聚乙烯吡咯烷酮对钻井液水合物抑制性能的影响研究

随着全球油气钻探由海洋浅水区向深水区发展，深水油气钻探中水合物的防治研究也得到了日益重视。聚乙烯吡咯烷酮作为一种非常成熟的水合物动力学抑制剂，被广泛应用于油气生产运输中。向应用于某浅水油气田的钻井液中添加0.5wt%、1.0wt%和2.0wt%的聚乙烯吡咯烷酮，首先对其低温常规性能进行实验评价。结果表明，0.5wt%和1.0wt%的聚乙烯吡咯烷酮的加入对钻井液的流变性能不会产生明显影响，2.0wt%的聚乙烯吡咯烷酮加入会影响钻井液的流变性能而导致钻井液无法满足钻井需求；随后在4℃、6 MPa ~ 10 MPa条件下，利用1.2 L定容反应釜，通过观察温度和压力的变化，研究了0.5wt%和1.0wt%聚乙烯吡咯烷酮加入后对钻井液中水合物形成的影响，研究结果表明：当温度为4℃、进气压力在6 MPa ~ 10 MPa时，进气后500 min内聚乙烯吡咯烷酮对钻井液中的水合物形成具有一定的抑制作用，浓度越高抑制效果越明显，但聚乙烯吡咯烷酮的加入不能完全抑制水合物的生成。

CAS Key Laboratory of Gas Hydrate,Guangzhou Institute of Energy Conversion,Chinese Academy of Science,Guangzhou 510640, China

With the development of oil and gas drilling from shallow water area to the deep water area, more and more attention has been paid to inhibition on natural gas hydrate in deep water drilling. As a perfect hydrate kinetic inhibitor, polyvinylpyrrolidone (PVP) was widely used in oil and gas production and transportation. Drilling fluids with different PVP concentrations were used in a shallow water gas field. Firstly, the low temperature normal performance was evaluated. Then the inhibition of PVP in the drilling fluid was investigated at 4oC and 6 ~ 10 MPa in a 1.2-liter reactor through temperature and pressure change during reaction. The experimental results show that 2.0wt% of PVP can affect the rheological properties which will not meet the requirements of drilling. The PVP of 0.5wt% and 1.0wt% have inhibiting effect in the drilling fluid, the higher concentration the more obvious suppression. However, the addition of the PVP cannot completely inhibit the formation of hydrate.