钻井液降黏剂SSMA的本体聚合制备与性能

为探究本体聚合法合成的磺化苯乙烯-马来酸酐（SSMA）在水基钻井液中降黏性能的优劣，以苯乙烯（St）、马来酸酐（MA）为原料，分别采用本体聚合和溶液聚合制得苯乙烯-马来酸酐（SMA），磺化后制得SSMA，并对不同方法制得的磺化苯乙烯-马来酸酐（SSMA）在钻井液中的降黏效果和抗温抗盐性能进行评价。结果表明，2种方法合成的SSMA都可有效地拆散钻井液中黏土颗粒形成的空间网状结构，但在盐水和高温条件下2者表现出不一样的降黏效果。①在淡水基浆中，2者均表现出好的降黏效果，当加量达到0.75%时，本体聚合制得的SSMA在淡水基浆中降黏率可达95.38%，溶液聚合制得的SSMA在基浆中的降黏率为85.54%。②在盐水基浆中，与溶液聚合制备的SSMA相比，本体聚合制备的SSMA的降黏作用更强，具有更好的抗盐性能，当加量达到1%时，其降黏率可达53.33%。③在高温老化实验中，本体聚合制得的SSMA在基浆中的降黏性能较溶液聚合制得的SSMA受高温影响较小，在老化温度为230℃时，仍可保持40%以上的降黏率，具有更好的抗温性能。④在高密度基浆中，本体聚合法制备的SSMA具有较高的降黏率，220℃老化后降黏率仍在60%以上，高于溶液聚合法制备的SSMA在高密度基浆中47.45%的降黏率。 

Study on the Performance of SSMA-A Thinner Made Through Mass Polymerization

Mass polymerization and solution polymerization were used to prepare styrene-maleic anhydride (SMA) with styrene (St) and maleic anhydride (MA). The two SMAs made were then sulfonated to sulfonated styrene-maleic anhydride (SSMA). SSMAs made from the two methods were evaluated for their abilities in drilling fluids to reduce viscosity and to resist the effects of high temperature and salt contamination. It was found that the two SSMAs made both can effectively tear apart the spatial networking structure formed by the clay particles in the drilling fluid. In saltwater muds and at high temperatures, the two SSMAs performed differently in viscosity reduction. First, in fresh water base drilling fluids, the two SSMAs both can reduce mud viscosity efficiently. At a concentration of 0.75%, the SSMA made through mass polymerization can reduce the viscosity by 95.38%, while the SSMA made through solution polymerization can reduce the viscosity by 85.54%. Second, in saltwater drilling fluids, the SSMA made through mass polymerization had better viscosity reduction ability and better salt resistance. At a concentration of 1%, the viscosity of saltwater drilling fluids can be reduced by 53.33% by the SSAM made through mass polymerization. Third, in aging experiments at elevated temperatures, the viscosity reducing performance of the SSMA made through mass polymerization was less affected by temperature than that of the SSMA made through solution polymerization. After aging at 230℃, the rate of viscosity reduction (by the SSMA made through mass polymerization) was still maintained at 40% or higher. Fourth, in high density drilling fluids, SSAM made through mass polymerization had higher rate of viscosity reduction. After aging at 220℃, the rate of viscosity reduction was still maintained at 60% or higher, higher than the rate of viscosity reduction of SSMA made through solution polymerization, which was 47.45% in high density drilling fluids.