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Fracture propagation law of temporary plugging and diversion fracturing in shale reservoirs under completion experiments of horizontal well with multi-cluster sand jetting perforation
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作者 ZOU Yushi LI Yanchao +3 位作者 YANG Can ZHANG Shicheng MA Xinfang ZOU Longqing 《Petroleum Exploration and Development》 SCIE 2024年第3期715-726,共12页
This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion w... This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion with multi-cluster sand jetting perforation.The effects of temporary plugging agent(TPA)particle size,TPA concentration,single-cluster perforation number and cluster number on plugging pressure,multi-fracture diversion pattern and distribution of TPAs were investigated.A combination of TPAs with small particle sizes within the fracture and large particle sizes within the segment is conducive to increasing the plugging pressure and promoting the diversion of multi-fractures.The addition of fibers can quickly achieve ultra-high pressure,but it may lead to longitudinal fractures extending along the wellbore.The temporary plugging peak pressure increases with an increase in the concentration of the TPA,reaching a peak at a certain concentration,and further increases do not significantly improve the temporary plugging peak pressure.The breaking pressure and temporary plugging peak pressure show a decreasing trend with an increase in single-cluster perforation number.A lower number of single-cluster perforations is beneficial for increasing the breaking pressure and temporary plugging peak pressure,and it has a more significant control on the propagation of multi-cluster fractures.A lower number of clusters is not conducive to increasing the total number and complexity of artificial fractures,while a higher number of clusters makes it difficult to achieve effective plugging.The TPAs within the fracture is mainly concentrated in the complex fracture areas,especially at the intersections of fractures.Meanwhile,the TPAs within the segment are primarily distributed near the perforation cluster apertures which initiated complex fractures. 展开更多
关键词 shale temporary plugging and diversion fracturing multi-cluster sand jetting perforation distribution of temporary plugging agent fracture propagation law
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Dissolvable temporary barrier:a novel paradigm for flexible hydrogel patterning in organ-on-a-chip models
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作者 Ding Wang Qinyu Li +5 位作者 Chenyang Zhou Zhangjie Li Kangyi Lu Yijun Liu Lian Xuan Xiaolin Wang 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第2期153-166,共14页
A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled... A combination of hydrogels and microfluidics allows the construction of biomimetic three-dimensional(3D)tissue models in vitro,which are also known as organ-on-a-chipmodels.The hydrogel patterningwith awell-controlled spatial distribution is typically achieved by embedding sophisticated microstructures to act as a boundary.However,these physical barriers inevitably expose cells/tissues to a less physiologically relevant microenvironment than in vivo conditions.Herein,we present a novel dissolvable temporary barrier(DTB)strategy that allows robust and flexible hydrogel patterning with great freedom of design and desirable flow stimuli for cellular hydrogels.The key aspect of this approach is the patterning of a water-soluble rigid barrier as a guiding path for the hydrogel using stencil printing technology,followed by a barrier-free medium perfusion after the dissolution of the DTB.Single and multiple tissue compartments with different geometries can be established using either straight or curved DTB structures.The effectiveness of this strategy is further validated by generating a 3D vascular network through vasculogenesis and angiogenesis using a vascularized microtumor model.As a new proof-of-concept in vasculature-on-a-chip,DTB enables seamless contact between the hydrogel and the culture medium in closed microdevices,which is an improved protocol for the fabrication ofmultiorgan chips.Therefore,we expect it to serve as a promising paradigm for organ-on-a-chip devices for the development of tumor vascularization and drug evaluation in the future preclinical studies. 展开更多
关键词 Dissolvable temporary barrier Hydrogel patterning Microfluidics Organ-on-a-chip Vascularization
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HVOF-sprayed HAp/S53P4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants
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作者 Carlos A.Poblano-Salas John Henao +6 位作者 Astrid L.Giraldo-Betancur Paola Forero-Sossa Diego German Espinosa-Arbelaez Jorge A.González-Sánchez Luis R.Dzib-Pérez Susana T.Estrada-Moo Idelfonso E.Pech-Pech 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第1期345-360,共16页
Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HA... Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro conditions.In the present work,75%wt.HAp-25%wt.S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 BG composite coatings on a bioresorbable AZ31 alloy.The study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those coatings.Different characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite coatings.The results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal expansion.It was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the coatings.In addition,in-vitro electrochemical studies were performed on the obtained HAp/S53P4 BG composite coatings and compared against the uncoated AZ31 alloy.The results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(SBF). 展开更多
关键词 Coatings Composites Thermal spray temporary implants Hydrogen evolution
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Qualitative exploration of home life experiences and care needs among elderly patients with temporary intestinal stomas
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作者 Si-Meng Wang Jian-Ling Jiang +5 位作者 Rui Li Juan-Juan Wang Chun-Hong Gu Jia Zeng Xiao-Hui Wei Mei Chen 《World Journal of Gastroenterology》 SCIE CAS 2024年第22期2893-2901,共9页
BACKGROUND This study employed a phenomenological research approach within qualitative research to explore the challenges encountered by elderly individuals with temporary colostomies in managing their daily lives and... BACKGROUND This study employed a phenomenological research approach within qualitative research to explore the challenges encountered by elderly individuals with temporary colostomies in managing their daily lives and care needs.Protecting the anus surgery combined with temporary colostomy has emerged as a prevalent treatment modality for low rectal cancer.However,the ileostomy is susceptible to peri-stoma skin complications,as well as fluid,electrolyte,and nutritional imbalances,posing challenges to effective management.The successful selfmanagement of patients is intricately linked to their adjustment to temporary colostomy;nonetheless,there remains a dearth of research examining the factors influencing self-care among temporary colostomy patients and the obstacles they confront.AIM To investigate the lived experiences,perceptions,and care requirements of temporary colostomy patients within their home environment,with the ultimate goal of formulating a standardized management protocol.METHODS Over the period of June to August 2023,a purposive sampling technique was utilized to select 12 patients with temporary intestinal stomas from a tertiary hospital in Shanghai,China.Employing a phenomenological research approach,a semi-structured interview guide was developed,and qualitative interviews were conducted using in-depth interview techniques.The acquired data underwent coding,analysis,organization,and summarization following Colaizzi’s seven-step method.RESULTS The findings of this study revealed that the experiences and needs of patients with temporary intestinal stomas can be delineated into four principal themes:Firstly,Temporary colostomy patients bear various burdens and concerns about the uncertainty of disease progression;secondly,patients exhibit limited self-care capabilities and face information deficits,resulting in heightened reliance on healthcare professionals;thirdly,patients demonstrate the potential for internal motivation through proactive self-adjustment;and finally,patients express a significant need for emotional and social support.CONCLUSION Home-living patients with temporary intestinal stomas confront multifaceted challenges encompassing burdens,inadequate self-care abilities,informational deficits,and emotional needs.Identifying factors influencing patients’self-care at home and proposing strategies to mitigate barriers can serve as a foundational framework for developing and implementing nursing interventions tailored to the needs of patients with temporary intestinal stomas. 展开更多
关键词 ELDERLY temporary intestinal stomas Life experiences Intestinal ostomy complications Qualitative study
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Laser speckle contrast imaging to predict the effect of temporary spinal cord stimulation in postherpetic neuralgia patients: A prospective observational study
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作者 Xiang Huang Dacheng Tang +3 位作者 Pan Chen Lumiao Chen Xiaohong Li Xiaoping Wang 《Journal of Innovative Optical Health Sciences》 SCIE EI CSCD 2024年第1期69-75,共7页
Temporary spinal cord stimulation(tSCS)can effectively reduce the pain and severity of postherpetic neuralgia(PHN).However,there are no effective and objective methods for predicting the effects of tSCS on PHN.Laser s... Temporary spinal cord stimulation(tSCS)can effectively reduce the pain and severity of postherpetic neuralgia(PHN).However,there are no effective and objective methods for predicting the effects of tSCS on PHN.Laser speckle contrast imaging(LSCI)is frequently used in neurology to evaluate the effectiveness of treatment.To assess the accuracy of LSCI in predicting the impact of tSCS on PHN,14 adult patients receiving tSCS treatments for spinal nerve-innervated(C6-T2)PHN participated in this observational study.Visual analog scale(VAS)assessments and LSCI bloodflow images of the-ngers were recorded after the tSCS procedure.The results showed that the VAS scores of all patients decreased signi-cantly.Moreover,the bloodflow index(BFI)values were signi-cantly higher than they were before the procedure.Increased bloodflow and pain alleviation were positively correlated.The-ndings indicated that spinal nerve PHN(C6-T2)was signi-cantly reduced by tSCS.Pain alleviation by tSCS was positively correlated with increased bloodflow in the hand.The effect of tSCS on PHN may thus be predicted using an independent and consistent indicator such as LSCI. 展开更多
关键词 Laser speckle contrast imaging temporary spinal cord stimulation postherpetic neuralgia
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Clinical Efficacy of GBR Technique Combined with Temporary Bridgework-Guided Gingival Contouring in Treating Upper Anterior Tooth Loss with Labial Bone Defects
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作者 Yu Ma Jirui Ma 《Journal of Clinical and Nursing Research》 2024年第6期171-176,共6页
Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.M... Objective:To investigate the clinical effect of the guided bone regeneration(GBR)technique combined with temporary bridgework-guided gingival contouring in treating upper anterior tooth loss with labial bone defects.Methods:From July 2023 to April 2024,80 patients with upper anterior tooth loss and labial bone defects were admitted to the hospital and selected as evaluation samples.They were divided into an observation group(n=40)and a control group(n=40)using a numerical table lottery scheme.The control group received treatment with the GBR technique,while the observation group received treatment with the GBR technique combined with temporary bridges to guide gingival contouring.The two groups were compared in terms of clinical red aesthetic scores(PES),labial alveolar bone density,labial bone wall thickness,gingival papillae,gingival margin levels,and patient satisfaction.Results:The PES scores of patients in the observation group were higher than those in the control group after surgery(P<0.05).The bone density of the labial alveolar bone and the thickness of the labial bone wall in the observation group were higher than those in the control group.The levels of gingival papillae and gingival margins were lower in the observation group after surgery(P<0.05).Additionally,patient satisfaction in the observation group was higher than in the control group(P<0.05).Conclusion:The GBR technique combined with temporary bridge-guided gingival contouring for treating upper anterior tooth loss with labial bone defects can improve the aesthetic effect of gingival soft tissue,increase alveolar bone density and the thickness of the labial bone wall,and enhance patient satisfaction.This approach is suitable for widespread application in healthcare institutions. 展开更多
关键词 Upper anterior teeth loss Labial bone defects Guided bone regeneration(GBR)technique temporary bridgework-guided gingival contouring
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Plugging behaviors of temporary plugging particles in hydraulic fractures 被引量:1
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作者 GUO Jianchun ZHAN Li +5 位作者 LU Qianli QI Tianjun LIU Yuxuan WANG Xin CHEN Chi GOU Xinghao 《Petroleum Exploration and Development》 SCIE 2023年第2期464-472,共9页
Using the visualized experimental device of temporary plugging in hydraulic fractures, the plugging behaviors of temporary plugging particles with different sizes and concentrations in hydraulic fractures were experim... Using the visualized experimental device of temporary plugging in hydraulic fractures, the plugging behaviors of temporary plugging particles with different sizes and concentrations in hydraulic fractures were experimentally analyzed under the conditions of different carrier fluid displacements and viscosities. The results show that the greater the carrier fluid viscosity and displacement, the more difficult it is to form a plugging layer, and that the larger the size and concentration of the temporary plugging particle, the less difficult it is to form a plugging layer. When the ratio of particle size to fracture width is 0.45, the formation of the plugging layer is mainly controlled by the mass concentration of the temporary plugging particle and the viscosity of the carrier fluid, and a stable plugging layer cannot form if the mass concentration of the temporary plugging particle is less than 20 kg/m^(3)or the viscosity of the carrier fluid is greater than 3 mPa·s. When the ratio of particle size to fracture width is 0.60, the formation of the plugging layer is mainly controlled by the mass concentration of the temporary plugging particle, and a stable plugging layer cannot form if the mass concentration of the temporary plugging particle is less than 10 kg/m^(3). When the ratio of particle size to fracture width is 0.75, the formation of the plugging layer is basically not affected by other parameters, and a stable plugging layer can form within the experimental conditions. The formation process of plugging layer includes two stages and four modes. The main controlling factors affecting the formation mode are the ratio of particle size to fracture width, carrier fluid displacement and carrier fluid viscosity. 展开更多
关键词 hydraulic fracture temporary plugging and diversion temporary plugging particle plugging characteristics construction parameters combination
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Complex fracture propagation model and plugging timing optimization for temporary plugging fracturing in naturally fractured shale 被引量:1
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作者 TANG Xuanhe ZHU Haiyan +1 位作者 CHE Mingguang WANG Yonghui 《Petroleum Exploration and Development》 2023年第1期152-165,共14页
In this paper,a viscoelasticity-plastic damage constitutive equation for naturally fractured shale is deduced,coupling nonlinear tensile-shear mixed fracture mode.Dynamic perforation-erosion on fluid re-distribution a... In this paper,a viscoelasticity-plastic damage constitutive equation for naturally fractured shale is deduced,coupling nonlinear tensile-shear mixed fracture mode.Dynamic perforation-erosion on fluid re-distribution among multi-clusters are considered as well.DFN-FEM(discrete fracture network combined with finite element method)was developed to simulate the multi-cluster complex fractures propagation within temporary plugging fracturing(TPF).Numerical results are matched with field injection and micro-seismic monitoring data.Based on geomechanical characteristics of Weiyuan deep shale gas reservoir in Sichuan Basin,SW China,a multi-cluster complex fractures propagation model is built for TPF.To study complex fractures propagation and the permeability-enhanced region evolution,intersecting and competition mechanisms between the fractures before and after TPF treatment are revealed.Simulation results show that:fracture from middle cluster is restricted by the fractures from side-clusters,and side-clusters plugging is benefit for multi fractures propagation in uniformity;optimized TPF timing should be delayed within a higher density or strike of natural fractures;Within a reservoir-featured natural fractures distribution,optimized TPF timing for most clustered method is 2/3 of total fluid injection time as the optimal plugging time under different clustering modes. 展开更多
关键词 shale gas naturally fractured shale temporary plugging fracturing fracture propagation plugging timing discrete fracture network finite element method
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Emergency internal iliac artery temporary occlusion after massive hemorrhage during surgery of cesarean scar pregnancy:A case report 被引量:1
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作者 Ji-Ping Xie Lin-Lin Chen +3 位作者 Wen Lv Wu Li Hui Fang Guang Zhu 《World Journal of Clinical Cases》 SCIE 2023年第17期4065-4071,共7页
BACKGROUND Cesarean scar pregnancy(CSP)is rare but may result in uterine rupture during pregnancy or massive hemorrhage during abortion procedures.Awareness of this condition is increasing,and most patients with CSP a... BACKGROUND Cesarean scar pregnancy(CSP)is rare but may result in uterine rupture during pregnancy or massive hemorrhage during abortion procedures.Awareness of this condition is increasing,and most patients with CSP are now diagnosed early and can be managed safely.However,some atypical patients are misdiagnosed,and their surgical risks are underestimated,increasing the risk of fatal hemorrhage.CASE SUMMARY A 27-year-old Asian woman visited our institution because of abnormal pregnancy,and she was diagnosed with a hydatidiform mole through transvaginal ultrasound(TVS).Under hysteroscopy,a large amount of placental tissue was found in the scar of the lower uterine segment,and a sudden massive hemorrhage occurred during the removal process.The bilateral internal iliac arteries were temporarily blocked under laparoscopy,and scar resection and repair were rapidly performed.She was discharged in good condition 5 d after the operation.CONCLUSION Although TVS is widely used in the diagnosis of CSP,delays in the diagnosis of atypical CSP remain.Surgical treatment following internal iliac artery temporary occlusion may be an appropriate management method for unanticipated massive hemorrhage during CSP surgery. 展开更多
关键词 Internal iliac artery temporary occlusion Cesarean scar pregnancy Uterine artery embolization MISDIAGNOSIS HYSTEROSCOPY LAPAROSCOPY Case report
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维生素C对禁食黄颡鱼抗氧化能力和肌肉品质的影响 被引量:2
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作者 汪兰 夏雨婷 +9 位作者 胡澳 陈朗 郭晓嘉 乔宇 吴文锦 石柳 黄云 彭条凤 熊光权 陈胜 《广东海洋大学学报》 CAS CSCD 北大核心 2024年第1期20-26,共7页
【目的】研究添加不同浓度维生素C对禁食暂养黄颡鱼(Pelteobagrus fulvidraco)抗氧化能力和肌肉品质的影响,为提升鲜活黄颡鱼耐运性和肌肉品质提供理论依据。【方法】随机将黄颡鱼分为4组:T0-0(0 mg/L V_(C),暂养0 d)、T0-5(0 mg/L V_(... 【目的】研究添加不同浓度维生素C对禁食暂养黄颡鱼(Pelteobagrus fulvidraco)抗氧化能力和肌肉品质的影响,为提升鲜活黄颡鱼耐运性和肌肉品质提供理论依据。【方法】随机将黄颡鱼分为4组:T0-0(0 mg/L V_(C),暂养0 d)、T0-5(0 mg/L V_(C),暂养5 d)、T10-5(10 mg/L V_(C),暂养5 d)、T30-5(30 mg/L V_(C),暂养5 d),每组40尾鱼,检测血清、肌肉的抗氧化物质以及肌肉品质指标。【结果】T5-0组黄颡鱼血清中GSH-PX、CAT、GSH活性以及MDA浓度,肌肉中CAT、GSH活性和MDA浓度显著低于T1-0组(P<0.05);其纤维结构变得紧密,pH下降,白度增加,持水力增加,肌肉品质指标显著升高(P<0.05)。与T0-5及T30-5组相比,T10-5组血清中SOD、CAT、GSH、GSH-PX活性显著较高(P<0.05),MDA浓度较低;肌肉中SOD、GSH活性与血清中结果变化相同;持水力进一步增加。在质构方面,T10-5组剪切力、硬度、弹性、咀嚼性、黏性均高于T0-5组及T30-5组。【结论】添加10 mg/L的V_(C)能进一步显著提高黄颡鱼的抗氧化能力和肌肉品质(P<0.05),但30 mg/L V_(C)添加不利于黄颡鱼肌肉品质的提升,甚至对其产生负面影响。 展开更多
关键词 维生素C 黄颡鱼 暂养 运输应激 抗氧化能力 肌肉品质
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致密砂岩气藏暂堵压裂裂缝起裂扩展实验模拟 被引量:1
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作者 孔祥伟 许洪星 +1 位作者 时贤 陈杭 《油气藏评价与开发》 CSCD 北大核心 2024年第3期391-401,共11页
针对鄂尔多斯盆地SD区块盒8段储层低孔低渗、非均质性强、常规压裂裂缝形态单一等问题,基于断裂力学理论,考虑缝内流体压降,结合盒8段储层岩石力学参数,开展暂堵压裂裂缝与初次压裂裂缝在整个接触过程中的相互作用力学研究。计算分析了... 针对鄂尔多斯盆地SD区块盒8段储层低孔低渗、非均质性强、常规压裂裂缝形态单一等问题,基于断裂力学理论,考虑缝内流体压降,结合盒8段储层岩石力学参数,开展暂堵压裂裂缝与初次压裂裂缝在整个接触过程中的相互作用力学研究。计算分析了不同裂缝走向、井斜角、方位角等参数对压裂裂缝参数的影响规律,起裂压力随井斜角和方位角的增加而减小;起裂角随井斜角增加而减小直至为0°,随方位角先增加而后减小。通过制备人工水泥试样,利用大尺寸真三轴物模实验系统模拟了暂堵压裂中新缝起裂及其转向行为,评价了不同井斜角、方位角下新缝起裂、转向及延伸行为和起裂压力及裂缝改造面积等参数。实验结果表明:井斜角增大,初次及二次起裂压力呈减小的趋势,裂缝更易转向且改造面积越大。井斜角相同时,裂缝起裂压力随井筒方位角增加而逐渐减小,裂缝改造面积随方位角增加而增大。方位角90°螺旋射孔相比方位角0°螺旋射孔形成的裂缝更为复杂,定面射孔可调控水平井破裂压力及初始破裂位置,初始破裂产生于射孔井筒界面、孔道中部等不同位置,控制射孔射角介于75°~90°。研究结果为低渗透致密砂岩气藏暂堵压裂设计提供了依据。 展开更多
关键词 真三轴 暂堵压裂 起裂扩展 破裂压力 起裂角 裂缝改造面积
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一种新型柔性绳结暂堵球的性能评价及现场应用
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作者 李昌恒 彭长江 +3 位作者 邓咸安 邓志勇 许威 关海萍 《精细石油化工》 CAS 2024年第5期20-23,共4页
评价了新型柔性绳结暂堵球的降解性、承压性及封堵性。结果表明,该新型柔性绳结堵球密度为1.0~1.1 g/m^(3),与常规压裂液密度接近,有利于压裂液的携带,50℃以上温度条件下可完全溶解,封堵孔眼后承压能力达60 MPa。应用于长庆油田现场41... 评价了新型柔性绳结暂堵球的降解性、承压性及封堵性。结果表明,该新型柔性绳结堵球密度为1.0~1.1 g/m^(3),与常规压裂液密度接近,有利于压裂液的携带,50℃以上温度条件下可完全溶解,封堵孔眼后承压能力达60 MPa。应用于长庆油田现场41口井,平均暂堵升压幅度10.3 MPa,暂堵后工作压力提高4.1 MPa,较颗粒暂堵剂升压幅度提高80%以上。 展开更多
关键词 压裂暂堵 层间暂堵 柔性绳结 应用
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基于坐封受力模型的暂堵球封堵效果影响因素与参数优化
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作者 孔祥伟 时贤 +1 位作者 李赛 齐天俊 《科学技术与工程》 北大核心 2024年第13期5350-5357,共8页
暂堵球在射孔孔眼及压裂裂缝中的坐封状态影响其封堵稳定性,暂堵球封堵效果决定暂堵转向压裂技术的成败。通过建立暂堵球坐封受力计算模型,研究了压裂液排量、密度、暂堵球及孔眼参数对暂堵球坐封受力状态及其封堵效率的影响,实验模拟... 暂堵球在射孔孔眼及压裂裂缝中的坐封状态影响其封堵稳定性,暂堵球封堵效果决定暂堵转向压裂技术的成败。通过建立暂堵球坐封受力计算模型,研究了压裂液排量、密度、暂堵球及孔眼参数对暂堵球坐封受力状态及其封堵效率的影响,实验模拟了不同射孔参数、压裂排量及暂堵球/压裂液性能对封堵效果的影响。结果表明:暂堵球受拖拽力、脱离力及持球力随压裂液排量的增加而增大,暂堵球更易坐封;压裂液及暂堵球密度对暂堵球坐封封堵效率影响不大;暂堵球粒径大于孔眼直径时,暂堵球坐封封堵效率随粒径增加而增大,当暂堵球直径小于孔眼直径时,暂堵球不容易坐封;射孔孔眼数增加影响暂堵球坐封封堵效率。实验评价暂堵球最佳直径为9.0 mm,最佳泵送排量大于4.0 m^(3)/min时,有助于提高暂堵球坐封成功率,增强暂堵压裂设计的可靠性。 展开更多
关键词 水力压裂 暂堵转向 暂堵球 受力模型 坐封效率
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湖泊深水暂养过程中鳙鱼品质变化研究
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作者 凌俊 陈小雷 +7 位作者 江河 汪长祥 童开满 潘庭双 胡玉婷 段国庆 周华兴 汪焕 《安徽农业科学》 CAS 2024年第3期80-87,共8页
为了研究天然水体长成鳙鱼在不同月份暂养过程中鳙鱼体形、肌肉营养、滋味、免疫及抗氧化物质的变化,采集花亭湖5月、8月、11月和次年3月暂养鳙鱼进行系统研究。结果显示,从体形来看,暂养处理对鳙鱼有瘦身效果;不同月份鳙鱼肌肉基本营... 为了研究天然水体长成鳙鱼在不同月份暂养过程中鳙鱼体形、肌肉营养、滋味、免疫及抗氧化物质的变化,采集花亭湖5月、8月、11月和次年3月暂养鳙鱼进行系统研究。结果显示,从体形来看,暂养处理对鳙鱼有瘦身效果;不同月份鳙鱼肌肉基本营养成分含量有差别,暂养处理后,鳙鱼肌肉蛋白质和脂肪含量降低,水分和灰分含量升高;脂肪酸组成发生变化,主要表现在饱和脂肪酸(SFA)含量降低,多不饱和脂肪酸(PUFA)含量升高;肌肉免疫和抗氧化成分含量随着暂养时间的延长显著降低;游离氨基酸总量随着暂养时间的延长不断提高,呈现甜味氨基酸占比不断提高;呈味核苷酸总量提高。 展开更多
关键词 鳙鱼 暂养 营养 免疫 抗氧化 滋味
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改性聚乙醇酸暂堵剂研发及其在河南油田的应用
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作者 冯兴武 刘正奎 +3 位作者 郑桐 尹晓静 杨琪 段军 《石油地质与工程》 CAS 2024年第3期23-28,共6页
酸溶性暂堵剂对地层伤害较大,解堵较麻烦,油溶性暂堵剂不适合高含水的油层;河南油田低渗透油藏地层温度为50~120℃,注水驱油见水快,常规水溶性聚乙醇酸暂堵剂和聚乳酸暂堵剂水解温度大于80℃,不能完全满足低渗透油藏暂堵压裂的需求。结... 酸溶性暂堵剂对地层伤害较大,解堵较麻烦,油溶性暂堵剂不适合高含水的油层;河南油田低渗透油藏地层温度为50~120℃,注水驱油见水快,常规水溶性聚乙醇酸暂堵剂和聚乳酸暂堵剂水解温度大于80℃,不能完全满足低渗透油藏暂堵压裂的需求。结合颗粒类水溶性聚乙醇酸暂堵剂和聚乳酸暂堵剂的特性和暂堵原理,采用催化剂和抑制剂使聚乙醇酸和聚乳酸发生酯化反应,生成聚乙醇酸和聚乳酸融合物,再加入成核剂及结晶促进剂,可得到改性聚乙醇酸暂堵剂。经测试,改性聚乙醇酸暂堵剂在50~120℃温度下具有常规聚乙醇酸暂堵剂的溶解性能和暂堵强度;当改性聚乙醇酸暂堵剂的总用量占比达到18%、粗粒径与细粒径质量配比接近1:1时,其封堵强度大于40 MPa,暂堵性能良好。现场试验7井次,加入改性聚乙醇酸暂堵剂后,单井施工压力最高增加了6.1 MPa,日增油5.3 t,取得了明显的增油效果。 展开更多
关键词 暂堵剂 转向压裂 聚乙醇酸 水溶性 暂堵强度
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气管舌瓣造口改良气管切开术在困难气管切开患者中的应用
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作者 叶凡 方潇碧 +3 位作者 夏志刚 吴聪 林刃舆 李贺 《温州医科大学学报》 CAS 2024年第6期477-481,共5页
目的:探讨气管舌瓣造口改良气管切开术在困难气管切开患者中的应用价值。方法:选取2016年11月至2021年12月在温州医科大学附属第一医院接受气管切开术的困难气管切开患者42例进行回顾性分析,按气管切开方式不同分为暂时性气管切开术组(2... 目的:探讨气管舌瓣造口改良气管切开术在困难气管切开患者中的应用价值。方法:选取2016年11月至2021年12月在温州医科大学附属第一医院接受气管切开术的困难气管切开患者42例进行回顾性分析,按气管切开方式不同分为暂时性气管切开术组(25例)和气管舌瓣造口改良气管切开术组(17例)。分析2组患者的术后首次换管时间、渗血量、术后并发症、决策时间和手术时间等指标。结果:与暂时性气管切开术组相比,气管舌瓣造口改良气管切开术组在术后首次换管时间、渗血量方面具有显著优势(P<0.05)。气管舌瓣造口改良气管切开术组较暂时性气管切开术组手术决策时间明显缩短(P<0.05);但两组手术时间差异无统计学意义(P>0.05)。气管舌瓣造口改良气管切开术组出现1例皮下气肿并发症,暂时性气管切开术组出现2例局部感染,3例意外脱管和1例气囊破裂。结论:气管舌瓣造口改良气管切开术相较暂时性常规气管切开术在术后并发症及结局方面有一定的优势。 展开更多
关键词 困难气管切开 气管舌瓣造口改良气管切开术 暂时气管切开术
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球形破片侵彻弹道明胶实验研究
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作者 李红莲 康华荣 +8 位作者 李运良 吴祖堂 谭书舜 赵奇峰 肖遥 黄国欣 许洋洋 朱玉荣 张向荣 《兵器装备工程学报》 CAS CSCD 北大核心 2024年第10期61-68,82,共9页
为研究破片对人体的力学损伤机理,采用弹道明胶作为人体软组织替代物,开展了球形破片侵彻明胶实验研究。球形破片驱动装置为57/10二级轻气炮,利用超高速摄像机记录了Φ4 mm、Φ5 mm、Φ6 mm球形钢质破片,以600~1150 m/s速度侵彻明胶过程... 为研究破片对人体的力学损伤机理,采用弹道明胶作为人体软组织替代物,开展了球形破片侵彻明胶实验研究。球形破片驱动装置为57/10二级轻气炮,利用超高速摄像机记录了Φ4 mm、Φ5 mm、Φ6 mm球形钢质破片,以600~1150 m/s速度侵彻明胶过程,并采用图像处理方式获取了明胶瞬时空腔数据。实验结果表明:瞬时空腔直径随着时间推移形成两个膨缩阶段,呈现周期性变化规律;基于实测球形破片速度-位移衰减关系,定量描述了3种直径球形破片侵彻明胶的运动规律;根据球形钢质破片的存速系数比29.90 mm^(-1),可快速预测该类破片侵彻弹道明胶过程中侵彻深度与侵彻速度之间的关系。研究结果可为深入分析生物致伤机理提供参考。 展开更多
关键词 球形破片 弹道明胶 瞬时空腔 损伤机理 运动规律
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非常规致密油储层压裂增能一体化技术分析 被引量:3
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作者 张涛 李宪鹏 +1 位作者 梁健美 王德晴 《中外能源》 2024年第1期70-76,共7页
针对试验区非常规致密油储层常规缝网压裂改造体积有限,压后递减快、稳产差,采出程度低的问题,采用压裂增能一体化工艺,从平衡压力、提高缝控体积及保持能量入手,总结出“补、压、闷、控”的技术思路,通过前置补充能量、增大裂缝与储层... 针对试验区非常规致密油储层常规缝网压裂改造体积有限,压后递减快、稳产差,采出程度低的问题,采用压裂增能一体化工艺,从平衡压力、提高缝控体积及保持能量入手,总结出“补、压、闷、控”的技术思路,通过前置补充能量、增大裂缝与储层接触面积、闷井扩散压力、控制返排等方式,达到压裂增能一体化的目的。现场实施效果表明,采用多级暂堵技术改造体积提高1倍以上,闷井扩散25~30d,无效返排率降低近15个百分点,达到了入井液保持地层能量的目的。与以往单井缝网压裂、整体缝网压裂相比,增油强度分别提高0.27t/(d·m)、0.34t/(d·m);压后前3个月平均单井日增油3.0t,是同期甜点压裂和整体压裂的1.2倍和1.8倍,提产效果显著。结合现场实施及效果分析,优化完善参数设计,形成压裂增能一体化设计原则。 展开更多
关键词 压裂增能 前置补能 多级暂堵 闷井扩散 控制返排 改造体积
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多级暂堵诱导分支缝开启规律
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作者 孙正龙 刘彦成 +4 位作者 尹虹橙 杨璐 张迎春 高计县 何江 《科学技术与工程》 北大核心 2024年第10期4084-4090,共7页
缝内多级暂堵是提高缝内净压力,激活侧向分支缝,增大侧向改造带宽,提升层内油气动用程度的有效手段之一。研究缝内多级暂堵转向规律对指导优化暂堵方案至关重要,其难点是建立缝内暂堵模拟方法。针对裂缝性超低渗储层,基于等效黏度方法,... 缝内多级暂堵是提高缝内净压力,激活侧向分支缝,增大侧向改造带宽,提升层内油气动用程度的有效手段之一。研究缝内多级暂堵转向规律对指导优化暂堵方案至关重要,其难点是建立缝内暂堵模拟方法。针对裂缝性超低渗储层,基于等效黏度方法,建立了缝内多级暂堵数值模型,系统研究了逼近角、应力差、暂堵次数对分支缝开启的影响规律,研究结果表明:当水平应力差≥5 MPa且逼近角较大(≥60°)时,水力裂缝倾向于穿过天然裂缝,沿当前方向扩展,无法激活天然裂缝;水平应力差≤5 MPa时且逼近角较小(≤30°)时,水力裂缝遇到天然裂缝后能够开启钝角分支;缝内初次暂堵能够有效开启高逼近角下一级分支缝,缝内二次暂堵能够开启二级分支缝;采用缝内多级暂堵能够提高单井最高日产油量至2倍,平均日产油量提升至3倍。本文研究成果对缝内多级暂堵压裂设计奠定了模型和方法基础。 展开更多
关键词 缝网压裂 多级暂堵 分支缝 二次转向
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长阳天池口清江特大桥主拱圈悬臂浇筑斜拉扣挂系统设计 被引量:1
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作者 周水兴 孙峰 段佳旺 《世界桥梁》 北大核心 2024年第3期61-67,共7页
长阳天池口清江特大桥主桥为净跨径242 m的非对称上承式钢筋混凝土拱桥,主拱圈采用单箱单室截面,宽9.5 m、高4.0 m。资丘岸和五峰岸半跨主拱圈各分为24个和21个节段,第1个节段采用支架现浇,其余节段采用斜拉扣挂悬臂浇筑法施工。扣索采... 长阳天池口清江特大桥主桥为净跨径242 m的非对称上承式钢筋混凝土拱桥,主拱圈采用单箱单室截面,宽9.5 m、高4.0 m。资丘岸和五峰岸半跨主拱圈各分为24个和21个节段,第1个节段采用支架现浇,其余节段采用斜拉扣挂悬臂浇筑法施工。扣索采用星式和扇形组合方式布置,位于墩顶和扣塔的扣索为星式布置,位于交界墩墩身的扣索为扇形布置,并将墩身上的扣锚索设计成连续索以避免在墩身上搭设张拉平台;扣塔由8根∅800 mm×16 mm钢管组成,两岸扣塔分别高52.68 m和60.12 m;根据锚索最大索力,设计了能承受800 kN张拉力的岩锚索。建立主拱圈悬臂浇筑施工阶段MIDAS Civil有限元模型,对斜拉扣挂系统扣锚索索力进行计算,通过拆除部分扣索和调整扣锚索索力,施工期间主拱圈截面最大拉应力、扣塔最大偏位、主拱圈成拱后线形均满足要求。 展开更多
关键词 钢筋混凝土拱桥 主拱圈 悬臂浇筑 斜拉扣挂系统 扣锚索 拉应力 扣塔偏位 成拱线形
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