视电阻率测井数据处理的应用研究

影响土的电阻率的因素众多,土的视电阻率大小与土的工程力学指标密切相关。在阐述视电阻率测井基本原理的基础上,采用三极测深的方式采集数据,对比分析所测得的三种类型土的视电阻率值,并结合土工试验结果,依据试验数据归纳总结出亦庄地区典型土的电阻率值与土的饱和度、含水率、天然密度之间的相关性。当土体趋于饱和时,土的视电阻率趋于稳定,约等于水的视电阻率,土体视电阻率值随着含水率增大而减小,而随着天然密度的增大而增大。     

Analysis and numerical simulation of the meteorological observations at a tropical coastal site Chennai in India

Meteorological measurements were carried out at North Chennai semi rural area during pre-monsoon period as a part of an air quality study program. Analysis of the data showed the effects of coastal terrain namely the land-sea breeze circulation, temperature cooling during the sea breeze, difference in onset times at these sites etc. Sea breeze onset was observed with a sharp turning of the wind from westerly to south easterly associated with rise in wind speed. Advection speed of the front was about 2.0 m s^− 1. A simple mesoscale meteorological model (MAM-I) developed at Kalpakkam for coastal atmospheric dispersion estimation was used to simulate the observed characteristics. All the major features observed could be simulated by the model while significant difference was noticed in sea breeze frontal movement. MAM results were also inter-compared with MM5. There were no significant differences in the estimate of mean parameters by both the models. It is concluded that the simple model, which takes less run time in a desktop PC, is adequate enough for practical application of providing wind field for plume dispersion models at coastal sites.     

Distributed empirical algorithms to estimate catchment scale sediment connectivity and yield in a subtropical region

The intensity of soil loss and sediment delivery, representing hydrologic and geomorphic processes within a catchment, accelerates with rapid changes in land cover and rainfall events. An underlying component of sustainable management of water resources is an understanding of spatial and temporal variability and the adverse influences of regional parameters involved in generating sediment following widespread changes in land cover. A calibrated algorithm of soil loss coupled with a sediment delivery ratio (SDR) was applied in raster data layers to improve the capability of a combined model to estimate annual variability in sediment yields related to changes in vegetation cover identified by analyses of SPOT imagery. Four catchments in Kangaroo River State forest were assessed for annual changes in sediment yields. Two catchments were selectively logged in 2007, while the two other sites remained undisturbed. Results of SDR estimates indicated that only a small proportion of total eroded sediment from hillslopes is transported to catchment outlets. Larger SDR values were estimated in regions close to catchment outlets, and the SDR reduced sharply on hillslopes further than 200–300 m from these areas. Estimated sediment yield increased by up to 30% two years after land cover change (logging) in 2009 when more storm events were recorded, despite the moderate density of vegetation cover in 2009 having almost recovered to its initial pre‐logging (2005) condition. Rainfall had the most significant influence on streamflow and sediment delivery in all catchments, with steeply sloping areas contributing large amounts of sediment during moderate and high rainfall years in 2007 and 2009. It is concluded that the current scenario of single‐tree selection logging utilized in the study area is an acceptable and environmentally sound land management strategy for preservation of soil and water resources. Copyright © 2013 John Wiley & Sons, Ltd.     

核磁共振测井时域分析法数值模拟及影响因素分析

核磁共振测井时域分析法已广泛用于评价油气层,并获得了很多成功应用实例.然而,由于储层结构的复杂性以及孔隙流体性质的多变,也常常见到应用失败的实例,影响了时域分析法的应用效果.本文通过数值模拟研究时域分析法在不同储层条件下识别流体的效果,并分别从孔隙流体类型、地层孔径变化、信噪比以及采集参数等方面,分析影响时域分析法应用...     

浅层地热能勘察和评估应用研究

对浅层地温能工程场地进行勘察和应用条件评估是地源热泵系统方案设计的重要环节。以南京板桥地产浅层地热能勘探应用为例,介绍多功能地下水能量测井仪的功能及其在浅层地热能勘探中的应用,探讨水文地质前期勘探工作对浅层地热能资源开采的作用与意义。该测井仪能够在单井中,一次性完成对浅层地热能参数:地下水的水量、温度、电导、各含水层的静水头高度、储水量、地下水的水平和垂向运动流速和方向、地层渗透系数、导水系数等的定量测量,查明地下水的层间补给关系,为热泵选型、埋深和分布密度提供平面矢量、垂向断面高程等多种高精度参数。     

松辽盆地昌德气田深层登三、四段底界面特征

松辽盆地昌德气田登娄库组三、四段是深层主要产气层位,但井震地层界面不一致阻碍了该区油气勘探。从岩性、测井和地震等方面对登三、四段主要特征及关键界面特征进行综合研究,获取各段界面主要特征,并据此进行了对界面确定的调整。登三、四段岩性以泥岩为主,发育湖相和曲流河相。登三段电阻曲线呈高频中高幅指状或箱型,底面为一套砂岩组底界,泥岩组顶面,GR 负台阶,电阻正台阶,地震剖面上具有上超和顶超的特征。登四段电阻曲线呈中高频中幅指状夹箱型,底界面为泥岩地层底界、砂岩地层顶界,GR 正台阶,电阻负台阶,地震剖面上表现为整一。井震对比统层后,登三段底面有12 口井,登四段底面有8 口井进行调整。     

Evaluation of the reservoir permeability of anthracite coals by geophysical logging data

Permeability is one of the most significant reservoir parameters. It is commonly obtained by experiment, history simulation, injection/falloff well test and geophysical logging. Among these, geophysical logging remains as the most economic and efficient technique in evaluating coal permeability in the vicinity of an open-hole. In this paper, geophysical logging data are used to evaluate the coal reservoir permeability for the No. 3 coal seam in the southern Qinshui Basin (Fanzhuang and Zhengzhuang coal zones). Ideally coal reservoirs consist of coal matrix and fracture networks that can be represented by a model called a collection of sheets. Based on the model, coal reservoir permeability can be quantitatively calculated using the theoretical formula of k_f = 8.50 × 10^− 4 w²φ_f, in which fracture width (w) and fracture porosity (φ_f) were obtained by dual laterolog and density logging data, respectively. Calculative results show that coal reservoir permeability ranged from 0.017 mD to 0.617 mD for the Fanzhuang coal zone and from 0.047 mD to 1.337 mD for the Zhengzhuang coal zone. The permeability decreases with coal burial depth, reflecting variations in penetration capability of coal reservoirs at varying depths. Comparing results with those from injection/falloff well tests, however, shows that the model-calculated permeability is slightly higher. This is expected because the model did not include the influence from coal anisotropy.     

测井曲线在阜新雷家区煤田勘探中的应用

雷家井田位于辽宁省阜新彰武县西北12km,通过分析该区三侧向电阻率、密度、自然伽马等测井曲线特征,确定了孙家弯组、沙海组、沙海组、九佛堂组等地层界线及4、5、6等煤层的赋存形态：4煤和5煤全区发育,为主要可采煤层;6煤组全区发育,南薄北厚,局部可采。     

横波测井的原理和方法研究

充液井孔中的偶极子声源能在周围岩层和土层中激发弯曲模式声波，它们在截止频率附近，沿井轴传播的速度为井壁介质的横波速度．使用可调声功率源使偶极子声波测井系统能适应软、硬地层的现场井孔测试．相关法算出横波声速，野外测试的结果和理论计算值相符．计算动弹模量和剪切模量，确定破碎层位置，可用于工程地质勘察中