Optimization of nonconventional wells under uncertainty using statistical proxies

The determination of the optimal type and placement of a nonconventional well in a heterogeneous reservoir represents a challenging optimization problem. This determination is significantly more complicated if uncertainty in the reservoir geology is included in the optimization. In this study, a genetic algorithm is applied to optimize the deployment of nonconventional wells. Geological uncertainty is accounted for by optimizing over multiple reservoir models (realizations) subject to a prescribed risk attitude. To reduce the excessive computational requirements of the base method, a new statistical proxy (which provides fast estimates of the objective function) based on cluster analysis is introduced into the optimization process. This proxy provides an estimate of the cumulative distribution function (CDF) of the scenario performance, which enables the quantification of proxy uncertainty. Knowledge of the proxy-based performance estimate in conjunction with the proxy CDF enables the systematic selection of the most appropriate scenarios for full simulation. Application of the overall method for the optimization of monobore and dual-lateral well placement demonstrates the performance of the hybrid optimization procedure. Specifically, it is shown that by simulating only 10% or 20% of the scenarios (as determined by application of the proxy), optimization results very close to those achieved by simulating all cases are obtained.     

高新技术产业集聚的城市化响应与反馈机制研究

高新技术产业集聚与城市化存在互动机制。一方面,高新技术产业结构效应影响了城市化动力机制,集聚效应则促进了城市外部经济的发展,使城市化表现出不同的模式特征和地域特征;另一方面,城市化促进了高新技术发展所需要素资源的聚集与流动,为高新技术产业集聚提供人力资本保障,还为高新技术企业提供创新的源动力。文章以苏州高新区的高新技术产业发展和城市化互动关系佐证了这一理论,并认为建立二者之间切实可行的调控模式是当务之急。     

关于我国国家基础地理信息系统数据库按内容分级的探讨——以1∶5万数据库为例

在诸多地理信息系统中,基础地理信息系统是各类地理信息系统用户的统一空间载体,面向全社会和各专业部门,因而国家基础地理信息系统数据库的产品需求既是最广泛的,也是最复杂的。本文针对社会上不同行业、部门对国家基础地理信息系统数据库产品的不同需求程度,以1∶5万数据库为例,采用调查、统计分析和空间分析的方法,把国家基础地理信息系统数据库按内容创造性地分为三个等级,并得出“国家基础地理信息1∶5万数据库内容等级划分方案”,为下一步三级数据库产品生产提供了参考。     

基于MPI的机群并行计算系统平台构建

在高性能计算机领域,机群并行系统已成为一种重要的系统结构。这里介绍了机群并行系统的特点和发展现状;给出了将PC机或工作站通过高速以太网连接,使用TCP/IP作为标准的通信协议,利用MPI作为分布式的并行计算软件环境,在Windows平台和Unix平台上搭建用户自己的PC机群系统的两种方法;还给出了MPI安装中需要注意的关键步骤。实践表明,PC机群系统具有高性能、高可用性和极高的性价比。     

煤与瓦斯突出预报的理想灰贴近函数聚类关联分析

从预报煤与瓦斯突出所获取的数据信息知，其信息多数为灰色特征。为突出其灰色特性，本文采用理想灰贴近函数聚类关联分析预测预报煤与瓦斯突出的危险程度，并将此方法同模糊聚类预测预报法和模糊聚类关联分析预报法及模糊聚类相似分析预报法进行了对比分析。由对比分析可知，采用4种数学方法预测预报煤与瓦斯是否突出，给出的结论是一致的，只是预测预报是否发生的可能程度略有差别。其中关联分析比相似分析计算过程较简单，且相似分析在确定编号时，有时受截值λ取值影响。尽管如此，但不影响预测预报结果。所以，不论是采用模糊聚类，还是灰色聚类数学方法预报煤与瓦斯突出均是可行的，可在实践中应用。     

沁水盆地煤层气钻井工艺方法

针对沁水盆地煤层气概况,地层情况及开采条件,介绍了参数井、生产井、多分支地面煤层气水平开发井、丛式井等钻井工艺、钻具组合、井身结构及井身质量要求.     

数字地震仪的发展历史及展望

地震仪经历了光点，模拟和数字的变化，数字地震仪本身由16位发展到24位，其附属设备（电缆，检波器）也是到了不同程度的发展。近年来，I／O等公司利用MEMS技术研制了新型地震检波器，这一新的发展对于地震采集尤其是多分量采集带来重要影响。     

分布式侵蚀预报模型中网格面积的选定——以黄土高原丘陵沟壑区为例

在分布式土壤侵蚀过程模型中 ,承载数据以及进行运算的最小单元 ,即基本地块的选取是非常关键的 ,它直接关系到模型的模拟精度和运算数据量。目前大多数分布式模型都采用平均布设矩形网格的方法 ,这种方法在基本网格的大小选取上存在着盲目性和不统一性。本文以黄土高原丘陵沟壑区为例 ,利用GIS和SPSS分析了黄土高原丘陵沟壑区属性均一的基本地块在面积上的统计规律 ,给出了基本地块选取的合理依据 ,以促进建立更好的分布式模型     

Alpine medicinal plant trade and Himalayan mountain livelihood strategies

Commercial alpine medicinal plants are collected from the wild by local rural households throughout the Himalaya and sold in order to increase household incomes. Recent studies indicate that this annual trade amounts to thousands of tonnes of roots, rhizomes, tubers, leaves, etc., worth millions of US dollars. The main market is in India. Based on a national survey, including the most commonly traded species, and a village study this paper investigates the importance of the alpine medicinal plant trade at national and local levels in Nepal. The national survey included standardized open-ended interviews with 232 harvesters, 64 local traders, 66 central wholesalers, 47 regional wholesalers, and 16 production companies. The village survey is based on the daily records of household activities in 15 households in a one-year period. The annual Nepalese alpine and sub-alpine medicinal plant trade is conservatively estimated to vary from 480 to 2500 t with a total harvester value of US$0.8–3.3 million; the average harvester value is estimated at US$66.0 ± 99.0. The trade in 1997/98 amounted to 1600 t with a harvester value of US$2.3 million and an export value equivalent to 2.5% of total export from Nepal. Medicinal plant harvesting was found to constitute an integrated part of local livelihood strategies, contributing from 3 to 44% (average of 12%) of the annual household income. Importance at household level depended on land and animal holdings, and the availability of adult male labour. The validity and reliability of methods and analyses is evaluated, and issues of conservation and management of alpine medicinal plant species under the community forestry scheme are discussed.     

我国制造业集群分布现状及其发展特征

目前，在我国很多地区，例如长江三角洲和珠江三角洲，以个别市、县、镇或村为范围，集中某种产品的生产所形成的制造业集群表现出极强的活力和竞争力。集群中的很多企业根据不同技术能力，纷纷进入了全球价值链，已经使中国成为跨国公司控制之下的“世界工厂”。文章从目前局限性的资料出发，将这一现象的分布现状进行了分析，并对其发展特征进行了描述。认为，在新型工业化道路中，企业只有在本地舍作和结网，加强创新，才能有效地插入全球价值链，参与国际竞争。为此，需要通过政策的支持，鼓励合作的信用环境，使价值链上的各级企业以及利益相关者进行合作。