原油在储层介质中的加水裂解生气模拟实验   总被引：5，自引：2，他引：5  

冯子辉  侯读杰等 《沉积学报》2002,20(3):505-509

采用高温高压热模拟实验方法,开展了原油在砂岩和火成岩储层介质中的加水裂解生气模拟实验研究.结果表明,原油开始大量裂解的温度是400℃,随模拟温度增加,甲烷相对含量增大,乙烷以上重烃气尤其是丙烷相对含量减小.其中砂岩的油水混合物裂解生气主要发生在450～500℃之间,生气窗范围小,对应的烃气产率高,火成岩的油水混合物裂解生气主要发生在450～600℃之间,生气窗范围大,对应的烃气产率小.模拟烃气的组分碳同位素分馏显著,随模拟温度增加呈变重趋势.在裂解生气过程中,水解加氢和催化作用对烃气的组成、产率和碳同位素分布有重要影响。  相似文献   

沉积盆地深部流体的地球化学特征及油气成藏效应初探   总被引：34，自引：0，他引：34  

金之钧  张刘平等 《地球科学》2002,27(6):659-665

以济阳坳陷东营凹陷和塔里木盆地塔中地区为例，在前人深部流体研究的基础上，应用同位素地球化学、有机地球化学及热力学定量模型，对沉积盆地深部流体的活动特征及其油气成藏效应进行了初步的探讨。研究表明，在东营凹陷不仅存在着幔源富二氧化碳流体（H2O＋CO2）的活动，而且还存在着幔源富氢流体（H2O＋CH4＋H2）的活动。塔里木盆地塔中地区也发现了幔源富二氧化碳的活动。深部流体上升过程中热能传递的定量研究表明，幔源流体是良好的热能载体。东营凹陷和塔中地区的有机质异常热变现象证实了深部流体的热效应。有机质热演化生烃不仅需要热，而且是个缺氢的过程，富氢流体注入沉积盆地势必对油气的生成产生影响。加氢热模拟实验结果表明，加氢可大幅度提高烃源岩的产烃率；对腐泥型干酪根而言，加氢生烃效应最显著的阶段是在生烃高峰之后，产率可增加147％以上；腐植型干酪根的加氢生烃效应在各个阶段都较显著。在东营凹陷和塔中地区分别发现了深部流体促进烃源岩生烃的现象。因此，深部流体在能量上和物质上对油气的生成均可构成重要的影响。  相似文献   

DNDC模型对我国旱地N2O释放的拟合对比分析   总被引：5，自引：1，他引：5  

徐文彬  刘广深  洪业汤  LI Changsheng  陈旭晖 《矿物学报》2002,22(3):222-228

本文根据贵州省玉米－油菜轮作田、休耕地和大豆－冬小麦轮作田的N2O释放通量及其影响因子季节变化的是观测结果，对比分析了DNDC模型计算与三试验田田间观测在N2O释放通量及其主要影响因子季节变化上的拟合程度。结果表明，对N2O释放通量、土壤NO3^-和NH4^ 含量、土壤湿度和土温，模型计算结果与田间观测具有相似的季节变化模式和相近的数值，模型较好地反映了上述参数的动态变化过程。据此，推算出贵州省农业土壤N2O年释放量，并分析了气候变化和农业活动对释放量的潜在影响。  相似文献   

地下水数值计算中断层处理的"切割-导通法"   总被引：2，自引：0，他引：2  

牛建立 《煤田地质与勘探》2002,30(5):39-40

从对断层导水性能的分析出发 ,提出了地下水数值计算中断层处理的“切割—导通法” ,既考虑断层侧向导水性 ,又考虑了其垂向导水性 ,更符合断层导水的实际情况 ,也易于描述较大断裂在走向上的导水性差异。  相似文献   

Evaluation of the Reduction in Uncertainty Obtained by Conditioning a 3D Stochastic Channel to Multiwell Pressure Data     

Fengjun Zhang  Albert C. Reynolds  Dean S. Oliver 《Mathematical Geology》2002,34(6):715-742

A stochastic channel embedded in a background facies is conditioned to data observed at wells. The background facies is a fixed rectangular box. The model parameters consist of geometric parameters that describe the shape, size, and location of the channel, and permeability and porosity in the channel and nonchannel facies. We extend methodology previously developed to condition a stochastic channel to well-test pressure data, and well observations of the channel thickness and the depth of the top of the channel. The main objective of this work is to characterize the reduction in uncertainty in channel model parameters and predicted reservoir performance that can be achieved by conditioning to well-test pressure data at one or more wells. Multiple conditional realizations of the geometric parameters and rock properties are generated to evaluate the uncertainty in model parameters. The ensemble of predictions of reservoir performance generated from the suite of realizations provides a Monte Carlo estimate of the uncertainty in future performance predictions. In addition, we provide some insight on how prior variances, data measurement errors, and sensitivity coefficients interact to determine the reduction in model parameters obtained by conditioning to pressure data and examine the value of active and observation well data in resolving model parameters.  相似文献   

Combination of Dependent Realizations Within the Gradual Deformation Method     

Lin Y. Hu 《Mathematical Geology》2002,34(8):953-963

Gradual deformation is a parameterization method that reduces considerably the unknown parameter space of stochastic models. This method can be used in an iterative optimization procedure for constraining stochastic simulations to data that are complex, nonanalytical functions of the simulated variables. This method is based on the fact that linear combinations of multi-Gaussian random functions remain multi-Gaussian random functions. During the past few years, we developed the gradual deformation method by combining independent realizations. This paper investigates another alternative: the combination of dependent realizations. One of our motivations for combining dependent realizations was to improve the numerical stability of the gradual deformation method. Because of limitations both in the size of simulation grids and in the precision of simulation algorithms, numerical realizations of a stochastic model are never perfectly independent. It was shown that the accumulation of very small dependence between realizations might result in significant structural drift from the initial stochastic model. From the combination of random functions whose covariance and cross-covariance are proportional to each other, we derived a new formulation of the gradual deformation method that can explicitly take into account the numerical dependence between realizations. This new formulation allows us to reduce the structural deterioration during the iterative optimization. The problem of combining dependent realizations also arises when deforming conditional realizations of a stochastic model. As opposed to the combination of independent realizations, combining conditional realizations avoids the additional conditioning step during the optimization process. However, this procedure is limited to global deformations with fixed structural parameters.  相似文献   

Numerical Calculation of Equivalent Cell Permeability Tensors for General Quadrilateral Control Volumes     

Chuanping He  Michael G. Edwards  Louis J. Durlofsky 《Computational Geosciences》2002,6(1):29-47

A new method for upscaling fine scale permeability fields to general quadrilateral-shaped coarse cells is presented. The procedure, referred to as the conforming scale up method, applies a triangle-based finite element technique, capable of accurately resolving both the coarse cell geometry and the subgrid heterogeneity, to the solution of the local fine scale problem. An appropriate averaging of this solution provides the equivalent permeability tensor for the coarse scale quadrilateral cell. The general level of accuracy of the technique is demonstrated through application to a number of flow problems. The real strength of the conforming scale up method is demonstrated when the method is applied in conjunction with a flow-based gridding technique. In this case, the approach is shown to provide results that are significantly more accurate than those obtained using standard techniques.  相似文献   

2-D viscoelastic FEM simulation on stress state in the deep part of a subducted slab     

刘亚静  叶国扬  毛兴华  宁杰远 《地震学报(英文版)》2002,15(3):301-308

Introduction It is found that there are some relationships between the thermal structures of subduction zones and the deep seismicity, while the mechanism relates the thermal structure and the deep seismicity is still unsure (Helffrich, Brodholt, 1991; Furukawa, 1994; Kirby, et al, 1996). From 1980s, geoscientists have constituted a series of numerical simulations on the stress states of subduction slabs. Based on the kinetic computation of Sung and Burns (1976a, b), Goto, et al (1983, 1987…  相似文献   

含预制软弱带的岩石破裂过程的数值模拟   总被引：2，自引：1，他引：2  

焦明若  张国民  唐春安  傅宇方 《地震学报》2002,24(1):35-41

考虑到岩石脆性破坏过程中介质的不均匀性之特点，对岩石样品中含预制弱介质条带的岩石样品破坏过程进行二维有限元数值模拟，并对弱介质带的破坏贯通过程、新的断层的产生和有关的地震活动进行了研究．数值模型展示了岩石从变形、微观破坏到整体破坏的全过程以及微震活动的时空分布特征．应力、应变和微震活动的时空分布形象地描绘了岩石变形的局部化和时空迁移等现象，这与实际地壳中所观测到的现象是一致的．此外，模拟结果与实验观测结果也是一致或相似的．   相似文献   

基于GIS与ANN耦合技术的地裂缝灾情非线性模拟预测系统——以山西榆次地裂缝灾害为例   总被引：4，自引：0，他引：4       下载免费PDF全文

武强  陈珮珮  董东林  孙卫东  魏迎春 《地震地质》2002,24(2):249-257

现代地裂缝在世界许多国家普遍存在 ,已成为当今世界范围内的主要地质灾害之一。本文在详尽分析了山西榆次地裂缝的各个致灾因子的基础上 ,利用GIS技术建立了地质学意义上的专题层 ;然后采用人工神经网络技术构建出了地裂缝灾害活动性的评价模型 ,并建立了地裂缝活动性的评价系统 ,对榆次地裂缝进行了灾害活动性评价 ,为榆次市城建和国土规划等部门的正确决策提供了重要的科学依据  相似文献