苏里格气田大位移水平井钻井液技术

Drilling fluid techniques for extended reach horizontal wells in Sulige gas field

苏里格气田安定组、直罗组、石千峰组和石盒子组泥岩地层易发生严重井壁垮塌,且因水平位移大、水平段长、井眼小易导致井眼清洁与润滑问题。针对苏里格气田的地质构造、岩层特性和水平井的井身结构特点进行了研究,对石盒子泥岩地层取样做了全岩矿物分析和黏土矿物分析,找出了影响井壁稳定的原因。针对苏里格地区地质特点、井身结构及保护油气层的要求,系统地分析了水平气井施工的钻井液技术难点,提出分地层采用不同的钻井液体系,并对钻井液处理方法与钻井施工的技术措施进行了阐述。4口高难度水平井的安全施工表明,苏里格气田大位移水平井钻井液技术能满足该地区大位移水平井施工的需要,可为高效开发苏里格气田钻井施工提供支持。

The mudstone formation ofAnding,Zhiluo,Shiqianfeng,and Shihezi in Sulige gas field are subject to severe wellbore collapse when drilling horizontal wells.And due to the great horizontal deviation,long horizontal section,and small borehole,it is subject to the trouble of wellbore cleaning and lubrication.The reason affecting wellbore stability was obtained by studying the geological structure,formation properties and well structure characteristics of horizontal wells in Sulige gas field,focusing on the analysis of the whole-rock and clay mineral taken from Shihezi mudstone formation.Meanwhile,the difficulties of drilling fluid technology for horizontal wells in Sulige area were analyzed systematically.According to the geological characteristics,wellbore structure and reservoir protection requirements,the drilling technical measure of using different drilling fluid systems in different formations was put forward,and the drilling fluid treatment methods and drilling operation techniques were illustrated.The safe drilling operations for the 4 high difficult horizontal wells prove that the drilling fluid techniques for extended reach horizontal wells in Sulige gas field can meet the needs of drilling large displacement horizontal wells,and provide drilling operation experience for efficiently developing Sulige gas field.