江汉油田复杂情形的固井质量评价

Jianghan Oil Field Well Cementation Quality Assessment under Complex Circumstances

在固井质量评价过程中,出现了海相碳酸盐岩快速地层、盐韵律层镜像现象、双层以至多层套等复杂情形,需要深入分析CBL、VDL测井资料信息及地层的地球物理特性,以便研究不同信息的形成机理,从而给出准确合理的解释和评价结论。实践表明,单一的CBL测井不适于快速地层的固井质量评价,必须采用声波变密度测井,以VDL的评价结论为主进行综合评价。产生镜像特征的固井质量评价也不能用单一声幅测井进行评价,而应该进行声波密度测井,严格遵循用完井声波测井与变密度波形重叠法进行评价,以Ⅱ界面结果为准。

During quality review of well cementation,some complex situations occurred such as marine facies fast carbonatite formation,salt rhythmic succession mirror image and double or even multiple layers overlaps.To get precise explanations and evaluations of these phenomena,this paper suggests studying CBL and VDL logging data and stratum＇s physical and geographical features to explore the forming mechanism of different data.The results showed that CBL logging data alone cannot meet the demands of fast stratum＇s well cementation quality assessment so that a comprehensive assessment must be carried out based on VDL reviews.Likewise,acoustic amplitude logging alone is not enough for mirror image featured well cementation quality assessment.VDL technique should also be employed and assessment should stick to well completion acoustic logging plus VDL wave overlap method based on the results of interface II.