四川盆地深井钻井液材料分解规律研究

STUDY ON THE MATERIAL DECOMPOSITION LAW OF DEEP WELL DRILLING FLUID IN SICHUAN BASIN

分析了四川盆地蓬莱气区钻井酸性气体来源,并导致钻井液流变性变差的原因。相同区块不同钻井液体系在老化后,有机盐聚合物钻井液在100℃热滚2 d钙离子分别从1160、1100 mg/L降至280、0 mg/L,表明有机盐聚合物钻井液中有二氧化碳产生。对钻井液材料的热滚和稳定性测试发现,在150℃钻井液单剂老化过程中钻井液用降滤失剂羧羟基烷烯共聚物(L)有明显的酸性气体产生,且磺化钻井液体系材料的二氧化碳产生量明显小于聚合物材料。对材料进行MS-DC分析可知,L产生的二氧化碳的总的量较多;钻井液用降滤失剂阳离子小分子聚合物(YLZ)等抗温性相对较差,并在160℃开始分解。

The frequent invasion of acidic gases during drilling in the Penglai gas field of the Sichuan Basin leads to poor rheological properties of the drilling fluid.A series of studies have been conducted to identify the source of acidic gases in the drilling fluid.Research have found that after aging of different drilling fluid systems in the same block,the calcium ions in the organic salt polymer drilling fluid decreased from 1160 and 1100 mg/L to 280 and 0 mg/L,respectively,after hot rolling at 100℃for 2 days,indicating that the production of carbon dioxide in the organic salt polymer drilling fluid.According to the thermal rolling and stability tests of drilling fluid materials,during the single agent aging process of drilling fluid at 160℃,reagents such as L(carboxyl hydroxyalkylene copolymer)produce significant acidic gases.The carbon dioxide production of sulfonated drilling fluid system materials was significantly lower than that of polymer materials.According to the MS-DC analysis of the material,L produces the largest total amount of carbon dioxide.YLZ(cationic small molecular polymer as a fluid loss additive for drilling fluid)has relatively poor temperature resistance and begins to decompose at 150℃.