Abstract:

Most of the oil fields in China have entered the middle and late stage of exploitation, and the well produced fluid has a high water content. FRP pipes are widely used in surface gathering system of oilfield because of their excellent corrosion resistance. At the same time, in order to save heating energy, low?temperature transportation process can be used to transport high water?cut crude oil, but the possible adhesion problem of crude oil is a serious threat to system safety.Therefore, it is important to investigate the interfacial properties of FRP pipe wall/crude oil to reveal the adhesion mechanism of low?temperature transportation of crude oil with high water?cut. The interfacial properties of crude oil on the FRP surface and stainless steel surface were investigated based on the contact angle apparatus. In the aqueous phase, the contact angle of oil droplet on the solid surface increased with decreasing temperature, and the contact angle of oil droplet on the FRP surface is larger than that on the stainless steel surface. The interfacial tension of oil droplet increased with decreasing temperature in the aqueous phase, and compared to the stainless steel surface, the adhesion work of oil droplet on the FRP surface is lower. And the cohesion work of oil droplet decreased with increasing temperature in the aqueous phase. Crude oil is not easy to adhere to the FRP pipe in the gathering system, FRP pipe is more conducive to the implementation of low?temperature transportation process.

Key words: High water?cut crude oil, Low?temperature transportation, Fiber reinforced plastics pipe, Interface characteristics

摘要：

我国大部分油田已进入开采中后期，油井采出液含水率较高，玻璃钢管道因其良好的抗腐蚀性广泛应用于油田地面集输系统。同时，为了节约加热能耗，可采用低温集输工艺输送高含水原油，但可能出现的原油黏附问题严重威胁系统安全。因此，探究玻璃钢管壁/原油界面特性，对揭示高含水原油低温集输黏附机理具有重要意义。基于接触角仪探究了含蜡原油在玻璃钢和不锈钢表面的界面特性。结果表明，在水相中，油滴在不同材质平板的接触角随温度的降低而增大，且油滴在玻璃钢表面的接触角大于在不锈钢表面的接触角，油滴在水相中的界面张力随温度的降低而增大；与不锈钢表面相比，油滴在玻璃钢表面的黏附功较小，油滴之间的内聚功随温度的升高而减小；在集输系统中，凝油不易黏附于玻璃钢管道，玻璃钢管道更有利于低温集输工艺的实施。

关键词: 高含水原油, 低温集输, 玻璃钢管道, 界面特性