超细低伤害加重压裂液在元坝地区的应用

为解决元坝地区致密砂岩气藏水力压裂破裂压力高、施工难度大的问题,研制出新型超细低伤害加重压裂液。该加重压裂液使用了采用混合溶剂法制备的粒度分布在20~40 nm范围的固体颗粒加重剂,在100 g基液中添加70 g纳米粒子加重剂后,密度达到1.50 g/cm3,与胍胶体系完全相容,配伍性好;在120℃、170 s-1剪切2 h黏度仍有77.5 m Pa·s;对岩心基质伤害率小于30%,具有低伤害性质。元坝气田陆相致密储层现场试验取得良好效果,在破裂压力高的致密储层具有良好的推广应用前景。

Application of superfine and low damage weighting fracture fluid in Yuanba

In order to address the problems of high fracturing pressure and construction difficulties in hydraulic fracturing of tight sandstone gas pools in Yuanba area, a new superfine, low damage weighting fracture fluid was developed specially. In this fluid, the mixed solvent method was mainly used to prepare solid weighting agent with the particle size between 20 nm and 40 nm, then adding 70 g of nanometer particle weighting agent to 100 g base fluid, the fluid density was up to 1.50 g/cm3, which was fully compatible with guar system; after 2 hours shearing at 120℃ and 170 s-1, its viscosity was still as high as 77.5 mPa·s; its damage rate to core matrix was less than 30%, so it was of low damage property. It is simple in technology, low cost, good compatibility and easy to back flow, and its resistance reducing rate was up to about 70%. Field test on continental tight reservoir in Yuanba was fruitful and enjoyed a favorable application prospect for tight reservoirs with high fracturing pressures.