提高聚醚多元醇钻井液性能的添加剂研究

Study on Key Additives for Improving Performance of Polyether Polyalcohol Drilling Fluid

根据不同井温需求,开发了2种浊点温度的钻井液用聚醚多元醇页岩抑制剂BDSC-300L-A、BDSC-300L-B,其浊点(3%)分别为55、70℃,页岩线性膨胀率降低率大于50%,且不起泡。通过配套关键添加剂的研究,形成了钻井液用聚醚多元醇的3项使用新技术:井下浊点调控技术,通过添加无机盐、阴离子表面活性剂,实现了同一产品浊点温度可调节;抑制防塌协同增效技术,通过添加钾盐抑制剂有效减缓甚至完全抑制黏土水化膨胀;高效抑泡消泡技术,通过添加一种有机硅聚醚型高效消泡剂(加量为10 mg/L)就能有效消除各种表面活性剂在钻井液中产生的泡沫。多元醇产品及相应的外加剂应用技术对提高强抑制醇类水基钻井液综合性能起到了重要的技术支持作用。

Two kinds of polyalcohol having different cloud points are developed for use in wells with different temperatures to stabilize unstable shale or claystone formations. The 3% BDSC-300L-A and 3% BDSC-300L-B polyalcohol solutions, having cloud points of 55 ℃ and 70 ℃, respectively, suppressed the ratio of swelling of shale cores by more than 50% at 93 ℃, without causing any foams in their solutions. Study on key additives for the drilling fluid formulated with the polyether polyalcohols gave birth to three new technologies; first, controlling the cloud point of the polyalcohols downhole. By adding inorganic salts and anionic surfactants into the mud, the cloud point of a polyalcohol can be adjusted, and a reversible change of oil-in-water mud to water-in-oil mud at the same borehole temperature can be achieved. Second, the synergetic effect between the polyether polyalcohol and potassium salts greatly retarded or even completely inhibited the hydration and swelling of claystone and shale. Third, by adding an organic silicone(10 mg/L) into the polyether polyalcohol mud, foaming was effectively and efficiently eliminated. Polyalcohol additives and the application thereof play an important role in enhancing the inhibitive capacity of water base drilling fluids.