STUDY ON BEST WORKOVER TIMING AND WORKOVER PROPOSAL FOR CASING DAMAGED WELL

Casing damage causes great economic losses, and for the casing damaged wells, it is necessary to choose a best timing and suitable techniques for workover. However, experience plays too important a role to achieve good result and accuracy. An economic evaluation model for the workover well is established using the non-linear planning method.Through fixing parameter for model, analysing the sensitivity of different model parameter to workover job economic benefit, obtaining the main factor affects benefit of workover job is probability product of casing restoring and casing appling time, and a best timing as well as an overall proposal for workover operation is worked out based on which with the present workover technologies available. Field application proved it to be successful.