低渗储层改造低伤害压裂液体系研究

为了有效控制和降低压裂液对储层的伤害,提高压裂液体系的增油效果,降低压裂成本,在玛湖凹陷风城组低孔、低渗及非均质储层的压裂改造中,针对胍胶类压裂液残渣含量较多,容易对储层造成伤害,同时胍胶压裂液在碱性条件下交联,高矿化度对压裂液性能影响较大等原因,开展了低伤害压裂液体系改性黄原胶的研究。通过现场研究结果表明,改性黄原胶可以克服碱性环境、高矿化度以及硼离子的影响,破胶后残渣含量为90 mg/L,比HPG的残渣含量少56.5%,有效的减少了破胶液残渣对地层的伤害。在玛湖凹陷斜坡区进行了13井次的储层改造,10口井次获得工业油流,获油率55.6%,取得了较好的改造效果。

Study on Low Damage Fracturing Fluid System for Low Permeability Reservoir Reconstruction

In order to effectively control and reduce the damage of fracturing fluid to reservoir, further improve the effect of fracturing fluid and reduce the cost of fracturing, in the fracturing process of low porosity and low permeability heterogeneous reservoir of Fengcheng group of Mahu depression, because high concentration of guanidine fracturing fluid is easy to cause damage to the reservoir, meanwhile, the cross-linking of guanidine gum fracturing fluid under alkaline conditions easy happens, and the influence of high salinity on the performance of fracturing fluid is easy, modification of xanthan gum for low damage fracturing fluid has been carried out. The results of research show that modified xanthan gum can overcome the influence of alkaline environment, high salinity and boron ion; after gel breaking, the residue content is 90 mg/L, less than 56.5% of the residue content of HPG, which effectively reduces the damage to the formation caused by the broken gel liquid residue. 13 times of reservoir reformation have been carried out in the slope area, 10 wells have obtained industrial oil flow, the oil recovery rate is 55.6%, and better reconstruction results have been achieved.