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1.
昆北油田切12井区E_3~1主要是一套近源且位于不整合面上的辫状河三角洲相沉积,岩性主要为含砾砂岩和砂砾岩,由于受沉积环境、成岩作用、构造等因素的影响,岩性复杂、成熟度低、分选差、孔隙结构具有多重性、有效储层与非有效储层混杂、储层非均质性极强,因此,采用了更精细的岩石物理相对储层非均质性进行了研究。以岩性资料、测井资料及其解释成果为基础,选取了反映沉积、成岩、构造作用的自然伽马、自然电位、声波时差、密度和裂缝孔隙度5个参数,运用加权平均法计算了反映岩石物理相的综合评价系数。在此基础上,采用逐点岩石物理相综合评价系数,运用变异系数法对储层非均质性进行了计算,按照变异系数值大小将工区储层非均质性分为3类:第Ⅰ类弱非均质性,变异系数≤0.2;第Ⅱ类中等非均质性,变异系数在0.2～0.4之间;第Ⅲ类强非均质性,变异系数0.4。根据这个标准对储层平面非均质性进行了评价。 相似文献
2.
油井开采过程中油层变形的流固耦合分析 总被引：7，自引：0，他引：7
在油气开采过程中,随着油气的不断采出,必然造成孔隙流体压力的逐渐降低,由此导致储层岩石骨架的有效应力增大,使得油层产生变形或压实。当油层产生变莆或压实时,对油气生产将造成不利影响。比如：使得油藏的渗透率降低,继而使油井的产能降低,同时,油层的变形直接影响着油井和套管的变形与破坏等等。敢开采过程中油层的变形可以描述为三维变形与三维流体流动场的耦合问题,利用可变形多孔介质中流体渗流的流固耦合有限元数值 相似文献
3.
油气储层流动单元研究综述 总被引：19，自引：8，他引：11
流动单元是垂向及横向上连续的、影响流体流动的、岩石物理性质相似的储集岩体。其概念的内涵大体经历了从沉积相单元到岩石相单元再到岩石物理相单元等不同阶段,流动单元的划分体现了定量描述和评价油气储集层非均质性的新思路和新方法。划分流动单元的新方法具体包括：①根据断层、隔层、夹层、渗透率韵律、层理、裂缝、孔隙结构等控制流动单元边界的成因分类法;②沉积岩相划分法;③以地质研究为主的储层层次分析法;④利用流动层段指标（FZI）、压汞曲线上进汞饱和度达35g时的孔喉半径（Rss）等参数值的岩石微观孔隙结构法;⑤利用渗流系数、存储系数、净与毛厚度比的分类法;⑥利用振幅、波阻抗属性的地震属性分析法。其中前3种以宏观地质、沉积岩相及岩石方法为主;第4,5种方法以微观、定量的岩石物理参数为主要依据;第6种基本上属于间接方法。根据储层流动单元法建立的三维储层非均质模型为油田开发提供了新的可靠的地质依据。 相似文献
4.
5.
《地球科学进展》2020,(4)
页岩气的规模开采已逐步实现高产和稳产,作为替代能源弥补油气能源短缺成为可能。页岩储层致密,微纳米孔发育,具有吸附解吸特征和扩散、滑脱效应。同时天然裂缝、层理等发育,水平井体积压裂后水力裂缝不规则扩展,具有多场耦合跨尺度流动效应。其产能预测困难且不确定性大,制约着页岩储层的高效开发和评价。考虑页岩气多尺度多重输运特征,综述了基于双重介质模型、多重介质模型以及复杂缝网模型的页岩气水平井产能预测数值模型的研究发展现状。认为双重介质和多重介质产能模型均弱化了页岩储层压后开采时复杂缝网系统提供的庞大的可渗流面积和通道,不能综合表征页岩气全尺度多重耦合运输特征。而基于复杂缝网的页岩气水平井产能预测数值模型提供了多尺度流动嵌入的缝网系统,解决流动系统性的同时又精确表征了各尺度流动。产能可靠预测需要获得符合储层地质特征、岩石力学行为、高压流体冲击流固耦合作用机理的复杂缝网形态表征。缝网表征是页岩气水平井产能预测的关键。 相似文献
6.
《物探化探计算技术》2017,(4)
以传统岩石物理实验研究低孔、低渗、高复杂性孔隙结构储层的宏观岩石物理性质,不仅成本高、周期长、误差大且难以定量研究储层微观因素对岩石物理属性的影像规律。通过Micro-CT扫描与高级成像处理技术,构建与真实岩心相等价的精确代表性孔隙空间模型,利用Avizo-XLab求解器数值模拟计算以N-S为控制方程的孔隙流体流动及以达西定律计算岩石渗流参数。通过计算结果的可视化处理,以三维流线展示孔隙空间流体流动,以高度梯度图展示孔隙压力分布场,使模拟结果清晰直观。研究表明,基于数字平台仿真孔隙微流动及测量岩石渗流参数具有高可信度。该研究方式弥补了传统岩石物理实验的不足,为数字化研究岩石物理属性提供借鉴。 相似文献
7.
辽河油田兴隆台太古界古潜山储层评价标准研究 总被引：1，自引：0，他引：1
兴隆台古潜山是辽河坳陷中重要的深层潜山油藏,对提高辽河油田原油产量具有重要意义。兴隆台太古界潜山主要
储层由变质岩和岩浆岩组成,其中变质岩储层包括黑云斜长片麻岩、黑云母变粒岩、斜长角闪岩、角闪岩和混合岩。储集
空间以构造裂缝为主,储层渗透性好。在测井曲线对储层敏感因素分析的基础上,选用现有测井资料中带有裂缝信息的电
阻率、声波时差、密度、自然电位幅度差和双侧向等测井数据,应用测井交会图方法,结合试油工作的结果,寻找规律,
得出了针对兴隆台古潜山储层进行定量及定性识别和评价的标准,即：岩石密度＜2.75 g/cm3
,自然电位幅度差≥7 Ω·m,
双侧向幅度差20~1 500 Ω·m,深侧向电阻率20~2 000 Ω·m,声波时差170~230 μs/m。通过生产测井解释数据进行了验证,
证明上述储层评价标准基本适用,为兴隆台古潜山油井调层提供了理论基础。 相似文献
8.
《中国煤炭地质》2020,(6)
为了深入探讨应力场、裂隙场、渗透场三场耦合条件下的压裂缝延伸规律。首先基于有效应力原理,考虑煤储层应力敏感性,建立了动态渗透率计算模型;其次,考虑相应的滤失系数动态变化对裂缝扩展的影响,基于PKN模型建立了改进的压裂缝延伸模型,并进行实际单井的应用及分析;最后,运用ABAQUS软件模拟滤失系数动态条件下应力演化规律与压裂缝延伸过程,并将理论值与数值模拟值进行对比分析。结果表明,压裂缝延伸过程中储层渗透率变化最大,增大了约22.25倍;滤失系数次之,增大了约7.03倍;孔隙度变化最小,增大了约2.02倍,而裂缝延伸距离随压裂时间的增长而增长,但前期增长较快,后期基本趋于稳定,当压裂时间为60min,压裂缝延伸距离为141.23m,与数值模拟结果(132.8m)较为吻合,从而验证了模型的正确性,研究成果可为实际施工控制提供理论依据。 相似文献
9.
为了解马岭油田南二区延9油藏长期注水后储层特征的变化及产生机理,通过室内物理模拟实验方法,结合矿场2口检查井取心分析结果,研究了注水前后储层物性、孔喉特征和渗流特征的变化。结果表明:长期注水后,由于注入水对储层的作用主要集中在孔隙的喉道部分,储层渗透率明显增大,孔隙度增加较小;储层物性的增加主要与水洗后粘土矿物含量的降低、水洗程度、储层初始渗透率大小和裂缝的开启有关,其中裂缝开启对储层物性的影响最显著;水洗后储层岩石表面油膜脱落,岩石润湿性由亲油性变为亲水性。以上综合作用的结果使油水两相流动能力增强、两相区范围变宽,水驱油效率增大。可见马岭油田南二区延9油藏注水开发中储层的变化有利于油田开发。 相似文献
10.
青西凹陷下白垩统下沟组是该区致密油的主要储集层,本次研究通过普通薄片和铸体薄片观察以及高压压汞等分析测试手段,从岩石学特征、储集空间类型以及孔隙结构特征等方面剖析下沟组致密泥云岩储层特征。结果表明:1)下沟组储层岩石类型以深灰色一灰色纹层状泥质白云岩和白云质泥岩为主,泥级斜长石含量较高,增大了储层岩石脆性,易于产生裂缝;2)泥云岩储层储集空间多样,既有原生孔隙,也有因构造和溶蚀作用形成的构造微裂缝和溶蚀缝洞;3)泥云岩储层的孔隙度和渗透率较低,属于低孔低渗储层,不同岩性之间储层物性差别较大;4)高压压汞测试结果显示:排驱压力和中值压力较高,孔喉半径较小,整体表现出孔隙结构差、非均质性强的特点;5)根据孔隙结构均质系数E_p将研究区储层分为3类:Ⅰ类储层E_p1.29,储层孔喉分选好,孔隙结构非均质性弱;Ⅱ类储层,1.29E_P1.79,孔喉分选较好;Ⅲ类储层E_p1.79,储层孔喉分选差。 相似文献
11.
A new laboratory set-up for measurements of electrical, hydraulic, and osmotic fluxes in clays 总被引：4，自引：0，他引：4
Katja Heister Pieter J. Kleingeld Thomas J.S. Keijzer J.P. Gustav Loch 《Engineering Geology》2005,77(3-4):295-303
If clays are subjected to flows of fluid, electrical charge, chemicals, or heat, in most cases, flows of different types occur simultaneously, even if only one driving force is acting. These are so-called coupled flows. Examples of coupling phenomena are streaming potential and electroosmosis, induced by the flows of fluid and electrical charge, respectively.
Since the 1960s, laboratory devices have been constructed to measure streaming potentials and/or electroosmosis in clays or clayey soils. Due to their mechanical and hydraulic properties, clays are not easy to work with. Consequently, laboratory devices have to deal with various complications. A new design for an experimental set-up is proposed. Contrary to earlier devices, the clay sample is mounted in a flexible wall permeameter, which avoids sidewall leakage caused by the possible swell or shrink of the clay. Gold-coated gauze electrodes completely cover the surfaces of the sample, which are in contact with the solution reservoirs that ensure one-dimensional flow. In addition, the thickness of the sample is monitored during the experiment. The chemical composition of the reservoir fluids is controlled during the experiment. The device is flexible with respect to changing the solutions of both reservoirs independently, applying different hydraulic gradients, and measuring or applying electrical potentials. Finally, it is possible to mount undisturbed clay samples in the set-up, keeping them in situ during the whole experiment.
With this set-up, an extensive program of measurements of coupling phenomena like streaming potentials, electroosmosis, and membrane potentials in a sodium montmorillonite is started. Preliminary results of streaming potential measurements are presented and demonstrate that the build-up of a streaming potential due to a hydraulic gradient is a reproducible process that influences the water flow through the clay, and that the extent of the streaming potential depends on the salt concentration of the permeating solution. 相似文献
12.
In an attempt to detect streaming potentials induced by subsurface water flows, we have observed the horizontal electric field (self-potential) variations across stationary electric dipoles near geothermal wells in the Takinoue geothermal area, Japan. We observed variations of self-potential which seem to be associated with the water flows in the aquifer, induced by turning on and off the flow of the wells. Amplitudes of the variations are 3–5 mV across 60–200 m dipoles, and can be explained well with a proposed electrokinetic model: the streaming potential coefficient of − 15 mV/bar and/or the ζ-potential of −50 to −100 mV in the aquifer are appropriate to explain the observed data by the model. The obtained electrokinetic coupling coefficients are in situ ones and determined for crustal rock-water system under high temperature (˜200°C) condition. The present results, together with a laboratory study by Ishido and Mizutani (1981), give fundamental information on electrokinetic coupling coefficients in the earth's interior, and are very important when we make quantitative interpretations of self-potentials generated by geothermal activity on the basis of electrokinetic effects. 相似文献
13.
优势渗流通道的形成会影响油藏注水开发的效果,如何判别与预测优势渗流通道成为研究重点。本文提出了基于
开发流体势场的蚁群算法预测优势通道的方法,认为开发流体势场包括位能、压能、动能及界面能,流体在油藏内部分
布的差异,决定了油藏内部流体势能大小的差异。将蚁群算法理论引入到油藏开发中,提出了以流体势场为基础的蚁群算
法模型。在东河1油田进行运用,在建立油藏流体势模型的基础上,对过井流体势剖面进行了蚁群算法模拟。在模拟初
期,受层内流体势分布差异性影响,不同韵律小层内部高浓度信息素的分布存在差异,即优势通道分布存在差异。在模拟
后期,受层间流体势分布差异性影响,高浓度信息素主要集中在CIII2-2、3-1和3-2小层,即在这些小层中优势通道较发
育,运用动态资料进行验证,效果较好。 相似文献
14.
《Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy》2000,25(4):329-332
The streaming potential due to fluid flow in rocks was measured on saturated sandstones. During triaxial failure test, the electrokinetic coupling coefficient was increased at about 72–86% of the failure stress. This increase is thought to be due to an increase of the macroscopic zeta potential in the shear zone where new surfaces are created and connected, allowing fluid to flow through these new cracks. The streaming potential variations could therefore be used as a precursor of the rupture. Measurements were also performed on volcanic samples, with the aim of using electrokinetic phenomena to monitor volcanic activity. Streaming potential was found to depend on the transport properties i. e., permeability and formation factor. Theoretical consideration suggest that such a dependence should be caused by surface conductivity, but this is not the case here. 相似文献
15.
有效应力对裂缝型低渗透砂岩油藏压力响应的影响 总被引：6，自引：4，他引：2
为了研究裂缝孔隙型低渗油藏中流体在双重介质之间的渗流规律及其影响,建立了双重介质间流体窜流的数学模型,并利用拉氏变换数值反演方法给出近似解析解;通过数值计算,研究窜流压力的动态特征,分析储容系数及窜流系数对压力响应的影响;通过压敏试验研究了有效应力对双重介质低渗油藏渗流能力的影响。研究结果表明：储容系数主要决定双重介质之间发生窜流现象的早晚,储容系数越大,发生窜流的时间越晚;储容系数越小,发生窜流的时间越早。窜流系数主要决定双重介质之间发生窜流压力的大小,窜流系数越大,发生窜流的压力越小;窜流系数越小,发生窜流的压力越大。有效应力对裂缝型低渗透油藏的渗流能力影响很大,有效应力的增加能够大大降低裂缝型油藏渗透率和孔隙度,以致降低储层的储容系数和窜流系数,从而影响双重介质间窜流压力的动态特征。因此,在裂缝型低渗透砂岩油藏开采中,保持压力、防止储层伤害是非常重要的。 相似文献
16.
为了获取非饱和带水流过程的信息,借助流动电位正演模型,通过数值实验探讨非降雨和降雨两种条件下非饱和带流动电位和水流过程的关系,然后用南京中山植物园试验场地野外观测的流动电位和张力数据加以对比和验证。野外试验表明:流动电位可以有效地反映非饱和带水流过程。在夏季无降雨入渗的条件下,日周期变化的地表地下温度差导致水分的运动,流动电位准确地指示了非饱和带含水量和毛细压力的变化情况,从而指示出了水分运移的方向;在夏季有降雨入渗的条件下,降雨锋面推进之处,含水量和流动电位同时有明显的响应,进而根据不同位置的流动电位对降雨入渗响应的时刻差,直接求出入渗锋面的推进速度。 相似文献
17.
Based on the theory of double-porosity, a novel mathematical model for multiphase fluid flow in a deforming fractured reservoir is developed. The present formulation, consisting of both the equilibrium and continuity equations, accounts for the significant influence of coupling between fluid flow and solid deformation, usually ignored in the reservoir simulation literature. A Galerkin-based finite element method is applied to discretize the governing equations both in the space and time domain. Throughout the derived set of equations the solid displacements as well as the fluid pressure values are considered as the primary unknowns and may be used to determine other reservoir parameters such as stresses, saturations, etc. The final set of equations represents a highly non-linear system as the elements of the coefficient matrices are updated during each iteration in terms of the independent variables. The model is employed to solve a field scale example where the results are compared to those of ten other uncoupled models. The results illustrate a significantly different behaviour for the case of a reservoir where the impact of coupling is also considered. © 1997 by John Wiley & Sons, Ltd. 相似文献
18.
Modeling semi-steady state near-well flow performance for horizontal wells in anisotropic reservoirs
This paper presents a novel methodology to model semi-steady state horizontal well flow performance in an anisotropic reservoir taking into account flow in the near-well region for an arbitrary well trajectory. It is based on an analytical productivity model describing coupled axial reservoir flow and radial well inflow. In order to apply this model in an anisotropic reservoir, the permeability field relative to the radial direction perpendicular to the well trajectory and the axial direction along the well trajectory must first be determined. A classical space transformation is used in concert with rotational transforms to obtain a virtual isotropic model. The transformation preserves the volumes and pressures. It is not a novel concept, but different from previous approaches in the sense that it is only applied in the near-well domain to formulate an equally isotropic media. As a result, the use of this virtual isotropic model requires the Dietz shape factor for an ellipse, transformed from the original cylindrical near-well domain. The Dietz shape factors are determined numerically in this research. The semi-steady state well/near-well model is implemented in a numerical simulator incorporating formation anisotropy and wellbore hydraulics. The specific productivity index along the well trajectory is generated using the virtual configuration. Numerical results for different anisotropy ratios and also incorporating frictional losses in the well are presented. Furthermore, the well/near-well model is applied in coupling with streamline reservoir model for a water flooding case. This appears to be the first coupling of a well hydraulics model and a streamline simulator. It presents the application of the well/near-well model in integrated reservoir simulation in an efficient and accurate manner. The results demonstrate that the coupling approach with a streamline reservoir model and the well/near-well is of great potential for advanced well simulation efficiently. 相似文献
19.
缝洞型油藏大尺度可视化水驱油物理模拟实验及机理 总被引：1，自引：0，他引：1
缝洞型碳酸盐岩油藏由于其缝洞组合关系的复杂性,使得储层流体的渗流规律有别于常规油藏。根据某油田奥陶系缝洞型碳酸盐岩的实际情况设计制作了大尺度可视化物理模型,并按照现场实际设计了二注三采的实验井网及注采方案,以应用物理模拟实验来研究缝洞型碳酸盐岩油藏的开发特征及油井生产规律。结合实验结果,利用J.Cruz-Hernández建立的数学模型对生产数据进行拟合,以研究缝洞型碳酸盐岩油藏中流体的渗流机理,J.Cruz-Hernández数学模型中的空间系数和流动速度对采收率影响较大,提出模型的改进应考虑重力分异作用、溶洞比例等影响因素。 相似文献
20.
Shale gas production has gradually achieved high and stable output, which makes it possible to make up for the shortage of oil and gas energy as an alternative energy source. Shale reservoir is compact, with well-developed nano-pore, and has the characteristics of adsorption and desorption, diffusion and slippage. At the same time, there are a large number of natural cracks, bedding and foliation. Hydraulic fractures expand irregularly after volume fracturing in horizontal wells. The whole system has multi-field coupling and cross-scale flow effects. Productivity prediction of shale gas is difficult and uncertain, which restricts the efficient development and evaluation of shale reservoirs. In this paper, the development status of productivity numerical models for shale gas horizontal wells is reviewed in consideration of the multi-scale transport characteristics of shale gas. These models include dual media capacity models, multiple media capacity models, and complex seam productivity models. It is considered that the dual medium and multi-media productivity models weaken the large permeable flow area and channel provided by the complex seam network system after shale reservoir lamination, and cannot comprehensively characterize the full-scale coupled transport characteristics of shale gas. The numerical model for productivity prediction of shale gas horizontal wells based on complex fracture network provides a multi-scale flow embedded fracture network system, which solves the problem of systematic flow without losing the ability to accurately characterize each scale flow. It is necessary to obtain the complex fracture network morphological characterization which conforms to reservoir geological characteristics, rock mechanical behavior and fluid-solid coupling mechanism. Fracture network characterization is the key to the productivity prediction of shale gas horizontal wells. 相似文献