深井水包油钻井液高温高压密度特性模拟实验研究

Simulating test study on the HTHP density characteristics of oil-in-water drilling

深井、超深井中井下温度和压力高,井下钻井液密度变化较大,易引发一些复杂事故的发生。利用石油大学(华东)泥浆研究室研制的高温高压钻井液密度模拟试验装置,针对欠平衡深井钻井用的一种水包油钻井液体系,开展了高温高压条件下的钻井液密度特性模拟实验研究,为进一步开展井下钻井液静液柱压力的预测研究奠定了基础。研究结果表明,同一油水比水包油钻井液在同一温度下,密度随压力呈线性上升趋势,且两种温度下的上升斜率基本相近,在同一压力下密度随温度上升而下降;在不同油水比条件下,每种水包油钻井液在同一温度下,密度随压力上升的斜率基本相近,在同一压力下密度随油水比增大而下降。

Because of the high downhole temperature and pressure in the deep and super-deep wells, drilling fluid density and rheological behavior change widely, which leads to some complicated downhole troubles. Simulating tests on drilling fluid density characteristics in HTHP condition are carried out, using the oil-in-water drilling fluid as the sample and by utilizing the simulation testing apparatus recently developed by the drilling fluid laboratory in Petroleum University. Testing results show that in the same temperature and with the same oil water ratio, the drilling fluid density rise linearly with the rise of pressure, while under the same pressure, the density drops with the rise of temperature. When the oil to water ratios are different, the density drops with the rise of oil/water ratio in the same pressure condition.