川西新场须二段新10-1H水平井安全快速钻井技术

川西新场构造须二段气藏储层埋深较大,范围一般为4600～5200m,孔隙度和渗透率较低,孔隙度范围在1%～4%之间,渗透率普遍低于0.06×10-3μm2。由于须二段气藏获得高产、稳产的储层类型主要为致密的裂缝-孔隙型,因此水平井是开发此类气藏的有效技术。以川西新场构造第一口水平井——新10-1H水平井为例,分析了该构造须二段水平井安全快速钻井的难点,并提出相应技术对策:直井段一开井段采用塔式钻具组合,二开井段采用钻头和直螺杆配合塔式钻具,并根据实时测量数据,采取小钻压吊打等措施,确保井眼的防斜打直;通过动力钻具与MWD配合控制井眼轨迹,并根据MWD实时测量数据分析井下情况,合理调整井眼轨迹,确保井眼轨迹的精确控制;根据地层岩性特点,优选牙轮钻头和PDC钻头,是提高钻速的关键;水平段钻进施工时,采用复合金属离子聚磺防漏水包油钻井液体系,能够有效润滑、防卡,降低摩阻至250kN以下,保障钻进的顺利进行。

Safe and Fast Drilling Technology for Xin10-1H Horizontal Well in Xu-2 Member of Xinchang, West Sichuan

In Xinchang structure of West Sichuan,Xu-2 member is a dense fractured reservoir which is buried at 4600-5200m with 1%-4% of porosity and below 0.06x10-3~m2 of permeability.Horizontal well technology can effectively develop such gas reservoir with high and stable production.In this paper,taking Xinl0-1H well the first horizontal well of Xinchang structure as an example ,the difficulties encountered in safe and fast drilling are analyzed and corresponding technical measures are proposed：tapered drillstring assembly is used at first spud-in straight hole section ,and bit and straight helicoid hydraulic motor as well is used at second spud-in straight hole section.Well is drilled under low pressure for ensuring deviation preventing and vertical drilling according to the real time measured data.Downhole motor and MWD can be applied to well track control to- gether,and accurate control on well track may be realized through rational adjustment of it according to the analysis of downhole by the MWD real-time data.Cone rock bit and PDC bit are optimized according to the lithology of the formations,and it＇s the key of enhancing the drilling rate.In the process of horizontal section drilling,mud-loss-control oil-in-water drilling fluid system with complex metallic ion polymer sulfonate is ap- plied to effective lubrication and anti-jamming,and friction resistance may be dropped below 250kN and the drilling may be completed successfully.