长庆油田致密气水平井超长水平段安全钻井完井技术

Safe Drilling and Completion Technologies for Ultra-Long Horizontal Section of Tight Gas Horizontal Wells in Changqing Oilfield

为了提高长庆气田致密气开发效益,加大部署水平段长超4000 m的水平井,但随着水平段长度增加,面临井眼轨迹控制困难、钻井液携岩难度大、钻具起下钻摩阻大、泥页岩井壁易失稳和尾管难以下至设计井深等技术难点。为此,应用优化钻具组合及强度校核技术,以保证施工的安全性;研发高性能水基环保钻井液体系并配合井眼清洁监测技术,以实现超长水平段的安全钻进;采用破裂板悬浮器下套管技术,以确保套管下入顺利;并结合该油田的实际情况提出了具体的技术措施,形成了长庆油田致密气水平井超长水平段安全钻井完井技术。长庆油田3口致密气水平井的超长水平段应用该技术后,均顺利完井,表明其可以保证超长水平段的安全施工。长庆油田致密气水平井超长水平段安全钻井完井技术为长庆油田致密气高效开发提供了技术途径。

In order to enhance the efficient development of tight gas,Changqing Oilfield has scaled up the deployment of horizontal wells with a horizontal section over 4000 meters.However,with the increase of horizontal section,technical challenges are encountered,including bad well trajectory control,hard sand transportation by drilling fluids,tight hole while tripping,unstable mudstone hole section,and uneasy setting of tail pipe into designed depth.Therefore,the bottom hole assembly(BHA)optimization and strength check technologies were employed to ensure a safe operation,and a environment-friendly high-performance water-based drilling fluid system combined with the borehole cleaning and monitoring technology was developed to realize the safe drilling of ultra-long horizontal sections.The casing running technology of rupture disk levitating device was applied to ensure a smooth casing operation.Furthermore,a series of specific technical measures were proposed based on the actual situation of oilfield.Therefore,the safe drilling and complement technologies for ultra-long horizontal sections of tight gas horizontal wells in Changqing Oilfield came into being.The technologies have been applied in the ultra-long horizontal sections of 3 tight gas horizontal wells in Changqing Oilfield,with successful well completion,which showed that the technologies could effectively ensure the safe construction of ultra-long horizontal sections.The successful applications show that the technologies can provide technical mothodology for efficeent development of tight gas wells in the Changqing Oilfield.