含动力学抑制剂的聚合醇钻井液水合物抑制性研究

Inhibition of Polyethylene Glycol Drilling Fluid with Kinetic Inhibitor for Marine Gas Hydrates Formation

对含动力学抑制剂的聚合醇钻井液水合物抑制性进行了实验研究。实验结果表明,加入PVP的水基聚合醇钻井液能够有效抑制甲烷水合物的生成,而PVP(K90)的抑制效果明显优于PVP(K30)。在温度为0℃、初始压力为18 MPa的条件下,只需向水基聚合醇钻井液中添加1%的PVP(K90),就能够确保循环管路中20 h内不会生成水合物。

During the drilling in marine gas hydrates bearing sediment （GHBS）, the methane gas released by hydrates decomposed enters the circulating pipeline of drilling fluid. Once the condition of temperature and pressure is appropriate, hydrates will be reformed, which will block the circulating pipeline clogging, and lead to a series of drilling accidents. Therefore, the hydrates formation inhibition of the drilling fluid is very critical. The experiments showed that the water-based drilling fluid with polyethlene glycol and PVP can effectively inhibit the methane hydrates formation, and the inhibition of PVP（K90） is obviously stronger than that of PVP（K30）. Adding 1% of PVP（K90） into the drilling fluid is suerely able to prevent the formation of any hydrates in the circulating pipeline within 20 h at 18 MPa and 0 ℃.