Horizontal well-stimulation is the key to unconventional resource exploration and development.The development mode of the well plant helps increase the stimulated reservoir volume.Nevertheless,fracture interference be...Horizontal well-stimulation is the key to unconventional resource exploration and development.The development mode of the well plant helps increase the stimulated reservoir volume.Nevertheless,fracture interference between wells reduces the fracturing effect.Here,a 2D hydro-mechanical coupling model describing hydraulic fracture(HF)propagation is established with the extended finite element method,and the effects of several factors on HF propagation during multiple wells fracturing are analyzed.The results show that with an increase in elastic modulus,horizontal principal stress difference and injection fluid displacement,the total fracture area and the reservoir stimulation efficiency are both improved in all three fracturing technologies.After a comparison of the three technologies,the method of improved zipper fracturing is proposed,which avoids mutual interference between HFs,and the reservoir stimulation effect is improved significantly.The study provides guidance for optimizing the fracturing technology of multiple horizontal wells.展开更多
Focusing on the extending length restriction of the completion screen pipe resistance running into ultra-short radius horizontal well,this paper proposed technology of hydraulic drive completion tubular string running...Focusing on the extending length restriction of the completion screen pipe resistance running into ultra-short radius horizontal well,this paper proposed technology of hydraulic drive completion tubular string running into ultra-short radius horizontal well.Innovative hydraulic drive tools and string structure are designed,which are composed of guide tubing,hydraulic drive tubing and non-metallic completion screen pipe from inside to outside.A novel mechanical-hydraulic coupling model is established.Based on the wellbore structure of an ultra-short radius horizontal well for deep coalbed methane,the numerical calculations of force and hydraulic load on tubular strings were accomplished by the mechanical-hydraulic coupling model.The results show that the extending length of completion tubular string with the hydraulic drive is 17 times that of conventional completion technology under the same conditions.The multi-factor orthogonal design is adopted to analyze the numerical calculations,and the results show that the extending length of the completion tubular string is mainly affected by the completion tubular string structure and the friction coefficient between the non-metallic composite continuous screen pipe and the wellbore.Two series of hydraulic drive completion tubular string structures suitable for ultra-short radius horizontal wells under different conditions are optimized,with the extending limits of 381 m and 655 m,respectively.These researches will provide theoretical guidance for design and control of hydraulic drive non-metallic composite continuous completion screen pipe running into ultra-short radius horizontal wells.展开更多
The second-tier extended metropolises in the Changjiang (Yangtze) River Delta, including Suzhou, Wuxi and Changzhou near Shanghai, are becoming the most active and new innovative industrial agglomerating areas. Manufa...The second-tier extended metropolises in the Changjiang (Yangtze) River Delta, including Suzhou, Wuxi and Changzhou near Shanghai, are becoming the most active and new innovative industrial agglomerating areas. Manufacturing industries in these second-tier cities have been in rapid growth due to increasing foreign investment. Nevertheless, the economic prospect of these cities is still constrained by a lack of local R&D capacity and production services, which are mainly dependent upon Shanghai. This paper analyses the impact of globalization on the new economic sectors in these cities, the change of industrial structure, the limitation of urban development and the problem of sustainability. Then, the paper analyses the conditions for the high-tech industry and production services in these areas. Also, it applies the industrial organization theory to these cities and examines how these cities can cooperate with each other in terms of horizontal linkages. Finally, the paper gives the future growth prospects in high-tech industry and production services.展开更多
基金funded by Shaanxi Natural Science Basic Research Program Project Study on Liquid Propellant High Energy Gas Fracturing Mechanism in Radial Well Based on Phase Field Method(No.2019JQ-824)NSFC Projects Evolution Mechanism and Effectiveness Evaluation of Fracture Network Produced by Volume Fracturing with Tighter Clusters in Continental Shale Oil Reservoir(No.52274040)+1 种基金Study on Thermal Secondary Pore Evolution and Salt Precipitation Regulation Mechanism in Fire Flooding Reservoirs Based on Multi-field Coupling of Thermal-Flow-Solid-Chemical(No.52274039)Xi’an Shiyou University Youth Scientific Research and Innovation Team Operation Funds in 2018 Flow Mechanism of Complex Reservoirs and High Efficiency Development and Oil Production Technology(No.115080020).
文摘Horizontal well-stimulation is the key to unconventional resource exploration and development.The development mode of the well plant helps increase the stimulated reservoir volume.Nevertheless,fracture interference between wells reduces the fracturing effect.Here,a 2D hydro-mechanical coupling model describing hydraulic fracture(HF)propagation is established with the extended finite element method,and the effects of several factors on HF propagation during multiple wells fracturing are analyzed.The results show that with an increase in elastic modulus,horizontal principal stress difference and injection fluid displacement,the total fracture area and the reservoir stimulation efficiency are both improved in all three fracturing technologies.After a comparison of the three technologies,the method of improved zipper fracturing is proposed,which avoids mutual interference between HFs,and the reservoir stimulation effect is improved significantly.The study provides guidance for optimizing the fracturing technology of multiple horizontal wells.
基金Supported by the Innovative Research Group Project of China National Natural Science Foundation(51821092)Key Project of China National Natural Science Foundation(U1762214).
文摘Focusing on the extending length restriction of the completion screen pipe resistance running into ultra-short radius horizontal well,this paper proposed technology of hydraulic drive completion tubular string running into ultra-short radius horizontal well.Innovative hydraulic drive tools and string structure are designed,which are composed of guide tubing,hydraulic drive tubing and non-metallic completion screen pipe from inside to outside.A novel mechanical-hydraulic coupling model is established.Based on the wellbore structure of an ultra-short radius horizontal well for deep coalbed methane,the numerical calculations of force and hydraulic load on tubular strings were accomplished by the mechanical-hydraulic coupling model.The results show that the extending length of completion tubular string with the hydraulic drive is 17 times that of conventional completion technology under the same conditions.The multi-factor orthogonal design is adopted to analyze the numerical calculations,and the results show that the extending length of the completion tubular string is mainly affected by the completion tubular string structure and the friction coefficient between the non-metallic composite continuous screen pipe and the wellbore.Two series of hydraulic drive completion tubular string structures suitable for ultra-short radius horizontal wells under different conditions are optimized,with the extending limits of 381 m and 655 m,respectively.These researches will provide theoretical guidance for design and control of hydraulic drive non-metallic composite continuous completion screen pipe running into ultra-short radius horizontal wells.
文摘The second-tier extended metropolises in the Changjiang (Yangtze) River Delta, including Suzhou, Wuxi and Changzhou near Shanghai, are becoming the most active and new innovative industrial agglomerating areas. Manufacturing industries in these second-tier cities have been in rapid growth due to increasing foreign investment. Nevertheless, the economic prospect of these cities is still constrained by a lack of local R&D capacity and production services, which are mainly dependent upon Shanghai. This paper analyses the impact of globalization on the new economic sectors in these cities, the change of industrial structure, the limitation of urban development and the problem of sustainability. Then, the paper analyses the conditions for the high-tech industry and production services in these areas. Also, it applies the industrial organization theory to these cities and examines how these cities can cooperate with each other in terms of horizontal linkages. Finally, the paper gives the future growth prospects in high-tech industry and production services.
