗流特征等方面系统开展了水驱开发前后储层物性变化规律及机理研究。结果表明,经长期水驱开发,储层中黏土矿物总量呈减少趋势,其中高岭石含量降低,伊/蒙混层含量增加;岩石平均孔隙半径增加,孔隙喉道和孔隙结构变好;平均孔隙度和渗透率都有不同程度增大,其中孔隙度增幅不大,渗透率增幅较为明显,储层储集物性变好,但非均质程度增强;润湿性表现为更强的亲水性,驱油效率也随之增高。该研究成果对Z油田高含水期剩余油挖潜和注采结构调整的措施制定有一定的指导意义。 相似文献
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Pore structure is a critical parameter to estimate the reservoir quality and evaluate the resource potential. However, the pore structure and heterogeneity of the unconventional tight oil reservoirs of Permian Lucaogou Formation of Jimusaer Sag, Junggar Basin are not studied well. In this paper, the multifractal analysis based on the NMR T2 distributions was applied to investigate the pore structure and heterogeneity. The reservoir quality index (RQI) and flow zone indicator (FZI) were calculated using porosity and permeability. Two parameters T35 and T50 were newly defined as relaxation times corresponding to the 35% and 50% saturation on the T2 reverse accumulative curve, respectively. The results showed that the RQI, and FZI values were extremely low, and that the NMR T2 distributions of water saturated samples had much short relaxation components with no or little long relaxation components, indicating a complex and poor microscopic pore structure of tight oil rocks. The typical multifractal characteristics, such as the large values of singularity strength range (Δα), revealed that the pore structures of samples were strongly heterogeneous. It was also found that the clay contents have an obvious influence on the multifractal parameters, and the FZI and new defined T35 are two good indicators for heterogeneity of pore structure. In addition, the feasibility and applicability of calculating the multifractal parameters from NMR and other well logs were discussed. 相似文献
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The preservation of good petrophysical properties (high porosity/high permeability) at great depth in carbonate rocks may lead to the existence of a deeply buried reservoir (DBR), a target of interest for the oil industry. One of the key processes controlling diagenesis of the burial environment is Pressure Solution Creep (PSC), an efficient compaction process responsible for the evolution of porosity and permeability in many carbonate reservoirs. In this experimental study, we examine the effect of i) the presence of oil in the pore space and ii) its timing of injection on the PSC process and the petrophysical properties of a carbonate rock. The experiments were performed using a flow-through high-pressure cell, allowing the simulation of the pressure/stresses and temperature conditions of a DBR. Multi-disciplinary data (mechanical, chemical, petrographical and petrophysical) demonstrate that, without oil in the pore space, the main diagenetic process is the PSC, a process reducing by three the initial porosity but having no influence on intrinsic water permeability. An early injection of oil prior to water circulation causes the inhibition of PSC by the coating of the grains, leading to the preservation of porosity. Conversely, a late injection of oil does not preserve initial porosity. The dataset obtained from these experiments show the importance of the timing of oil charging in a reservoir in the preservation of initial porosity at great depth by the inhibition of PSC. However, the coating of grains by hydrocarbons may also inhibit further diagenetic processes leading to a creation of secondary porosity at depth. 相似文献
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为了确保高89-1区块CO2混相驱项目的顺利实施,依据该区块的精细油藏描述成果,在优化适于CO2混相驱模型基础上,建立了符合油藏地质特点的三维地质模型。在此基础上对开发指标进行计算,对五个参数（井网、开发方式、压力水平、注入量和采油速度）进行优化,并提出了推荐方案,预测采收率可达23.10%,比弹性开采方式提高15.16%。 相似文献
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根据在J油田中收集到的X-射线薄片铸体资料、地层水分析资料、覆压校正孔渗分析资料、粒度分析资料、敏感性分析及试油资料等,对区域内的低电阻率油层微观机理进行了分析,认为J油田低电阻率油层的微观形成机理主要为黏土矿物及微孔隙裂缝发育作用,此外润湿性、粒度大小及地层水矿化度作用在研究区内对低阻油层的存在也有一定的影响。 相似文献
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酸化是解除该类储层伤害,恢复、提高油气井产能最主要的手段。对于各种特定的伤害类型若仅采用笼统的酸化措施,往往难以取得理想的增产效果,如何从伤害机理的角度出发对症解除污染是研究者面临的重要课题。NP油田Ed1储层在以往的酸化改造中,由于对钻井泥浆伤害机理认识不够准确,导致酸液选择存在较大的盲目性,严重影响解堵效果。为解决上述问题,提出酸化解堵设计方法,通过泥浆固相粒度和滤液红外波谱分析试验评价,明确了Ed1储层钻井泥浆伤害产生的机理。在此基础上,设计在同一组试验内先模拟泥浆伤害的产生,发现岩心伤害后渗透率降低至基准渗透率的0.12倍,然后比较评价不同类型的酸液解除该类泥浆污染的能力,最终筛选出解堵效果最好的4%多氢酸体系推荐现场施工使用。 相似文献