呼图壁储气库气井冲蚀规律初探

The Study on Gas Well Erosion Rules of Hutubi Gas Storage

对于地下储气库而言,由于强注强采,高速流动的气体对管柱产生的冲蚀磨损是影响气井管柱寿命的重要因素。针对气井冲蚀问题,研究了材料冲蚀的不同内在机理,包括微切削理论、基于单点冲蚀的切削模型、锻造挤压理论、变形磨损理论、二次冲蚀理论和弹塑性压痕破裂理论。结合呼图壁储气库气井实际管柱结构与生产状况,认为微切削理论和变形磨损理论是主要的冲蚀破坏机理,并指出了管柱和井下工具不同部位所适用的不同的破坏机理。分析了造成气井冲蚀的影响因素,主要包括粒子的冲蚀角度、冲蚀速度、粒度、砂粒含量以及材料的硬度、弹性模量、类型、腐蚀对冲蚀的影响、环境温度等,并针对呼图壁储气库的实际情况,提出了减少甚至避免气井冲蚀的具体防护措施。呼图壁储气库优选的改良型13Cr气井管柱,具有良好的耐冲蚀性能。

For the underground gas storage ,due to intensive injection and production ,erosion damage of the strings caused by high-velocity flowing gas is an important factor of gas well string life.Aiming at the gas well erosion,the different inner mechanisms of material erosion are researched including micro-cutting theory, cutting model based on single point erosion,forging compression theory,deformational worn theory,secondary erosion theory and elastoplastic creasing disruptive theory.According to the actual string structure and production status of the gas wells in Hutubi gas storage,we know that the micro-cutting theory and deformational worn theory are the main erosion attack mechanisms,and different parts of string and downhole tools have different attack mechanism.The influencing factors of gas well erosion are analyzed including erosion angle, erosion velocity,granularity,sand contents of the particles and hardness,elastic modulus,type of the material and corrosion and environment temperature.Aiming at the actual situation of Hutubi gas storage,protective measures of reducing and even avoiding erosion are proposed.Optimal modified 13Cr gas well string in Hutubi gas storage has good performance of erosion resistance.