Spatial Patterns and Controlling Factors of Soil Organic Carbon and Total Nitrogen in the Three River Headwaters Region,China

The alpine ecosystem has great potential for carbon sequestration.Soil organic carbon(SOC)and total nitrogen(TN)are highly sensitive to climate change,and their dynamics are crucial to revealing the effect of climate change on the structure,function,and services of the ecosystem.However,the spatial distribution and controlling factors of SOC and TN across various soil layers and vegetation types within this unique ecosystem remain inadequately understood.In this study,256 soil samples in 89 sites were collected from the Three River Headwaters Region(TRHR)in China to investigate SOC and TN and to explore the primary factors affecting their distribution,including soil,vegetation,climate,and geography factors.The results show that SOC and TN contents in 0-20,20-40,40-60,and 60-80 cm soil layers are 24.40,18.03,14.04,12.40 g/kg and 2.46,1.90,1.51,1.17 g/kg,respectively;with higher concentrations observed in the southeastern region compared to the northwest of the TRHR.One-way analysis of variance reveals that SOC and TN levels are elevated in the alpine meadow and the alpine shrub relative to the alpine steppe in the 0-60 cm soil layers.The structural equation model explores that soil water content is the main controlling factor affecting the variation of SOC and TN.Moreover,the geography,climate,and vegetation factors notably indirectly affect SOC and TN through soil factors.Therefore,it can effectively improve soil water and nutrient conditions through vegetation restoration,soil improvement,and grazing management,and the change of SOC and TN can be fully understood by establishing monitoring networks to better protect soil carbon and nitrogen.

Variations in evaporation from water surfaces along the margins of the Badain Jaran Desert over nearly 60 years and influencing factors

Based on meteorological data collected over nearly 60 years(1960-2017)from four national meteorological stations along the margins of the Badain Jaran Desert,this study analyzed the spatiotemporal variations in evaporation from water surfaces and identified the dominant controlling factors.Methods used included linear trend analysis,linear tendency estimation,the departure method,the rank correlation coefficient-based method,and Multiple Linear Regression(MLR).Results indicate notable spatiotemporal differences in evaporation distribution and evolution.Spatially,average annual evaporation exhibited a pronounced altitude effect,decreasing at a rate of about 8.23 mm/m from east to west with increasing altitude.Temporally,annual evaporation showed significant upward trends after 1996 at the northeastern(Guaizi Lake)and western(Dingxin)margins,with rates of 132 mm/10a and 105 mm/10a,respectively.Conversely,along the northwestern(Ejina Banner)and southern(Alxa Right Banner)margins of the desert,an evaporation paradox was observed,with annual evaporation trending downward at rates of 162 mm/10a and 187 mm/10a,respectively,especially after 1987.The dominant factors controlling evaporation varied spatially:Average annual temperature and relative humidity influended the western margin(Dingxin),average annual temperature was the key factor for the northeastern margin(Guaizi Lake),and average wind speed was crucial for the northern(Ejina Banner)and southern(Alxa Right Banner)margins.

Impact of Controllable Factors on Export Performance of SMEs in Jordan

Exporting is of great interest for SMEs in Jordan from both microeconomic and macroeconomic perspective.The objective of this study was to identify to what extent specific internal factors contribute to export success of SMEs in Jordan.This study hypothesized that export performance of SMEs is directly affected by three groups of internal factors.These include firm characteristics,managerial characteristics,and marketing strategy.A multiple case approach is used to conduct this research and a structured interview is developed to collect the data directly from the participants.A pattern matching approach was used to test the hypotheses.The results show that export performance is positively affected by firm characteristics,managerial characteristics,and marketing strategy.Additionally,the demographic characteristics of managers and adaptation of distribution channels are unlikely to have an influence on export performance.This was unexpected,because of the plenty of empirical evidences in the literature that support the impact of these variables on export success.

Development characteristics and controlling factors of fractures in lacustrine shale and their geological significance for evaluating shale oil sweet spots in the third member of the Shahejie Formation in the Qikou Sag, Bohai Bay Basin

Natural fractures are critical for shale oil and gas enrichment and development. Due to the extremely high heterogeneity of shale, the factors controlling the formation of internal fractures, especially horizontal fractures, remain controversial. In this study, we integrate thin section analysis and microcomputed tomography(CT) data from several lacustrine shale samples from the third member(Es3) of the Shahejie Formation, Qikou Sag, Bohai Bay Basin, to assess the fractures in detail. The goal is to reveal the development characteristics, controlling factors, and geological significance for evaluating sweet spots in a shale oil play. The fractures in the Es3contain high-angle structural and horizontal bed-parallel fractures that are mostly shear and extensional. Various factors influence fracture development,including lithofacies, mineral composition, organic matter content, and the number of laminae. Structural fractures occur predominantly in siltstone, whereas bed-parallel fractures are abundant in laminated shale and layered mudstone. A higher quartz content results in higher shale brittleness, causing fractures, whereas the transformation between clay minerals contributes to the development of bedparallel fractures. Excess pore pressure due to hydrocarbon generation and expulsion during thermal advance can cause the formation of bed-parallel fractures. The density of the bed-parallel and structural fractures increases with the lamina density, and the bed-parallel fractures are more sensitive to the number of laminae. The fractures are critical storage spaces and flow conduits and are indicative of sweet spots. The laminated shale in the Es3with a high organic matter content contains natural fractures and is an organic-rich, liquid-rich, self-sourced shale play. Conversely, the siltstone, massive mudstone, and argillaceous carbonate lithofacies contain lower amounts of organic matter and do not have bed-parallel fractures. However, good reservoirs can form in these areas when structural fractures are present and the source, and storage spaces are separated.

Associated Factors to Poor Blood Pressure Control in Hypertensives Followed Up at the Campus University Hospital of Lome (Togo)

Introduction: Hypertension is a real public health issue and its control is very difficult. We aim to determine the frequency of uncontrolled hypertension in hypertensive patients followed up as an outpatient at the campus university hospital of Lome (Togo) and to search for the associated factors. Methodology: The study was cross-sectional, descriptive and analytical, carried out from February (2022) to August 2022 in 260 hypertensive patients aged 22 years old, followed up (on an) as an outpatient for at least 3 months at the Lome University Hospital campus. A univariate then multivariate analysis were conducted in order to highlight the most common factors significantly linked to uncontrolled. Results: The mean age of hypertensives was 56.4 ± 12.7 years, the sex ratio (M/F) was 0.59. Prevalence of uncontrolled blood pressure was 42%. Associated Factors to poor blood pressure control in our study were age > 60 years (OR = 1.6 CI [1.17 - 2.50]), low socio-economic level (OR = 2.2 CI [1.96 - 4.33]), high cardiovascular risk level (OR = 3.1 CI [2.18 - 4.52]), non-adherence to regular blood pressure monitoring (OR = 3.3 CI [2.21 - 5.55]), low compliance to treatment (OR = 4.1 CI [2.33 - 6.76]) and a chronic renal failure (OR = 2.1 CI [1.21 - 3.10]). Conclusion: Nearly half of the hypertensives in our study had poorly controlled blood pressure by antihypertensive treatment medication. The factors of this poor control were age > 60 years, low socio-economic level, high or very high level of cardiovascular risk, low compliance to treatment, and renal failure.

Spatial-temporal heterogeneity and controlling factors of evapotranspiration in Nujiang River Basin based on Variable Infiltration Capacity(VIC)model

Land surface evapotranspiration(ET)is a critical component in the hydrological cycle but has not well been understood in data-scarce areas especially in river basins,like Nujiang River(NRB)which is characterized by large elevation gradient and different vegetation zones with complex processes of water and energy exchange.The quality of ET from optical remote sensing is constrained by cloud cover which is common in the NRB in the monsoon seasons.To understand factors controlling the spatial-temporal heterogeneity of ET in NRB,we employed the Variable Infiltration Capacity(VIC)hydrological model by parameter optimization with support of quality controlled remote sensing ET product and observed river runoff series in the river.The modeled ET has increased during 1984-2018,which might be one of the reasons for the runoff decrease but precipitation increase in the same period.ET increase and runoff decrease tended to be quicker within altitudinal band of 2000-4000 m than in other areas in NRB.We observed that ET variation in different climatic zones were controlled by different factors.ET is generally positively correlated with precipitation,temperature,and shortwave radiation but negatively with relative humidity.In the Tundra Climate(Et)zone in the upper reach of NRB,ET is controlled by precipitation,while it is controlled by shortwave radiation in the snow climate with dry winter(Dw)zone.ET increase is influenced by the increase of temperature,wind speed,and shortwave radiation in the middle and downstream of NRB with warm temperate climate,fully humid(Cf)and warm temperate climate with dry winter(Cw).

Enrichment model and major controlling factors of below-source tight oil in Lower Cretaceous Fuyu reservoirs in northern Songliao Basin,NE China

Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.

Differences in hydrocarbon accumulation and controlling factors of slope belt in graben basin: A case study of Pinghu Slope Belt in the Xihu sag of the east China Sea Shelf basin(ECSSB)

The Pinghu slope belt in the Xihu sag of the East China Sea Shelf Basin(ECSSB) is a crucial hydrocarbon production area in eastern China. However, due to the complex geological conditions, publications have lacked comprehensive research on the spatial-temporal coupling relationships of primary factors that impact hydrocarbon accumulation in the Pinghu slope belt. Furthermore, the hydrocarbon distribution patterns and the controlling factors across different study areas within the same slope belt are not yet fully understood. This study extensively utilized three-dimensional seismic data, well logging data,geochemical analysis, fluorescence analysis, and oil testing and production data to address these issues.Following a “stratification and differentiation” approach, the study identified seven distinct hydrocarbon migration and accumulation units(HMAU) in the Pinghu slope area based on the structural morphology characteristics, hydrocarbon source-reservoir-cap rock patterns, hydrocarbon migration pathways, and hydrocarbon supply range. Detailed analysis was conducted to examine the hydrocarbon distribution patterns and controlling factors within each migration and accumulation unit across different structural units, including high, medium, and low structural components. All data sources support a “southern-northern sub-area division, eastern-western sub-belt division, and variations in hydrocarbon accumulation” pattern in the Pinghu slope belt. The degree of hydrocarbon accumulation is controlled by the factors of structural morphology, hydrocarbon generation potential of source rocks, the spatial position of source slopes, fault sealing capacity, and sand body distribution. Furthermore, different coupling patterns of faults and sand bodies play a pivotal role in governing hydrocarbon enrichment systems across various migration and accumulation units. These observations indicate that three hydrocarbon accumulation patterns have been established within the slope belt, including near-source to far-source gentle slope with multiple hydrocarbon kitchens in the XP1-XP4 zones, near-source to middle-source gentle slope with dual-hydrocarbon kitchens in the XP5 zone, and near-source steep slope with a single hydrocarbon kitchen in the XP6-XP7 zones. These findings contribute to enhancing the theoretical system of hydrocarbon accumulation in the slope belt.

Baoziwan-Majiashan Area of Jiyuan Oilfield Analysis of Reservoir Characteristics and Main Control Factors in Long 4 5 Section

Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10−3 µm2. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir.

Study on Influencing Factors and Control Points of Design Estimate of Landscaping Engineering

In recent years,China’s landscaping projects have developed vigorously,and the growth rate of urban garden green space areas has been maintained at about 5%.Overall,with the development of the national economy and the support of macro policies,people’s demand for close to nature and beautify the environment is gradually increasing,which has brought new growth momentum for the development of the landscaping industry.Simultaneously,from the perspective of future economic development and urban development,the landscaping industry still has a lot of room for development.However,with the rapid development of landscape engineering,the problem of cost control of landscape engineering is becoming more prominent,the phenomenon of budget overestimation is common,and there are many factors affecting the cost of landscape engineering,which brings difficulties and challenges to the analysis of its influencing factors and cost management.How to scientifically analyze the influencing factors and control the cost has become an important link in the landscaping project.To solve the above problems,this paper takes the design stage of landscaping engineering as the background,takes the design estimate of landscaping engineering as the research object,through literature research and data collection,fully excavates the main influencing factors of the design estimate stage of landscaping engineering,analyzes the key points of cost control,and provides reference ideas and directions for the later cost management and control.

四川盆地东部侏罗系陆相页岩优质储层发育机理及其油气地质意义

四川盆地东部复兴地区涪页10井在侏罗系自流井组东岳庙段测试获得高产油气流,进一步证实了陆相页岩具有巨大的油气勘探潜力。但东岳庙段页岩具有高黏土矿物含量、富介壳夹层和较高有机质热演化程度等特殊性,是一种新类型陆相页岩,其优质储层发育特征及影响因素尚缺乏系统研究。为此,综合利用X射线衍射、薄片鉴定、氩离子抛光扫描电镜、压汞—液氮吸附联测、主微量元素分析和纳米CT等多技术手段,深入剖析了东岳庙段陆相页岩储层发育特征,探讨了优质页岩储层发育的控制因素,最后明确了其油气地质意义。研究结果表明:(1)东岳庙段陆相页岩具有“多孔缝共生—无机孔为主—大孔大喉”的储集空间发育特征,发育以黏土矿物晶间孔为主的8种类型孔隙和成岩收缩缝、生烃超压缝等类型微裂缝,无机孔占比为80%~90%,孔隙结构以介孔和宏孔为主,页岩孔喉半径较大,纹层状介壳/粉砂黏土页岩相和纹层状介壳黏土页岩相2种纹层状页岩具有较好的烃源岩品质,为东岳庙段优质储层类型;(2)纹层状介壳黏土页岩相储层具有“高黏土矿物扩孔—高演化生孔—层偶界面成缝—超压保孔缝”的成储机制,沉积环境控制了纵向上页岩垂向非均质性,高黏土矿物含量对增大储集空间有积极作用,半深湖沉积环境保障了优质岩相的发育,纹层沉积构造与页岩形成的层偶界面为应力弱面,易形成微裂缝;(3)较高有机质热演化阶段发生的黏土矿物转化作用、有机质热解和溶蚀作用直接影响了“大孔大喉”的储集空间特征,超压系统、致密介壳隔层为孔缝的保持奠定了保存基础。结论认为,取得的研究成果进一步完善了陆相复杂岩相页岩优质储层发育机理认识,丰富了中国陆相页岩油气地质理论,为新类型陆相页岩油气的勘探选区、选层提供了理论指导。

准噶尔盆地东部隆起煤层气成藏条件与选区评价

准噶尔盆地东部隆起具有较好的煤层气勘探前景,开展煤层气选区与评价,将为该区煤层气勘探提供科学依据和勘探方向。利用探井钻测录试资料、岩心分析测试数据和地震资料,开展井—震标定和地震剖面解释,编制了侏罗系八道湾组和西山窑组煤层连井剖面和煤层厚度分布图;分析了研究区内煤层气气源、煤岩基本特征、储层物性、含气性和保存条件等成藏主控因素。研究表明:(1)西山窑组煤层在沙奇凸起以北五彩湾凹陷—梧桐窝子凹陷连片分布,在沙奇凸起以南则主要分布于吉木萨尔凹陷—吉南凹陷;八道湾组煤层分割性较强,主要分布于凹陷内部分地区。(2)区内存在自源型煤层生物成因气、低成熟热成因气和深部外源型高成熟气条件。(3)煤岩有机组分以惰质组为主,镜质组次之,壳质组少量;煤岩镜质组反射率低(0.39%~0.47%),为低煤级煤;煤岩瓦斯气体成分主要为N_(2)、CO_(2)和CH_(4),其中N_(2)占绝对优势;煤岩总含气量中可燃气体(CH_(4))含量低。(4)煤层气富集成藏模式分为山前断陷富集成藏模式、深部凹陷富集成藏模式和开放斜坡逸散模式。(5)建立了煤层气评价参数和划分标准,五彩湾凹陷、梧桐窝子凹陷、吉木萨尔凹陷和吉南凹陷为煤层气勘探有利区;沙帐断褶带和石钱滩凹陷为较有利区;石树沟凹陷和古城凹陷为不利区。

黄河河道的主控因素及其衍生地质问题

在黄河的形成与演化研究中,长久被轻视但极为重要的记录是河道的形态、产出位置及其与河岸地质体的依存关系。研究认为,黄河河道总体呈现长线型延伸、短折线拐弯、锯齿状摆动3种延伸样式,区域大地构造演化、断裂构造作用等内动力地质作用是黄河河道形成与演化的主控因素,青藏高原、鄂尔多斯地块周缘和华北平原是区域大地构造演化所形成的3个独特构造-地貌单元,流域的构造因素分别造就了反Z形、“几”字形和宽V形3种几何学形态迥异的河道组合样式,3种样式河段在形成与演化中,衍生出各自特有的地质、工程、开发与保护等方面问题,据此提出了开发治理建议。

高管限薪方式与国有企业高质量发展

2009年和2015年中华人民共和国人力资源和社会保障部和国务院国有资产监督管理委员会先后出台了国有企业高管限薪规定,采取了绝对限薪和相对限薪两种不同方式,因此,有必要明晰哪一种方式更有利于促进国有企业高质量发展。以2010—2023年的A股国有企业为样本进行研究,结果表明:与绝对限薪相比,相对限薪更能够促进国有企业高质量发展,且相对限薪程度越高、内部控制质量越高,上述关系越明显。进一步研究发现,相对限薪促进国有企业发展质量提高是通过降低盈余管理、提高创新效率等路径实现的,且这种作用路径在产品市场竞争度高的国有企业和实体国有企业中更明显。研究结论对合理制定和有效实施限薪政策及提高企业内部控制质量,促进国有企业高质量发展具有启示意义。

四川盆地东南部南川地区煤层气地质特征及富集主控因素

四川盆地东南部南川地区上二叠统龙潭组深层煤层气勘探取得重要战略突破,展现出该区煤层气良好的勘探潜力。为揭示其富集主控地质因素,利用钻井、岩心、测井及实验分析等资料,从龙潭组煤层分布、煤岩煤质、物性、含气性以及可压裂性特征等方面入手,开展了煤层气地质特征与富集主控地质因素研究。研究表明:(1)龙潭组主力煤层具有分布稳定(厚度2.8~5.7 m)、煤体结构好(主要为原生结构煤)、镜质组含量高(平均含量79.7%)、热演化程度较高(R_(o)平均为1.9%)和灰分产率较低(平均14.3%)的特点,具备形成煤层气藏的基本条件;(2)煤储层为孔隙—裂隙型储层,微孔占比78%,其比表面积占比达99.6%,有利于煤层气的吸附及压裂后渗流;(3)煤层总含气量为14.0~46.7 m^(3)/t,游离气占比为39%~44%,具有“高含气、富含游离气、过饱和”及含气量随埋深增加而增大的特征;(4)研究区地应力适中(35~60 MPa),两向水平应力差异系数小(<0.1),顶底板条件好,可形成良好的应力隔挡,有利于压裂改造;(5)南川地区煤层气富集主控地质因素为沉积环境控制含煤建造、演化程度控制生烃强度、保存条件控制富集程度。

永磁轮毂电机最优磁链矢量无权重价值函数模型预测转矩控制

永磁轮毂电机的外转子通常与轮辋轮胎直接相联结,相比内转子永磁驱动电机,转动惯量较大,其速度响应明显滞后负载变化。因此,复杂运行工况下,永磁轮毂电机驱动系统转速不稳定,电动车辆行走路径易出现偏移。为解决轮毂驱动下电动车辆的这一固有技术难题,提出一种磁链为唯一约束条件的无权重价值函数模型预测转矩控制(model predictive torque control,MPTC)策略,可实现复杂多变动态工况下电动车辆稳定运行的工作需求。所提价值函数将转矩、定子磁链幅值约束统一为定子磁链矢量的优化,消除了权重系数的整定,提高了复杂运行工况下轮毂电机的反应速度。同时,引入有效电压矢量与零电压矢量切换瞬间的定子磁链,以此为评估依据选择最优电压矢量,可降低转矩与定子磁链脉动,从而提高轮毂电机转速控制精度。实验验证了控制方法的正确性和有效性。

深层煤岩压裂液稠化剂吸附损害机理与控制对策

选取鄂尔多斯盆地石炭系本溪组典型8~#深层煤岩开展静态吸附和动态损害实验,评价压裂液稠化剂羟丙基胍胶和聚丙烯酰胺在深层煤岩表面的吸附量和吸附引起的渗透率损害;采用原子力显微镜定量表征稠化剂的吸附形貌,分析稠化剂吸附的主要控制因素,同时采用Zeta电位、傅里叶红外光谱、X射线光电子能谱等技术揭示稠化剂的吸附机理。研究表明:实验条件下,深层煤岩对羟丙基胍胶、聚丙烯酰胺的吸附量分别为3.86mg/g和3.29mg/g,吸附后煤岩渗透率分别下降35.24%~37.01%和14.31%~21.93%;压裂液稠化剂吸附层厚度与稠化剂质量分数正相关,与温度负相关,pH值降低将减小羟丙基胍胶吸附层厚度、使聚丙烯酰胺吸附层厚度分布频率更集中;官能团缩聚、分子间作用力是深层煤岩吸附压裂液稠化剂的化学和物理作用力。通过优化稠化剂质量分数、对稠化剂分子进行化学改性、对聚合物进行氧化生热降解、添加解吸附剂等方法可降低煤岩微纳米级孔隙、裂缝的损害风险。

一种低电压应力的三电平PFC电路研究

三电平及多电平电路具有更小的直流侧电压脉动和降低电路损耗的优点,并且能使直流侧电流波形更接近正弦化,因此提出一种基于四开关三电平PFC电路。利用四个开关管进行组合,使其具有多向开关功能,不仅能将输出电压抬升至三电平,降低开关管电压应力,还能为电感充电提供回路。同时该电路在每个模态最多两个开关管开通并共用一个脉冲信号,一定意义上简化了控制复杂度。最后,通过搭建一个额定功率为800 W的实验平台,验证理论分析正确性。

鄂尔多斯盆地神府区块深部煤层气井产量主控因素及合理压裂规模优化

鄂尔多斯盆地神府区块深层煤层气井产量差异大,主控因素认识不清。为进一步揭示神府区块深层煤层气井生产规律,查明气井产能关键影响因素,指导深层煤层气高效开发,基于神府区块基础地质资料、生产数据和前人研究成果,剖析了区内典型煤层气井生产动态特征,从单井对比、整体规律上认识神府区块深层煤层气井产量主控因素,其中含气量和压裂规模对产量影响较大。利用皮尔逊多元相关系数回归技术对各产能影响因素进行了定量评价,确定深层煤层气压后产能的影响因素,按相关性排序依次为:含气量>压裂砂量>施工排量>压裂液量>构造深度>厚度。明确地质条件一定时,合理的压裂规模是深部煤层气井高效开发的关键。并综合不同专业形成了“地质气藏—压裂—经济评价”多专业一体化研究方法,以经济效益为目标,利用数值模拟方法进行深层煤层气井井距和压裂规模耦合优化研究,确定神府区块最优井距为300 m、最优簇间距20 m、最优裂缝半长120 m,为神府区块深层煤层气资源高效开发提供技术支撑。

基于深度学习的页岩油生产井最终可采储量预测模型--以吉木萨尔凹陷芦草沟组为例

针对吉木萨尔页岩油地质、工程和流体参数复杂,传统动态分析方法难以明晰页岩油水平井最终可采储量(EUR)主控因素的现状,提出了一种结合主成分分析(PCA)和深度神经网络(DNN)的页岩油水平井EUR预测模型,开展了数据降维、生产预测以及主控因素分析。研究结果表明:1)相比传统DNN模型,主成分分析-深度神经网络(PCA-DNN)模型能够有效减少数据噪声,避免过拟合,更好地利用数据中的关键信息,预测精度提高了10.84%;2)页岩油单井/井组EUR的主要影响因素包括压裂簇数、储层品质、原油黏度和水平段长度,其中簇数优化范围为5~6簇/100 m,水平段长优化范围为1000~1500 m;3)针对单井开发,增大改造程度是提高单井采收率的关键;针对井组开发,需要在优选试验区和提高原油可动性的基础上,优化压裂设计。该研究成果可为页岩油新井优化设计和老井提高采收率方案制定提供理论指导。