迪那2气田井筒高温解堵液体系

迪那2高压气田部分井存在出砂严重、生产管柱堵塞等问题，严重影响了气井安全、稳定生产，针对这一问题研制了一种耐高温螯合型高效解堵剂。首先，根据迪那气田的岩性特征，通过络合滴定试验优选了对钙、铝、铁金属离子螯合能力强的有机磷酸螯合剂，然后将该螯合剂与氢氟酸及有机弱酸相互组合，形成了多种解堵液基础配方体系。通过岩粉溶蚀和腐蚀实验，评价了一系列体系的溶解率、耐温及缓蚀能力，并由此确定了2种性能较好的解堵液体系，同时使用现场井筒堵塞物样品对其进行了溶解验证实验。结果表明，该体系能够耐受160℃的高温，随着时间的延长，溶蚀率不断增加，最高可达到75%。与土酸相比，新型解堵剂水溶液不仅酸度较低，腐蚀作用较弱，具有良好的溶解能力，还能够有效防止二次沉淀。对现场堵塞物溶解前后的矿物成分和溶液进行测试表明，该解堵液能够快速地溶解大部分的堵塞物，缓慢地溶解石英、长石等矿物，钙、镁、铝和硅等金属离子均能被有效溶解到溶液中，是性能优越的高温解堵液体系。 

Study on High Temperature Block Removing Fluids Used on Dina-2 Ges Field

Severe sand production and blocking of production string have been encountered in Dina-2 Gas field, seriously affecting the safe and steady production of the well. An efficient high temperature chelating block removing agent has been developed to deal with the problems above mentioned. Based on the study on the characteristics of the rocks found in the Dina gas field, a high temperature organophosphorus acid chelant that can efficiently chelate calcium, aluminum and iron ions was selected through complexometric titration. The chelant was then mixed with hydrofluoric acid and weak organic acids in different ratios to form many base block removing fluids. The blocking removing fluids were then tested through dissolution and corrosion of rock powders for their dissolving rate, high temperature resistance and corrosion inhibitive capacity. Two formulations with better performance were chosen through the tests. The dissolving ability of the two block removing fluids was verified by reacting them with the blockage found in a well. It was found that the block removing fluids were able to function properly at 160℃. The dissolving rate of the block removing fluids was increasing with time, with a maximum of 75%. Compared with mud acid, the new block removing fluids have these advantages such as low acidity, weak corrosiveness, high dissolving capacity, and ability to effectively prevent secondary sedimentation. Analyses of the mineral components and solution of the blockage reacted with the block removing fluids have shown that the block removing fluid are able to quickly dissolve most of the blockage and slowly dissolve quartz and feldspar etc., and metallic ions such as calcium, magnesium, aluminum and iron ions can be effectively dissolved into the solutions, demonstrating the block removing fluids of their superior high temperature performance.