摘要
塔里木油田哈拉哈塘、哈得等区块裸眼完成的油气井,因井壁垮塌、出砂,严重影响正常生产。常规液力冲捞砂工艺在这类低压、易漏井中无法建立循环,难以完成冲砂需求。通过分析研究提出一种用双壁钻杆加井口注氮气的冲砂工艺,并用瞬态多相流软件OLGA进行模拟。分析了钻杆内外两种不同注入方式下,井筒内注入气及冲砂液复杂的流动现象。得出钻杆外注氮气无冲砂效果、钻杆内注气能搅动冲砂液在井筒内形成闭式循环的结论。最后通过参数的敏感性分析,针对钻杆内注气的双壁冲砂工艺,得出结论:最佳注气量为13308~26617 m 3/d;注气阀的合理位置为静液面处;管柱的理想组合为内管长度1000 m、外管尺寸127 mm;冲砂过程始终为负压。该工艺在塔里木油田的成功应用,为深层低压井的冲砂提供了技术借鉴。
Normal production of wells with open-hole completion in Halahatang and Hade in Tarim Oilfield has been badly affected by well-bore collapse and sand breakthrough.The use of conventional hydraulic sand flushing technique is unable to build up circulation in these low pressure,leaky wells and therefore unable to meet the sand flushing target.Based on research analysis,this paper presents a sand flushing process of nitrogen injection into dual-wall drill pipe at well head.A computer simulation model is built using multiphase pipeline dynamic simulation model OLGA,to study the complex flow phenomena of the injected gas and the sand flushing fluid,for two injection cases of injecting inside and outside the drill pipe.The simulation results concluded that nitrogen injection outside the drill pipe does not have any desired effect;while nitrogen injection inside the drill pipe is able to form a closed loop circulation and agitate sand flushing fluid.From the sensitivity analysis of operation parameters of nitrogen injection into the drill pipe,it can be concluded that:1)the optimum gas injection rate is between 13308 and 26617 m 3/d;2)sensible location for gas injection valve is at static liquid surface;3)optimum dimension of drill pipe assembly is 1000 m inner pipe length with outer pipe size of 127 mm;4)the entire sand flushing process should be done under negative pressure.The above sand flushing process is successfully applied in Tarim Oilfield,and can be used as a technical reference for sand flushing of low-pressure deep zone wells.
作者
王发清
任今明
兰美丽
秦德友
周行文
王方智
Wang Faqing;Ren Jinming;Lan Meili;Qin Deyou;Zhou Xingwen;Wang Fangzhi(PetroChina Tarim Oilfield Company,Korla,Xinjiang,841000,China)
出处
《天然气与石油》
2020年第4期53-59,共7页
Natural Gas and Oil
基金
国家科技重大专项“超深超高压高温气井优快完井与采气技术”(2016 ZX 05051003)。
关键词
双壁钻杆
搅动
冲砂
低压
Dual-wall drill pipe
Agitation
Sand flushing
Low pressure
