共查询到20条相似文献，搜索用时 199 毫秒
1.
CO_2-原油体系混相状态的渗流特性 总被引：1，自引：0，他引：1
为认识混相状态的CO2在油藏中的渗流特征,利用高温高压三维模拟装置对CO2-地层原油体系在油藏环境条件下的混相驱替过程进行研究.实验发现:模型产出液量与注入量存在较大差异;采收率、含水和气油比曲线亦表现出CO2在孔隙介质中渗流的复杂特征.由实时监测的含水饱和度分布场图分析认为:CO2与原油混相后,流体粘度降低、渗流阻力减小,这是提高采收率的重要原因之一;同时,CO2/原油相与部分接触水能形成近似于三相混相的状态.实验研究还表明CO2以高密度气体形式进入饱和水、饱和油无法进入的微孔隙,这是注入量和产出量不一致的主要原因. 相似文献
2.
长堤油田桩11块是位于济阳坳陷沾化凹陷长堤断裂带东侧的一个自西向东倾斜的鼻状构造,其馆下段为一强底水驱动的岩性构造层状普通稠油油藏,以水平井开发为主。本文以岩心、测井以及多种分析测试资料为基础,建立了油藏精细地质模型,以动态分析和数值模拟为手段,建立底水稠油油藏水平井开发效果评价标准,对油藏开发效果进行评价,分析影响开发效果的主要因素,为改善该块整体的生产效果,提高原油采收率打下基础。 相似文献
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胡状集油田胡12块沙三中层状、中渗、严重非均质性油藏目前处于"高含水、低采出"阶段。研究表明主力油层严重水淹,改变了储层渗流特征,形成优势渗流通道,导致注入水产生无效循环,驱油效率下降,开发效益变差。为了改善开发效果,研究优势渗流通道形成的门槛,是识别与评价优势渗流通道,并进一步刻画其空间分布,探讨其对剩余油分布控制的关键。利用胡12块沙三中87小层概念地质模型,通过油藏数值模拟方法,模拟计算了87小层优势渗流通道产生的时机(下限或门槛),并进一步利用实际注水井组的已知生产、监测及地质资料分析获得优势渗流通道的认识与采用数值模拟方法获得的认识进行了对比。结果表明,建立在87小层精细油藏描述、表征和概念建模基础上的油藏数值模拟研究是优势渗流通道研究的有力手段。 相似文献
4.
本文以辽河油田某断块油藏为研究对象,基于室内实验,结合正交设计试验,以提高原油采收率程度为评价指标,开展了稠油油藏注超临界CO_2驱影响因素研究,并分析了不同变量对注超临界CO_2驱油效率的影响权重。结果表明:CO_2驱油效率随渗透率、气体注入量、油藏温度的增加而增加,随原油粘度的增加而降低,其中:渗透率对原油采收率的影响程度最大,其次是原油粘度、气体注入量、油藏温度、压力。最后,本文总结并分析了我国注CO_2驱油提高原油采收率技术存在的主要问题,并提出拟解决措施。 相似文献
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根据低渗裂缝性砂岩油藏的储层特征,建立适合裂缝性砂岩油藏渗流的等效连续介质模型;通过实验得出有效压力改变对储层孔隙度、渗透率影响的规律;考虑低渗透油藏渗流时启动压力梯度和低渗储层的流-固耦合特性,将渗流力学与弹塑性力学相结合,建立起适合低渗透油藏的流-固耦合渗流数学模型,并给出其数值解.在黑油模型和弹塑性有限元程序的基础上,编制了计算低渗透油藏流-固耦合渗流的计算软件.通过数值模拟和不考虑流-固耦合时的计算结果相比,可以看出低渗油藏中流-固耦合效应十分明显. 相似文献
7.
研究了辽河油田静17块油藏高黏原油流体性质及其对开采效果的影响.静17块油藏具有含蜡量高(22.56%～40.68%)、凝固点高(44～59°C)、黏度大、屈服值小等特点.凝固点随着含蜡量的增加而逐渐上升,例如当含蜡量大于10%,凝固点高于35°C,含蜡量为40%时,凝固点约为54°C.黏度随温度升高而降低,如温度为40°C时,黏度为1.343 7×109 mPa·s,温度为60°C时,黏度为1.094 9×102 mPa·s.利用油藏数值模拟方法研究了不同注水温度开采条件下,5口水平井的产量变化.结果表明,注水温度为60°C时,其产油量比注水温度为20°C时的产油量提高了20%～30%.由实验结果得知,60°C是一个重要的临界温度,在这个温度以上,原油呈牛顿流体状态,蜡晶不会析出,黏度明显降低.因此,保持油藏地层温度高于60°C,降低流体黏度,是提高采收率的一个重要条件. 相似文献
8.
强非均质油藏注水开发过程中随着水洗程度的加深．高渗层水淹严重，低渗层无法动用或动用程度较低，油层平面及纵向动用差异日益增大，严重影响注水开发效果．以强非均质油藏板9断块为例，针对油藏本身的流体特性及注水开发特点，从油、气、水三相渗流达西运动方程和物质守恒角度出发，建立了该断块油藏三维三相渗流数学模型．优化设计合理的网格系统以及算法组合对该断块进行了数值模拟研究，准确描述剩余潜力分布．有针对性的提出综合治理措施．使开发效果得到明显改善，为同类断块油藏的开发提供指导和借鉴。 相似文献
9.
动态预测油藏有效应力的三维弹塑性有限元模型 总被引：2，自引：0，他引：2
本文根据油藏应力与渗流相互作用的耦合机理,建立了一个用于油藏有效应力动态预测的三维弹塑性模型。该模型强调了油藏在注采交变载荷作用下应力与渗流的力学耦合效应,以及油藏岩石弹塑性变形的力学特性,并采用弹塑性增量有限元法求解,最后给出了算例. 相似文献
10.
复杂断块油藏数值模拟新思路 总被引：6，自引：0，他引：6
油藏数值模拟是油田开发的重要手段 ,但复杂断块油藏的模拟难度很大。通常将油藏作为一个整体进行模拟 ,不能准确反映地下地质情况和生产历史 ,拟合程度相对较差。笔者在对孤东油田七区这个复杂断块油藏进行数值模拟的基础上 ,提出了模型建立和动态拟合的新思路。应用这条思路 ,在七区的数值模拟方面取得了较好的效果。1 模型建立复杂断块油藏在开发后期 ,已收集到丰富的动态地质资料 ,建立了比较精细的三维地质模型。计算机数值模型的建立可反映这些精细地质特征 :( 1)微构造图的加载。人工控制的微构造图比通过井点直接勾画的构造图更能… 相似文献
11.
Numerical modelling of the dynamic process of oil displacement by water in sandstone reservoirs with random pore structures 
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下载免费PDF全文 In order to maintain the production rate of a reservoir and improve the displacement efficiency, it is crucial to have an in-depth understanding of the process of oil displacement by water. However, with respect to the conceptualization of porous media of a reservoir, very limited efforts have been made to the pore structures inside the reservoirs. In this paper, the pore structures of a sandstone reservoir were generated by using the method of random growth algorithm. Based on the randomly generated model, a theoretical model to describe the dynamic process of oil displacement by water in the sandstone reservoir was established, and then corresponding numerical modelling was performed. The effects of the displacement velocity, the viscosity ratio of oil-water phase and the porosity of reservoirs on the displacement performance were also analyzed. Results show that due to a great difference in the viscosity between oil and water phases, the moving interface of water phase is not uniform, and the viscous fingering occurs, tending to proceed along the direction with the minimum flow resistance. There is not a linear relationship between the displacement velocity and the displacement efficiency. Too high displacement velocities do not lead to much better displacement efficiency, while a higher pressure drop is caused.Choosing a proper displacement velocity is indispensable in practical engineering. A lower oil-water viscosity ratio is more favorable to obtain high displacement efficiency. Under the present simulation conditions, when the viscosity ratio is 1.2, the displacement efficiency reaches 96.2% at a moderate Reynolds number. The porosity is not a sole factor determining the displacement performance. Even for the same porosity, the shape and length of preferential flow paths are different and randomly distributed,causing a different displacement performance. A large tortuosity tends to result in a low hydraulic conductivity and displacement efficiency. 相似文献
12.
In the development of oil and gas reservoirs, the transport of miscible fluids in porous rocks is a key issue for oil and gas recovery. The simplified unidirectional flow model is employed to investigate the effects of the viscosity ratio on dispersion in semi-infinite homogenous media. The viscosity is supposed to be unsteady due to changing component concentration over time. In cases of both a viscosity ratio larger and less than 1, the pollutant concentration and flow velocity are computed at different initial conditions and viscosity ratios. The analytical solutions are then developed by introducing new variables and transforming the equation governing advection–diffusion equation in semi-infinite homogeneous media with a continuous source. A comparison of the numerical solution with the analytical solution revealed a similarity over 98%, highlighting the usability of the analytical solution. If the viscosity ratio is larger than 1, flow velocity declines exponentially and concentration attenuates with transporting time. In addition, the timescale plays a significant role and the effects become more prominent in long-term transport. In the case of a viscosity ratio less than 1, both the timescale and viscosity ratio variables have little influence on the changing speed of the concentration profile. This work helps to predict the position and the time required to reach the harmless pollutant concentration when monitoring fracturing fluids transportation into groundwater system and would be especially useful in designing and interpreting laboratory experiments studying the miscible flow. 相似文献
13.
INTRODUCTIONThe distribution of remaining oil is often de-scribed qualitatively .The remaining oil distributedinthe whole reservoir is calculated according to thecharacteristics of the space distribution of the satura-tion of remaining oil . Logging data are required toaccomplish this . However , many such projects can-not be completed.This method of studyingremainingoil distribution cannot be quantified efficiently and isunable to provide an effective quantitative forecast ofthe distribu… 相似文献
14.
G. Asadollahfard A. Khodadi N. Javadifar 《Journal of the Geological Society of India》2013,82(6):712-718
Soil pollution by crude oil is a challenging environmental issue for oil producing countries. Several methods have been developed for remediation of the contaminated soil including washing with different detergents. In this work, we applied UTCHEM simulator model to the sand columns polluted by 10000 and 30000 ppm of crude oil which was treated with 0.05, 0.1 and 0.2 wt% of a biological detergent, saponin. The results showed a good agreement between simulated and pilot study. The maximum remediation was 61% with a pH of 9 when we utilized 0.2 wt% saponin for the column contaminated with 30000 ppm of crude oil. 47% remediation was achieved with a pH of 9 when 0.1wt% of detergent was applied to the same column. Sensitivity analysis indicated an increase in remediation by increasing the pH with the optimum pH of 11. The best possible concentrations of surfactant solutions were 0.1 and 0.2 wt% for 10000 and 30000 ppm pollution, respectively, resulting in crude oil removal efficiencies of 69% and 72%, respectively. Simulation results also indicated that an increase in the permeability of the sand columns would also result in an increased remediation. 相似文献
15.
水平井含水率上升影响因素 总被引：1，自引：1，他引：0
利用塔里木油田塔中4油田(TZ4)底水油藏相关的地质、流体数据建立数值模型。在所建模型的基础上,应用数值模拟计算的累积产油、产水和产液量回归俞启泰水驱特征曲线,以反映水平井见水特征的参数b。以参数b为研究对象,采用正交试验的方法研究不同因素对b值的影响,筛选影响水平井见水特征的主要因素,认为原油粘度、油层厚度、非均质性及水平井水平段在油藏中的位置是影响水平井含水上升趋势的主要指标。最后建立主要因素与b值的关系式,结合俞启泰曲线b值图版,提出预测水平井见水规律的公式——图版法(F-b法)。应用F-b法对塔里木水平井含水率进行预测,并与其他相关方法及实际生产数据对比,认为F-b法可作为预测塔里木油田水平井含水率、估算可采储量的一种有效方法。 相似文献
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核磁共振在孔南官195断块剩余油挖潜中的应用 总被引：2，自引：1，他引：1
大港油田孔南官195断块单井日产能力较低,层间层内矛盾恶化,部分油组水淹严重,剩余油分布规律认识不清.利用核磁共振技术,从微观角度研究不同流动单元的驱油特点和剩余油分布特点.研究发现:I类流动单元样品驱油效率比Ⅱ类流动单元高7.47%,但Ⅱ类流动单元样品水驱后聚合物驱油效率提高6.35%,剩余油主要分布于油层动用程度差的流动单元中.在完善注采系统基础上,挖潜时对I、Ⅱ类流动单元通过层间卡封和堵水调剖挖掘中上部剩余油,对Ⅲ、Ⅳ类流动单元采取补孔、打新井方式提高储量动用程度.采取一系列挖潜措施后,预计官195断块最终采收率将能提高5.1%. 相似文献
18.
Reusable, reticulated, polyurethane foams are broadcast at sea, absorb oil in the presence of water, are recovered, oil removed and foam particles rebroadcast. Combining dimensional and mathematical analysis with experimental data, a mathematical model of foam sorption efficacy and rate is developed showing the system to be practical. Oil viscosity, wave height, recovery ship speed, and system geometry influence foam selection. 相似文献
19.
Recovery from incompletely water-wet fractured reservoirs can be extremely low. A reason for the low recovery is related to
wetting issues, whereas the reason for slow recovery can be the non-equilibrium behavior of capillary pressure. One of the
non-equilibrium theories is developed by Barenblatt et al. and it modifies both capillary pressure and relative permeabilities.
The other theory is developed by Hassanizadeh et al. and it only deals with non-equilibrium effects for capillary pressure.
To incorporate non-equilibrium in larger-scale problems, we apply homogenization to derive an upscaled model for fractured
reservoirs in which the non-equilibrium effects are included. We formulate a fully implicit three-dimensional upscaled numerical
model. Furthermore, we develop a computationally efficient numerical approach to solve the upscaled model. We use simulations
to determine the range of delay times and capillary-damping coefficients for which discernable effects occur in terms of oil
recovery. It is shown that at low Peclet numbers, i.e., when the residence time of the fluids in the fracture is long with
respect to the imbibition time, incorporation of delay times of the order of few months have no significant effect on the
oil recovery. However, when the Peclet number is large, the delay times reduce the rate of oil recovery. We discuss for which
values of the delay time (Barenblatt) and capillary-damping coefficient (Hassanizadeh), significant delays in oil production
occur. 相似文献
20.
Xavier Raynaud Knut-Andreas Lie Halvor Møll Nilsen Atgeirr Rasmussen 《Computational Geosciences》2016,20(3):495-507
Polymer injection is a widespread strategy in enhanced oil recovery. Polymer increases the water viscosity and creates a more favorable mobility ratio between the injected water and the displaced oil. The computational cost of simulating polymer injection can be significantly reduced if one splits the governing system of two-phase equations into a pressure equation and a set of saturation/component equations and use a Gauss–Seidel algorithm with optimal cell ordering to solve the nonlinear systems arising from an implicit discretization of the saturation/component equations. This approach relies on a robust single-cell solver that computes the saturation and polymer concentration of a cell, given the total flux and the saturation and polymer concentration of the neighboring cells. In this paper, we consider a relatively comprehensive polymer model used in an industry-standard simulator, and show that, in the case of a discretization using a two-point flux approximation, the single-cell problem always admits a solution that is also unique. 相似文献