井底净化选井模糊决策方法研究

Study on fuzzy decision-making method for well selection of bottomhole clean-up

为了解决井底伤害问题，川西气田每年都进行20余井次的井底净化施工，但在对川西气田近5a井底净化施工井进行跟踪发现，不正确的选井施工，不仅无法取得预期效果，而且浪费了作业费用，针对这一问题，利用模糊决策方法，以历年来施工井的效果总结分析为基础，制定了模糊决策指标，通过专家系统对各项指标进行了科学打分，形成了井底净化选井模糊决策打分表，利用该表对2015年施工的井底净化井进行指导选井及背靠背评价。分析表明，该模糊决策打分系统与气并净化效果符合率达到100％，说明该方法能够有效地指导施工选井。

In order to solve the problem of downhole damage, Chuanxi （West Sichuan） Gasfield conducts more than 20 well-time of downhole cleaning each year. However, by tracing the downhole cleaning operation results in Chuanxi Gasfield in recent five years, it has been found that the incorrect selecting well operation cannot achieve the desired effect but waste the operating cost. Aiming at this problem, by fuzzy decision method, based on summary and analysis of the effect of the operated wells in the past years, the fuzzy decision indexes were formulated; then, each index was scored by an expert system to form the scoring table of fuzzy decision for selecting wells in downhole cleaning. This table was applied to guide the selection of downhote cleaning wells operated in 2015, and to conduct back-to-back evaluation. The study result indicates that the coincidence rate between this fuzzy decision scoring system and gas well cleaning effect is up to 100%, thus this method can effectively guide well selection in operation.