The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce...The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce water resources on the site. These unfavorable factors have brought great difficulties to the on-site mining process. Now, a nano-composite green environmental protection slick water fracturing fluid system CQFR can be quickly dissolved because of the larger specific surface area, and the small molecular size makes the damage to the reservoir less than 5%, and the average drag reduction effect can reach more than 73%. It can quickly and well dissolve and maintain performance under high salinity conditions and fracturing flowback fluids. It responds well to the complex reservoir conditions on the construction site and makes the flowback fluid recyable, which greatly reduces the consumption of water resources on the construction site and effectively improves the construction efficiency and economic benefits.展开更多
An innovative method for high-speed micro-dicing of SiC has been proposed using two types of diamond dicing blades,a resin-bonded dicing blade and a metal-bonded dicing blade.The experimental research investigated the...An innovative method for high-speed micro-dicing of SiC has been proposed using two types of diamond dicing blades,a resin-bonded dicing blade and a metal-bonded dicing blade.The experimental research investigated the radial wear of the dicing blade,the maximum spindle current,the surface morphology of the SiC die,the number of chips longer than 10μm,and the chipped area,which depend on the dicing process parameters such as spindle speed,feed speed,and cutting depth.The chipping fractures in the SiC had obvious brittle fracture characteristics.The performance of the metal-bonded dicing blade was inferior to that of the resin-bonded dicing blade.The cutting depth has the greatest influence on the radial wear of the dicing blade,the maximum spindle current,and the damage to the SiC wafer.The next most important parameter is the feed speed.The parameter with the least influence is the spindle speed.The main factor affecting the dicing quality is blade vibration caused by spindle vibration.The optimal SiC dicing was for a resin-bonded dicing blade with a spindle speed of 20000 rpm,a feed speed of 4 mm/s,and a cutting depth of 0.1 mm.To improve dicing quality and tool performance,spindle vibrations should be reduced.This approach may enable high-speed dicing of SiC wafers with less dicing damage.展开更多
This paper presents the development and testing of a novel internal dissipation connection for the use of post-tensioned rocking columns.The solution is one of the many referring to the dissipative controlled rocking(...This paper presents the development and testing of a novel internal dissipation connection for the use of post-tensioned rocking columns.The solution is one of the many referring to the dissipative controlled rocking(DCR)bridge design philosophy.The internal dissipaters are carefully designed to be cost-effective and reduce the over-all construction cost.The dissipaters are fully threaded,Grade 300 bars connected to the permanent column and foundation longitudinal reinforcement with threaded couplers.In this research,a DCR column is subjected to subsequent earthquake events,and the dissipaters’strain design limits are chosen such that there is no need for replacing after a significant seismic event.The result is a recommended design strain limit of 1.5%for the dissi-paters that guarantees the structural integrity of the DCR column after a seismic event.Additionally,a cumulated strain of 5%is recommended for the dissipaters before replacement is suggested.The proposed connection de-tailing with replaceable internal dissipaters,combined with post-tensioned high strength bars and well-confined concrete,provided self-centring capabilities(no residual displacement),dissipation capacity and significantly less damage in the bridge column than a traditional reinforced concrete solution.展开更多
The Yan'an Gas Field is located in the southeastern part of the Ordos Basin,and its low-permeability tight sandstone gas reservoirs are characterized by thin reservoirs,poor physical properties and complex overlap...The Yan'an Gas Field is located in the southeastern part of the Ordos Basin,and its low-permeability tight sandstone gas reservoirs are characterized by thin reservoirs,poor physical properties and complex overlapping relationships.In addition,its surface is loess tableland,which makes it difficult to predict reservoirs by using seismic data.As a result,existing engineering technologies for gas field development cannot support the efficient development of this field.In order to optimize the development methods and technologies of the Yan'an Gas Field,the Yanchang Petroleum(Group)Co.Ltd.has developed to a set of key technologies suitable for the benefit development of this field concerning reservoir prediction,well pattern optimization,drilling and completion,reservoir protection,fracturing stimulation and ground gathering and transportation after nearly ten years of theoretical and technical researches.First,an effective reservoir prediction technology based on dynamic knowledge base was developed.It improves the drilling ratio of effective sandbody dramatically and achieves the accurate tracking of stable single sandbody in the range of 3-5 m.Second,a three-dimensional exploitation mode of hybrid well pattern based on the irregular diamond-shaped well pattern was established.It includes the multi-layer commingled production of cluster well and the single-layer production of horizontal well.Compared with regular well patterns,the well number is reduced by 6.9%and well pattern control is increased by 8%.Third,high-efficiency drilling technology for vulnerable reservoirs with collapse and leakage in the same well was developed.It improves wellbore wall stability,shortens drilling cycle and protects reservoir.Fourth,the multi-layer long-span fracturing of vertical/directional wells in one operation and the CO_(2)and hydraulic fracturing treatment of horizontal wells were realized to improve single well production significantly.Fifth,the medium-pressure gathering and transportation system in loess tableland with downhole throttling,branch-on-branch inter-well tandem and centralized alcohol injection as the core technologies was established.It reduces workload,shortens construction cycle and improves economic benefit.In conclusion,these development technologies play a crucial role in the development,appraisal and productivity construction of the Yan'an Gas Field.Through the application of these key technologies,the benefit development of this field is realized with an annual natural gas production capacity of 50×10^(8)m^(3).Furthermore,they are conducive to the enrichment and development of the theories and technologies for developing tight sandstone gas reservoirs in China,and they can be used as a reference for the development of similar gas fields.展开更多
文摘The Sulige gas field is a typical low-pressure low-permeability tight sandstone gas reservoir. The reservoir has poor seepage capacity, strong heterogeneity, high mineralization of formation water and extremely scarce water resources on the site. These unfavorable factors have brought great difficulties to the on-site mining process. Now, a nano-composite green environmental protection slick water fracturing fluid system CQFR can be quickly dissolved because of the larger specific surface area, and the small molecular size makes the damage to the reservoir less than 5%, and the average drag reduction effect can reach more than 73%. It can quickly and well dissolve and maintain performance under high salinity conditions and fracturing flowback fluids. It responds well to the complex reservoir conditions on the construction site and makes the flowback fluid recyable, which greatly reduces the consumption of water resources on the construction site and effectively improves the construction efficiency and economic benefits.
基金This work was supported by the National Natural Science Foundation of China(Grant No.51305278)LiaoNing Revitalization Talents Program,China(Grant No.XLYC2007133)the Natural Science Foundation of Liaoning Province,China(Grant No.2020-MS-213).
文摘An innovative method for high-speed micro-dicing of SiC has been proposed using two types of diamond dicing blades,a resin-bonded dicing blade and a metal-bonded dicing blade.The experimental research investigated the radial wear of the dicing blade,the maximum spindle current,the surface morphology of the SiC die,the number of chips longer than 10μm,and the chipped area,which depend on the dicing process parameters such as spindle speed,feed speed,and cutting depth.The chipping fractures in the SiC had obvious brittle fracture characteristics.The performance of the metal-bonded dicing blade was inferior to that of the resin-bonded dicing blade.The cutting depth has the greatest influence on the radial wear of the dicing blade,the maximum spindle current,and the damage to the SiC wafer.The next most important parameter is the feed speed.The parameter with the least influence is the spindle speed.The main factor affecting the dicing quality is blade vibration caused by spindle vibration.The optimal SiC dicing was for a resin-bonded dicing blade with a spindle speed of 20000 rpm,a feed speed of 4 mm/s,and a cutting depth of 0.1 mm.To improve dicing quality and tool performance,spindle vibrations should be reduced.This approach may enable high-speed dicing of SiC wafers with less dicing damage.
文摘This paper presents the development and testing of a novel internal dissipation connection for the use of post-tensioned rocking columns.The solution is one of the many referring to the dissipative controlled rocking(DCR)bridge design philosophy.The internal dissipaters are carefully designed to be cost-effective and reduce the over-all construction cost.The dissipaters are fully threaded,Grade 300 bars connected to the permanent column and foundation longitudinal reinforcement with threaded couplers.In this research,a DCR column is subjected to subsequent earthquake events,and the dissipaters’strain design limits are chosen such that there is no need for replacing after a significant seismic event.The result is a recommended design strain limit of 1.5%for the dissi-paters that guarantees the structural integrity of the DCR column after a seismic event.Additionally,a cumulated strain of 5%is recommended for the dissipaters before replacement is suggested.The proposed connection de-tailing with replaceable internal dissipaters,combined with post-tensioned high strength bars and well-confined concrete,provided self-centring capabilities(no residual displacement),dissipation capacity and significantly less damage in the bridge column than a traditional reinforced concrete solution.
基金Project supported by the National High-tech Research and Development Plan(863 Program)project“new technology for shale gas exploration and development”(No.:2013AA064501)Shaanxi Science and Technology Research and Development Plan project“Natural gas exploration and development innovation team of Shaanxi Yanchang Petroleum”(No.:2015KCT-17).
文摘The Yan'an Gas Field is located in the southeastern part of the Ordos Basin,and its low-permeability tight sandstone gas reservoirs are characterized by thin reservoirs,poor physical properties and complex overlapping relationships.In addition,its surface is loess tableland,which makes it difficult to predict reservoirs by using seismic data.As a result,existing engineering technologies for gas field development cannot support the efficient development of this field.In order to optimize the development methods and technologies of the Yan'an Gas Field,the Yanchang Petroleum(Group)Co.Ltd.has developed to a set of key technologies suitable for the benefit development of this field concerning reservoir prediction,well pattern optimization,drilling and completion,reservoir protection,fracturing stimulation and ground gathering and transportation after nearly ten years of theoretical and technical researches.First,an effective reservoir prediction technology based on dynamic knowledge base was developed.It improves the drilling ratio of effective sandbody dramatically and achieves the accurate tracking of stable single sandbody in the range of 3-5 m.Second,a three-dimensional exploitation mode of hybrid well pattern based on the irregular diamond-shaped well pattern was established.It includes the multi-layer commingled production of cluster well and the single-layer production of horizontal well.Compared with regular well patterns,the well number is reduced by 6.9%and well pattern control is increased by 8%.Third,high-efficiency drilling technology for vulnerable reservoirs with collapse and leakage in the same well was developed.It improves wellbore wall stability,shortens drilling cycle and protects reservoir.Fourth,the multi-layer long-span fracturing of vertical/directional wells in one operation and the CO_(2)and hydraulic fracturing treatment of horizontal wells were realized to improve single well production significantly.Fifth,the medium-pressure gathering and transportation system in loess tableland with downhole throttling,branch-on-branch inter-well tandem and centralized alcohol injection as the core technologies was established.It reduces workload,shortens construction cycle and improves economic benefit.In conclusion,these development technologies play a crucial role in the development,appraisal and productivity construction of the Yan'an Gas Field.Through the application of these key technologies,the benefit development of this field is realized with an annual natural gas production capacity of 50×10^(8)m^(3).Furthermore,they are conducive to the enrichment and development of the theories and technologies for developing tight sandstone gas reservoirs in China,and they can be used as a reference for the development of similar gas fields.
