液体药高能气体压裂技术

LIQUID PROPELLANT HIGH ENERGY GAS FRACTURING TECHNIQUE

液体药火药高能气体压裂是利用以氧化剂、燃烧剂、溶剂 ,添加适量的燃烧敏化剂为主要组分 ,配制成液体状的高能材料 ,进行油气井增产、增注作业的一种高能气体压裂技术。文章就液体药氧化剂、燃烧剂的选择、液体药的配方 ,经优化设计计算 ,找出了适合现场应用的液体药组成 ;文中还对液体发射药点火和燃烧性能进行了论述 ,研究了现场井下液体药点火工艺和点火药量。由于液体发射药燃速慢 ,最高压力仅 5 0～ 6 0MPa ,井下装填药可达 5 0 0～ 12 0 0kg ,压力持续时间 4 0s左右。由于其压力持续时间长 ,因此可以造成宽长裂缝 ,缝长可达 2 5 5 0m ,与水力压裂缝长相近。增产比为 2 .5 5 ,有效期达 6个月以上 ,特别适用于低渗油气藏致密油层的压裂。文中介绍了液体药现场试验的结果及其取得的地质与经济效益。

The liquid propellant high energy gas fracturing technique is a method of carrying out oil / gas well stimulation by use of the liquid high energy material being mainly composed of oxidant, combustion agent, solvent and some combustion sensitizer. The liquid propellant composition suitable to in-situ application was found through the selection of oxidant and combustion agent of the liquid propellant and through the optimal design calculation of liquid propellant formulation. The liquid propellant ignition and burning performance are expounded and the downhole liquid propellant ignition technology and its used volume are analyzed in the paper. The top pressures were only 50 - 60 MPa because of the liquid propellant's being slowly burned, and the downhole propellant-pack volume may be up to 500-1200 kg with a pressure duration of about 40 s. The wide and long fractures might be formed owing to a long pressure-maintaining period, the fracture lengths being ranged from 25 m to 50 m similar to the hydraulic fracture lengths. The productivity increasing ratios were 2. 5 - 5 with a valid period of more than six months. Therefore it is specially applicable to the tight payzone fracturing in low permeability oil / gas reservoirs. The field test results of the liquid propellant high energy gas fracturing and its geological signification and economic returns are introduced in the paper.