In this paper, a model is proposed for the prediction of the width of arching in hoppers resulted from sudden changes in solid feed rates. Such changes in solid feed rate usually come from the collision on the surface...In this paper, a model is proposed for the prediction of the width of arching in hoppers resulted from sudden changes in solid feed rates. Such changes in solid feed rate usually come from the collision on the surface of the moving-bed in the standpipe. The model also takes into account the effect of the powder height in the standpipe of the hopper. The model proves to be adaptable for predicting operational conditions to avoid arching by keeping constant powder height in the main standpipe with interstitial gas flow.展开更多
The application of lead as tem porary w ater - sealing m aterial for the stan dpipes in under ground mine is reported . It is considered that lead is a good w ater - sealing m aterial in un derground mine , especia...The application of lead as tem porary w ater - sealing m aterial for the stan dpipes in under ground mine is reported . It is considered that lead is a good w ater - sealing m aterial in un derground mine , especially for irregular opening with high - pressure rushing w ater . Leadseal is cheap , easy to use and less har m ful to w orkers an d environ m ent and m ay have widerapplication .展开更多
According to the comprehensive tests on the rising height of capillary water for seven kinds of differ- ent coarse grained soil by use of the method of standpipe, the relationship between the rising height of capillar...According to the comprehensive tests on the rising height of capillary water for seven kinds of differ- ent coarse grained soil by use of the method of standpipe, the relationship between the rising height of capillary water and time was obtained, and the influencing factors and rules were analyzed. The data of the steady rising height of capillary water were obtained, and the regression equation of coarse grained soil on steady height and physical indexes （effective grain dl0 and porosity n） was found. Compared with Hazen＇s and other expressions that could estimate the steady height of capillary water of coarse grained soil, the proposed method is satisfactory and the defects of the latter were pointed out.展开更多
Ultra-deep and complex formations are characterized by narrow safety density windows and challenging well control.The combined use of multiple well-killing methods or temporary adjustments to well-killing strategies i...Ultra-deep and complex formations are characterized by narrow safety density windows and challenging well control.The combined use of multiple well-killing methods or temporary adjustments to well-killing strategies is becoming common.However,conventional well-killing models often struggle to calculate the parameters required for these special cases.In this paper,a boundary matrix for wellkilling fluid density and volume is proposed to unify the driller's method,the engineer's method,and the weight-while-circulating method.Furthermore,a dynamic unified well-killing model is developed to enable the synergistic regulation of multiple well-killing methods.The model also can be applied with or without accounting for gas dissolution.Using this model,it is able to dynamically track key parameters during well killing and shut in the well at any time to determine the standpipe and casing pressures.The results indicate that the casing pressure drops to zero before the well-killing fluid returns to the annulus wellhead,and continued injection of the fluid leads to a gradual increase in standpipe pressure,a phenomenon not previously accounted for.The discrepancy between the actual and calculated standpipe/casing pressures after shut-in can be utilized to assess whether the downhole gas kick is effectively controlled.Through real-time adjustments to the boundary matrix,updated wellkilling parameters can be derived for conventional method,multi-method combination,temporary strategy modification,and other well-killing scenarios.The model was applied to two field wells under water-and oil-based drilling fluids.No secondary downhole complications occurred during well killing,and the calculated pressure curves closely matched the measured construction pressure curves,confirming the model's reliability and applicability.This study provides valuable theoretical guidance for enhancing well control safety in ultra-deep and complex formations.展开更多
基金Supported by the China Petrochemical Corporation.
文摘In this paper, a model is proposed for the prediction of the width of arching in hoppers resulted from sudden changes in solid feed rates. Such changes in solid feed rate usually come from the collision on the surface of the moving-bed in the standpipe. The model also takes into account the effect of the powder height in the standpipe of the hopper. The model proves to be adaptable for predicting operational conditions to avoid arching by keeping constant powder height in the main standpipe with interstitial gas flow.
文摘The application of lead as tem porary w ater - sealing m aterial for the stan dpipes in under ground mine is reported . It is considered that lead is a good w ater - sealing m aterial in un derground mine , especially for irregular opening with high - pressure rushing w ater . Leadseal is cheap , easy to use and less har m ful to w orkers an d environ m ent and m ay have widerapplication .
文摘According to the comprehensive tests on the rising height of capillary water for seven kinds of differ- ent coarse grained soil by use of the method of standpipe, the relationship between the rising height of capillary water and time was obtained, and the influencing factors and rules were analyzed. The data of the steady rising height of capillary water were obtained, and the regression equation of coarse grained soil on steady height and physical indexes （effective grain dl0 and porosity n） was found. Compared with Hazen＇s and other expressions that could estimate the steady height of capillary water of coarse grained soil, the proposed method is satisfactory and the defects of the latter were pointed out.
基金supported by the National Natural Science Foundation of China(52474018,52227804,U22B2072,52404012)the National Key Research and Development Program of China(2023YFC3009200)the Science Foundation of China University of Petroleum,Beijing(2462023BJRC008,2462024XKBH006)。
文摘Ultra-deep and complex formations are characterized by narrow safety density windows and challenging well control.The combined use of multiple well-killing methods or temporary adjustments to well-killing strategies is becoming common.However,conventional well-killing models often struggle to calculate the parameters required for these special cases.In this paper,a boundary matrix for wellkilling fluid density and volume is proposed to unify the driller's method,the engineer's method,and the weight-while-circulating method.Furthermore,a dynamic unified well-killing model is developed to enable the synergistic regulation of multiple well-killing methods.The model also can be applied with or without accounting for gas dissolution.Using this model,it is able to dynamically track key parameters during well killing and shut in the well at any time to determine the standpipe and casing pressures.The results indicate that the casing pressure drops to zero before the well-killing fluid returns to the annulus wellhead,and continued injection of the fluid leads to a gradual increase in standpipe pressure,a phenomenon not previously accounted for.The discrepancy between the actual and calculated standpipe/casing pressures after shut-in can be utilized to assess whether the downhole gas kick is effectively controlled.Through real-time adjustments to the boundary matrix,updated wellkilling parameters can be derived for conventional method,multi-method combination,temporary strategy modification,and other well-killing scenarios.The model was applied to two field wells under water-and oil-based drilling fluids.No secondary downhole complications occurred during well killing,and the calculated pressure curves closely matched the measured construction pressure curves,confirming the model's reliability and applicability.This study provides valuable theoretical guidance for enhancing well control safety in ultra-deep and complex formations.
