泡沫钻井液发泡剂抗温性评价方法

Applicability of Methods for Evaluating Temperature Resistance of Foaming Agents Used in Foam Drilling Fluids

为了满足钻井深部低压地层、地热和干热岩等不同地层温度的泡沫钻井液,笔者对关键组分发泡剂的抗温性评价方法进行了适应性研究。基于机械搅拌的热滚评价法和干粉加热法,对比分析了3种工业化抗高温发泡剂十二烷基苯磺酸钠SDBS、十二烷基硫酸钠SDS和α-烯烃磺酸钠AOS,考察了温度对其起泡性、泡沫流体稳定性和流变性影响。实验结果表明,采用评价方法不同,同一发泡剂实验结果不同,采用热滚评价法时,室温-190℃,SDS抗温性能优于AOS和SDBS,但SDS抗温小于200℃,而AOS和SDBS在240℃、16 h环境下,依然具有良好的起泡性;采用干粉加热评价法,AOS和SDBS抗温不低于260℃、4 h,SDS抗温低于150℃、3 h。在实验的基础上,针对微泡沫钻井液的研发,推荐使用热滚法评价发泡剂的抗温性能,并针对不同地层温度给出适宜性建议。

The applicability of several methods used to evaluate the high temperature stability of foaming agents was studied in an effort to find the most applicable method for selecting the best foaming agent used to formulate high temperature foam drilling fluids.Three industrial high temperature foaming agents,sodium dodecyl benzene sulfonate(SDBS),sodium dodecyl sulfate(SDS)and sodiumα-olefin sulfonate(AOS)were tested and compared using hot rolling method and dry powder heating method,both of which are based on mechanical mixing.Investigation of the effects of temperature on the foaming property of these foaming agents and the stability and rheology of the foaming fluids showed that the same foaming agent evaluated with different methods gives different results.Using the hot rolling method to test at 0–190℃,the performance of SDS is better than that of AOS and SDBS;on the other hand,SDS cannot perform properly at temperatures above 200℃,while AOS and SDBS,after hot rolling at 240℃for 16 hours,still had good foaming performance.Evaluating the performance of the three foaming agents with dry powder heating method showed that AOS and SDBS,after heating at 260℃for 4 hours,still foamed,while SDS can only last for 3 hours at 150℃.Based on the evaluation and other tests,it is recommended that hot rolling test method be used to evaluate the performance of foaming agents;with this method,the effects of temperature on the performance of foaming agents can be understood and suggestion can be given to the formulation of foaming fluids used for drilling at different temperatures.