In this paper,shale samples of Lower Silurian Longmaxi Fm,taken from the ChangningeWeiyuan area in the Sichuan Basin,were selected tofigure out the influence of reservoir primary water on the adsorption laws and theflow ...In this paper,shale samples of Lower Silurian Longmaxi Fm,taken from the ChangningeWeiyuan area in the Sichuan Basin,were selected tofigure out the influence of reservoir primary water on the adsorption laws and theflow capacity of shale gas.Experimental samples with different water saturations were prepared using the adsorption equilibrium method.Then,high-pressure isothermal adsorption experiments were carried out,and the isothermal adsorption effects and mechanisms of shale under different water saturations were discussed.Finally,theflow capacity of shale gas under different water saturations was tested using the independently developed steady-stateflow test device.And the following research results were obtained.First,the presence of primary water in micronenanometer pores of shale reservoirs reduces the adsorption capacity of shale.When the water saturation is 40%,the simulated total gas content is 18%lower than that in the conventional calculation result.Second,the apparent shale permeability is a function of pressure.Due to the effect of Knudsen diffusion,the apparent shale permeability increases significantly with the decrease of pressure under low pressure.When the average pressure is 5 MPa and the water saturation reaches 50%,the apparent shale permeability is about 70%lower than that of a dry sample.Third,when the water saturation is lower than the critical value,water is mainly presented as non-movable water in micropores and mesopores,and it has less effect on theflow capacity of shale gas.When the water saturation is greater than the critical value,the lodging point of water is changed,resulting in significant reduction of the shale gasflow capacity.It is concluded that an accurate understanding of the original water saturation and critical water saturation of shale reservoirs helps to calculate shale gas reserves accurately and predict gas well production rate rationally.展开更多
Summary:Changes of maximum expiratory flow at 25%and 50%of vital capacity(MEF2s and MEFso,respectively),and predominant parameters indicating small airways function in asthmatics before and after bronchodilator(BD)rev...Summary:Changes of maximum expiratory flow at 25%and 50%of vital capacity(MEF2s and MEFso,respectively),and predominant parameters indicating small airways function in asthmatics before and after bronchodilator(BD)reversibility test have been less interpreted.Our study aimed to investigate the clinical role of changes of MEF2s and MEFso before and after BD reversibility test in diagnosing asthma.Forced expiratory volume in the first second(FEV),MEF2s,and MEFso were measured before and after BD reversibility test in 207 asthmatic patients using standard process.Forty healthy individuals were enrolled as controls.Receiver operating characteristic(ROC)curve was used to assess the diagnostic accuracy of reversibility of MEF2s and MEFgo before and after BD reversibility test(OMEF 2s%and AMEF so%,respectively)in diagnosing asthma.Among these functional criteria,AMEF2;%and 0MEFs%≥25%performed the best diagnostic performance.The sensitivity,specificity,and accuracy of AMEF 25%≥25%as an objcctive diagnostic test for asthma were 63.29%,87.50%,and 67.21%,and of AMEFs0%≥25%were 79.23%,85.00%,and 80.16%,respectively.The area under the ROC curve of the indicators was 0.8203 and 0.9104,respectively.By contrast,an increase in FEV≥12%and 200 mL demonstrated a sensitivity of 62.32%,specificity of 82.50%,and accuracy of 65.59%in diagnosing asthma.The changes of MEF2s and MEFso before and after BD reversibility test may be of additional value in the clinical diagnosis of asthma,with cutoff values of 25%being the most.展开更多
The microscopic heterogeneity of pore-throat structures in tight sandstone is a crucial parameter for understanding the transport mechanism of fluid flow.In this work,we firstly developed the new procedure to characte...The microscopic heterogeneity of pore-throat structures in tight sandstone is a crucial parameter for understanding the transport mechanism of fluid flow.In this work,we firstly developed the new procedure to characterize the pore size distribution(PSD)and throat size distribution(TSD)by combining the nuclear magnetic resonance(NMR),cast thin section(CTS),and constant-rate mercury injection(CRMI)tests,and used the permeability estimated model to verify the full-scale PSD and TSD.Then,we respectively analyzed the fractal feature of the pore and throat,and characterized the heterogeneity of pores and throats.Finally,we elaborated the effect of the pore and throat heterogeneity on the gas-phase seepage capacity base on the analysis of the simple capillary tube model and gas-flooding experiment.The results showed that(1)The PSD and TSD of the tight sandstone sample ranged from 0.01 to 10 mm and from 0.1 to 57 mm,respectively,mainly contributed by the micropores and mesopores.Meanwhile,the permeability estimated by the PSD and TSD was consistent with the experimental permeability,and relative error was lower than 8%.(2)The PSD and TSD exhibited multifractal characteristics,and singularity strength range,Δα,could be used as the indicator for characterizing the heterogeneity of pore and throat.Furthermore,the throat of the sample showed stronger heterogeneity than that the pore.(3)The throats played an important role for the fluid transport in the tight sandstone,and the effect of the throat heterogeneity on the gas-phase seepage capacity was different under the lower and higher injection pressure.The macropores and micropores maybe respectively become the preferential migration pathways at the lower and higher injection pressure.In the end,the identification plate was established in our paper,and could be described the relationship among the throat heterogeneity,injection pressure,permeability and flow path of the gas phase in the tight sandstone.展开更多
In this study, we simulated water flow in a water conservancy project consisting of various hydraulic structures, such as sluices, pumping stations, hydropower stations, ship locks, and culverts, and developed a multi...In this study, we simulated water flow in a water conservancy project consisting of various hydraulic structures, such as sluices, pumping stations, hydropower stations, ship locks, and culverts, and developed a multi-period and multi-variable joint optimization scheduling model for flood control, drainage, and irrigation. In this model, the number of sluice holes, pump units, and hydropower station units to be opened were used as decision variables, and different optimization objectives and constraints were considered. This model was solved with improved genetic algorithms and verified using the Huaian Water Conservancy Project as an example. The results show that the use of the joint optimization scheduling led to a 10% increase in the power generation capacity and a 15% reduction in the total energy consumption. The change in the water level was reduced by 0.25 m upstream of the Yundong Sluice, and by 50% downstream of pumping stations No. 1, No. 2, and No. 4. It is clear that the joint optimization scheduling proposed in this study can effectively improve power generation capacity of the project, minimize operating costs and energy consumption, and enable more stable operation of various hydraulic structures. The results may provide references for the management of water conservancy projects in complex river networks.展开更多
After hydraulic fracturing treatment,a reduction in permeability caused by the invasion of fracturing fluids is an inevitable problem,which is called water blocking damage.Therefore,it is important to mitigate and eli...After hydraulic fracturing treatment,a reduction in permeability caused by the invasion of fracturing fluids is an inevitable problem,which is called water blocking damage.Therefore,it is important to mitigate and eliminate water blocking damage to improve the flow capacities of formation fluids and flowback rates of the fracturing fluid.However,the steady-state core flow method cannot quickly and accurately evaluate the effects of chemical agents in enhancing the fluid flow capacities in tight reservoirs.This paper introduces a time-saving and accurate method,pressure transmission test(PTT),which can quickly and quantitatively evaluate the liquid flow capacities and gas-drive flowback rates of a new nanoemulsion.Furthermore,scanning electron microscopy(SEM)was used to analyze the damage mechanism of different fluids and the adsorption of chemical agents on the rock surface.Parallel core flow experiments were used to evaluate the effects of the nanoemulsion on enhancing flowback rates in heterogeneous tight reservoirs.Experimental results show that the water blocking damage mechanisms differ in matrices and fractures.The main channels for gas channeling are fractures in cracked cores and pores in non-cracked cores.Cracked cores suffer less damage from water blocking than non-cracked cores,but have a lower potential to reduce water saturation.The PTT and SEM results show that the permeability reduction in tight sandstones caused by invasion of external fluids can be list as guar gum fracturing fluid>slickwater>brine.Parallel core flow experiments show that for low-permeability heterogenous s andstone reservoirs with a certain permeability ratio,the nanoemulsion can not only reduce reverse gas channeling degree,but also increase the flowback rate of the fracturing fluid.The nanoemulsion system provides a new solution to mitigate and eliminate water blocking damage caused by fracturing fluids in tight sandstone gas reservoirs.展开更多
Modern processing plants use a variety of control loop networks to deliver a finished product to the market.Such control loops,like control valves,are designed to keep process variables such as pressure,temperature,sp...Modern processing plants use a variety of control loop networks to deliver a finished product to the market.Such control loops,like control valves,are designed to keep process variables such as pressure,temperature,speed,flow,etc.within the appropriate operating range and to ensure a quality product is produced.All control valves have a bypass so that production can proceed if maintenance is needed for the control valve as part of the control loop.The important point is that in both operation and maintenance situations,the bypass valve and the control valve should have approximately the same flow capacity to provide nearly the same amount of pressure.This paper presents a case study in seawater service on the selection of manual bypass valves for a 16″control valve in class 150 and titanium material.A 16″butterfly valve of class 150 was chosen for the control valve bypass,which provided a much higher flow capacity than the control valve.In this paper,four solutions are recommended to achieve the same coefficient value(Cv)for the control and bypass valve.Using the reduced size butterfly valve could be the cheapest and best solution.On the other hand,selecting the same control valve for bypass line is the most expensive but maybe the most reliable solution.Using a flow orifice for throttling could be ranked as the second expensive option and the second reliable one.Selection of butterfly valve for throttling is the second cheapest option,but it has the least reliability.Different parameters such as space and weight saving,cost as well as reliability have been considered in evaluation of different solutions.展开更多
The effect of tip-blade cutting on the performance of a large scale axial fan was investigated using computational fluid dynamics(CFD)methods.Experiments verified the numerical simulations.The original fan was compare...The effect of tip-blade cutting on the performance of a large scale axial fan was investigated using computational fluid dynamics(CFD)methods.Experiments verified the numerical simulations.The original fan was compared with the one with tip-cutting in terms of dimensionless characteristic and aerodynamic performance in tip region under the conditions of the maximum efficiency point and near-stall point.The results showed that double leakage flow occurred in tip clearance at maximum efficiency point and spillage of leakage flow from leading edge occurred in tip-blade region at near-stall point for the both two fans;and that tip-cutting with 6% of blade height could reduce the intensity of tip-leakage vortex and increase flow capacity in tip blade region,and hold the stall margin almost the same as the original fan.The maximum efficiency of the fan with tip-cutting was improved by1%,and the ability of total pressure rising was obviously greater than the original fan.展开更多
Acid fracturing is an indispensable technology in the efficient development of carbonate oil and gas rosarvoirs.As for deep and ultra-deep marine carbonate oil and gas reservoirs,however,existing acid fracturing techn...Acid fracturing is an indispensable technology in the efficient development of carbonate oil and gas rosarvoirs.As for deep and ultra-deep marine carbonate oil and gas reservoirs,however,existing acid fracturing technologies can hardly create complex fracture networks because of their particular engineering and geological characteristics.In order to realize the efficient three-dimensional development of deep and ultra-deep marine carbonate oil and gas reservoirs,this paper revealed the acid fracturing difficulties of this kind of reservoirs based on the engineering and geological characteristics of deep marine carbonate oil and gas reservoirs in China.Then,by taking the efficient three-dimensional development of deep and ultra-deep marine carbonate oiland gas reservoirs as the target,the technical conceptof three-dimensional acid fracturing(3D-AF)was putforward based on the techniques of volume acid fracturing and deep acid fracturing.In addition,its technical connotation was il lustrated,and its key technologies were described in detail.Finally,its development direction in the next step was pointed out.And the following research results were obtained.First,the 3D-AF technology contains three basic connotations:(1)selecting the corresponding acid penetration technology according to reservoir types so as to realize sufficient resarvoir stimulation on the plane;(2)creating complex acid-fracture volume with higher flow conductivity under high closed pressure;(3)deploying acid-fracture volume rationally along the long hole section so as to realize sufficient reservoir stimulation in the wellbore direction.Second,there are three key technologies of 3D-AF,i.e.,the technology for predicting the effective acid-penetrate distance under the coupling action of multi-feld,multi-scale and multi-fluid,the technology for optimizing the flow conductivity of complex acid-fracture volume,and the technology for precisely deploying acid in the long section of horizontal well or highly deviated well.Third,in order to promote the further development of 3D-AFtechnology,it is necessary to carry out researches on three technologies,i.e.,the technology for predicting and reducing the fracturing pressure of ultra-deep reservoir,the tech-nology for predicting the geometry of acid-fracture body ina strongly heterogeneous reservoir,and the staged reservoir production technology and new fluid technology with high temperature resistance,low reaction rate and low friction resistance coefficient for long hole sections(over 7000 m).展开更多
基金supported by the National Science and Technology Major Project“Shale gas reservoir engineering and gas recovery technology”(No.:2016ZX05037)National Science and Technology Major Project e Changning-Weiyuan shale gas demonstration project“Research and application of shale gas geological evaluation and development optimization technology”(No.:2016ZX05062-002)PetroChina Major Science and Technology Project“Evaluation and selection of favorable area for shale gas production and optimization of development technology policy in Sichuan Basin”(No.:2016E-0611).
文摘In this paper,shale samples of Lower Silurian Longmaxi Fm,taken from the ChangningeWeiyuan area in the Sichuan Basin,were selected tofigure out the influence of reservoir primary water on the adsorption laws and theflow capacity of shale gas.Experimental samples with different water saturations were prepared using the adsorption equilibrium method.Then,high-pressure isothermal adsorption experiments were carried out,and the isothermal adsorption effects and mechanisms of shale under different water saturations were discussed.Finally,theflow capacity of shale gas under different water saturations was tested using the independently developed steady-stateflow test device.And the following research results were obtained.First,the presence of primary water in micronenanometer pores of shale reservoirs reduces the adsorption capacity of shale.When the water saturation is 40%,the simulated total gas content is 18%lower than that in the conventional calculation result.Second,the apparent shale permeability is a function of pressure.Due to the effect of Knudsen diffusion,the apparent shale permeability increases significantly with the decrease of pressure under low pressure.When the average pressure is 5 MPa and the water saturation reaches 50%,the apparent shale permeability is about 70%lower than that of a dry sample.Third,when the water saturation is lower than the critical value,water is mainly presented as non-movable water in micropores and mesopores,and it has less effect on theflow capacity of shale gas.When the water saturation is greater than the critical value,the lodging point of water is changed,resulting in significant reduction of the shale gasflow capacity.It is concluded that an accurate understanding of the original water saturation and critical water saturation of shale reservoirs helps to calculate shale gas reserves accurately and predict gas well production rate rationally.
基金This project was supported by the National Natural Science Foundation of China(No.81970024)partly by Scientific Research Project of Wuhan Health Committee(No.WX16C45).
文摘Summary:Changes of maximum expiratory flow at 25%and 50%of vital capacity(MEF2s and MEFso,respectively),and predominant parameters indicating small airways function in asthmatics before and after bronchodilator(BD)reversibility test have been less interpreted.Our study aimed to investigate the clinical role of changes of MEF2s and MEFso before and after BD reversibility test in diagnosing asthma.Forced expiratory volume in the first second(FEV),MEF2s,and MEFso were measured before and after BD reversibility test in 207 asthmatic patients using standard process.Forty healthy individuals were enrolled as controls.Receiver operating characteristic(ROC)curve was used to assess the diagnostic accuracy of reversibility of MEF2s and MEFgo before and after BD reversibility test(OMEF 2s%and AMEF so%,respectively)in diagnosing asthma.Among these functional criteria,AMEF2;%and 0MEFs%≥25%performed the best diagnostic performance.The sensitivity,specificity,and accuracy of AMEF 25%≥25%as an objcctive diagnostic test for asthma were 63.29%,87.50%,and 67.21%,and of AMEFs0%≥25%were 79.23%,85.00%,and 80.16%,respectively.The area under the ROC curve of the indicators was 0.8203 and 0.9104,respectively.By contrast,an increase in FEV≥12%and 200 mL demonstrated a sensitivity of 62.32%,specificity of 82.50%,and accuracy of 65.59%in diagnosing asthma.The changes of MEF2s and MEFso before and after BD reversibility test may be of additional value in the clinical diagnosis of asthma,with cutoff values of 25%being the most.
基金financial support from the Youth Science and Technology Innovation Team of Southwest Petroleum University(No.2018CXTD10)the National Natural Science Foundation Project of China(No.51874248 and No.U19B2010).
文摘The microscopic heterogeneity of pore-throat structures in tight sandstone is a crucial parameter for understanding the transport mechanism of fluid flow.In this work,we firstly developed the new procedure to characterize the pore size distribution(PSD)and throat size distribution(TSD)by combining the nuclear magnetic resonance(NMR),cast thin section(CTS),and constant-rate mercury injection(CRMI)tests,and used the permeability estimated model to verify the full-scale PSD and TSD.Then,we respectively analyzed the fractal feature of the pore and throat,and characterized the heterogeneity of pores and throats.Finally,we elaborated the effect of the pore and throat heterogeneity on the gas-phase seepage capacity base on the analysis of the simple capillary tube model and gas-flooding experiment.The results showed that(1)The PSD and TSD of the tight sandstone sample ranged from 0.01 to 10 mm and from 0.1 to 57 mm,respectively,mainly contributed by the micropores and mesopores.Meanwhile,the permeability estimated by the PSD and TSD was consistent with the experimental permeability,and relative error was lower than 8%.(2)The PSD and TSD exhibited multifractal characteristics,and singularity strength range,Δα,could be used as the indicator for characterizing the heterogeneity of pore and throat.Furthermore,the throat of the sample showed stronger heterogeneity than that the pore.(3)The throats played an important role for the fluid transport in the tight sandstone,and the effect of the throat heterogeneity on the gas-phase seepage capacity was different under the lower and higher injection pressure.The macropores and micropores maybe respectively become the preferential migration pathways at the lower and higher injection pressure.In the end,the identification plate was established in our paper,and could be described the relationship among the throat heterogeneity,injection pressure,permeability and flow path of the gas phase in the tight sandstone.
基金supported by the Water Conservancy Science and Technology Project of Jiangsu Province(Grant No.2012041)the Jiangsu Province Ordinary University Graduate Student Research Innovation Project(Grant No.CXZZ13_0256)
文摘In this study, we simulated water flow in a water conservancy project consisting of various hydraulic structures, such as sluices, pumping stations, hydropower stations, ship locks, and culverts, and developed a multi-period and multi-variable joint optimization scheduling model for flood control, drainage, and irrigation. In this model, the number of sluice holes, pump units, and hydropower station units to be opened were used as decision variables, and different optimization objectives and constraints were considered. This model was solved with improved genetic algorithms and verified using the Huaian Water Conservancy Project as an example. The results show that the use of the joint optimization scheduling led to a 10% increase in the power generation capacity and a 15% reduction in the total energy consumption. The change in the water level was reduced by 0.25 m upstream of the Yundong Sluice, and by 50% downstream of pumping stations No. 1, No. 2, and No. 4. It is clear that the joint optimization scheduling proposed in this study can effectively improve power generation capacity of the project, minimize operating costs and energy consumption, and enable more stable operation of various hydraulic structures. The results may provide references for the management of water conservancy projects in complex river networks.
基金financially supported by the National Science Foundation of China(Grant No.51804033)China Postdoctoral Science and Foundation(Grant No.2018M641254)the National Science and Technology Major Projects of China(Grant Nos.2016ZX05051,2016ZX05014-005,and 2017ZX05030)。
文摘After hydraulic fracturing treatment,a reduction in permeability caused by the invasion of fracturing fluids is an inevitable problem,which is called water blocking damage.Therefore,it is important to mitigate and eliminate water blocking damage to improve the flow capacities of formation fluids and flowback rates of the fracturing fluid.However,the steady-state core flow method cannot quickly and accurately evaluate the effects of chemical agents in enhancing the fluid flow capacities in tight reservoirs.This paper introduces a time-saving and accurate method,pressure transmission test(PTT),which can quickly and quantitatively evaluate the liquid flow capacities and gas-drive flowback rates of a new nanoemulsion.Furthermore,scanning electron microscopy(SEM)was used to analyze the damage mechanism of different fluids and the adsorption of chemical agents on the rock surface.Parallel core flow experiments were used to evaluate the effects of the nanoemulsion on enhancing flowback rates in heterogeneous tight reservoirs.Experimental results show that the water blocking damage mechanisms differ in matrices and fractures.The main channels for gas channeling are fractures in cracked cores and pores in non-cracked cores.Cracked cores suffer less damage from water blocking than non-cracked cores,but have a lower potential to reduce water saturation.The PTT and SEM results show that the permeability reduction in tight sandstones caused by invasion of external fluids can be list as guar gum fracturing fluid>slickwater>brine.Parallel core flow experiments show that for low-permeability heterogenous s andstone reservoirs with a certain permeability ratio,the nanoemulsion can not only reduce reverse gas channeling degree,but also increase the flowback rate of the fracturing fluid.The nanoemulsion system provides a new solution to mitigate and eliminate water blocking damage caused by fracturing fluids in tight sandstone gas reservoirs.
文摘Modern processing plants use a variety of control loop networks to deliver a finished product to the market.Such control loops,like control valves,are designed to keep process variables such as pressure,temperature,speed,flow,etc.within the appropriate operating range and to ensure a quality product is produced.All control valves have a bypass so that production can proceed if maintenance is needed for the control valve as part of the control loop.The important point is that in both operation and maintenance situations,the bypass valve and the control valve should have approximately the same flow capacity to provide nearly the same amount of pressure.This paper presents a case study in seawater service on the selection of manual bypass valves for a 16″control valve in class 150 and titanium material.A 16″butterfly valve of class 150 was chosen for the control valve bypass,which provided a much higher flow capacity than the control valve.In this paper,four solutions are recommended to achieve the same coefficient value(Cv)for the control and bypass valve.Using the reduced size butterfly valve could be the cheapest and best solution.On the other hand,selecting the same control valve for bypass line is the most expensive but maybe the most reliable solution.Using a flow orifice for throttling could be ranked as the second expensive option and the second reliable one.Selection of butterfly valve for throttling is the second cheapest option,but it has the least reliability.Different parameters such as space and weight saving,cost as well as reliability have been considered in evaluation of different solutions.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20113218120006)
文摘The effect of tip-blade cutting on the performance of a large scale axial fan was investigated using computational fluid dynamics(CFD)methods.Experiments verified the numerical simulations.The original fan was compared with the one with tip-cutting in terms of dimensionless characteristic and aerodynamic performance in tip region under the conditions of the maximum efficiency point and near-stall point.The results showed that double leakage flow occurred in tip clearance at maximum efficiency point and spillage of leakage flow from leading edge occurred in tip-blade region at near-stall point for the both two fans;and that tip-cutting with 6% of blade height could reduce the intensity of tip-leakage vortex and increase flow capacity in tip blade region,and hold the stall margin almost the same as the original fan.The maximum efficiency of the fan with tip-cutting was improved by1%,and the ability of total pressure rising was obviously greater than the original fan.
基金supported by the National Natural Science Foundation of China"Research on acidizing mechanism under the coupling of temperature,fracture flow,acid-rock reaction,and stress damage for fractured carbonate rocks"(No.51704249)National Natural Science Foundation of China"Acid fracturing of low-permeability and tight oil and gas reservoirs"(No.51525404)the China Postdoctoral Science Foundation-General Program Research on acidizing mechanism of fracture network in deep,high-temperature,fractured carbonat rocks"(No.2017M623063).
文摘Acid fracturing is an indispensable technology in the efficient development of carbonate oil and gas rosarvoirs.As for deep and ultra-deep marine carbonate oil and gas reservoirs,however,existing acid fracturing technologies can hardly create complex fracture networks because of their particular engineering and geological characteristics.In order to realize the efficient three-dimensional development of deep and ultra-deep marine carbonate oil and gas reservoirs,this paper revealed the acid fracturing difficulties of this kind of reservoirs based on the engineering and geological characteristics of deep marine carbonate oil and gas reservoirs in China.Then,by taking the efficient three-dimensional development of deep and ultra-deep marine carbonate oiland gas reservoirs as the target,the technical conceptof three-dimensional acid fracturing(3D-AF)was putforward based on the techniques of volume acid fracturing and deep acid fracturing.In addition,its technical connotation was il lustrated,and its key technologies were described in detail.Finally,its development direction in the next step was pointed out.And the following research results were obtained.First,the 3D-AF technology contains three basic connotations:(1)selecting the corresponding acid penetration technology according to reservoir types so as to realize sufficient resarvoir stimulation on the plane;(2)creating complex acid-fracture volume with higher flow conductivity under high closed pressure;(3)deploying acid-fracture volume rationally along the long hole section so as to realize sufficient reservoir stimulation in the wellbore direction.Second,there are three key technologies of 3D-AF,i.e.,the technology for predicting the effective acid-penetrate distance under the coupling action of multi-feld,multi-scale and multi-fluid,the technology for optimizing the flow conductivity of complex acid-fracture volume,and the technology for precisely deploying acid in the long section of horizontal well or highly deviated well.Third,in order to promote the further development of 3D-AFtechnology,it is necessary to carry out researches on three technologies,i.e.,the technology for predicting and reducing the fracturing pressure of ultra-deep reservoir,the tech-nology for predicting the geometry of acid-fracture body ina strongly heterogeneous reservoir,and the staged reservoir production technology and new fluid technology with high temperature resistance,low reaction rate and low friction resistance coefficient for long hole sections(over 7000 m).
