储气库注采井环空保护液的研制与性能评价

Research and Performance Evaluation of Annulus Protection Fluid for Injection and Production Well of Gas Storage

为了解决大港储气库群注采管柱腐蚀、结垢问题,通过优选密度调节剂、缓蚀剂、除氧剂、阻垢剂及杀菌剂等各种功能添加剂,得备了一种密度在1.0数1.6 g/cm^3可调的环空保护液:基液+5%咪唑啉类缓蚀剂GL-3(主要成分为咪唑啉硫代磷酸酯)+2%肟类除氧剂二甲基酮肟(DMKO)+1%杀菌剂1227(十二烷基二甲基苄基氯化铵)+1.3%有机磷酸类阻垢剂ZC-21(主要成分为氨基三甲叉膦酸ATMP)+0.01%pH调节剂(碳酸钠),研究了该环空保护液的缓蚀性能、除氧性能、杀菌性能、阻垢性能及其对封隔器胶筒性能的影响。研究结果表明:钢片在该环空保护液的腐蚀速率可低至0.045 mm/a,环空保护液中氧含量可降至40 mg/L,杀菌率可达100%,对CaCO_3、CaSO_4、BaSO_4的阻垢率分别高达99%、93%、81%,且对封隔器胶筒几乎无影响。环空保护液可以有效缓解酸性气体产生的腐蚀加速现象,成本合理,可达到有效保护油套管的目的,适宜在含酸性气体的气藏应用。

In order to dissolve the corrosion and scaling problems of injection-production string for the Dagang gas storage,through the optimization of a variety of functional additives,such as density regulator,corrosion inhibitors,deoxidizer,scale inhibitors and fungicides,a kind of self-healing annulus protection fluid（SHAPF）,whose density can be adjusted within 1.0—1.6 g/cm^3,was developed as follows：base solution ＋5% imidazoline corrosion inhibitor GL-3（imidazoline dithio phosphate as main component）＋2% oxime deoxidizer dimethyl ketoxime（DMKO）＋ 1% bactericide 1227（dodecyl dimethyl benzyl ammonium chloride）＋ 1.3%organic phosphate scale inhibitor ZC-21（ATMP as main component）＋ 0.01% pH regulator（sodium carbonate）. Corrosion inhibition property,oxygen removal performance,sterilizing performance,scale inhibition performance of SHAPF and effect of SHAPF on the performance of the packer rubber tube of was examined. The experimental results showed that,the corrosion rate of steel sheet in the SHAPF could be as low as 0.045 mm/a,oxygen in the solution could be reduced to 40 mg/L,the sterilization rate could reach up to 100%,the anti-scaling rate of the SHAPE to CaCO_3 and CaSO_4,BaSO_4 scale could reach as high as 99%,93% and 81%,respectively,and the SHAPF almost had no effect on the packer rubber tube. The SHAPF could buffer effectively hydrogen ions dissolved by acid gases and remain the related properties. Hence,the SHAPF can achieve the goal of effective protection of tubing and casing and is suitable for application in the acidic gas reservoir.