套损井最佳修井时机和修井策略研究

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

套管损坏将造成很大的经济损失 ,套损井的修复必须找准修井时机和选择合适的修井工艺 ,但现场一般靠经验判断 ,准确性较差。应用非线性规划方法 ,建立了大修井经济评价模型 ,通过确定模型参数 ,分析不同模型参数对修井经济效益影响的敏感性 ,得出常规修井套损修复概率与使用年限概率的积是影响修井经济效益的主要因素 ,其它因素均在其控制下发生作用。另外 ,通过对该模型的求解 ,得出在现有修井技术水平下 ,必须在套损较轻时修井 ,通径大于 90mm时是最佳修井时机 ,整体的修井策略是尽量多地采用先进修井技术 ,先修难度小、油井产量高、水井注水量高且对周围影响大的井。经现场应用 ,取得了良好的效果。

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.