In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil...In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields.展开更多
The influence of staggered distance on the failure of floor bed is locally and temporarily defined in double longwall mining on the confined aquifer. When the longwall mining reaches a certain scale, the deepest fai...The influence of staggered distance on the failure of floor bed is locally and temporarily defined in double longwall mining on the confined aquifer. When the longwall mining reaches a certain scale, the deepest failure of floor bed depends on macroscopic technological parameters of mining and geological conditions. The temporary as well as the terminal failure depth does not change with the mining staggered distance (5~30 m). Based on the mining and geological conditions on the 2 635 double longwall mining panel of Yangzhuang Coal Mine, the changes of abutment pressure was observed and numerically simulated. The result shows that the rational staggered distance should be not more than 10 m.展开更多
基金financially supported by the National Natural Science Foundation of China (Grant No.51674281)the Opening Fund of Shandong Provincial Key Laboratory of Oil&Gas Storage (Study on low temperature flow characteristics of oil and water in gathering pipeline)the Transportation Safety and the Fundamental Research Funds for the Central Universities
文摘In order to ensure the safety of the non-heating gathering and transportation processes for high water fraction crude oil,the effect of temperature,water fraction,and flow rate on the flow characteristics of crude oil with high water fraction was studied in a flow experimental system of the X Oilfield.Four distinct flow patterns were identified by the photographic and local sampling techniques.Especially,three new flow patterns were found to occur below the pour point of crude oil,including EW/O&W stratified flow with gel deposition,EW/O&W intermittent flow with gel deposition,and water single-phase flow with gel deposition.Moreover,two characteristic temperatures,at which the change rate of pressure drop had changed obviously,were found during the change of pressure drop.The characteristic temperature of the first congestion of gel deposition in the pipeline was determined to be the safe temperature for the non-heating gathering and transportation of high water cut crude oil,while the pressure drop reached the peak at this temperature.An empirical formula for the safe temperature was established for oil-water flow with high water fraction/low fluid production rate.The results can serve as a guide for the safe operation of the non-heating gathering and transportation of crude oil in high water fraction oilfields.
文摘The influence of staggered distance on the failure of floor bed is locally and temporarily defined in double longwall mining on the confined aquifer. When the longwall mining reaches a certain scale, the deepest failure of floor bed depends on macroscopic technological parameters of mining and geological conditions. The temporary as well as the terminal failure depth does not change with the mining staggered distance (5~30 m). Based on the mining and geological conditions on the 2 635 double longwall mining panel of Yangzhuang Coal Mine, the changes of abutment pressure was observed and numerically simulated. The result shows that the rational staggered distance should be not more than 10 m.
