低压漏失井氮气泡沫连续冲砂技术  

Nitrogen foam continuous sand flushing technique in low-pressure wells with lost circulations

作　　者：张康卫 李宾飞 袁龙 李松岩 刘刚[1] 骆志敏 Zhang Kangwei Li Binfei Yuan Long Li Songyan Liu Gang Luo Zhimin(Downhole Operation Company, PetroChina Dagang Oil field Company, Tianjin 300280, China School of Petroleum Engineering, China University of Petroleum, Shandong Qingdao 266580, China)

机构地区：[1]中国石油大港油田公司井下作业公司,天津300280 [2]中国石油大学石油工程学院,山东青岛266580

出　　处：《石油学报》2016年第B12期122-130,共9页Acta Petrolei Sinica

摘　　要：在低压漏失油井中采用氮气泡沫冲砂作业,可以减少冲砂液漏失,有效将地层出砂携带到地面,在井底形成负压或低压循环,激励产层,这是恢复油井产能的一项有效工艺技术。根据能量方程、质量守恒方程和动量守恒方程,建立了泡沫流体在井筒内流动的温度、压力分布的数学模型以及相应的边界条件和约束条件,给出了求解思路和计算程序。开发了泡沫冲砂设计软件,模拟计算了井筒条件下泡沫流体密度以及泡沫流体压力变化,优化气/液比、地面施工压力等施工参数,同时开展了连续泡沫流体冲砂技术研究,配套连续冲砂井口装置和工艺管柱,现场试验15井次,满足最低地层压力系数在0.5情况下循环冲砂要求,实现了不停泵连续冲砂210 m作业目的,最大程度保护了油气层,使施工安全性、环保性以及施工效率明显提高。Sand flushing operation with nitrogen loam m low-pressure w-, take sands from formations to the surface efficiently meanwhile it can also create a negative pressure circulation to increase output of production layers. Accordingly it is an efficient technique to recover production capacity of oil wells. This paper builds a mathematic model about temperature and pressure distribution of the flow of foam fluid in wells. This paper also builds relevant border and constrain conditions to provide solution methods and calculation procedures according to energy equation, mass conservation equation and momentum conservation equation. It develops sand flushing design software to calculate the changes of foam fluid density and pressure. The software also can optimize gas to liquid ratio, surface operation pressure, etc. We study the technique of continuous sand flushing with foam fluid and relevant wellhead equipment and pipe strings. We conduct field tests in 15 wells to meet require- ments of circulatory sand flushing when the lowest formation pressure ratio is 0.5 and complete 210 m sand flushing continuously without pump stop. So oil layers and environment are protected at utmost, security as well as efficiency is significantly improved in operations.

关 键 词：低压漏失 氮气 泡沫 连续冲砂 井筒 

分 类 号：TE358.1[石油与天然气工程—油气田开发工程]