大港油田油水井套管变形损坏规律与修复研究

Research on the Casing Deformation and Failure Law and Repair Technology of Oil/water Wells in Dagang Oilfield

随着注水开发的不断深入，大港油田套损、套变问题日益严重。统计数据显示，大港油田套损井达到1189口，其中套损油井692口，影响产量1311．8t／d，套损水井497口，影响注水量11964m3／d，并且仍以每年70～80口的速度递增。套损、套变不仅影响油田稳产基础，还造成注采井网的不完善，给油田区块的整体开发带来不利影响。通过对套变类型、分布区域、套损程度进行统计分析，对套管变形井修复工艺技术进行研究，指出泥浆密度、排量直接影响到取换套、打通道的进度．甚至成为能否顺利施工的重要因素。针对裸眼取换套所需的井控设备、井口工具、泥浆处理设备提出了基本要求，给出了打通道需要配套的工具清单。编制出套损、套变治理工艺流程，研究了缩径变形、弯曲变形、错断变形三种类型修复工艺技术，尤其是对不同的缩径和错断，制定了施工工艺步骤，并在现场进行应用。共修复套损、套变井33口．其中油井27口、水井6口，累计增油5520t，累计增注38749m3。

With further development of the water flooding in Dagang oilfield,the problem of casing deforma tion and failure is increasingly serious.At present,casing failure wells in Dagang oilfield have reached 1189,of which the casing failure oil wells are 692,affecting production output 1311.8 t per day,and casing failure water wells,constantly increasing at an annual rate of 70-80,are 497,affecting water injection rate 11964m3 per day.Casing deformation and failure not only affects the foundation of stable production,but also cause the imperfect of injection-production well pattern,which has adverse effects on the overall development of the blocks in the oilfield.Casing deformation types,distribution areas and casing failure degree are analyzed statistically,and repair technology for the casing deformation wells is studied.It is pointed out that mud density and discharge rate may influence the speed of casing taking off and replacing and running speed and may be the important factor of successful operation.Well control equipment,rig tool and mud condition equipment need for uncased casing replacing are proposed the request,and a complete set of tools for running is listed.Repair process of casing deformation and failure is made and repair technologies for reducing deformation,bending deformation and fault deformation are studied.Construction process steps are made especially for different reducing condition and fault situation.In the field application,33 wells with casing deformation and failure are repaired,and 27 oil wells and 6 water wells among them.Cumulative increased oil is 5520 t and cumulative increased water injection is 38749m3.