监测井下循环情况的迟到时间法在固井中的应用

Lag Time Method Used in Cementing

迟到时间是综合录井的基本参数之一,现广泛应用于录井工程中,但很少应用于钻完井其他环节。通过研究结合现场实践,总结出一套判断井下循环情况的迟到时间法。该方法充分利用迟到时间分析井下循环情况,对比分析参与流动的钻井液体积理论值以及实际计量值,可用于判断井下是否存在循环短路及短路位置,同时可用于分析井眼环空的窜流情况及其严重程度,从而为钻完井过程井下情况监测提供了一套简单、有效的手段。以缅甸某区块P-3井固井短路复杂情况处理为例,详细介绍了迟到时间法在该井补救固井施工过程中的成功应用,以期为该方法在固井等钻完井作业过程中的进一步推广应用提供参考借鉴。

Lag time is a basic parameter which is used extensively for well logging but seldom used in other parts of thewell drilling and completion at present.In this paper, a method for evaluation the downhole circulation condition by lagtime analysis is developed, and it can be used to confirm if there exits circulation short circuit and its position, compare thereal and theoretical volumes of drilling fluid, and analyze channel flow and its severity.Taking the well P-3 in Myanmaras an example, downhole circulation condition occurred during cementing, and the remedial measures were successfullyconducted by using the lag time method, which provides reference for lag time widely used for cementing and other parts ofthe well drilling and completion.