盐层技术套管环空带压处置技术  

HOW TO CONTROL SUSTAINED CASING PRESSURE IN SALT LAYERS

作　　者：卢俊安[1] 石希天[1] 刘双伟[1] 任自伟[1] 孙新堂[1] 查磊 LU Junan;SHI Xitian;LIU Shuangwei;REN Ziwei;SUN Xingtang;CHA Lei(Tarim Oilfield Company,China National Petroleum Corporation,Korla, Xinjiang 841000,China)

机构地区：[1]中国石油天然气集团公司塔里木油田分公司

出　　处：《钻采工艺》2019年第2期24-27,I0002,共5页Drilling & Production Technology

摘　　要：YD1区块位于塔里木盆地塔北隆起轮台凸起,该区块施工的高密度盐下水平井,技术套管固井面临井斜大、密度高、盐层造斜导致固井时套管不居中等难题。由于盐层段发育高压饱和盐水,在实际钻完井过程中多口井出现双级固井施工后环空带压,个别井环空带压超过套管四通旁通阀额定工作压力。为保证生产井长期安全生产及井控安全,分析盐层套管环空带压的原因,在API RP90环空压力评估测试程序的基础上,进行了降压、升压测试,利用饱和盐水运移过程中的盐结晶作用,采取环空控压放水的方法,消除了盐层技术套管环空超压的安全风险。通过3口井现场实践,形成了盐层技术套管环空带压处置技术。YD1 block is located at Luntai, Tabei uplift of Tarim Basin.High density subsalt horizontal wells are drilled at this block.The cementing there is faced with difficulties like high well inclination,high density, and casing unable to be centralized due to the deflecting effects of salt layer.Due to the development of high-pressure brine in the salt layer,sustained casing pressure occurs after the double-stage cementing in lots of production wells.The annular pressure even exceeds the rated working pressure of the valves of casing spool in some cases.In order to ensure long-term safe production, the causes of the annulus pressure are analyzed.The pressure bleed-down/build-up tests are carried out according to API RP90.By taking advantage of the salt crystallization during the brine migration process, the managed pressure discharge of water is adopted to solve sustained casing pressure in production wells.After tests in 3 wells, a set of technology to solve the annular casing pressure problem has been developed.

关 键 词：盐层固井 高压盐水 井筒完整性 环空带压 盐结晶 控压放盐水 

分 类 号：TE256[石油与天然气工程—油气井工程]