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.     

Transparency: aid or obstacle to effective defence of vulnerable environments from reservoir construction? Dam decisions and democracy in North East England

Public participation in transparent decisionmaking has been proposed as a panacea for environmental protection. Bargaining theory suggests drawbacks to transparency such as hardening of attitudes and intransigence. Yet achievement of consensus on environmental values for integrated water resource management demands public involvement. Historical study of attempts to prevent reservoir construction in upland valleys designated for protection of nature suggests that 'closed-door' bargaining proved more effective for environmentalists than open, public debate. Records now open for analysis of disputes over Teesdale and Farndale, 1950–1970, allow comparisons to be made between behind-the-scenes deliberations and 'open-door' public discussion. The ambition of progressing from public participation to devolution of environmental decisionmaking and responsibility to the local scale demands more conceptualization of the process of decisionmaking on water resource development.     

Semi-Analytic Modelling of Subsidence

This paper presents a forward model for subsidence prediction caused by extraction of hydrocarbons. The model uses combinations of analytic solutions to the visco-elastic equations, which approximate the boundary conditions. There are only a few unknown parameters to be estimated, and, consequently, calculations are very fast. The semi-analytic model is applicable to a uniform and layer-cake stratigraphy, with visco-elastic parameters changing per layer, and an arbitrary depletion pattern. By its capabilities to handle a multi-layered visco-elastic subsurface, the semi-analytic model fills the gap between the analytic single-layered elastic models available to date and the more elaborate numerical, e.g. finite element, models.     

地震属性分析中水平切片的应用

利用地震数据体中含有的丰富地质信息,可以有效地进行储层预测。层拉平水平切片地层学解释方法是先将地震剖面目的层段做层拉平处理,然后对切片顺地层层面追踪,勾绘出各种地层现象,并以地层学的观点加以解释。该方法在吉林探区扶新南部地区的应用中,对于识别河道的展布趋势取得了较好的效果,而且发现了多期叠置的扇型沉积体。另外,还可指导反演数据体的解释,做到对岩性体从定性到定量的描述。     

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。     

渤南洼陷罗151块火成岩油藏特征及开发对策

罗151块火成岩油藏是近年在济阳坳陷发现的中型油藏，油藏埋深3150m；在研究罗151井区火成岩成因、侵入期次、岩相学及储层非均质性的基础上，建立了火成岩储层概念模型，划分出角岩微孔隙型油藏及辉绿岩溶蚀孔隙-裂缝型油藏两个类型，纵向上分为4个带，平面上分为3个区；预测了火成岩储层发育的有利部位；部署了合理的开发井网，钻探后，完钻新井14口，平均单井日产油27t，取得了显著效果；火成岩油藏初期产能高，产量递减快，弹性产率低，依靠天然能量开采，最终采收率只有14．1％，可以进行注水开发，注水效果较好。     

台北凹陷中浅储集层孔隙预测及勘探有效下限探讨

在系统研究储层物性控制因素的基础上，分析台北凹陷中浅储集层物性分布规律以及压实程度特征，建立孔隙度一深度趋势法和压实减孔量法预测砂岩孔隙度．认为中侏罗统储层压实减孔量整体比较高，表现出“北高南低，生油凹陷内高、周边低”的特征．结合探井试油资料，确定侏罗系储集层有效下限的孔隙度值为9％，压实减孔量为34％，各构造带侏罗系储层深度有效下限总体上表现出“南深北浅、西深东浅”的特征．指出台北凹陷侏罗系储集层在有效下限以下勘探具有较大风险．     

马朗凹陷马1井储层长石中有机包裹体研究

根据对马朗凹陷马1井储层长石中有机包裹体的基本特征、均一温度、荧光及荧光光谱分析，得出有机包裹体均一温度为60～90℃．120～140℃，其对应的荧光颜色分别为黄色和蓝绿色。认为储层的油气运移经历了两期，第一期为烃类的主要运移、聚集期，油气为低成熟油；第二期为少量的烃类聚集，并判断出二叠系条湖组该段储层为油气产层。     

葛洲坝水利枢纽运行后泥沙冲淤变化分析

对葛洲坝水利枢纽及其运行情况和河段特性进行了介绍。分析认为葛洲坝水利枢纽运行前后的入库水沙特性基本一致。探讨了库区冲淤变化特点、淤积量及其分布,冲淤过程及达到冲淤平衡的时间。对坝下游河床的冲淤过程、冲淤量、达到冲淤平衡的时间以及河床粗化,河底高程历年变化及同流量水位降低的原因、降低量及变化过程进行了分析总结。研究结果可为进一步探讨三峡水利枢纽与葛洲坝水利枢纽联合调度运用后水库泥沙淤积变化规律提供参考。     

油田污水中Fe2+,S2-,DO及pH值对HPAM-酚醛CDG成胶性能影响的研究

在对河南油田双河矿区油田污水进行全分析的基础上，研究了污水中Fe^2 ,S^2-，溶解氧（DO）及污水的pH值对有机交联体系聚丙烯酰胺（HPAM）－酚醛胶态分散凝胶（CDG）成胶性能的影响。研究结果表明，Fe^2 ,S^2－，DO及污水的pH值对HPAM－酚醛体系的成胶性能都有影响当ρ（Fe^2 )=1.6mg/L,ρ（S^2-)=0.1mg/L,ρ（DO）=1.6mg/L，HPAM－酚醛体系就不能成胶；随着污水pH值的增大，CDG强度变弱。