一种超支化聚合物流变调节剂的室内研究与应用

Laboratory study and application of a hyperbranched polymer rheological modifier

针对陆丰油田高机械钻速条件下井眼清洁难所导致的憋泵、蹩扭矩和倒划眼困难等问题,室内以黄原胶为原料,2-丙烯酰胺-2-甲基丙磺酸(AMPS)、N-乙烯吡咯烷酮(NVP)为接枝单体,合成了一种超支化改性黄原胶HB-VIS,通过单因素实验确定了最佳合成条件为:m_(黄原胶)∶m_(单体)=1∶4,m_(AMPS)∶m_(NVP)=2∶1,反应温度为60℃,引发剂加量为0.5%。室内评价了HB-VIS的各项性能参数,结果表明,相比黄原胶,0.3%HB-VIS在提高钻井液动切力的同时,塑性黏度降低了14.3%,动塑比和3转值分别提升了23.3%和25.0%,更有助于高机械钻速条件下的井眼清洁。HB-VIS体系老化88 h后的动塑比和3转值保留率分别为65.1%和34.8%,显著优于黄原胶体系的30.8%和5.6%,具有更好的长时间热稳定性能。将该聚合物在陆丰油田进行应用,井眼清洁效果显著,应用前景广泛。

To address issues related to wellbore cleaning challenges under high mechanical drilling rates in the Lufeng Oilfield,which lead to pump pressure spikes,torque spikes,and difficulty in pulling back the drill string,an indoor synthesis of hyperbranched modified xanthan gum(HB-VIS)was performed.The raw materials used were xanthan gum,with 2-acrylamido-2-methylpropane sulfonic acid(AMPS)and N-vinylpyrrolidone(NVP)as graft monomers.Through single-factor experiments,the optimal synthesis conditions were determined as follows:m_(xanthan gum)∶m_(monomer)=1∶4,m_(AMPS)∶m_(NVP)=2∶1,reaction temperature of 60℃,and initiator dosage of 0.5%.The performance parameters of HB-VIS were evaluated indoors.The results show that compared with xanthan gum,0.3%HB-VIS can increase the dynamic shear force of drilling fluid while reducing the plastic viscosity by 14.3%.The dynamic-to-plastic ratio and 3-turn value increase by 23.3%and 25.0%,respectively,which is more conducive to wellbore cleaning under high mechanical drilling speed conditions。The dynamic-to-plastic ratio and 3-turn value retention rate of HB-VIS system after aging for 88 hours are 65.1%and 34.8%,respectively,which are significantly better than the 30.8%and 5.6%of the xanthan gum system,and had better long-term thermal stability.This polymer has been applied in Lufeng Oilfield,with remarkable wellbore cleaning effects and broad application prospects.