低压气井水侵伤害及解堵液体系研究与应用  

Study on and Application of a Blocking Removal System for Reservoir Damage by Water Invasion in Low Pressure Gas Wells

作　　者：廖云虎 林科雄 贾辉 罗刚 郑华安 任坤峰 LIAO Yunhu;LIN Kexiong;JIA Hui;LUO Gang;ZHENG Huaan;REN Kunfeng(Hainan Branch of CNOOC Ltd.,Haikou,Hainan 570312;Jingzhou Hanc new-technology research institute,Jingzhou,Hubei 434000)

机构地区：[1]中海石油(中国)有限公司海南分公司,海口570312 [2]荆州市汉科新技术研究所,湖北荆州434000

出　　处：《钻井液与完井液》2024年第6期824-832,共9页Drilling Fluid & Completion Fluid

基　　金：中海油南海西部上产2000万方专项“南海西部在生产油气田提高采收率技术研究”(CCL2019ZJFN1202);中海油综合性科研项目“高温高压气井增产与治理关键技术研究”(KJZH-2023-2204)。

摘　　要：南海D气田低压气井存在较为严重的水侵伤害问题,通过岩屑膨胀率实验、岩心水敏伤害实验、水锁伤害预测、岩心水侵驱替实验以及三维CT扫描分析等手段目标低压气井水侵伤害进行了研究,明确了水侵伤害的程度。通过对水侵防治剂和新型复合有机酸HWCP的性能评价及优化,结合缓蚀剂、防水锁剂和黏土稳定剂等处理剂,研制了一套适合海上低压气井水侵伤害治理的解堵液体系。研究结果表明:凝析水对低渗岩心的水敏伤害较为严重,水锁损害程度预测结果为弱~中等偏弱。储层天然岩心存在比较严重的水侵伤害现象,当驱替压力为0.5 MPa,驱替时间为180 min时,饱和地层水和凝析水的两块岩心水侵伤害率分别为59.76%和69.67%。解堵液体系具有较低的表面张力、良好的防膨效果和缓蚀性能、较强的水侵伤害解除能力,天然岩心注入水侵防治剂和解堵液后,驱替180 min后的渗透率恢复值可达100%以上。解堵工作液体系在南海D气田A9hSa井进行了现场应用,成功解除了水侵伤害,该井产气量从3.3×10^(4)m^(3)/d提升到9.0×10^(4)m^(3)/d以上,取得了良好的现场应用效果。Low pressure gas wells drilled in the gas field D in South China Sea have experienced serious formation damage by water invasion.The formation damage by water invasion was studied through laboratory experiments such as drilled cuttings swelling,core damage by water sensitivity,water block,core flooding with water invasion,as well as three dimensional CT scanning etc.With these experiments,the degree of formation damage by water invasion is understood.To deal with the formation damage by water invasion,a blocking removal fluid suitable for disposal of formation damage by water invasion encountered in offshore low pressure gas wells was developed with a selected water invasion control agent,a new compounded organic acid HWCP,a corrosion inhibitor,a water blocking removal agent and a clay inhibitor.Laboratory studies show that condensate water causes more serious water sensitive damage to cores with low permeability,while the water blocking damage by the condensate water is weak to medium.Cores taken from the reservoirs are easy to damage by water invasion;when displacing at 0.5 MPa for 180 min,two pieces of cores,one saturated with formation water and another with condensate water,have water invasion damage of 59.76%and 69.67%,respectively.The blocking removal fluid has low surface tension,good swelling inhibitive capacity,good corrosion inhibitive capacity and strong ability to relieve formation damage by water invasion.A natural core injected with the water invasion control agent and the blocking removal fluid has permeability recovery of 100%or higher after displacing for 180 min.The blocking removal fluid has been used on the well A9hSa drilled in the gas field D in South China Sea,and water invasion damage was successfully removed,the gas production of this well was increased from 3.3×10^(4)m^(3)/d to more than 9.0×10^(4)m^(3)/d,a good result of using the blocking removal fluid.

关 键 词：低压气井 水侵伤害 复合酸解堵液 水侵防治剂 现场应用 

分 类 号：TE258[石油与天然气工程—油气井工程]