新型VDA酸化转向剂研究及性能应用

Application of new VDA diverting acid system

盐酸酸化、酸压是碳酸盐岩油气藏主要增产措施之一,为了保证在非均质地层中酸液能够均匀推进,必须添加酸化转向剂。实验通过不同的方法合成不同的油田酸化转向剂(VDA),根据VDA酸化转向剂标准进行性能测定。对比可知,以硬脂酸为原料合成的盐酸质量分数为15%的转向酸溶液,在恒定90℃,170 s-1的剪切速率下,剪切1.5 h,其粘度先降低然后趋向稳定,其有很高的剪贴稳定性和热稳定性。且转向剂体系盐酸质量分数为15%时,其表观粘度最大为60 mPa.s,说明其变粘效果好。随后改变温度,对15%的酸化转向酸中进行流变性测试。随温度的升高,粘度逐渐变小。说明其有很好的流变性。最后对其做缓释性能和自发破胶性能测试,用15%的VDA酸化转向剂体系与碳酸钙反应可知其可以降低酸的消耗速度和很好的自发破胶能力,可用于油田生产。

Acidification and acid fracturing of carbonate reservoir rocks is one of the main measures to increase the production of oil in exploitation. In order to ensure that the acid in heterogeneous formations can even promote, the diverting acid agent was added. Different methods were used to synthesize different diverting acid agent; according to the VDA standard the performance evaluation was carried out. The VDA diverting acid system（15% ,prepared by stearic acid） at constant 90 ℃ ,170 s-t shear rate,1.5 h shear time,the apparent viscosity decreased first and then tended to be stable,so it has a high clip and thermal stability. And in the agent system, the mass fraction of hydrochloric acid was 15% ,the apparent vis- cosity is up to 60 mPa· s. Viscosity changed Significantly with the mass fraction of hydrochloric acid. The temperature for the rheological test of 15% VDA diverting acid system was adjus- ted. With the increasing temperature, the apparent viscosity became smaller and smaller. Its rheology is well. Finally, the performance testing of releasing properties and spontaneously breaking plastic were made. In the reaction of the VDA divert ing acid system （15% , prepared by stearic acid） with marble block, it was able to reduce the rate of acid consumption and had a good ability of spontaneously breaking the plastic. So it could be used for oil production.