It is very difficult to clearly detect the location of a burning area in a coal mine since it is hidden underground.So we conducted research on the distribution of the burning area before controlling it.Firstly,the or...It is very difficult to clearly detect the location of a burning area in a coal mine since it is hidden underground.So we conducted research on the distribution of the burning area before controlling it.Firstly,the original drilling technique was used to analyze and determine the loose and scope of caving of burning area through field test,and then obtained the gases and the temperature data in this area were according to the borehole data.By analyzing these data,we found out that the location of burning area concentrated in the loose and caving area;and finally,the location and development of the burning area within the tested area were accurately determined.Based on this theory,we used the ground penetrating radar(GPR) to find out the loose and caving scale in the burning area during the control process of the burning area,and then located the fire-extinguishing boreholes within target which we used to control burning fire in the section.A mobile comprehensive fire prevention and extinguishing system based on the three-phase foam fire prevention and control technique was then adopted and conducted in the burning area which took only 9 months to extinguish the 227,000 m 2 of burning area of 9# coal.This control technology and experience will provide a very important reference to the control of other coalfield fire and hillock fire in the future.展开更多
Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, ma...Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, mainly including limestone, muddy limestone and some bituminous shale. Many microfissures exist in the formation and the equivalent density of formation pore pressure ranged from 1.19g/cm3 to 1.59g/cm3. Asphalt or heavy oil kicks occurred in drilling three wells in one and a half years, which contaminated the drilling fluid and made well killing difficult due to the kicks and lost circulation in open hole. Gas and hydrogen sulfide （the concentration is up to 40000ppm） were present in the wells, and finally two wells were completely abandoned and one partially losL which frustrated the drilling engineering seriously. By analyzing the data of ＆e drilled wells, the paper summarized the causes of the troubles, and put forward suggestions and conclusions that can serve as reference and guideline for drilling well in ＆is area in the future.展开更多
With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would ...With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.展开更多
基金funded by the National Natural Science Foundation of China (No. 51134020)the State Key Laboratory of Coal Resources and Mine Safety Foundation (No.SKLCRSM08x06)the Natural Science Foundation of Jiangsu Province (No. BK2009004)
文摘It is very difficult to clearly detect the location of a burning area in a coal mine since it is hidden underground.So we conducted research on the distribution of the burning area before controlling it.Firstly,the original drilling technique was used to analyze and determine the loose and scope of caving of burning area through field test,and then obtained the gases and the temperature data in this area were according to the borehole data.By analyzing these data,we found out that the location of burning area concentrated in the loose and caving area;and finally,the location and development of the burning area within the tested area were accurately determined.Based on this theory,we used the ground penetrating radar(GPR) to find out the loose and caving scale in the burning area during the control process of the burning area,and then located the fire-extinguishing boreholes within target which we used to control burning fire in the section.A mobile comprehensive fire prevention and extinguishing system based on the three-phase foam fire prevention and control technique was then adopted and conducted in the burning area which took only 9 months to extinguish the 227,000 m 2 of burning area of 9# coal.This control technology and experience will provide a very important reference to the control of other coalfield fire and hillock fire in the future.
文摘Drilling crews of Sinopec have encountered a series of troubles when drilling a formation called kazhdumi of Yadavaran oilfield, Iran in the last few years. The formation is buried in the depth from 3300m to 3500m, mainly including limestone, muddy limestone and some bituminous shale. Many microfissures exist in the formation and the equivalent density of formation pore pressure ranged from 1.19g/cm3 to 1.59g/cm3. Asphalt or heavy oil kicks occurred in drilling three wells in one and a half years, which contaminated the drilling fluid and made well killing difficult due to the kicks and lost circulation in open hole. Gas and hydrogen sulfide （the concentration is up to 40000ppm） were present in the wells, and finally two wells were completely abandoned and one partially losL which frustrated the drilling engineering seriously. By analyzing the data of ＆e drilled wells, the paper summarized the causes of the troubles, and put forward suggestions and conclusions that can serve as reference and guideline for drilling well in ＆is area in the future.
文摘With large-scale use of kinds of motors, oilfield drilling electrical system always accompanied by serious power quality problem, including reactive current, harmonics current and grid voltage distortion, which would greatly threaten the safety and proper working of the whole system. This paper focuses on a power quality improvement project to solve these problems. A hybrid compensating scheme, including an active compensator and a passive compensator, is carried out. Because of the specificity of oilfield drilling electrical system, compensators are redesigned against features of this application background. And then the current detection point arrangement of this hybrid system is also taken into consideration to build the whole system much more effective and reliable. Now the improvement project is already implemented in application field, and the power quality of the system is greatly improved.
