宝浪油田煤层水泥封堵体系室内研究

Laboratory study of coal seam cement plugging/sealing technology in Baolang oilfield

针对宝浪油田高温(83～110℃)、高矿化度(30 000～250 000 mg/L),此外,部分井层因与煤层相距较近或油层与水层间夹层厚度小,导致大量注入水没有注入油层,而是进入了煤层。因此,选用波特兰水泥来封堵煤层,通过实验数据表明,向波特兰水泥中加入促凝剂A后,当浓度在0.10%～0.35%范围时,随着促凝剂浓度A的增大,候凝时间急剧减小,由68.0 h降低到17.5 h。而且煤颗粒越小,水泥胶结物的耐压能力就越高。经过聚合物交联体系封堵以后,水泥浆滤失量明显降低,只有12.8 mL,并且在15～35 h之间,随着时间的延长,水泥浆的稠度急剧上升。因此,通过总体评价所选水泥浆体系可以满足实际施工需要。

The study is designed to deal with high temperature（83～110℃）and hypersalinity （30 000～250 000 mg/L）in Baolang oilfield,adding to the fact that some layers in some wells are close to the coal seams or the interlayer depth between the oil layer and aqueous layer is quite thin,all these factors have made most of the injected water run into the coal seam rather into the oil layer.According to this situation,portland cement was used to seal the coal seam.The experiment results showed that after adding coagulant A to Portland cement,when the concentration was between 0.10%～0.35%and the concentration of coagulant A grew,the cement curing time decreased sharply which dropped from 68.0 h to 17.5 h.Also,the smaller the coal size was,the stronger compression capability the cements were.After plugging with cross -linked polymer system,the slurry filtration dropped dramatically which was only 12.8 mL and the cement curing time was between 15 h and 35 h, and over time the cement consistency sharply increased.In conclusion,the chosen cement slurry system could satisfy the requirements for direct construction based on the above appraisal.