浅海伸缩套管钻探工艺研究          下载免费PDF全文

王林清  马汉臣  许本冲  殷国乐  陈浩文  秦如雷  卢秋平 《探矿工程》2021,48(7):40-45

浅海取心钻探中钻遇易坍塌地层时,需要下放套管封隔地层,保证泥浆循环,换径继续钻进。现有常规下套管方法为使用带有钻台层甲板和套管层甲板的钻井船进行下放套管作业,部分无套管层甲板钻井船在遇到必须下套管的工况时,需临时搭建套管层平台进行下放套管作业,但受钻机和钻具体积及质量的限制。为解决无套管层甲板的钻井船在海洋钻探取心时需要下入套管的难题,设计了一种海洋钻探下入多层套管的工艺方法,利用可伸缩套管及相关设备,在海底井口与小型钻井船之间建立泥浆上返通道,封隔不稳定地层,实现泥浆回收循环及钻具升沉补偿。在钻井过程中,伸缩套管还可以起到导向定位的作用,防止潮差水流流速变化影响钻具下入,为浅海钻井节省时间和成本。  相似文献   

A feasibility assessment of the application of the Polluter-Pays Principle to ship-source pollution in Hong Kong     

《Marine Policy》2015

This article aims to assess the feasibility of applying the Polluter-Pays Principle (PPP) to its fullest measure in counteracting ship-source pollution in Hong Kong (HK). Ship-source pollution is of chief concern for HK׳s marine environmental protection. A comprehensive legal and policy framework has already been established to control and remedy ship-source pollution; nevertheless, the costs of implementing measures under this framework are largely undertaken by the government or through the public avenue, leading to an inconsistency with PPP, which is a principle rooted in HK environmental policy. Through an intensive literature review and questionnaire survey, the results of this study have revealed that the adequacy and/or effectiveness of the existing legal and policy framework for controlling and remedying ship-source pollution are questionable. In addition, despite varied understandings of PPP, the industry also supports the adoption of innovative legal and policy measures to apply PPP to its fullest measure in order to better control and remedy ship-source pollution. These findings provide useful evidence, and enable meaningful reflection on the existing legal and policy framework covering ship-source pollution.  相似文献   

Acceptance of the international compensation regime for tanker oil pollution – And its implications for China     

《Marine Policy》2015

The international compensation regime for tanker oil pollution has been successful in providing adequate and prompt compensation to pollution victims in its member states. Nevertheless, the attitudes of different countries toward acceptance of this regime have varied considerably. This paper aims to explain three main factors in the acceptance of the regime, including: (1) The level of economic development; (2) the risk of exposure to tanker oil spills; and (3) the financial burden associated with adherence to the International Oil Pollution Compensation Fund (IOPC). Using both fuzzy-set Qualitative Comparative Analysis and an Ordered Probit model, this study found two patterns causing upper-middle and high income countries to have a high acceptance level: (a) Those facing a medium risk of oil spills and having a low financial burden; and (b) those facing a high risk of oil spills. The study reveals that, for a country with a high risk of exposure to tanker oil spills, such as China, with its improvement in economic status it is far better for it to join the IOPC Fund, so as to provide better protection both for potential pollution victims and for the marine environment. The results of this study can also be applied to other countries that are considering whether or not to accept the international compensation regime for tanker oil pollution.  相似文献   

Saldanha Bay,South Africa II: estimating bay productivity     

GC Pitcher  ME Smith  TA Probyn 《African Journal of Marine Science》2015,37(4):513-520

Saldanha Bay is a narrow-mouth bay on the west coast of South Africa linked to the southern Benguela upwelling system. Bay productivity was investigated by use of the conventional light-and-dark bottle oxygen method, and, for comparison, through assimilation of the stable isotope tracer ¹³C. Gross community production GCP and net community production NCP, as determined from the oxygen method, were respectively 2.6 and 2.4 times higher than estimates determined from the stable isotope method. Chlorophyll a (Chl a) concentrations increased with the onset of spring and well-defined subsurface maxima developed in association with increasingly stratified conditions (mean water column Chl a concentrations ranged from 5.4 to 31.5?mg m^?3 [mean 15.5?mg m^?3; SD 7.6]). A sharp decline in photosynthetic rates P* (GCP normalised to Chl a concentration) with depth was attributed to light limitation, as demonstrated by the high vertical attenuation coefficients for downward irradiance K_d, which varied from 0.29 to 0.70?m^?1 (mean 0.48?m^?1; SD 0.12). Productivity maxima were consequently near-surface despite the presence of deeper subsurface biomass maxima. The community compensation depth Z_cc, where gross community production balances respiratory carbon loss for the entire community, ranged from 2.9 to 9.2?m (mean 5.8?m; SD 2.2), and was typically shallower than the 1% light depth for PAR (photosynthetically available radiation), Z1%PAR, which is traditionally assumed to be the depth of the euphotic zone and which ranged from 6.6 to 15.9?m (mean 9?m; SD 2.6). Autotrophic communities, where organic matter is produced in excess of respiratory demand, were confined on average to the upper 5.8?m of the water column, and often excluded the bulk of the phytoplankton community, where light limitation is considered to lead to heterotrophic community metabolism. Estimates of integrated water column productivity ranged from 0.84 to 8.46?g C m–2 d^?1 (mean 3.35?g C m^?2 d^?1; SD 1.9).  相似文献   

采用误差迭代补偿的高精度相位解缠方法     

张晓玲  郭立文  朱超猛  韦顺军 《成都信息工程学院学报》2015,30(1)

最小二乘相位解缠算法是一种全局算法,快速稳定简单易实现,但该算法未绕过相位不连续区易造成误差的全局扩散,导致结果存在较大误差.针对最小二乘相位解缠算法的缺陷,提出一种高精度相位解缠方法.该方法在基于快速傅里叶变换的最小二乘解缠算法基础上,采用误差迭代补偿技术,补偿解缠误差.仿真和实测相位数据的实验结果表明,该方法可有效提高解缠精度,且在仿真实验的定量分析中得出,在强相位噪声条件下,该方法的解缠精度比最小二乘算法提高一个数量级.  相似文献   

任意带高斯正形投影平面直角坐标系的选择     

王毅  张蓓 《东北测绘》2012,(1):194-195

坐标系统的选择对一项工程来说是一项必须首先进行的工作,同时坐标系统选择的适当与否关系到整个工程质量的好坏,因此对坐标系统的研究是一项非常重要和必需的工作。对于城市而言,使投影长度变形控制在允许的精度范围之内是建立独立坐标系统主要解决的问题,因此,独立坐标系统的建立主要是根据所在测区的不同来建立与本测区相适应的坐标系统,从而使其投影长度变形控制在允许范围之内。本文讨论通过建立城市抵偿坐标系解决变形问题的方法。  相似文献   

顾及模型误差的卡尔曼滤波相位解缠     

刘国林  闫满 《测绘科学》2012,37(2):170-172

本文提出一种顾及模型误差的卡尔曼滤波相位解缠算法,该算法在卡尔曼滤波的状态空间模型中引入一与误差因素有关的控制变量,对相位误差进行补偿,通过在解缠过程中将卡尔曼滤波增益限制在一定范围内,把误差阻遏在相当小的区域,最后对解缠相位进行卡尔曼滤波平滑操作,减少了误差的传播。分别采用仿真数据和真实InSAR数据进行实验,并与原卡尔曼滤波相位解缠结果进行对比分析,验证了本文方法的有效性。  相似文献   

安徽省会经济圈碳排放强度与生态补偿研究   总被引：2，自引：0，他引：2  

孙贤斌  傅先兰  倪建华  赵彤 《地域研究与开发》2012,31(1):135-138,155

通过对1997年和2007年碳排放强度分析,揭示安徽省会经济圈内各市县对碳排放的影响和区域差异,根据相关固碳价格计算省会经济圈市县的生态补偿标准。研究结果显示:(1)省会经济圈总体上为碳汇区,1997—2007年间碳排放总量增加1 049.9万t,年均增长14.4%,其中,合肥市碳排放量增长最大。(2)2007年经济圈内地均建设用地碳排放强度和地均碳排放强度分别增加为1997年的2.18,2.41倍。1997—2007年,省会经济圈内的碳排放量、地均碳排放强度和地均建设用地碳排放都呈现合肥市>巢湖市>六安市。(3)经济圈内各县市地均碳排放强度差异显著,建设用地平均碳排放强度以合肥市最高(784 t/hm2),其次是霍山县和金寨县,其他区域的建设用地平均碳排放强度相差不大。(4)2007年合肥市提供的生态补偿标准是12.8～105.1亿元,六安市和巢湖市得到的生态补偿标准范围分别为31.9～278.1,0.6～13.8亿元;各县市生态补偿差异也很大。  相似文献   

临沂市征地区片地价制订工作方法简析     

苑玉林 《山东地质》2010,(3):49-53

征地区片地价的制定是我国征地补偿标准的革新,对我国征地制度的完善有着重要作用。为此,在临沂市征地区片地价制定过程中总结了征地区片地价的制定步骤,对主要区片划分方法和征地区片地价测算方法的使用条件做出了概括,同时提出了征地区片地价测算中值得进一步思考的问题。  相似文献   

一种简易快速的时域地震波衰减补偿算法     

张瑾  冯晅  刘财  赵旭  张营  刘海燕  王乔 《吉林大学学报(地球科学版)》2010,(Z1)

针对地震波的能量随着传播时间的增加而递减,提出了一种时间补偿方法。通过调试与传播时间有关的两个可调参数进行地震波振幅补偿。模型试验证实了该方法可以有效地补偿能量的损失,而且在地层中地震波振幅衰减与品质因子Q值有关时,其中的一个可调参数可以用另一个可调参数和Q值来表示。也就是说,本文方法同样是一种反Q滤波方法。  相似文献