Casing Failure Mechanism And Preventive Measures Analysis In Jiangsu Oilfield

The total number of casing deformation wells in Jiangsu oilfield hasreached 189 by the end of 2005 since 1970s when Jiangsu oilfield enteredinto comprehensive production,and it greatlyrestricted the development. Inview of the serious status of tubing damage and the ascending amount ofcasing failure wells in Jiangsu oilfield,analysed the affect of damp on rockcharacter,studiedthepropertyofshaleexpansionandshalecreep,confirmedtherelationshipbetweentheYoung'smodulus,Poiccon'ratio,internalfrictionangleanddampbytestingthe rock characteristics.Exploredthecasedamagemachinism by analysising the factor of change of stress,cement mantle,perforation,porepressure,formationcreepdeformation,casestresschange,erode and treatment quality. Consummated the detect technique of wellcondition and casing failure including the temperature log,the temperatureisotope coping log,bearing caliper log,multi-armed caliper log,electromagnetic inspection etc. Created the restoring technique of casingfailure including mechanical plastic,bridge plugging ect. Improved theprevending technique in well drilling,cementation,shooting,corrosionprevention,optimizationoffractureacidizing,analysedthebestopportunityandstrategyofcasingfailurerestoring. Throughtheapplicationinoil field,part of casing deformation wells renewed its production,controled thenumber of deformation wells. Atechnic system that gived priority to defendand takes consideration of reserch,defend and cure was formed for casingdeformationwells.