Lost circulation controlling & killing material has been a focused issue since a long time ago.A novel leak resistance fluid with the raw materials such as SDS,SDBS,HES,PAM and proprietary productions has been dev...Lost circulation controlling & killing material has been a focused issue since a long time ago.A novel leak resistance fluid with the raw materials such as SDS,SDBS,HES,PAM and proprietary productions has been developed from laboratory.The experiment and application shows that the new leak resistance fluid can plug leaking passage of different sizes simultaneously.Observing with 1000 to 2000 time microscope,it is found that the working liquid contains a kind of spherical material which has the microstructure of "one core,two layers,and three membranes".When it is in a static state,the inside of the material looks like an airbag and the outside looks like some fuzzy things which has high gel strength.While when it is in a dynamic state,the fuzzy thing is cut or scattered and flow ability becomes much better.That is the reason why it is called fuzzy-ball.When the diameter or the width of the leak passage is greater than the fuzzy-ball's,the fuzzy-ball accumulates in conical shape to decompose the working fluid pressure of liquid column to achieve blocking;when the diameter or the width of the leak passage is equivalent to the fuzzy-ball's,the fuzzy-ball changes from sphere to oval-shape to increase the resistance to the leak passage and plug the holes;when the diameter or the width of the leak passage is smaller than the fuzzy-ball's,the leaks could be blocked up by the non-permeable membrane formed by the gel of high strength in the working fluid.In these cases,the leak passages of different sizes could be blocked comprehensively.展开更多
用基于Matlab的模糊控制工具箱设计了模糊PID控制算法,通过Matlab实时视窗目标(Real-Time Windows Target)环境实现了磁浮球物理实验装置的实时控制,并进行了相关的实验研究。采用Matlab的实时控制方法,控制器搭建方便、参数调整易于实...用基于Matlab的模糊控制工具箱设计了模糊PID控制算法,通过Matlab实时视窗目标(Real-Time Windows Target)环境实现了磁浮球物理实验装置的实时控制,并进行了相关的实验研究。采用Matlab的实时控制方法,控制器搭建方便、参数调整易于实现,适用于实验室中的实验研究。实验结果表明,设计的模糊PID控制器可以实现磁浮球系统的控制,在稳定性、抗干扰能力上明显优于传统的PID算法。展开更多
Fuzzy-ball working fluids(FBWFs)have been successfully applied in different development phases of tight reservoirs.Field reports revealed that FBWFs satisfactorily met all the operational and reservoir damage control ...Fuzzy-ball working fluids(FBWFs)have been successfully applied in different development phases of tight reservoirs.Field reports revealed that FBWFs satisfactorily met all the operational and reservoir damage control requirements during their application.However,the damage-control mechanisms and degree of formation damage caused by fuzzy-ball fluids have not been investigated in lab-scale studies so far.In this study,the degree of fuzzy-ball-induced damage in single-and double-layer reservoirs was evaluated through core flooding experiments that were based on permeability and flow rate indexes.Additionally,its damage mechanisms were observed via scanning electron microscope and energy-dispersive spectroscopy tests.The results show that:(1)For single-layer reservoirs,the FBWF induced weak damage on coals and medium-to-weak damage on sandstones,and the difference of the damage in permeability or flow rate index on coals and sandstones is below 1%.Moreover,the minimum permeability recovery rate was above 66%.(2)For double-layer commingled reservoirs,the flow rate index revealed weak damage and the overall damage in double-layer was lower than the single-layer reservoirs.(3)There is no significant alteration in the microscopic structure of fuzzy-ball saturated cores with no evidence of fines migration.The dissolution of lead and sulfur occurred in coal samples,while tellurium in sandstone,aluminum,and magnesium in carbonate.However,the precipitation of aluminum,magnesium,and sodium occurred in sandstone but no precipitates found in coal and carbonate.The temporal plugging and dispersion characteristics of the FBWFs enable the generation of reservoir protection layers that will minimize formation damage due to solid and fluid invasion.展开更多
基金supported by the National Key Scientific and Technological Project (2008ZX05024-04,2008ZX05036-003 and 2008ZX 05062)
文摘Lost circulation controlling & killing material has been a focused issue since a long time ago.A novel leak resistance fluid with the raw materials such as SDS,SDBS,HES,PAM and proprietary productions has been developed from laboratory.The experiment and application shows that the new leak resistance fluid can plug leaking passage of different sizes simultaneously.Observing with 1000 to 2000 time microscope,it is found that the working liquid contains a kind of spherical material which has the microstructure of "one core,two layers,and three membranes".When it is in a static state,the inside of the material looks like an airbag and the outside looks like some fuzzy things which has high gel strength.While when it is in a dynamic state,the fuzzy thing is cut or scattered and flow ability becomes much better.That is the reason why it is called fuzzy-ball.When the diameter or the width of the leak passage is greater than the fuzzy-ball's,the fuzzy-ball accumulates in conical shape to decompose the working fluid pressure of liquid column to achieve blocking;when the diameter or the width of the leak passage is equivalent to the fuzzy-ball's,the fuzzy-ball changes from sphere to oval-shape to increase the resistance to the leak passage and plug the holes;when the diameter or the width of the leak passage is smaller than the fuzzy-ball's,the leaks could be blocked up by the non-permeable membrane formed by the gel of high strength in the working fluid.In these cases,the leak passages of different sizes could be blocked comprehensively.
文摘用基于Matlab的模糊控制工具箱设计了模糊PID控制算法,通过Matlab实时视窗目标(Real-Time Windows Target)环境实现了磁浮球物理实验装置的实时控制,并进行了相关的实验研究。采用Matlab的实时控制方法,控制器搭建方便、参数调整易于实现,适用于实验室中的实验研究。实验结果表明,设计的模糊PID控制器可以实现磁浮球系统的控制,在稳定性、抗干扰能力上明显优于传统的PID算法。
基金The authors wish to thank the Ministry of Science and Technology of the People's Republic of China(2016ZX05066).
文摘Fuzzy-ball working fluids(FBWFs)have been successfully applied in different development phases of tight reservoirs.Field reports revealed that FBWFs satisfactorily met all the operational and reservoir damage control requirements during their application.However,the damage-control mechanisms and degree of formation damage caused by fuzzy-ball fluids have not been investigated in lab-scale studies so far.In this study,the degree of fuzzy-ball-induced damage in single-and double-layer reservoirs was evaluated through core flooding experiments that were based on permeability and flow rate indexes.Additionally,its damage mechanisms were observed via scanning electron microscope and energy-dispersive spectroscopy tests.The results show that:(1)For single-layer reservoirs,the FBWF induced weak damage on coals and medium-to-weak damage on sandstones,and the difference of the damage in permeability or flow rate index on coals and sandstones is below 1%.Moreover,the minimum permeability recovery rate was above 66%.(2)For double-layer commingled reservoirs,the flow rate index revealed weak damage and the overall damage in double-layer was lower than the single-layer reservoirs.(3)There is no significant alteration in the microscopic structure of fuzzy-ball saturated cores with no evidence of fines migration.The dissolution of lead and sulfur occurred in coal samples,while tellurium in sandstone,aluminum,and magnesium in carbonate.However,the precipitation of aluminum,magnesium,and sodium occurred in sandstone but no precipitates found in coal and carbonate.The temporal plugging and dispersion characteristics of the FBWFs enable the generation of reservoir protection layers that will minimize formation damage due to solid and fluid invasion.
