Improvement of Lagrangian relaxation performance for open pit mines constrained long-term production scheduling problem

Constrained long-term production scheduling problem(CLTPSP) of open pit mines has been extensively studied in the past few decades due to its wide application in mining projects and the computational challenges it poses become an NP-hard problem.This problem has major practical significance because the effectiveness of the schedules obtained has strong economical impact for any mining project.Despite of the rapid theoretical and technical advances in this field,heuristics is still the only viable approach for large scale industrial applications.This work presents an approach combining genetic algorithms(GAs) and Lagrangian relaxation(LR) to optimally determine the CLTPSP of open pit mines.GAs are stochastic,parallel search algorithms based on the natural selection and the process of evolution.LR method is known for handling large-scale separable problems; however,the convergence to the optimal solution can be slow.The proposed Lagrangian relaxation and genetic algorithms(LR-GAs) combines genetic algorithms into Lagrangian relaxation method to update the Lagrangian multipliers.This approach leads to improve the performance of Lagrangian relaxation method in solving CLTPSP.Numerical results demonstrate that the LR method using GAs to improve its performance speeding up the convergence.Subsequently,highly near-optimal solution to the CLTPSP can be achieved by the LR-GAs.

Basic Soil Productivity of Spring Maize in Black Soil Under Long-Term Fertilization Based on DSSAT Model

Increasing basic farmland soil productivity has significance in reducing fertilizer application and maintaining high yield of crops. In this study, we defined that the basic soil productivity （BSP） is the production capacity of a farmland soil with its own physical and chemical properties for a specific crop season under local environment and field management. Based on 22-yr （1990-2011） long-term experimental data on black soil （Typic hapludoll） in Gongzhuling, Jilin Province, Northeast China, the decision support system for an agro-technology transfer （DSSAT）-CERES-Maize model was applied to simulate the yield by BSP of spring maize （Zea mays L.） to examine the effects of long-term fertilization on changes of BSP and explore the mechanisms of BSP increasing. Five treatments were examined： （1） no-fertilization control （control）; （2） chemical nitrogen, phosphorus, and potassium （NPK）; （3） NPK plus farmyard manure （NPKM）; （4） 1.5 time of NPKM （1.5NPKM） and （5） NPK plus straw （NPKS）. Results showed that after 22-yr fertilization, the yield by BSP of spring maize significantly increased 78.0, 101.2, and 69.4% under the NPKM, 1.5NPKM and NPKS, respectively, compared to the initial value （in 1992）, but not significant under NPK （26.9% increase） and the control （8.9% decrease）. The contribution percentage of BSP showed a significant rising trend （P〈0.05） under 1.5NPKM. The average contribution percentage of BSP among fertilizations ranged from 74.4 to 84.7%, and ranked as 1.5NPKM〉NPKM〉NPK〉NPKS, indicating that organic manure combined with chemical fertilizers （I.5NPKM and NPKM） could more effectively increase BSP compared with the inorganic fertilizer application alone （NPK） in the black soil. This study showed that soil organic matter （SOM） was the key factor among various fertility factors that could affect BSP in the black soil, and total N, total P and/or available P also played important role in BSP increasing. Compared with the chemical fertilization, a balanced chemical plus manure or straw fertilization （NPKM or NPKS） not only increased the concentrations of soil nutrient, but also improved the soil physical properties, and structure and diversity of soil microbial population, resulting in an iincrease of BSP. We recommend that a balanced chemical plus manure or straw fertilization （NPKM or NPKS） should be the fertilization practices to enhance spring maize yield and improve BSP in the black soil of Northeast China.

Long-term organic and inorganic fertilizations enhanced basic soil productivity in a fluvo-aquic soil

The improvement of soil productivity depends on a rational input of water and nutrients, optimal field management, and the increase of basic soil productivity（BSP）. In this study, BSP is defined as the productive capacity of a farmland soil with its own physical and chemical properties for a specific crop season under local field management. Based on 19-yr data of the long-term agronomic experiments（1989–2008） on a fluvo-aquic soil in Zhengzhou, Henan Province, China, the decision support system for agrotechnology transfer（DSSAT ver. 4.0） crop growth model was used to simulate yields by BSP of winter wheat（Triticum aestivium L.） and summer maize（Zea mays L.） to examine the relationship between BSP and soil organic carbon（SOC） under long-term fertilization. Five treatments were included：（1） no fertilization（control）,（2） nitrogen, phosphorus and potassium fertilizers（NPK）,（3） NPK plus manure（NPKM）,（4） 1.5 times of NPKM（1.5NPKM）, and（5） NPK plus straw（NPKS）. After 19 yr of treatments, the SOC stock increased 16.7, 44.2, 69.9, and 25.2% under the NPK, NPKM, 1.5NPKM, and NPKS, respectively, compared to the initial value. Among various nutrient factors affecting contribution percentage of BSP to winter wheat and summer maize, SOC was a major affecting factor for BSP in the fluvo-aquic soil. There were significant positive correlations between SOC stock and yields by BSP of winter wheat and summer maize（P〈0.01）, and yields by BSP of winter wheat and summer maize increased 154 and 132 kg ha^（–1） when SOC stock increased 1 t C ha^（–1）. Thus, increased SOC accumulation is a crucial way for increasing BSP in fluvo-aquic soil. The manure or straw combined application with chemical fertilizers significantly enhanced BSP compared to the application of chemical fertilizers alone.

Assessment of Fatigue Strength of An Offshore Floating Production and Storage Unit

The procedure of assessment of structural fatigue strength of an offshore floating production and storage and offloading unit (FPSO) in this paper. The emphasis is placed on the long-term prediction of wave induced loading, the refined finite element model for hot spot stress calculation, the combination of stress components, and fatigue damage assessment based on S-N curve.

Improving performance of open-pit mine production scheduling problem under grade uncertainty by hybrid algorithms

One of the surface mining methods is open-pit mining,by which a pit is dug to extract ore or waste downwards from the earth’s surface.In the mining industry,one of the most significant difficulties is long-term production scheduling(LTPS)of the open-pit mines.Deterministic and uncertainty-based approaches are identified as the main strategies,which have been widely used to cope with this problem.Within the last few years,many researchers have highly considered a new computational type,which is less costly,i.e.,meta-heuristic methods,so as to solve the mine design and production scheduling problem.Although the optimality of the final solution cannot be guaranteed,they are able to produce sufficiently good solutions with relatively less computational costs.In the present paper,two hybrid models between augmented Lagrangian relaxation(ALR)and a particle swarm optimization(PSO)and ALR and bat algorithm(BA)are suggested so that the LTPS problem is solved under the condition of grade uncertainty.It is suggested to carry out the ALR method on the LTPS problem to improve its performance and accelerate the convergence.Moreover,the Lagrangian coefficients are updated by using PSO and BA.The presented models have been compared with the outcomes of the ALR-genetic algorithm,the ALR-traditional sub-gradient method,and the conventional method without using the Lagrangian approach.The results indicated that the ALR is considered a more efficient approach which can solve a large-scale problem and make a valid solution.Hence,it is more effectual than the conventional method.Furthermore,the time and cost of computation are diminished by the proposed hybrid strategies.The CPU time using the ALR-BA method is about 7.4%higher than the ALR-PSO approach.

济阳页岩油开发“三元”储渗理论技术与实践

基于济阳坳陷页岩油储层上万米岩心资料与60余口水平井的开发实践,提出济阳页岩油“储元”、“缝元”、“压元”的“三元”储渗理论。“三元”协同支撑济阳页岩油的富集高产:“储元”控制页岩油的富集,咸化湖盆无机孔-缝及灰-泥优质纹层组构发育利于页岩油储集,高生烃能力、高游离烃含量为高产提供物质基础;“缝元”控制页岩油的渗流,天然裂缝为页岩油的运移和聚集提供渗流通道,压裂改造缝沟通天然裂缝形成复杂缝网,为高产提供渗流基础;“压元”控制页岩油的高产稳产,高地层压力为油气运聚提供原始动力,压裂增能可进一步提高岩石及流体弹性能,强化孔缝原油渗吸置换,减缓应力敏感性,为长期稳产提供能量基础。基于“三元”储渗理论,形成了以立体井网优化、立体均衡压裂、全周期优化调控为核心的立体开发技术,有效指导了现场生产实施,为济阳页岩油规模化效益开发提供技术支撑。

多参数回归物质平衡法在水驱气藏气井生产动态预测中的应用

物质平衡法在水驱气藏气井生产动态指标预测中面临2项难题,即产能方程的建立和水侵量计算,影响指标预测精度。针对存在的问题,通过理论推导及经验回归,研究产能方程系数和气层压力、水侵量和气层总压差、产水量与产气量之间的变化规律。建立一种新的多参数回归物质平衡法:包括3个基础方程(水驱气藏物质平衡方程、二项式产能方程、井筒管流方程)和4个经验关系式(二项式产能方程系数A与气层压力、二项式产能方程系数B与气层压力、累计水侵量与气层总压差、累计产水量与累计产气量)。结果表明,多参数回归物质平衡法立足气井的生产动态数据,简化了产能方程建立和水侵量计算过程。经过实践检验,平均误差在5%以内,该方法满足现场实际要求。

考虑硫沉积影响的水平井稳产能力预测

水平井是高效开发高含硫气藏的主要井型。高含硫气藏在开发过程中,井筒附近压力下降,导致水平井井筒周围形成不规则的硫沉积区,严重的可能导致部分井筒单元没有气体流入。为了更好地对该类气藏进行气井稳产能力预测,构建了水平井分段渗流双区复合物理模型,建立了不稳定渗流数学模型,并采用Laplace积分变换、边界元和压降叠加对井底压力进行了求解。结合不稳定渗流数学模型与高含硫气藏物质平衡方程,构建气井稳产能力预测模型,分析了不同参数对稳产时间和井底压力的影响。研究结果表明:含硫饱和度、堵塞段与渗流段长度比值和水平段长度等对稳产时间和井底压力有着非常明显的影响,含硫饱和度和水平段长度与气井稳产时间呈指数变化关系。通过对元坝气藏某水平井进行实例分析,验证了该方法的准确性,该模型和方法的建立为高含硫气藏水平井稳产能力预测提供了理论依据。

我国保障粮食和重要农产品稳定安全供给的路径研究

保障粮食和重要农产品稳定安全供给是一个重大的战略性问题。稳定安全供给既强调保障粮食安全,同时将其他重要农产品的供给安全问题提高到了新的层次,是对过去“稳定供给”“有效供给”等诸多提法的深化拓展。本文在界定粮食和重要农产品稳定安全供给基本内涵的基础上,分析了我国粮食和重要农产品稳定安全供给面临的新形势和突出障碍。研究发现,我国粮食稳定安全供给水平整体上升,但棉花、生猪等重要农产品稳定安全供给水平存在波动。保障粮食和重要农产品稳定安全供给,面临粮食生产与水资源的空间匹配矛盾、农业供给体系韧性不强、农业生产激励机制不完善、农业生产空间拓展不快、现代农业产业体系不健全等挑战。因此,应树立和践行大农业观、大食物观,积极拓展农业战略性增长空间、提升水土资源匹配性、强化农业科技颠覆性创新、构建安全可靠的粮食和重要农产品供应链体系、健全现代乡村产业体系,全面提升粮食和重要农产品稳定安全供给能力。

长庆气区关停气井挖潜措施技术与展望

长庆气区天然气资源丰富,天然气田均为低渗—致密气田,主要以致密气为主。随着气田开发深入,存在气区关停井、低产井“存量大、分布广、复产难”实际问题,为气区的长期效益稳产带来艰巨挑战。文章通过开展长庆气区关停井措施挖潜实践及应用评价,结合气井动静态特征,分析气井关停的形成原因及技术难点,优选挖潜措施类型,优化工艺参数,强化效果评价,初步形成了“储层挖潜、井筒治理、地面配套”三大评价挖潜措施工艺技术系列,实施挖潜井1497口,累计增气超50×10^(8) m^(3),成效显著。随着长庆气区天然气勘探开发不断推进,气藏“埋藏深、储层薄、单井产量低、水气比高”特点更加突出,还需进一步开展老层剩余储量挖潜、层间储量动用、井筒复杂处理、积液停产井快速复产及综合治理、地面工艺技术配套等技术攻关,以实现气田气井挖潜措施工艺关键技术的迭代升级,更好支撑长庆气区的稳产及长远发展目标。长庆气田老井措施挖潜及增产技术体系的建立,助力了长庆气区的增储上产,为长庆气区稳固国内战略大气区地位及长期发展提供了较好的参考及借鉴。

“非遗+AI”模式下的湖南土特产包装创新设计

目的探究“非遗+AI”新模式下湖南土特产包装的创新设计形式,传承和发展非遗文化,提升土特产包装的文化内涵,提高传统包装的科技含量,以适应当代消费者不断提升的审美和消费需求。方法通过问卷调查、深度访谈等方法,分析“非遗+AI”模式与当代湖南土特产包装的设计现状,了解消费者对包装设计的不同需求,总结设计策略,并基于“非遗+AI”新模式下机器学习和深度学习技术,借助SD(Stable Diffusion,稳定扩散模型)架构下的Lora模型(Low-RankAdaptation of Large Language Models,大语言模型的低秩适用方法),进行踏虎凿花在岳阳王鸽土特产包装设计中的创新应用实践。结果生成出紧跟新时代数字技术,驱动非遗文化活态传承的包装设计图案,从而实现湖南土特产包装的创新设计探索。结论基于“非遗+AI”模式下的SD模型技术,对泸溪踏虎凿花进行创新转化并应用在湖南土特产岳阳王鸽包装设计中,既活化了传统手工艺的表达形式,又创新了土特产的包装表现手法,为其他非遗文化元素和产品包装的有机融合提供了新路径。

大庆油田原油高质量稳产必要条件及技术策略

大庆油田已全面进入“后油藏”“非常规”开发时代,面临着剩余资源劣质化、成本刚性增长、接替技术尚未成熟配套等诸多挑战,老油田如何继续保持产量规模、开发技术、经济效益、经营管理的高质量成为亟待解决的问题。从保障国家能源战略安全、当好标杆旗帜、高质量发展内涵3个维度系统分析新时代油田原油保持高质量稳产的战略意义,从待探明资源、未动用储量、已开发油田分类挖潜3个层次进一步夯实油田高质量发展的物质基础,从大庆油田稳产文化、主体技术、管理模式证实油田保持高质量稳产是客观规律使然。制定“稳定长垣、攻坚外围、突破页岩油”开发主线,优化技术领域,细化对策部署,明确大庆油田原油高质量稳产技术策略,为推动大庆油田成长“第二曲线”加速上扬发挥主力军作用。

辽西半干旱区玉米花生间作对不同降水年型下产量与水分利用效率的影响

针对辽西半干旱地区降雨不足、水资源分布不均等问题,筛选出更具有韧性的适应气候变化的种植模式,通过田间试验,以玉米(MS)和花生(PS)单作为对照,研究玉米花生2行/2行(M2P2)、玉米花生4行/4行(M4P4)和玉米花生8行/8行(M8P8)这3种间作种植模式对不同降水年型下的产量和水分利用效率的影响。结果表明:不同降水年型中玉米花生间作LER均大于1,3年M2P2、M4P4和M8P8处理土地当量比(land equivalent ratio,LER)分别为1.02~1.08,1.10~1.15,1.07~1.08,表明能够提高农田的生产力。随着间作条带宽度增加,玉米的间作优势和花生的间作劣势均减弱。玉米具有边行优势,花生则存在边行劣势,同一间作处理中边1行玉米产量显著高于其他边行和玉米单作,边1行花生产量则显著低于其他边行和花生单作。发挥玉米的边行优势,降低花生的边行劣势,是实现玉米花生间作高产高效的重要途径。玉米花生间作具有稳产性,其主要原因是不同降水年型的间作玉米产量以及收获指数差异不显著。随着间作带幅变小间作玉米收获指数、单位面积穗数、穗粒数和百粒重有增加趋势,而间作花生则下降。不同降水年份间,玉米单位面积穗数和穗粒数、花生单位面积荚数和荚粒数差异显著,玉米和花生百粒重差异不显著。不同降水年型中M4P4的LER和WER均最高(1.09~1.15),是适宜在辽西半干旱地区的间作种植模式。

漳泽水库浮游生物群落结构和鲢、鳙食性及鱼产力评估

为探究漳泽水库中鲢、鳙放养对富营养化控制的效果,基于碳(δ^(13)C)、氮(δ^(15)N)稳定同位素技术于2022年7月研究了漳泽水库鲢、鳙的主要食物来源和营养级,同时于2022年春夏及2023年秋季进行了浮游生物的群落组成调查和鲢、鳙鱼产力评估,探讨鲢、鳙控藻效果。结果表明,浮游植物对鲢、鳙的平均相对贡献分别为68.5%和68.8%,浮游动物对鲢、鳙的平均相对贡献分别为31.5%和31.2%,用来控藻的鲢、鳙均以浮游植物为主要食物来源。而浮游植物生物量有所增加,蓝藻代替2019年的绿藻成为新的优势种,水库富营养化未得到有效控制。根据浮游生物生物量估算鲢的鱼产力为732.521 t、鳙的鱼产力为310.106 t。本研究可为富营养化湖库中鲢、鳙控藻效果及生态利用提供参考。

新质生产力赋能冰雪运动的时态演变、样态创新与稳态发展

新质生产力是指以创新为主导的先进生产力质态,能够为冰雪运动的整体进步与升级创造机遇。通过分析新质生产力对于冰雪运动的赋能进程,得出其分为引入与适应新质生产力的初始阶段、深化与扩展新质生产力的发展阶段、稳定与优化新质生产力的成熟阶段三种时态演变;在发展样态上,分别涉及冰雪运动装备与训练方法的技术创新、赛事组织与运营模式的管理创新、冰雪运动传播途径的文化创新。为使新质生产力更好地赋能冰雪运动保持稳态发展,提出从政策方面构建有利于冰雪运动发展的环境;从人才方面加强冰雪运动专业人才的培育;从市场方面拓展冰雪运动的商业潜力与社会影响力等策略。通过将理念创新、科技创新与冰雪运动紧密结合,以新质生产力推动冰雪运动可持续发展,从而助力我国形成特色的现代化体育发展方式,同步建设科技强国和体育强国。

Shale oil development techniques and application based on ternary-element storage and flow concept in Jiyang Depression,Bohai Bay Basin,East China

The ternary-element storage and flow concept for shale oil reservoirs in Jiyang Depression of Bohai Bay Basin,East China,was proposed based on the data of more than 10000 m cores and the production of more than 60 horizontal wells.The synergy of three elements(storage,fracture and pressure)contributes to the enrichment and high production of shale oil in Jiyang Depression.The storage element controls the enrichment of shale oil;specifically,the presence of inorganic pores and fractures,as well as laminae of lime-mud rocks,in the saline lake basin,is conducive to the storage of shale oil,and the high hydrocarbon generating capacity and free hydrocarbon content are the material basis for high production.The fracture element controls the shale oil flow;specifically,natural fractures act as flow channels for shale oil to migrate and accumulate,and induced fractures communicate natural fractures to form complex fracture network,which is fundamental to high production.The pressure element controls the high and stable production of shale oil;specifically,the high formation pressure provides the drive force for the migration and accumulation of hydrocarbons,and fracturing stimulation significantly increases the elastic energy of rock and fluid,improves the imbibition replacement of oil in the pores/fractures,and reduces the stress sensitivity,guaranteeing the stable production of shale oil for a long time.Based on the ternary-element storage and flow concept,a 3D development technology was formed,with the core techniques of 3D well pattern optimization,3D balanced fracturing,and full-cycle optimization of adjustment and control.This technology effectively guides the production and provides a support to the large-scale beneficial development of shale oil in Jiyang Depression.

唐钢2号高炉长稳高效生产实践

长周期稳定顺行是高炉炼铁追求的目标,唐钢2号高炉开炉达产后,通过采取优化炉料结构、提高原燃料质量、优化高炉操作制度、强化管理等手段,高炉日产在8800 t/d以上,利用系数3.0 t/m^(3),实现了高炉的长稳高效生产。

河西务油田务45断块稳产对策研究

务45断块构造复杂,注水见效较差,历年来针对断块措施工作量少,使油藏长期处于低产状态生产,需加大断块综合治理工作,改善开发效果。本文通过区块研究准确认识油藏的开发生产规律,针对存在的问题和潜力进行分类梳理,并制定出相应的开发技术对策,以期为夯实老油田稳产基础提供参考。

“一点法”产能评价方法的内涵、矿场应用及改进

近年来,在四川盆地气井产能评价实践中发现,针对低渗强非均质性和中高渗储层,常规“一点法”适用性差。为探索并解决该问题,文中系统梳理并总结了“一点法”产能评价方法的不同形式,揭示了其内涵。“一点法”的内涵主要包括均质储层、可靠的稳定经验数、气井现场测试达到拟稳定渗流状态3个方面,围绕这3个方面的内涵,指明了“一点法”的矿场应用偏差。在此基础上,首先深入剖析了“一点法”计算参数的敏感性;其次对矿场应用提出了改进和数据处理方法,建立了稳定经验数与试井地层系数的经验关系式及不同层系试井地层系数与测井储能系数拟合关系式;再次,提出了不同类型气井测试数据评价方法及试油建议;最后应用文中建立的“一点法”改进方法对四川盆地不同气田的31口气井进行了计算对比,验证了方法的可靠性和可行性。该改进方法不仅适用于常规“一点法”的应用领域,也适用于具有低渗强非均质性、中高渗地质特征的气田,弥补了特定地质条件下常规“一点法”确定气井稳定产能误差大的不足,对于气田的开发设计、规模调整和现场生产组织均具有积极意义。