Formation water invasion is the most troublesome problem associated with air drilling. However, it is not economical to apply mist drilling when only a small amount of water flows into wellbore from formation during a...Formation water invasion is the most troublesome problem associated with air drilling. However, it is not economical to apply mist drilling when only a small amount of water flows into wellbore from formation during air drilling. Formation water could be circulated out of the wellbore through increasing the gas injection rate. In this paper, the Angel model was modified by introducing Nikurade friction factor for the flow in coarse open holes and translating formation water rate into equivalent penetration rate. Thus the distribution of annular pressure and the relationship between minimum air injection rate and formation water rate were obtained. Real data verification indicated that the modified model is more accurate than the Angel model and can provide useful information for air drilling.展开更多
Charge is a fundamental physical property of matter that is responsible for its interactions with electromagnetic fields. The real nature and the essence of charge are unknown. In this paper, a new theory is presented...Charge is a fundamental physical property of matter that is responsible for its interactions with electromagnetic fields. The real nature and the essence of charge are unknown. In this paper, a new theory is presented to describe the nature and the essence of electric charge is formulated based on the vortex model of the electron which has a finite size and has an irrotational vortex structure. This theory and the vortex model of the electron enables us, for the first time, to describe the origin of bivalency, stability, quantization, equality of the absolute values of the bivalent charges, to derive a simple formulation to calculate the electric charge based on hydrodynamics without the use any constant. The difference between negative and positive charge, is revealed and the charged particles interactions are described. The electric charge is an expression of accelerated spherical mass per area reduced by the stiffness of the vacuum which has the units <i>ε</i><sub>0</sub> ML<sup>3</sup>/T<sup>2</sup>. The calculated results based on these equations comply accurately with the experimental results.展开更多
The influence of elasticity on peristaltic transport of Herschel-Bulkley fluid in a tube of non-uniform cross-section is investigated.The exact solutions for flow quantities such as velocity,stream function,pressure g...The influence of elasticity on peristaltic transport of Herschel-Bulkley fluid in a tube of non-uniform cross-section is investigated.The exact solutions for flow quantities such as velocity,stream function,pressure gradient,and volume flow rate are derived.The relationship between flux and pressure difference is discussed.The effects of different pertinent parameters on variation of flux along the radius of the tube are analyzed through graphs.The results show that the yield stress and fluid behavior index has significant effect on flux variation of Herschel-Bulkley fluid in a non-uniform elastic tube.The effect of elastic parameters on flux variation is analyzed.Trapping phenomenon is presented graphically to understand the physical behavior of various parameters.In the absence of non-uniform parameter the present results are similar to the observations of Vajravelu et al.[19].展开更多
文摘Formation water invasion is the most troublesome problem associated with air drilling. However, it is not economical to apply mist drilling when only a small amount of water flows into wellbore from formation during air drilling. Formation water could be circulated out of the wellbore through increasing the gas injection rate. In this paper, the Angel model was modified by introducing Nikurade friction factor for the flow in coarse open holes and translating formation water rate into equivalent penetration rate. Thus the distribution of annular pressure and the relationship between minimum air injection rate and formation water rate were obtained. Real data verification indicated that the modified model is more accurate than the Angel model and can provide useful information for air drilling.
文摘Charge is a fundamental physical property of matter that is responsible for its interactions with electromagnetic fields. The real nature and the essence of charge are unknown. In this paper, a new theory is presented to describe the nature and the essence of electric charge is formulated based on the vortex model of the electron which has a finite size and has an irrotational vortex structure. This theory and the vortex model of the electron enables us, for the first time, to describe the origin of bivalency, stability, quantization, equality of the absolute values of the bivalent charges, to derive a simple formulation to calculate the electric charge based on hydrodynamics without the use any constant. The difference between negative and positive charge, is revealed and the charged particles interactions are described. The electric charge is an expression of accelerated spherical mass per area reduced by the stiffness of the vacuum which has the units <i>ε</i><sub>0</sub> ML<sup>3</sup>/T<sup>2</sup>. The calculated results based on these equations comply accurately with the experimental results.
文摘The influence of elasticity on peristaltic transport of Herschel-Bulkley fluid in a tube of non-uniform cross-section is investigated.The exact solutions for flow quantities such as velocity,stream function,pressure gradient,and volume flow rate are derived.The relationship between flux and pressure difference is discussed.The effects of different pertinent parameters on variation of flux along the radius of the tube are analyzed through graphs.The results show that the yield stress and fluid behavior index has significant effect on flux variation of Herschel-Bulkley fluid in a non-uniform elastic tube.The effect of elastic parameters on flux variation is analyzed.Trapping phenomenon is presented graphically to understand the physical behavior of various parameters.In the absence of non-uniform parameter the present results are similar to the observations of Vajravelu et al.[19].
