Brittleness characteristics of tight oil siltstones     

Wen-Hui Tan  Jing Ba  Meng-Qiu Guo  Hui Li  Lin Zhang  Ting Yu  Hao Chen 《应用地球物理》2018,15(2):175-187

Rock brittleness directly affects reservoir fracturing and its evaluation is essential for establishing fracturing conditions prior to reservoir reforming. Dynamic and static brittleness data were collected from siltstones of the Qingshankou Formation in Songliao Basin. The brittle–plastic transition was investigated based on the stress–strain relation. The results suggest that the brittleness indices calculated by static elastic parameters are negatively correlated with the stress drop coefficient and the brittleness index B₂, defined as the average of the normalized Young’s modulus and Poisson’s ratio, is strongly correlated with the stress drop. The brittleness index B₂, Young’s modulus, and Poisson’s ratio correlate with the brittle minerals content; that is, quartz, carbonates, and pyrite. We also investigated the correlation between pore fluid and porosity and dynamic brittle characteristic based on index B₂. Pore fluid increases the plasticity of rock and reduces brittleness; moreover, with increasing porosity, rock brittleness decreases. The gas-saturated siltstone brittleness index is higher than that in oil- or water-saturated siltstone; the difference in the brittleness indices of oil- and water-saturated siltstone is very small. By comparing the rock mechanics and ultrasonic experiments, we find that the brittleness index obtained from the rock mechanics experiments is smaller than that obtained from the ultrasonic experiments; nevertheless, both decrease with increasing porosity as well as their differences. Ultrasonic waves propagate through the rock specimens without affecting them, whereas rock mechanics experiments are destructive and induce microcracking and porosity increases; consequently, the brittleness of low-porosity rocks is affected by the formation of internal microcrack systems.  相似文献   

航空重力垂直梯度探测潜艇方法研究     

张志强  郑晗  崔银锋 《海洋测绘》2019,39(4):6-9

航空重力梯度测量属于被动探测,抗干扰能力强,如果能和其他探潜手段相配合将极大地提高航空搜潜的效率。针对航空重力梯度测量是否能够用于探测潜艇的问题,依据俄亥俄级弹道导弹核潜艇的结构特点,建立了适用于重力梯度计算的潜艇模型,分别给出了潜艇外壳、内部质量亏损产生的重力垂直梯度的计算方法,并对不同精度重力梯度仪可探测的潜艇重力垂直梯度值进行了计算,从航空反潜的角度对探测潜艇效果进行了分析。经计算表明,如航空重力梯度仪精度达到10~(-2) E,将具备一定的实际探潜效能;如精度达到10~(-4) E,反潜机搜索宽度可与现有航空磁性探潜相当。  相似文献   

N油田A油组钙质隔夹层地质特征及成因分析     

廖明光  黄志强  廖纪佳  梁文锋  张航  潘柯宇 《沉积与特提斯地质》2020,40(1):26-34

在油田开发过程中,隔夹层控制油气水运动规律,对于寻找剩余油具有重要控制作用。本文以N油田TF组2段A油组为研究对象,通过薄片、岩心测试、测井、碳氧同位素等资料综合分析,研究其钙质隔夹层的分布特征、岩石学特征、物性特征、测井识别特征,并从沉积环境、物质来源、成岩作用相结合的角度分析钙质隔夹层的成因。研究表明,A油组纵向上发育的三套钙质隔夹层主要发育在前滨滩坝沉积微相,顶钙与底钙的岩性以砂质生屑质灰岩为主,中钙为钙质砂岩;三套钙质隔夹层中生物碎屑主要以腕足、腹足、有孔虫为主,含少量棘皮、瓣鳃、红藻、介形虫、苔藓虫等;成岩作用主要为胶结作用,胶结物类型包含早期方解石胶结物、中期铁方解石胶结物、晚期铁白云石胶结物;碳氧同位素分析表明,隔夹层中碳主要来自于沉积过程中的海水,同时有少量来自于大气淡水和有机酸,Ca~(2+)主要来源于生物碎屑,其次为钙长石溶解、铝硅酸盐矿物的水化作用。  相似文献   

Assessment and zonation of storm surge hazards in the coastal areas of China     

Xianwu  Shi  Ziqiang  Han  Jiayi  Fang  Jun  Tan  Zhixing  Guo  Zhilin  Sun 《Natural Hazards》2020,101(1):39-57

Natural Hazards - Coastal inundation due to storm tides is computed using ADvanced CIRCulation (ADCIRC) model along the east coast of India. Inland inundation due to storm tides is calculated every...  相似文献   

Full moment tensor inversion constrained by double-couple focal mechanism for induced seismicity*          下载免费PDF全文

Yuyang Tan  Haijiang Zhang  Junlun Li  Chen Yin  Furong Wu 《地震科学（英文版）》2020,33(4):177-193

In this study, we propose a new method to determine full moment tensor solution for induced seismicity. This method generalizes the full waveform matching algorithm we have developed to determine the double-couple (DC) focal mechanism based on the neighbourhood algorithm. One major difference between the new method and the former one is that we adopt a new misfit function to constrain the candidate moment tensor solutions with respect to a reference DC solution in addition to other misfit terms characterizing the waveform matching. Through synthetic tests using a real passive seismic survey geometry, the results show the new constraint can help better recover the DC components of inverted moment tensors. We further investigate how errors in the velocity model and source location affect the moment tensor solution. The synthetic test results indicate that the constrained inversion is robust in recovering both the DC and non-DC components. We also test the proposed method on several real induced events in an oil/gas field in Oman using the same observation system as synthetic tests. While it is found that the full moment tensor solutions without using the DC constraints have much larger non-DC components than solutions with the DC constraints, both solutions are able to fit the observed waveforms at similar levels. The synthetic and real test results suggest the proposed DC constrained inversion method can reliably retrieve full moment tensor solutions for the induced seismicity.  相似文献   

四川盆地西北部二叠系栖霞阶层序地层特征及地质意义   总被引：2，自引：0，他引：2       下载免费PDF全文

胡笙  谭秀成  罗冰  张本健  张亚  苏成鹏  芦飞凡  李明隆 《古地理学报》2020,22(6):1109-1126

基于露头、钻井岩心和测录井资料,采用层序地层学理论与方法,将四川盆地西北部二叠系梁山组+栖霞组作为一个整体予以解剖,识别出梁山组底界面(Ⅰ型)、栖一段与栖二段界面(Ⅱ型)和栖霞组与茅口组界面(Ⅰ型)3个三级层序界面,将中二叠统栖霞阶划分为2个三级层序: 下部的SQ1层序对应梁山组+栖一段,上部的SQ2层序对应栖二段。通过栖霞阶层序地层格架分析,发现栖霞阶地层存在“底超顶削”的充填规律,统计并绘制SQ1与SQ2层序地层厚度等值线图,对研究区栖霞阶SQ1初期和SQ2期构造—古地理格局进行了恢复,在明确SQ2期为栖霞阶主要成滩期的基础上,结合岩溶发育单元及白云岩展布特征,讨论栖霞阶油气储集意义。结果表明:区内栖霞阶存在北西、北东向隆坳分异,汉南隆起、川北隆起、北缘隆起与广元—旺苍凹陷始终控制了区内沉积格局,指出广元—旺苍海槽雏形始于二叠系栖霞阶。研究区岩溶白云岩孔洞型储集层区与环广元—旺苍凹陷周缘的灰岩岩溶型储集层区为有利的勘探区。  相似文献   

西南岩溶山区地下水资源承载能力评价——以贵州省七星关区为例     

唐佐其  李瑞敏  谯文浪  殷志强  刘琼  陈武  赵德刚 《地质通报》2020,(1):124-130

以国家扶贫攻坚重点地区——贵州乌蒙山七星关区为例,参考"全国地质资源环境承载能力评价与监测预警"形成的评价理论和方法,结合岩溶石山区地下水资源水文地质条件及开发利用实际,探索构建岩溶石山区县域范围内地下水资源承载能力评价方法。通过系统评价七星关区地下水资源承载能力,认为该区地下水资源承载能力较大,但资源、开采强度、劣质水分布不均,降低了部分区域地下水资源承载能力。评价结果为区域国土空间规划及"三区三线"划定提供了依据。同时,该评价方法亦为岩溶地区地下水资源承载能力评价提供了借鉴。  相似文献   

保持局域特征的多源海冰图像融合与分类     

余志强  王廷伟  张晰  张杰  任鹏 《海洋学报(英文版)》2019,38(7):129-136

本文提出一种保持局域特征的多源海冰图像融合方法，并在此基础上进行海冰分类。本文提出的多源海冰图像融合方法包括保持空间局域融合和保持特征局域融合两方面。首先，通过学习得到投影矩阵和相似矩阵。投影矩阵将多源像素进行投影变换，得到保留像素空间局域特性的融合向量。相似矩阵度量像素特征间的相似性，通过拉普拉斯特征分解，得到保留像素特征局域相似性的融合向量。然后，将空间融合向量和特征融合向量进行像素综合，得到融合图像。在此基础上，本文设计一种滑动集成分类方法进行融合图像像素分类。提出的分类方法利用滑动集成的特点，在分类时增强刻画了海冰局域特性。由于本文的保持局域融合框架不仅刻画了海冰在物理空间中的邻接关系，而且考虑不同海冰类型的特征关系，因此其在多源图像（多光谱和合成孔径雷达（SAR）图像）的海冰分类任务中表现优异。实验结果表明本文提出的基于保持局域特征融合的多源海冰图像分类方法有效提升了海冰分类精度。  相似文献   

AUV重力测量的运动加速度建模及平台优选          下载免费PDF全文

张志强  李建成  郑晗  文无敌 《海洋测绘》2020,40(4):9-16

针对适合捷联式重力仪的AUV搭载平台的选型问题,基于国内AUV实际航行数据,分析了多推进器组合、推进器和浮力舱组合、推进器和鳍舵组合等3类AUV的定深航行运动特性;推导了AUV水下航行在3个坐标轴方向上对重力仪产生的运动加速度计算公式,得到运动加速度与AUV水下6个自由度运动要素的解析表达式;基于运动加速度分析,讨论了适用于水下移动重力测量的AUV平台和推进装置设计,进行了AUV搭载平台的优选,并给出了重力仪安装位置建议;选定的AUV实验平台实施移动重力测量验证试验重复线精度达到0.42mGal,验证了搭载平台优选的有效性。  相似文献   

地震站网全流程一体化监控平台建设进展     

王坦  师宏波  韩宇飞  代光辉  黄经国  刘艳琼  杨陈  祝杰  姬运达 《地震地磁观测与研究》2020,41(4):270-274

  相似文献