基于SVM的面向页岩气地质导向的LWD曲线预测研究

近年来我国能源供应日益紧张,积极开发国内储量丰富的页岩气资源是有效解决该问题的主要途径.水平井以其可增大泄油面积、提高单井产量成为开发页岩气的主要开发技术之一,由于页岩气储层具有隐蔽性、致密性、脆性和非均质各向异性等特点,加上我国页岩气藏埋藏深、有机碳含量较低,常规的钻井技术很难实现页岩气层较高的钻遇率,严重影响了压裂增产效果,地质导向是解决该问题的关键技术.鉴于国内页岩气井的地质导向主要使用一条随钻自然伽马而未测到密度、中子和电阻率等曲线,难以保持钻头在优质储层中钻进.为此,介绍了一种基于支持向量机的随钻测井曲线实时预测新方法,方法基于非线性回归支持向量机的基本原理,优选邻井的录井、校正后的测井等资料作为输入特征和输出特征,建立页岩气地质导向的随钻测井曲线预测模型,后使用本井的录井资料和实测测井资料进行预测和校正.实例分析表明,方法的预测结果准确度高、稳定性强,可有效指导钻头钻进,提高优质储层的钻遇率.     

模糊优选模型及其应用

模糊综合评判在经济中应用十分广泛,然而由于传统的模糊综合评判模型依赖于隶属函数的确定,并往往带有较强的“主观任意性”,且不同的函数组合对评判结果的影响较大,故评判结果有时难以令人信服.本文对适度型指标的相对隶属函数———优属度的计算提出了具体方法,使模糊优选模型更具有实用性.这一新的模糊优选途径,具有理论严谨,概念明确,计算简便实用的特点,是解决大系统模糊优选问题的有效方法.文中还结合港口类上市公司绩效的综合评价进行了实证分析,获得了理想的效果.     

三维油资源运移聚集的模拟和应用

盆地发育的运移聚集史数值模拟,其功能是重建油气盆地的运移聚集演化史,它对于油资源的勘探,确定油藏位置和计算油藏贮量,寻找新的油田,具有极其重要的价值.本文从地质科学实际出发,研究了三维问题的地质和渗流力学特征,提出二阶修正算子分裂隐式迭代格式,对着名油水运移聚集实验进行了数值模拟,结果基本吻合,并对胜利油田东营凹陷的实际问题进行数值模拟试验,结果和实际地质情况(油田位置等)基本吻合,成功解决了这一着名问题.     

基于多元回归的超短半径水平井累积产油预测方法

随着油田的持续开发和老油区作业频繁等原因使井况日趋恶化,加上油藏的非均质性,严重影响油田采收率的提高.如在开发区内补打更新井、加密井,其建井周期长、成本高.在套管内侧钻中短半径水平井,不但可以节约钻井成本,而且还可以增大油层裸露面积,提高采收率和经济效益.但若准确选择有利的侧钻井位,需要首先建立累积产油量与侧钻井相关参数的关系.根据建立的数值模拟概念模型和确定的水平井开采方案,用正交设计对有效厚度、无因次距顶高度、油水井距、平均渗透率、平均剩余油饱和度、水平井开采阶段完善程度等6项因素进行了组合,并计算了25个数值模拟方案.利用多元回归,从模拟计算结果得到计算注水正韵律油层10年累积产油量的多元回归公式,可作为下步优选侧钻井位的依据.     

振动钻削微小孔中钻头寿命与振动参数的二次回归试验研究

本文采用正交组合设计的试验方法，对振动钻削微小孔加工中钻头寿命与轴向振动参数之间的非线性关系进行了二次回归试验，得到了最优回归方程。用回归方程给出的最佳振动参数钻孔，钻头寿命提高了９６．３％     

基于模糊DEA的ERP系统选型方法

提出了一种基于模糊数据包络分析的企业资源计划系统选型方法.以系统的实施复杂性、预计实施成本、功能匹配度和系统供应商的企业形象等作为主要评价指标,运用模糊集相关理论争方法对系统选型过程中的不确定性进行刻画和描述,对候选系统的相对有效性进行客观评价,解决了系统选型过程中的不确定性和模糊性问题.并通过实证研究说明了该方法的应用.     

大位移井钻井风险灰元故障树原理研究

大位移井钻井技术是国外90年代发展起来的高新钻井技术,但钻井风险和钻井事故越来越引起人们的重视。因此本文在故障树分析基础上,结合灰元概念,对大位移钻井风险,首次提出了灰元故障树原理,成功地解决了大位移钻井风险预测和防范等问题。实例表明结果与其它方法吻合很好,符合实际,不仅对测算大位移井钻井风险适用,而且对于评估工程和经济领域的风险也适用,用途十分广泛。     

调水工程线路方案优选的灰色系统模型及其应用

调水工程为解决区域间水资源分布不均衡问题提供了一种有效途径 .调水工程线路方案的优选问题涉及社会、经济、环境、技术等多方面的因素 ,是一个复杂的多目标决策问题 .本文建立了其评价指标体系 ,应用 AHP法和信息熵方法相结合确定评价指标权重 ,建立了调水工程线路方案优选的灰色系统评价模型 .算例显示方法的有效性 .     

奖学金的评定与模糊优选数学模型

本文运用模糊数学思想 ,按照相对隶属度原则 ,通过制定各门课程之间的权重系数 ,建立了一种新的奖学金评定的模糊优选数学模型 .该模型解决了按总成绩排名评定法中所存在的一些问题 .使评定的结果更具科学性与合理性 ,同时模型可推广到其它评比当中     

钻井方案数值优化设计

钻井是一项很复杂的工艺过程,其中包含了5种17个参数。如何最优的搭配本身就较为繁锁,更何况其中有一项是钻头类型这一非数值因素。因而国内外大多处于单钻头优化设计的水平上。我们和实际单位结合研究出了一种全并序列优化钻井设计方案。这一方案用于实际取得了很好效果,现在介绍出来供参考。     

A stochastic model for drilling optimization

Drilling optimization problems in oilfields are usually formulated and solved by using deterministic mathematical models, in which uncertain (indeterminate) factors or random issues are not taken into consideration. However, it has been widely experienced that random factors (such as those from soil layers, drill bits, and surface equipment) greatly affect the drilling performance. This paper introduces a new stochastic model for describing such random effects. This model, when used to optimization design, is more practical and provides a better characterization for real oilfield situations as compared with other deterministic models, and has been demonstrated to be more efficient in solving real design problems of drilling optimizations.     

An optimization model for software component selection under multiple applications development

Component based software development (CBSD) is well acknowledged as a methodology which establishes reusability of software and reduce development cost effectively. While developing enterprise application using component based software engineering (CBSE) methods, software component selection plays a very important role in the process of component retrieval, adaptation and assembly. However, most of current researches focus on technical aspects from domain engineering and application engineering to improve reusability and system efficiency rather than application of optimization methods in CBSD management, especially application in component selection. Moreover, few existing researches have concerned about the situation where a software developer or enterprise develops multi-applications at the same time. By introducing the concept of reusability and a new formulation of compatibility matrix, an optimization model is proposed to solve component selection problem considering reusability and compatibility simultaneously. The model can be used to assist software developers in selecting software components when multi-applications are undertaken concurrently. Four experiments are conducted with the purpose to provide some insights in management perspective.     

Improving weighted information criterion by using optimization

Although artificial neural networks (ANN) have been widely used in forecasting time series, the determination of the best model is still a problem that has been studied a lot. Various approaches available in the literature have been proposed in order to select the best model for forecasting in ANN in recent years. One of these approaches is to use a model selection strategy based on the weighted information criterion (WIC). WIC is calculated by summing weighted different selection criteria which measure the forecasting accuracy of an ANN model in different ways. In the calculation of WIC, the weights of different selection criteria are determined heuristically. In this study, these weights are calculated by using optimization in order to obtain a more consistent criterion. Four real time series are analyzed in order to show the efficiency of the improved WIC. When the weights are determined based on the optimization, it is obviously seen that the improved WIC produces better results.     

求解复杂优化问题的基于信息熵的自适应蚁群算法

针对基本蚁群算法存在收敛速度慢、易陷入局部最优、计算复杂且不易求解连续优化问题等缺陷 ,提出了一种基于信息熵的改进自适应蚁群算法 ,采用由信息熵控制的路径选择及随机扰动策略实现了算法的自适应调节 ,克服了基本蚁群算法的不足 .典型的 NP-hard问题的计算实例表明 ,该方法具有较好的收敛性、稳定性和鲁棒性 ,可用于离散及连续的组合优化问题求解中 ,其不失为求解复杂组合优化问题的一种较好的方法 .     

Variable Selection Via Subtle Uprooting

This article proposes a variable selection method termed “subtle uprooting” for linear regression. In this proposal, variable selection is formulated into a single optimization problem by approximating cardinality involved in the information criterion with a smooth function. A technical maneuver is then employed to enforce sparsity of parameter estimates while maintaining smoothness of the objective function. To solve the resulting smooth nonconvex optimization problem, a modified Broyden–Fletcher–Goldfarb–Shanno (BFGS) algorithm with established global and super-linear convergence is adopted. Both simulated experiments and an empirical example are provided for assessment and illustration. Supplementary materials for this article are available online.     

基于正弦控制因子的Lateral变异鲨鱼优化算法

针对传统鲨鱼优化算法在求解高维目标函数时,易早熟收敛,陷入局部最优的缺陷.提出一种基于正弦控制因子的Lateral变异鲨鱼优化算法.通过正弦曲线的特性和自适应惯性权重,改善了传统鲨鱼优化算法中由于随机选取控制因子数值大小可能导致算法在迭代后期全局搜索能力降低的问题,提高了算法在迭代后期的全局收敛能力,并对最佳鲨鱼位置引入Lateral变异策略,加强了算法跳出局部最优的可能性.改进后的算法对多个shifted单峰,多峰以及固定维测试函数进行求解,实验结果表明,对比多种不同优化算法而言,本文所提LSSO算法具有更高的收敛精度和搜索速度.     

求解图着色问题的量子蚁群算法

针对经典的图着色问题,在蚁群算法的基础上结合量子计算提出一种求解图着色问题的量子蚁群算法. 将量子比特和量子逻辑门引入到蚁群算法中,较好地避免了蚁群算法搜索易陷入局部极小的缺陷,并显著加快了算法的运算速度. 通过图着色实例的大量仿真实验,表明算法对图着色问题的求解是可行的、有效的,且具有通用性.     

Analysis of crossovers and selections in a coarse-grained parallel genetic algorithm

The parallel genetic algorithms (PGA) have been developed for combinatorial optimization problems, and its parallel efficiencies have been investigated on a specific problem. These investigations were concerned with how to design a topology and the determination of the optimum setting for parameters (for example, size of subpopulations, migration interval, and so on) rather than the effectiveness of genetic operators. This paper investigates a relation between the parallel efficiency of the coarse-grained PGA and genetic (crossover and selection) operators for the traveling salesman problem on an MIMD parallel computer. The following genetic operators are considered: improved edge recombination (IERX), distance preserving (DPX), and complete subtour exchange (CSEX) crossovers, and two selection operators, which have relatively high selection pressures. Computational results indicate that the parallel efficiency is significantly affected by the difference of crossovers rather than the selections, and the PGA with CSEX gives better properties.     

石油公司投资组合优化模型研究

项目选择与资金优化配置是石油公司经常要解决的实际问题 ,科学地、规范地解决这一问题 ,对提高资金利用率 ,促进石油行业的健康发展具有重大意义 .本文结合石油公司项目特点 ,运用投资组合理论建立了石油项目选择与资金优化配置模型 ,并研究了相应求解方法     

Nonlinear multivariable modeling and stability analysis of vibrations in horizontal drill string

Nowadays, economical extraction of the oil and gas, and their products is an important problem. Up to now, vertical wells have been used for oil extraction but some wells exist that they cannot be reached by using the vertical drilling. Horizontal and directional drillings are some techniques to reach these wells. In this article, dynamics of the horizontal drill string is studied. According to the forces that affect the dynamics of drilling, its longitudinal vibration is analyzed. After determination of the boundary conditions and normal modes of the system with using mode summation method, displacement of the bit is obtained. Finally, dynamics of the horizontal drill string is simulated and the effect of increasing the number of modes and the mode convergence phenomenon is discussed. Through this study, while it is shown that four modes are sufficient for a reliable prediction of the stable and unstable conditions; five modes are included for the system analysis. Then, the effects of other parameters such as the mud frequency and constants of bit/rock interaction model are studied. Through the proposed parametric study, the stability of the system is investigated. Moreover, the dominant modes which cause the instability of the horizontal drilling process are determined.