基于直通式迷宫密封的海上平台井口装置研究

Research on Wellhead at Offshore Platform Based on Straight-through Labyrinth Seal

海上稠油开采面临瓶颈,而平台有杆采油技术是解决这一难题的合适途径。油井安全是海上平台有杆采油新工艺实施的前提和关键,基于新工艺开发了海上平台复合井口装置,可实现正常作业动态密封、断杆自动关井、停产手动封井等功能。基于流体动力学理论建立了井口密封泄漏模型,分析了密封结构各参数对泄漏量的影响,确定了密封本体结构,在0.1 mm间隙、10 MPa井口高压下泄漏量为2.728×10^-5 m^3/s。说明密封结构设计合理,能够达到关井密封井口、撤离平台的目的,以确保海上稠油热采井有杆采油新工艺的安全实施。

Offshore heavy oil exploitation faces bottlenecks,while platform-based rod pumping technology is the appropriate way to solve this problem.Oil well safety is the premise and key to the implementation of new technology for oil production on offshore platforms.Based on the new technology,developing the composite wellhead device for offshore platforms can realize the functions of dynamic sealing of normal operation,automatic shut-off of broken rods,and manual sealing while stopping oil production.Establishing the wellhead seal leakage model,analyzing the influence of various parameters of the sealing structure on the leakage amount,and determining the structure of the sealing body,which are based on the theory of fluid dynamics.The leakage amount is 2.728×10^-5 m^3/s under the high wellhead pressure of 10 MPa at 0.1 mm gap.These analysis results prove that the design of the sealing structure is reasonable,so it can achieve the purpose of sealing the wellhead and evacuating the platform,so as to ensure the safe implementation of the new technology of rod pumping for heavy oil production in the offshore thermal recovery well.