Island instantaneous coastline extraction based on the characteristics of regional statistics of multispectral remote sensing image

本研究采用IkOnOS遥感图像,选取波谱特征区,通过区域像元统计并计算各波段权重系数,将影像进行波谱归一化处理,使归一化的影像岛陆与海水特征更明显。在此基础上,采用最大类间方差法确定最佳分割阈值,对归一化的影像进行二值化,从而提取海岛岸线。该方法采用特征曲线法进行水陆分离,得到的二值图像保持了原图的有效边缘,采用二值形态学提取的海岸线连续可靠、信噪比高。结果表明,该方法简单、快速,能有效提取海岸线,具有实用价值。This study adopted IKONOS remote sensing images and selected spectral characteristic areas, through regional pixel statistics and calculating weight coefficients of each band, processed the images with the spectral normalized method, which made the features of islands, land and water features more obviously in the images.On this basis, the OTUS was used to determine the optimal segmentation threshold, and the normalization image binarization was made, thus the island coastline was extracted.This method used the characteristic curve method to separate the land and water, obtained the binarization images and maintained the original edge effectively.The coastline that was extracted by Binary Morphology was continuous, reliable and high signal-to-noise ratio.The results showed that this method could extract the coastline fast, simply and effectively, which had the practical value

Analysis on the land use and cover change in Tianjin Binhai New Area based on the remote sensing

采用全国土地分类系统,基于lAndSAT卫星TM遥感影像与天津滨海新区1:50,000地形图,进行相应数据处理,编制出2000年、2005年、2010年三期滨海新区土地利用/覆盖分类图,并运用土地利用转移矩阵对近10年来天津滨海新区土地利用/覆盖变化进行定量分析。在此基础上,进一步分析了经济、人口等驱动因子对土地利用/土地覆盖的影响。结果表明:十年间,滨海新区的建筑用地面积增加显著,而绿地、湿地、滩涂等高生态价值的土地向建筑用地、未利用地等开发建设用地大幅度转化,后五年变化尤为显著。This paper carries out quantitative analysis on the land use/cover(LU/C) change of Tianjin Binhai New Area in recent 10 years through using land use transition matrix from the three-stage LU/C classification maps of 2000, 2005 and 2010 drafted by means of the National Land Classification System of China based on Landsat TM satellite remote sensing image and the Tianjin Binhai New Area 1:50 000 relief maps.On this basis, the impact of such driving factors as the economy and population on LU/C is further analyzed.The results show that the area of the building land in Binhai New Area has increased significantly over the ten years, and the greenland, wetland, and shoals of high ecological value have been dramatically transformed into the building land and unused land for the development and construction, and the change is more significant in the later five years

Potential laws on the changes of shale in acid erosion process based on the fast matching method of dimensional analysis

The evolutionary laws of the physical and mechanical properties of shale reservoirs in the process of acid erosion have not been clarified. This paper provides the potential laws of pore size and the elastic modulus evolution of shale in the process of point-source acid erosion. The results show that the average pore size increment of the shale Delta r in the process of point-source acid erosion may be in accordance with the scaling law of two-fifth's power of the reaction time t, and the ratio of the elastic modulus E to the elastic modulus E-0 of the initial state which is E/E-0 is in accordance with the scaling law of the negative third power of the ratio r/r(0). The conclusion of the study has both theoretical and practical significance for assisting the fossil energy exploitation and supply. (c) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Characteristics and the formation mechanism of the heterogeneous microfractures in the tight oil reservoir of Ordos Basin, China

This study aims to investigate the characteristics and the formation mechanism of the heterogeneous microfractures in the upper Triassic Yanchang Formation tight oil reservoir of Ordos Basin, China with some new perspectives. In this paper, we define two sets of parameters describing the size and geometry of microfractures by using Feret diameter calculation and Legendre ellipse fitting. Then the unidirectional fracture zone and multidirectional fracture zone are also be defined. Results of the microfractures characterization show that when the lengths of microfractures are less than 600 mu m (and the widths are less than 90 mu m), the above two set of data show a good linear positive correlation, but when the lengths of microfractures continue to increase, the widths of microfractures begin to deviate from the linear relationship and gradually diverge. This indicates that the lengths and widths of microfractures are not strictly and steadily correlated, but their correlation has a threshold value. If the lengths of microfractures increase due to the change of internal or external stress, when the length value is higher than a certain value, the opening process of microfractures will begin to lose stability, and the widths will change gradually irregularly. Once the compaction process reach a certain extent, some of the microfractures opened previously will be temporarily closed, which will greatly promote the process of pressure-solution, and thus increase the microfracture tortuosity. The length, width, solidity and boundary tortuosity of microfractures could be used to distinguish two zones include the multi-directional fracture zone from the unidirectional fracture zone. The conclusion would provide the important scientific basis for the EOR applications of tight oil

Profound connotations of parameters on the geometric anisotropy of pores in which oil store and flow: A new detailed case study which aimed to dissect, conclude and improve the theoretical meaning and practicability of Umbrella Deconstruction method furtherly

Umbrella Deconstruction method has already been raised in a set of published papers accomplished by the author of this study and his collaborators. This method aimed to unlock the black box of the anisotropic pores, elements and minerals of reservoirs from a new perspective. Compared with all the previous case studies, the purpose of this study is to investigate the profound connotations and special significance of the geometric parameters describing the pores in the study of Umbrella Deconstruction method furtherly. This new case study shows the extreme points of reservoir properties could be the turning points of some complex geological processes. It also shows that there are two possible mechanisms which would control the geometry of the pore boundary, including the differential corrosion due to compaction process and the seepage process controlled by dominant channels. The location of the maximum and minimum values of eight sections and the angle between the maximum and minimum values had sig-nificance in the geologic mechanism and development processes. The conclusions suggest that, when we carry out the study of micro-anisotropy characterization, we should investigate what relative quantitative enlightenment can be brought to us by the change characteristics and laws of pore geometry parameters from both the geological and engineering perspectives. This will contribute to the further explanation and improvement of the practicability of Umbrella Deconstruction in pore characterization. (C) 2020 Elsevier Ltd. All rights reserved

Rapid Determination of Complete Distribution of Pore and Throat in Tight Oil Sandstone of Triassic Yanchang Formation in Ordos Basin, China

This study aimed to investigate the complete distribution of reservoir space in tight oil sandstone combining casting slices, field emission scanning electron microscopy (FE-SEM), the pore-throat theory model, high-resolution image processing, mathematical statistics, and other technical means. Results of reservoir samples from the Xin'anbian area of Ordos Basin showed that the total pore radius curve of the tight oil sandstone reservoir exhibited a multi-peak distribution, and the peaks appeared to be more focused on the ends of the range. This proved that pores with a radius of 1-50,000 nm provided the most significant storage space for tight oil, indicating that special attention should be paid to this range of the pore size distribution. Meanwhile, the complete throat radius curve of the tight oil sandstone reservoir exhibited a multi-peak distribution. However, the peak values were distributed throughout the scales. This confirmed that the throat radius in the tight oil sandstone reservoir was not only in the range of hundreds of nanometers but was also widely distributed in the scale approximately equal to the pore size. The new rapid determination method could provide a precise theoretical basis for the comprehensive evaluation, exploration, and development of a tight oil sandstone reservoir

The Wide Diameter Formula of a Directed Double Loop Network

给出了有向双环网络G(n;s1,s2)的宽直径公式,它由G(n;s1,s2)所确定的L-形瓦的4个参数a,b,p,q表示.令u=a-p,v=b-q,用D(G)与D2(G)分别表示G(n;s1,s2)的直径与宽直径,则(1)当u=1,v=1时,D2(G)=n-1.(2)当u>1,v>1时,D2(G)=D(G)+1=max{a+b-p-1,a+b-q-1}.(3)当u=1,v>1时,D2(G)=「b-1/v」+a+v-2.(4)当u>1,v=1时,D2(G)=「a-1/u」+b+u-2.In this paper,the wide diameter formula for a directed double-loop network G(n;s1,s2) is given.It is represented by four parameters a,b,p,q of the L-shape tile determined by the network G(n;s1,s2).Let u=a-p,v=b-q,and D(G) and D2(G) denote the diameter and the wide diameter of G(n;s1,s2) respectively.It is proved that (1)If u=1,v=1,then D2(G)=n-1.(2)If u>1,v>1,then D2(G)=D(G)+1=max{a+b-p-1,a+b-q-1}.(3)If u=1,v>1,then D2(G)= 「b-1/v」+a+v-2.(4)If u>1,v=1,then D2(G)=「a-1/u」+b+u-2.福建省科技三项经费(2006F5068);; 福建省自然科学基金(S0650036)资

长石粒内孔流体充注规律及分形特征：以鄂尔多斯盆地延长组致密砂岩储层为例

鄂尔多斯盆地延长组致密砂岩储层长石含量较高且脆性破裂发育广泛,目前对该类储层长石粒内孔流体充注规律及分形特征等了解仍然十分匮乏.综合铸体薄片、场发射扫描电镜、图像处理、分形维数计算等手段,提出"粒内充注"概念并对延长组储层长石粒内孔开展了微观充注过程定量模拟,指出长石粒内孔相对于粒间孔的特殊性.从时间上将粒内充注过程划分为前期非稳态充注和后期稳态充注两大阶段,转折点为充注关键时刻.依据充注速率值分布特点,将长石粒内孔某一时刻发生充注的所有空间位置划分为高速充注区、中速充注区、低速充注区三大充注区域,并建立了粒内充注波及系数幂函数变化曲线,厘清了流动轨迹分形维数的物理意义.研究成果可为鄂尔多斯盆地延长组储层油气成藏过程恢复提供较为重要的启示