D-二聚体联合Wells评分对恶性肿瘤患者合并急性肺栓塞的诊断价值

目的评估D-二聚体联合Wells评分对恶性肿瘤患者合并急性肺栓塞(APE)的诊断价值。方法选取2020年9月至2022年6月天津市人民医院收治的恶性肿瘤可疑APE患者60例,根据CT肺动脉造影检查结果将入选患者分为APE组(33例)和非APE组(27例)。对比两组患者间的临床特点,比较D-二聚体、Wells评分、D-二聚体联合Wells评分对恶性肿瘤合并APE的诊断价值。结果D-二聚体诊断恶性肿瘤合并APE的敏感度为81.8%、特异度为63.0%[受试者操作特征曲线下面积(AUC)=0.730,95%CI 0.601~0.858,Z=3.463,P=0.0005],Wells评分的敏感度为48.5%、特异度为92.6%(AUC=0.678,95%CI 0.542~0.814,Z=2.630,P=0.0085),D-二聚体联合Wells评分的敏感度为69.7%、特异度为74.1%(AUC=0.756,95%CI 0.635~0.878,Z=4.104,P<0.0001)。结论D-二聚体联合Wells评分对恶性肿瘤患者合并APE具有诊断价值。

Shallow Convection Dataset Simulated by Three Different Large Eddy Models

Shallow convection plays an important role in transporting heat and moisture from the near-surface to higher altitudes,yet its parameterization in numerical models remains a great challenge,partly due to the lack of high-resolution observations.This study describes a large eddy simulation(LES)dataset for four shallow convection cases that differ primarily in inversion strength,which can be used as a surrogate for real data.To reduce the uncertainty in LES modeling,three different large eddy models were used,including SAM(System for Atmospheric Modeling),WRF(Weather Research and Forecasting model),and UCLA-LES.Results show that the different models generally exhibit similar behavior for each shallow convection case,despite some differences in the details of the convective structure.In addition to grid-averaged fields,conditionally sampled variables,such as in-cloud moisture and vertical velocity,are also provided,which are indispensable for calculation of the entrainment/detrainment rate.Considering the essentiality of the entraining/detraining process in the parameterization of cumulus convection,the dataset presented in this study is potentially useful for validation and improvement of the parameterization of shallow convection.

Nanoscale cathodoluminescence spectroscopy probing the nitride quantum wells in an electron microscope

To gain further understanding of the luminescence properties of multiquantum wells and the factors affecting them on a microscopic level,cathodoluminescence combined with scanning transmission electron microscopy and spectroscopy was used to measure the luminescence of In_(0.15)Ga_(0.85)N five-period multiquantum wells.The lattice-composition-energy relationship was established with the help of energy-dispersive x-ray spectroscopy,and the bandgaps of In_(0.15)Ga_(0.85)N and GaN in multiple quantum wells were extracted by electron energy loss spectroscopy to understand the features of cathodoluminescence spectra.The luminescence differences between different periods of multiquantum wells and the effects of defects such as composition fluctuation and dislocations on the luminescence of multiple quantum wells were revealed.Our study establishing the direct relationship between the atomic structure of In_(x)Ga_(1-x)N multiquantum wells and photoelectric properties provides useful information for nitride applications.

血清白细胞表面分化抗原40配体联合Wells评分对产褥期深静脉血栓的诊断价值及其与凝血、血小板功能及炎症指标的相关性

目的探讨血清白细胞表面分化抗原40配体(CD40 ligand,CD40L)联合Wells评分对产褥期深静脉血栓(deep vein thrombosis,DVT)的诊断价值及其与凝血、血小板功能及炎症指标的相关性。方法选取2013年8月至2023年7月秦皇岛市妇幼保健院收治的107例产褥期DVT患者作为研究对象,设为DVT组。选取同期在秦皇岛市妇幼保健院分娩的健康产妇100例作为对照组。比较两组基本资料、血清CD40L、Wells评分及凝血、血小板功能及炎症指标,进行Pearson相关性分析,并采用受试者操作特征(receiver operating characteristic,ROC)曲线评价CD40L、Wells评分对产褥期DVT的诊断价值。结果两组研究对象的基本资料差异无统计学意义(均P>0.05)。相比于对照组,DVT组血清CD40L、Wells评分、凝血指标[D-二聚体(D-dimer,D-D)、纤维蛋白原(fibrinogen,FIB)]、血小板功能指标[血小板黏附率(platelet adhesion rate,PAdT)、血小板聚集率(platelet aggregation rate,PAgT)、P选择素(P-selection)]、炎症因子[白细胞介素-6(interleukin-6,IL-6)/IL-1β、高敏C反应蛋白(high-sensitivity c-reactive protein,hs-CRP)]更高(P<0.05),凝血指标(凝血酶原活化时间、凝血酶原时间)更低(P<0.05)。经过Pearson相关性分析,D-D、FIB、PAdT、PAgT、P-selection、IL-6、IL-1β、hs-CRP与产褥期VTE患者血清CD40L、Wells评分均呈正相关(P<0.05),APTT、PT与血清CD40L、Wells评分呈负相关(P<0.05)。ROC曲线显示,血清CD40L联合Wells评分诊断产褥期DVT的AUC、敏感度均显著高于各指标单独诊断(P<0.05)。结论血清CD40L联合Wells评分可提高产褥期DVT的诊断效能,有利于疾病的早期确诊,并及时采取治疗措施。

Reanalysis of energy band structure in the type-II quantum wells

Band structure analysis holds significant importance for understanding the optoelectronic characteristics of semiconductor structures and exploring their potential applications in practice. For quantum well structures, the energy of carriers in the well splits into discrete energy levels due to the confinement of barriers in the growth direction. However, the discrete energy levels obtained at a fixed wave vector cannot accurately reflect the actual energy band structure. In this work, the band structure of the type-II quantum wells is reanalyzed. When the wave vectors of the entire Brillouin region(corresponding to the growth direction) are taken into account, the quantized energy levels of the carriers in the well are replaced by subbands with certain energy distributions. This new understanding of the energy bands of low-dimensional structures not only helps us to have a deeper cognition of the structure, but also may overturn many viewpoints in traditional band theories and serve as supplementary to the band theory of low-dimensional systems.

微小RNA物质、血栓标志物、Wells评分系统联合预测高龄髋部骨折DVT风险价值

目的探究微小RNA物质、血栓标志物、下肢深静脉栓塞评分(Wells评分)系统联合对高龄髋部骨折深静脉血栓形成(DVT)风险的预测价值,为减少DVT发生提供诊断依据。方法选取2020年10月—2022年10月我院收治的105例高龄髋部骨折患者,根据术后1周是否发生DVT分为DVT组(34例)、未DVT组(71例)。比较两组临床资料,于入院后术前进行Wells评分评估,并检测两组微小RNA物质[微小RNA-374b-5p(miR-374b-5p)、微小RNA-664b-3p(miR-664b-3p)]、血栓标志物[凝血酶-抗凝血酶复合物(TAT)、可溶性血栓调节蛋白(sTM)、纤溶酶α2抗纤溶酶复合物(PIC)、组织型纤溶酶原激活物-抑制剂复合物(t-PAIC)],分析DVT发生的影响因素,通过受试者工作特征曲线(ROC)、决策曲线分析(DCA)Wells评分、miR-374b-5p、miR-664b-3p、sTM、PIc、TAT、t-PAIC联合对高龄髋部骨折DVT风险的预测价值及临床效用。结果DVT组术前血浆FDP水平及Wells评分高度可能占比高于未DVT组(P<0.05);DVT组miR-374b-5p相对表达量高于未DVT组,miR-664b-3p相对表达量低于未DVT组(P<0.05);DVT组血浆sTM、PIC、TAT、t-PAIC水平均高于未DVT组(P<0.05);FDP、Wells评分、miR-374b-5p、miR-664b-3p、sTM、PIC、TAT、t-PAIC均为高龄髋部骨折患者发生DVT的影响因素(P<0.05);Wells评分、miR-374b-5p、miR-664b-3p、sTM、PIC、TAT、t-PAIC预测高龄髋部骨折DVT风险的AUC值分别为0.666、0.734、0.750、0.730、0.764、0.761、0.800,各指标联合预测高龄髋部骨折患者发生DVT的AUC最大,为0.921,且具有良好临床效用(P<0.05)。结论miR-374b-5p、miR-664b-3p、sTM、PIC、TAT、t-PAIC、Wells评分系统联合预测高龄髋部骨折DVT风险的预测效能较高,临床效用良好。

血清同型半胱氨酸检测联合Wells评分对慢性阻塞性肺疾病急性加重期患者发生静脉血栓栓塞症的预测价值研究

目的探究血清同型半胱氨酸(Hcy)检测联合Wells评分对慢性阻塞性肺疾病急性加重期患者发生静脉血栓栓塞症(VTE)的预测价值。方法选取2021年4月-2023年4月我院收治的94例慢性阻塞性肺疾病急性加重期患者,根据是否发生VTE分为VTE组20例和非VTE组74例。采用酶联免疫吸附测定(ELISA)法检测血清中Hcy水平。对全部患者进行Wells评分。Spearman相关性分析Hcy表达水平与Wells评分的关系;ROC曲线分析血清Hcy检测联合Wells评分对慢性阻塞性肺疾病急性加重期患者发生VTE的预测价值;Logistic回归分析影响慢性阻塞性肺疾病急性加重期患者VTE发生的因素。结果与非VTE组相比,VTE组患者C-反应蛋白(CRP)、D-二聚体(D-D)、Hcy水平以及Wells评分水平显著升高,动脉血氧分压(PaO_(2))水平显著降低(P<0.05)。Pearson相关性分析显示,慢性阻塞性肺疾病急性加重期患者Hcy表达水平与Wells评分呈正相关关系(r=0.491,P<0.05)。二者联合预测慢性阻塞性肺疾病急性加重期患者发生VTE的AUC高于血清Hcy表达水平与Wells评分单独预测的AUC值(Z=5.303,P<0.001;Z=9.151,P<0.001)。Logistic回归分析结果显示Hcy、Wells评分为VTE发生的影响因素(P<0.05)。结论慢性阻塞性肺疾病急性加重期发生VTE患者血清Hcy水平和Wells评分显著上升,二者联合检测对慢性阻塞性肺疾病急性加重期发生VTE的预测价值优于单一指标检测。

Evaluation of the Shallow Gas Hydrate Production Based on the Radial Drilling-Heat Injection-Back Fill Method

It has been evidenced that shallow gas hydrate resources are abundant in deep oceans worldwide.Their geological back-ground,occurrence,and other characteristics differ significantly from deep-seated hydrates.Because of the high risk of well construction and low production efficiency,they are difficult to be recovered by using conventional oil production methods.As a result,this paper proposes an alternative design based on a combination of radial drilling,heat injection,and backfilling methods.Multi-branch holes are used to penetrate shallow gas hydrate reservoirs to expand the depressurization area,and heat injection is utilized as a supplement to improve gas production.Geotechnical information collected from an investigation site close to the offshore production well in the South China Sea is used to assess the essential components of this plan,including well construction stability and gas production behavior.It demonstrates that the hydraulic fracturing of the 60mbsf overburden layer can be prevented by regulating the drilling fluid densities.However,the traditional well structure is unstable,and the suction anchor is advised for better mechanical performance.The gas produc-tion rate can be significantly increased by combining hot water injection and depressurization methods.Additionally,the suitable produc-tion equipment already in use is discussed.

A CFD Model to Evaluate Near-Surface Oil Spill from a Broken Loading Pipe in Shallow Coastal Waters

Oil spills continue to generate various issues and concerns regarding their effect and behavior in the marine environment,owing to the related potential for detrimental environmental,economic and social implications.It is essential to have a solid understanding of the ways in which oil interacts with the water and the coastal ecosystems that are located nearby.This study proposes a simplified model for predicting the plume-like transport behavior of heavy Bunker C fuel oil discharging downward from an acutely-angled broken pipeline located on the water surface.The results show that the spill overall profile is articulated in three major flow areas.The first,is the source field,i.e.,a region near the origin of the initial jet,followed by the intermediate or transport field,namely,the region where the jet oil flow transitions into an underwater oil plume flow and starts to move horizontally,and finally,the far-field,where the oil re-surface and spreads onto the shore at a significant distance from the spill site.The behavior of the oil in the intermediate field is investigated using a simplified injection-type oil spill model capable of mimicking the undersea trapping and lateral migration of an oil plume originating from a negatively buoyant jet spill.A rectangular domain with proper boundary conditions is used to implement the model.The Projection approach is used to discretize a modified version of the Navier-Stokes equations in two dimensions.A benchmark fluid flow issue is used to verify the model and the results indicate a reasonable relationship between specific gravity and depth as well as agreement with the aerial data and a vertical temperature profile plot.

Study on the Impact of Massive Refracturing on the Fracture Network in Tight Oil Reservoir Horizontal Wells

Class III tight oil reservoirs have low porosity and permeability,which are often responsible for low production rates and limited recovery.Extensive repeated fracturing is a well-known technique to fix some of these issues.With such methods,existing fractures are refractured,and/or new fractures are created to facilitate communication with natural fractures.This study explored how different refracturing methods affect horizontal well fracture networks,with a special focus on morphology and related fluid flow changes.In particular,the study relied on the unconventional fracture model(UFM).The evolution of fracture morphology and flow field after the initial fracturing were analyzed accordingly.The simulation results indicated that increased formation energy and reduced reservoir stress differences can promote fracture expansion.It was shown that the length of the fracture network,the width of the fracture network,and the complexity of the fracture can be improved,the oil drainage area can be increased,the distance of oil and gas seepage can be reduced,and the production of a single well can be significantly increased.

Physico−mathematical model of the voltage−current characteristics of light-emitting diodes with quantum wells based on the Sah−Noyce−Shockley recombination mechanism

Herein,a physical and mathematical model of the voltage−current characteristics of a p−n heterostructure with quantum wells(QWs)is prepared using the Sah−Noyce−Shockley(SNS)recombination mechanism to show the SNS recombination rate of the correction function of the distribution of QWs in the space charge region of diode configuration.A comparison of the model voltage−current characteristics(VCCs)with the experimental ones reveals their adequacy.The technological parameters of the structure of the VCC model are determined experimentally using a nondestructive capacitive approach for determining the impurity distribution profile in the active region of the diode structure with a profile depth resolution of up to 10Å.The correction function in the expression of the recombination rate shows the possibility of determining the derivative of the VCCs of structures with QWs with a nonideality factor of up to 4.

Wells评分联合D-二聚体水平对重症肺血栓栓塞患者近期预后不良的预测分析

目的分析Wells评分联合血浆D-二聚体(D-D)水平对重症肺血栓栓塞(PTE)患者近期预后不良的预测价值。方法选取2016年1月—2020年11月江苏省人民医院收治的127例重症PTE患者,均随访至出院后6个月,根据近期预后将其分为预后良好组与预后不良。对比两组Wells评分、血浆D-D水平,比较出院护理满意度;采用多因素Logistic回归性分析法分析重症PTE患者近期预后不良的影响因素;以受试者工作特征(ROC)曲线评估Wells评分与血浆D-D水平对重症PTE患者近期预后不良的预测作用。结果127例重症PTE患者Wells评分为6~9(8.01±1.16)分,血浆D-D水平为7.65~8.88(8.35±0.66)μg/mL;经Pearson相关系数分析,患者Wells评分、血浆D-D水平均与肺栓塞严重程度指数(PESI评分)呈正相关(r=0.825、0.613,P<0.05);近期预后不良率为25.20%;预后良好组Wells评分、血浆D-D水平均显著低于预后不良组(P<0.05),两组出院护理满意度无差异(P>0.05);经多因素Logistic回归分析,PESI评分、B型钠尿肽(BNP)、Wells评分、血浆D-D均是重症PTE患者预后不良的危险因素(P<0.05);Wells评分联合血浆D-D水平联合预测重症PTE患者近期预后不良的灵敏度、曲线下面积(AUC)均高于单独预测(P<0.01)。结论重症PTE近期预后不良者Wells评分及血浆D-D水平均显著高于预后良好者,此二项指标均与患者近期预后不良关系密切,并均对患者近期预后不良具有一定的预测价值,但二者联合应用时的预测价值更高,可作为临床评估重症PTE患者近期预后的重要指标。

Microbial Analysis of Drinking Water from Randomly Selected Boreholes and Shallow Wells around Hargeisa, Somaliland

Background: Shallow wells and boreholes are vital sources of potable water in Hargeisa. This water can be polluted by runoff, in particular during the rainy season, causing outbreaks of waterborne infections. Objectives: This research aimed at evaluating the microbial quality of shallow wells and boreholes water around Hargeisa, Somaliland. Methods: The total coliform and Escherichia coli count were done by using the membrane filtration method. Overall, 100 ml of each water sample was filtered via a 0.45 μm membrane filter, and then the filters were put on m-Endo agar plates that were incubated at 37°C for 24 to 48 hours. Results: The mean value of total coliform counts for the boreholes and shallow wells ranged from 1.288 × 103 to 8.8 × 103 CFU/100ml, while the mean value of total E. coli counts also ranged from 3.5 × 102 to 4.429 × 103 CFU/100ml. Results from this study have demonstrated that all water sources (Arabsiyo, Dararweyne, Darasalaam, Dabaraqas, and Jaleelo) don’t comply with the WHO guideline for drinking water. Results from the analysis of water samples of 28 wells demonstrated a significant correlation between total coliform and E. coli counts (P = 0.01). Therefore, this water is not fit for human consumption unless it is treated. Conclusion: This study has demonstrated that all results of both mean values of total coliform and E. coli counts from groundwater of selected shallow wells and boreholes were beyond WHO standards, so water from Arabsiyo, Jaleelo, Dabaraqas, Dararweyne, and Darasalaam requires treatment before human consumption.

急诊中不明原因的呼吸困难患者应用Wells评分及D-二聚体变化对肺栓塞的诊断和风险评估的价值分析

目的探究急诊中不明原因的呼吸困难患者应用Wells评分及D-二聚体(D-D)对肺栓塞的诊断和风险评估的价值。方法纳入2019年1月至2021年7月因不明原因呼吸困难到诸暨市人民医院就诊的74例急性肺栓塞患者、91例非肺栓塞患者为研究对象,分析Wells评分及D-D水平变化对肺栓塞的诊断价值及对预后的预测价值。结果Wells评分及D-D水平联合检测诊断肺栓塞及预测患者预后的AUC均>0.85,D-D≥534.40μg/L是影响急性肺栓塞预后的危险因素(P<0.05)。结论Wells评分及D-D水平检测对肺栓塞具有诊断价值,对肺栓塞患者死亡风险有一定的预测价值。

Tp-Te间期、D-二聚体、简化的Wells评分对肺栓塞的诊断价值

目的:探讨Tp-Te间期、D-二聚体、简化的Wells评分对肺栓塞的预测价值,以期发现更适合临床疑诊肺栓塞的评估模型。方法:回顾性分析2021年6月-2022年9月于随州市中心医院就诊的可疑肺栓塞患者69例。以CT肺动脉血管成像作为诊断金标准,分为肺栓塞组与对照组。收集所有患者详细资料,完成常规心电图、D-二聚体检测。记录心电图一般指标及胸导联QT间期、Tp-Te间期,完成Wells评分。比较Tp-Te间期、D-二聚体、Wells评分对肺栓塞的预测价值。结果:心电图V1导联诊断价值最高;V1导联Tp-Te间期、D-二聚体、简化的Wells评分联合诊断与单一手段相比差异有统计学意义(P<0.05);D-二聚体≥0.5 mg/L联合简化Wells评分优势比最高(8.05)。结论:Tp-Te间期、D-二聚体、简化的Wells评分可用于肺栓塞早期评估。

D-D、Fib联合WELLS评分对下肢骨折术后深静脉血栓形成的预测价值

目的探讨D-二聚体(D-D)、纤维蛋白原(Fib)联合WELLS评分对下肢骨折术后深静脉血栓形成(DVT)的预测价值。方法选取2020年1月至2022年1月陆军第七十三集团军医院收治的80例下肢骨折术后患者为研究对象,根据下肢血管超声检查结果[是否形成DVT]分为DVT组(n=17)和非DVT组(n=63),比较两组一般资料、凝血功能指标[活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)、国际标准化比值(INR)、D-D、Fib]及WELLS评分,采用多因素logistic回归分析下肢骨折术后患者发生DVT的独立影响因素,并通过受试工作者特征(ROC)曲线分析D-D、Fib、WELLS评分及三者联合预测DVT的价值。结果DVT组PT、INR、D-D、Fib水平及WELLS评分显著高于非DVT组,差异有统计学意义(P<0.05);两组APTT水平比较,差异无统计学意义(P>0.05)。多因素logistic回归分析显示,D-D、Fib、WELLS评分是发生DVT的独立危险因素(P<0.05)。D-D、Fib、WELLS评分及三者联合诊断DVT的曲线下面积(AUC)分别为0.831、0.793、0.872、0.974,三者联合诊断DVT的效能高于单一指标(P<0.05)。结论D-D、Fib联合WELLS评分可以提高下肢骨折术后DVT发生的预测价值,值得临床推广应用。

The impact of earlier flood recession on metacommunity diversity of wintering waterbirds at shallow lakes in the middle and lower Yangtze River floodplain

The hydrological regime in wetlands plays an important role in the process of wintering waterbird metacommunity assemblage.However,increasing frequency of extreme climate and the intensification of human activities,such as the construction of sluices and dams,have resulted in frequently abnormal hydrological regime in the middle and lower Yangtze River floodplain.In recent years,earlier flood recession has become one of the main hydrological problems faced in the shallow lakes,having a great impact on wetland biodiversity.It is necessary to understand the impact of earlier flood recession on waterbirds,an indicator of wetland biodiversity,and the metacommunity concept is helpful to elucidate the underlying mechanism involved in the processes of assemblage by waterbird communities.In this study,we surveyed the wintering waterbirds at three sub-lakes of Caizi Lakes during 2019-2020 and 2020-2021 and compared the richness,abundance,alpha and beta diversity of waterbirds in and among local metacommunities under earlier flood recession and normal hydrological regime.The results showed that the earlier flood recession reduced the species richness in the early stage and abundance in the late stage,it also reduced the Shannon-Wiener index in the early stage and increased the dissimilarity between and within waterbird metacommunities in the late stage.The partition of beta diversity showed that the turnover component played a major role in the process of waterbird metacommunity assemblage.It was found that the earlier flood recession reduced the richness,abundance in different stages of flood recession,which also increased the turnover of waterbirds.Metacommunities with high habitat heterogeneity had better resistance to abnormal hydrological regime,which resulted in high dissimilarity between and within metacommunities.The results of this study provide important information for waterbird conservation and water level management at shallow lakes in the middle and lower Yangtze River floodplain.

以Wells评分为指导的护理干预对腰椎间盘突出症患者术后深静脉血栓形成的影响

目的分析以Wells评分为指导的护理干预模式对预防腰椎间盘突出症患者手术治疗后深静脉血栓形成的影响。方法以2021年1―12月安阳市安钢总医院骨六科拟行手术治疗的83例腰椎间盘突出症患者作为研究对象进行前瞻性分析。采用随机数字表法将其分为观察组与对照组。其中对照组接受常规术后护理,观察组在此基础上加用基于Wells评分为指导的护理模式。比较两组患者护理期间深静脉血栓发生率、临床指标、实验室指标。结果试验期间观察组因未完成相应指标检查脱落2例,因个人原因申请退出试验脱落1例;对照组无脱落,最终观察组39例,对照组41例。干预后观察组患者深静脉血栓发生率低于对照组,腿围增长低于对照组,住院时间短于对照组,活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)长于对照组(P<0.05)。结论基于Wells评分的护理模式可有效降低腰椎间盘突出症患者术后深静脉血栓的发生率。

The June 2022 Khost earthquake in southeastern Afghanistan:A complicated shallow slip event revealed with InSAR

On June 22,2022,the Mw6.2 earthquake in southeastern Afghanistan caused a severe disaster.We used the Sentinel-1A ascending and descending track images of the European Space Agency and interferometric synthetic aperture radar(In SAR)to obtain the coseismic surface deformation field of the earthquake,which showed that the earthquake caused complex ruptures of multiple faults and various types.Using the dislocation model of the elastic half-space,we determined the focal parameters and slip distribution on the fault plane of this event.The results reveal that:(1)the seismogenic fault of this event is an unknown fault on the northeastern edge of the Katawaz microblock;(2)The slip on the fault plane is mainly in the range of 0—8 km along the dip,with maximum slips about 2 m at a depth of 2 km,which projected on the surface is 69.44°E,32.96°N.This event suggests that,similar to the Chaman,Ghazaband and other large faults,the faults inside the microblock also play an important role in adjusting for the collision stress between India and Europe.

Subsection and superposition method for reservoir formation damage evaluation of complex-structure wells

Kinds of complex-structure wells can effectively improve production,which are widely used.However,in the process of drilling and completion,complex-structure wells with long drilling cycle and large exposed area of reservoir can lead to the fact that reservoir near wellbore is more vulnerable to the working fluid invasion,resulting in more serious formation damage.In order to quantitatively describe the reservoir formation damage in the construction of complex-structure well,taking the inclined well section as the research object,the coordinate transformation method and conformal transformation method are given according to the flow characteristics of reservoir near wellbore in anisotropic reservoir.Then the local skin factor in orthogonal plane of wellbore is deduced.Considering the un-even distribution of local skin factor along the wellbore,the oscillation decreasing model and empirical equation model of damage zone radius distribution along the wellbore direction are established and then the total skin factor model of the whole well is superimposed to realize the reservoir damage evaluation of complex-structure wells.Combining the skin factor model with the production model,the production of complex-structure wells can be predicted more accurately.The two field application cases show that the accuracy of the model can be more than 90%,which can also fully reflect the invasion characteristics of drilling and completion fluid in any well section of complex-structure wells in anisotropic reservoir,so as to further provide guidance for the scientific establish-ment of reservoir production system.