变壁厚连续管

Tapered Coiled Tubing

随着我国深层及海洋油气资源的深入开发,深井、超深井数量不断增加,对连续管作业下入深度提出了更高要求。常规单一壁厚连续管受到悬挂自重制约,下入深度受到限制,很难满足在深井、超深中作业深度的要求。中国石油集团宝鸡石油钢管公司开发了一种采用预制的壁厚逐渐均匀变化的钢带作为过渡段制成的变壁厚连续管。这种变壁厚连续管不同壁厚的各个部位性能均一、稳定,减重效果显著,各段剩余拉力均衡,安全系数高。通过强度、静水压、金相组织、硬度、低周疲劳等测试,证实性能达到了CT90钢级连续管的要求。

The number of deep wells and super-deep wells are continually rising with development of China’s deep-layer and offshore oil and gas resources,thus leading to a higher demand for setting depth of coiled tubing service.The conventional coiled tubing(CT)with a single wall thickness,constrained by its own hanging weight,has a limited setting depth and is difficult to satisfy the demand for setting depth in the deep well and super-deep well services.CNPC Baoji Petroleum Steel Pipe Co.Ltd.has developed a kind of CT with a variable wall thickness,which adopts the uniformly changing prefabricated wall thickness made of the steel strip as a variable wall thickness in the transition period.This kind of CT with a variable wall thickness is uniform and stable for different wall thicknesses,with a remarkable weight-reducing result.The remaining tensile strength is uniform at various levels and has a high safety coefficient.The test on strength,static hydraulic pressure,rigidity of fine texture and low-cycle fatigue confirms this kind of CT reaches the requirements on the steel grade of CT90.