Liquid Explosives For Low Permeability Gas-oil Reservoir

Stimulation technology of exploding in fracture is the key to the recovery of low permeability gas-oil reservoir. According to the characteraitics of the stimulation technology of exploding in fracture, requirements of safety, physic-chemical properties and detonation of liquid explosive were summarized in this paper, and two serious of explosives were studied systematically, which were respectively based on perchloric acid and nitromethane. The conclusions as follow were broutht forth:(1) The mixture liquild explosive based on perchloric acid with safty, no poison and no smell, owned good detonation transmission performance while its bad compatibility with metal was not suitable for the timulation technology of exploding in fracture;(2) The mixture liquild explosive based on nitromethane with small critical diameter of booster and velocity in medium level could be detonated simply and reliably, which was feasible to the timulation technology of exploding in fracture in some degree;(3) The safety, physic-chemical properties and detonation of three formulations of mixture liquild explosive based on nitromethane (nitromethane/ethylenediamine/cellulose acetate/ aluminum powder = 78/5/5/12, 76/5/5/14, 75/5/4/16) were tested. The three formulations of mixture liquild explosive were with densties from 1.06 g/mL to 1.11 g/mL, pH values all 8.0, viscosities between 1283 mPa-s and 3760 mPa-s, volatilization ratios arround 2.0%, mechanical sensitivity 0, flame sensitivity 0, bullet impact 0, velocities from 3512 m/s to 4608 m/s, explosion heats from 5698 kJ/kg to 5783 kJ/mol, detonation volumes from 619 L/kg to 662 L/kg, critical diameters of booster between 2.5 mm and 3.0 mm, explosive brisance about 23 mm, and work capacities between 310 mL and 362 mL, which met the requirements of stimulation technology of exploding in fracture to produce oil or gas in low-permeability reservoir.The results of prediction to the stimulation explosion effect indicate that the side longth of rock particles is between 0.180 mm and 0.538 mm, which is near the particle size of hydraulic fracturing proppant and the fractures stretch 3.06 m to 3.57 m to form fracture network to improve the permeability and output field.