The burst, collapse and axial strengths of casing are directly related to wall thickness, and hence are reduced by wear. The casing must be designed so that wear will not reduce the strength of the casing below that which will enable the well to be drilled and operated safely and efficiently. 1 Introduction Unless there … Influence of wear on casing strength

Ditch Magnets The metal worn away from the casing and tooljoint is carried by the mud to the shaker header box where it will be attracted to the ditch magnet. Not all the metal particles will be trapped and so the amount of metal cannot be used as an exact quantitative measurement of metal worn … Monitoring Casing Wear

Casing wear is very important as it effects the system integrity. A casing scheme is designed based on the properties of the chosen casing. Casing wear changes the thickness of casing walls and therefore changes its properties related to its capability to withstand the various loads exerted on it. This should be taken into consideration … Casing wear and solutions

Casing failure can have various causes. Casing may fail after exceeding, even once, the ultimate tensile or compressive strength, but also after repeated load cycles below the ultimate tensile or compressive strength. This phenomenon is known as fatigue, and practically all materials are subject to it. 1 Introduction The effects of surface condition, corrosion, temperature, … Influence of fatigue on casing strength

Once a casing string has been successfully cemented in place and tested, subsequent operations must be planned to ensure that the casing remains fit for purpose. Condition monitoring systems should be implemented to highlight the potential problems so that timely action can be taken. 1 Drillpipe tool joint hardfacing Tool joint hardfacing on drillpipe should … Monitoring Casing Condition

General guidelines to minimise casing wear include: limiting build up rates deepening kick-off points optimising drillstring design to reduce contact loads or employing suitable hardbanding minimising rotating hours modifying operating practices to reduce well tortuosity and rotating hours using drillpipe protectors or torque reducing subs in critical zones. Drill Pipe Protectors and Torque Reducing Subs … Minimising Casing Wear

Corrosion can pose a major threat to the installations whether above or below ground. With particular respect to casing, corrosion can impair the ability of the casing to perform its functions in two ways. Firstly, metal loss will reduce the wall thickness of the casing and hence its capacity to withstand the design loads. Secondly, … Influence of corrosion on casing strength