基于多材质复合管柱的裸眼井壁支撑工艺及应用

已完钻超深裸眼水平井侧钻技术是经济、高效开发油藏剩余油的主要手段之一，传统的磨铣钢套管开窗侧钻技术存在下入摩阻大、磨铣耗时长导致开窗失败等问题。为此，提出了基于多材质复合管柱的超深水平井裸眼井壁支撑工艺，结合中国西北油田已完钻超深裸眼水平井井况，首先，提出了基于“铝合金+碳钢”的多材质复合管柱组合及设计方法；其次，开展了基于管柱实物屈曲实验数据的管柱临界屈曲载荷计算模型适用性评价，并优选出了适合于“铝合金+碳钢”多材质复合管柱的屈曲临界载荷计算模型；最后，研究了综合考虑管柱扭矩、摩阻、刚性、井眼条件、管柱强度及材质的多材质复合管柱下入性分析方法，并利用下入性分析软件对西北油田顺北X1井、X2井、X3井、X4井复合管柱进行了下入可行性评价。该方法在X1井和X2井得到成功应用，进一步论证了该工艺现场应用的可行性。研究成果可为超深水平井裸眼井壁支撑的复合管柱设计和下入可行性评价提供理论参考。

An Open-hole Wall Support Technology Based on Multi-material Composite String and Its Application

The use of sidetracking technology for completed ultra-deep open-hole horizontal wells is one of the main means to develop the remaining oil economically and efficiently. The traditional milling steel casing sidetracking technology has some problems, such as large running friction and long milling time and so on. Therefore, an ultra-deep horizontal well open-hole wall support technology based on multi-material composite pipe string is proposed, combined with the well conditions of the ultra-deep open-hole horizontal well that has been drilled in the Northwest Oilfield in China. The paper firstly proposes a multi material composite string combination and design method based on “aluminum alloy + carbon steel”. Secondly, the applicability evaluation of the critical buckling load calculation model based on the actual buckling test data of the string is carried out, and the buckling critical load calculation model suitable for “aluminum alloy + carbon steel” multi material composite string is optimized; thirdly, the trip-ability analysis software of multi material composite string is developed, which comprehensively considers the torque, friction, rigidity, borehole conditions, string strength and material. The feasibility evaluation of composite string of Shunbei X1, X2, X3 and X4 wells in Northwest Oilfield is evaluated by using the trip-ability analysis software. The technology has been successfully applied in Well X1 and Well X2, which further demonstrates the feasibility of field application of the technology. The result provides a theoretical reference for the design of composite string of ultra-deep openhole horizontal wells wall support and trip-ability evaluation.