Study Of Liquid Explosive Fracturing And Developing Technology In Low Permeability Coal Seam

As the exploitation degree of conventional oil and gas resources becoming more aggravated day by day and the energy consumption growing in intensity,the development of Coal Bed-methane?CBM?,one of the unconventional resources,is becoming more and more appreciated by GOC.The development of CBM in China is late and there exists some problems: The characteristic of coal seam is complex,water sensitivity phenomenon is serious and the water resource of the main CBM production areas is poor.So the tendency of CBM production is fracturing without water and “Factory” work platform.In consideration of these reasons and the advantages of High Energy Gas Fracturing?HEGF?,the experiment and research of liquid explosive fracturing in low permeability coal seam is explored.The systematic analysis of characteristics of coal seam,such as reservoir physical property,the mechanical properties of coal and fluid characteristics of reservoir,provides the basis for the development of low permeability coal seam.The fructuring techniques of development are also analyed.Combined with the mechanism and characteristics of liquid explosive fracturing,the mechanism of desorption of CBM is analyzed: press-down desorption of relaxing in-situ stress,temperature-up desorption of heating effect,replacement desorption of combustion products and pulse oscillation impact.At the same time,the feasibility of this technique,which includes reservoir physical properties of coal seal,the mechanical properties of coal,the cost of construction technology and so on,is analyzed.The crack dynamic loading model of deflagration fracturing,gas filtration rate equation and the model for calculating the filtration volume quantity in coal seam are established.By using the Java programming software,we can get the datas that we need: the filtration rate is 1.12m/s,filtration volume is 2116.92m3/s.Through the ideal gas state equation,we can get the loading rate is 100.56GPa/s,which can form the crack whose length is 16.86 m,width is 1.53 mm.In the formula of liquid explosive, NH NO is oxidant and C H O is burner.On the basis of Cacl₂,the preparation of the spacer is formed.The three dimensional decomposition method of the peak pressure is used to calculate the consumption of liquid explosive,which is 16.61 kg,and the ignition pattern is “vertical well detonating device through mechanical impact booster pipeline explosive device”.The experiment and research of liquid explosive fracturing of Z2-005 CBM well in Qin Shui Basin is developed,and the CBM production is good after the fracturing,which gets good economic benefits.The success of liquid explosive fracturing not only has important practical significance to the development of low permeability coal seam,but also broadens the new direction of fracturing about unconventional oil and gas.