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211.
Dynamic data integration for structural modeling: model screening approach using a distance-based model parameterization 总被引:2,自引:0,他引:2
This paper proposes a novel history-matching method where reservoir structure is inverted from dynamic fluid flow response.
The proposed workflow consists of searching for models that match production history from a large set of prior structural
model realizations. This prior set represents the reservoir structural uncertainty because of interpretation uncertainty on
seismic sections. To make such a search effective, we introduce a parameter space defined with a “similarity distance” for
accommodating this large set of realizations. The inverse solutions are found using a stochastic search method. Realistic
reservoir examples are presented to prove the applicability of the proposed method. 相似文献
212.
塔里木盆地巴楚地区中奥陶统一间房组露头礁滩复合体储层地质建模及其对塔中地区油气勘探的启示 总被引:2,自引:0,他引:2
通过1:5万礁滩复合体地质填图,在巴楚地区共发现大小不等的礁滩复合体90余个,层位为中奥陶统一间房组二段.台缘为礁滩复合体密集发育区,礁滩体规模大,台内为礁滩复合体零星发育区,礁滩体规模小。通过对6个典型礁滩复合体的解剖,研究了礁滩复合体的微相类型、组合和各微相的岩石特征、生物群落,并对其生长发育阶段进行了分析。根据6个典型礁滩复合体及礁间的大量铸体薄片鉴定和物性资料,分析了储层的特征、成因和非均质性,建立了台缘礁及礁间、台内礁及礁间2种背景条件下的储层地质模型。巴楚地区露头礁滩复合体储层地质模型对塔中地区上奥陶统良里塔格组礁滩复合体的勘探具有重要的指导意义,并为勘探实践所证实。 相似文献
213.
214.
215.
地面核磁共振模型约束反演含水层参数 总被引:1,自引:1,他引:0
导电模型的地面核磁共振感应电动势是含水量的非线性函数.引入模型约束的迭代反演方法求解该非线性问题的反演.在反演过程中,根据理论公式计算迭代过程中灵敏度矩阵,并采用平坦模型和光滑模型两种约束.对均匀半空间、层状导电模型和实际数据进行了反演模拟,结果表明,模型约束迭代反演方法能从地面核磁共振感应电动势获得含水层较为合理的含水量及分布,且该结果可以从作为初始模型的均匀含水量分布反演得到.对无噪音数据,平坦模型和光滑模型约束对反演的含水量分布影响不大;但当数据存在一定的噪音时,平坦模型约束将比光滑模型约束获得更为精确的含水层参数. 相似文献
216.
吉林省中部农业土壤中滴滴涕的残留特征 总被引:3,自引:0,他引:3
通过分析研究吉林省中部农业土壤中DDT的含量和组成,探讨了该区土壤中DDT的残留特征及其可能的生态风险。研究结果表明,吉林省中部农业土壤中普遍残留DDT,质量分数为0.384~54.159μg/kg,残留水平较低,土壤DDT同系物中以p,p’-DDT和p,p-’DDE为主。DDT的组成表明,土壤中DDT主要是过去输入环境的DDT及其降解产物,但近期仍有少量的DDT输入。生态风险评估则显示该区土壤中的DDT具有一定的生态风险,应予以重视。 相似文献
217.
随着地形高差增大、地貌单元多变、近地表模型复杂,目前被广泛应用的初至折射静校正的精度已无法满足精细勘探的要求。初至层析静校正技术,由给定的初始模型进行正演,用射线追踪方法得到初始模型的初至波,利用该初至波和实际拾取的初至波进行比较,计算地表模型的修正量,反复迭代求得准确的地表模型。山西省国阳新能股份有限公司二矿390水平九采扩区地表标高940~1100m,地貌单元复杂,在对该区资料处理时,利用初至层析折射静校正,经9次迭代计算后,真实地刻划出近地表模型。在二种静校正技术对比中,初至折射静校正不但近地表模型精度低于层析折射静校正,而且其叠加剖面精细程度也远低于层析静校正,如在初至折射静校正叠加剖面同相轴上呈现的凹凸形态,在层析静校正叠加剖面并无显示,且后者剖面的信噪比也比前者明显提高。 相似文献
218.
鄂尔多斯盆地苏里格气田盒8气藏为弹性驱动的河流相低效气藏,储层非均质性强,在开发中普遍见水。根据试采情况将气藏储层分为气层、水层、气水层三类,开展气、水层的测井识别研究。以区内26口井50个射孔层段各层的试油结果作为依据,选出了700个样本点作为判识建模的标本,以声波时差和中子孔隙度等8个原始测井值作为判识变量组合,采用模糊判别分析,建立了各层的判识模型。回判结果表明,模型对气层精度达到97%,水层为89%,气水层为94%。利用未参加建模的出水井射孔段对模型进行验证,判识结果基本符合实际情况,模型具有较高精度。 相似文献
219.
Patterns of crystallographic preferred orientation are referred to as texture. The specific subject of texture analysis is
the experimental determination and interpretation of the statistical distribution of orientations of crystals within a specimen
of polycrystalline material, which could be metals or rocks. The objective is to relate an observed pattern of preferred orientation
to its generating processes and vice versa. In geosciences, texture of minerals in rocks is used to infer constraints on their
tectono-metamorphic history. Since most physical properties of crystals, such as elastic moduli, the coefficients of thermal
expansion, or chemical resistance to etching depends on crystal symmetry and orientation, the presence of texture imparts
directional properties to the polycrystalline material.
A major issue of mathematical texture analysis is the resolution of the inverse problem to determine a reasonable orientation
density function on SO(3) from measured pole intensities on
, which relates to the inverse of the totally geodesic Radon transform. This communication introduces a wavelet approach into
mathematical texture analysis. Wavelets on the two-dimensional sphere
and on the rotational group SO(3) are discussed, and an algorithms for a wavelet decomposition on both domains following the
ideas of Ta-Hsin Li is given. The relationship of these wavelets on both domains with respect to the totally geodesic Radon
transform is investigated. In particular, it is shown that the Radon transform of these wavelets on SO(3) are again wavelets
on
. A novel algorithm for the inversion of experimental pole intensities to an orientation density function based on this relationship
is developed. 相似文献
220.
The dynamics and thermodynamics of large ash flows 总被引:6,自引:6,他引:0
Ash flow deposits, containing up to 1000 km3 of material, have been produced by some of the largest volcanic eruptions known. Ash flows propagate several tens of kilometres
from their source vents, produce extensive blankets of ash and are able to surmount topographic barriers hundreds of metres
high. We present and test a new model of the motion of such flows as they propagate over a near horizontal surface from a
collapsing fountain above a volcanic vent. The model predicts that for a given eruption rate, either a slow (10–100 m/s) and
deep (1000–3000 m) subcritical flow or a fast (100–200 m/s) and shallow (500–1000 m) supercritical flow may develop. Subcritical
ash flows propagate with a nearly constant volume flux, whereas supercritical flows entrain air and become progressively more
voluminous. The run-out distance of such ash flows is controlled largely by the mass of air mixed into the collapsing fountain,
the degree of fragmentation and the associated rate of loss of material into an underlying concentrated depositional system,
and the mass eruption rate. However, in supercritical flows, the continued entrainment of air exerts a further important control
on the flow evolution. Model predictions show that the run-out distance decreases with the mass of air entrained into the
flow. Also, the mass of ash which may ascend from the flow into a buoyant coignimbrite cloud increases as more air is entrained
into the flow. As a result, supercritical ash flows typically have shorter runout distances and more ash is elutriated into
the associated coignimbrite eruption columns. We also show that one-dimensional, channellized ash flows typically propagate
further than their radially spreading counterparts.
As a Plinian eruption proceeds, the erupted mass flux often increases, leading to column collapse and the formation of pumiceous
ash flows. Near the critical conditions for eruption column collapse, the flows are shed from high fountains which entrain
large quantities of air per unit mass. Our model suggests that this will lead to relatively short ash flows with much of the
erupted material being elutriated into the coignimbrite column. However, if the mass flux subseqently increases, then less
air per unit mass is entrained into the collapsing fountain, and progressively larger flows, which propagate further from
the vent, will develop.
Our model is consistent with observations of a number of pyroclastic flow deposits, including the 1912 eruption of Katmai
and the 1991 eruption of Pinatubo. The model suggests that many extensive flow sheets were emplaced from eruptions with mass
fluxes of 109–1010 kg/s over periods of 103–105 s, and that some indicators of flow "mobility" may need to be reinterpreted. Furthermore, in accordance with observations,
the model predicts that the coignimbrite eruption columns produced from such ash flows rose between 20 and 40 km.
Received: 25 August 1995 / Accepted: 3 April 1996 相似文献