适合海上某气田高温高压低渗储层的修井液体系

针对海上某高温高压低渗气田修井作业过程中修井液易对储层造成污染伤害以及对井下管柱易产生严重腐蚀等问题，室内以可溶性复合盐加重材料HGBZ为基础，并结合抗高温缓蚀剂HSJ-S、耐温抗盐防水剂HAD-2以及抗高温键合剂HJH-2等主要处理剂，研制了一套适合海上高温高压低渗气田的双保型高温高密度修井液体系，并对其综合性能进行了评价。结果表明:该修井液体系的基本性能良好，密度在1.03～1.80 g/cm3之间可调；修井液具有较好的防腐蚀效果，对井下设备钢材的腐蚀速率低于0.076 mm/a；修井液对目标气田储层段黏土矿物的防膨效果较好，防膨率可以达到95%以上；修井液与储层段地层水具有较好的配伍性，不会产生结晶沉淀等；修井液体系可以有效降低天然岩心的自吸水量，并且经过修井液污染后的天然岩心在长时间高温条件下的渗透率恢复值可以达到90%以上，具有良好的储层保护效果。X井使用双保型高温高密度修井液体系修井过程顺利，未发生井下复杂事故，修井后产能恢复率较高，说明研究的双保型高温高密度修井液体系能够满足海上高温高压低渗气田的修井作业要求。 

Study on Workover Fluid Suitable for High Temperature,High Pressure and Low Permeability Reservoirs in Offshore Gas Field

In view of the problems that workover fluid is easy to cause pollution damage to reservoir and serious corrosion to downhole pipe string during workover operation in a high-temperature, high-pressure and low-permeability gas field on the sea, the laboratory is based on soluble composite salt weighting material HGBZ, combined with high-temperature corrosion inhibitor HSJ-S, temperature and salt resistant waterproof agent HAD-2 and high-temperature bonding agent HJH-2, A set of dual maintenance high temperature and high density workover fluid system suitable for offshore high temperature, high pressure and low permeability gas fields is developed, and its comprehensive performance is evaluated. The results show that the basic performance of the workover fluid system is good, and the density is adjustable between 1.03-1.80 g/cm3; Workover fluid has good anti-corrosion effect, and the corrosion rate of downhole equipment steel is less than 0.076 mm/a; The workover fluid has a good anti swelling effect on clay minerals in the reservoir section of the target gas field, and the anti-swelling rate can reach more than 95%; Workover fluid has good compatibility with formation water in reservoir section and will not produce crystallization precipitation, etc; Workover fluid system can effectively reduce the self-absorption water of natural core, and the permeability recovery value of natural core polluted by workover fluid can reach more than 90% under high temperature for a long time, which has good reservoir protection effect. Well X uses the dual protection high temperature and high density workover fluid system, the workover process is smooth, there is no downhole complex accident, and the productivity recovery rate is high after workover, indicating that the dual protection high temperature and high density workover fluid system studied can meet the workover requirements of offshore high temperature, high pressure and low permeability gas fields.