石油钻采工艺2024，Vol.46Issue(1)：89-96,8.DOI:10.13639/j.odpt.202310044
海上稠油冷采井多元热流体吞吐堵塞机理及活性油解堵
Blocking mechanism of multicomponent thermal fluid huff-and-puff and unblocking with surfactant oil in offshore heavy oil cold production wells
摘要
Abstract
In Nanpu Oilfield of the Bohai Sea,heavy oil cold production wells are produced using multicomponent thermal fluid huff-and-puff with temperatures below 150℃.However,severe reservoir plugging occurs after huff-and-puff,leading to decreased or halted oil production.Through laboratory experiments on the causes of reservoir plugging,it was clarified that the viscosity of heavy oil increases after emulsification with injected water,enhancing the liquid resistance effect of droplets(aggregates)passing through pore throats,thereby increasing the"startup pressure".When the displacement pressure in the emulsification zone is lower than the startup pressure,reservoir plugging occurs.Experiments were conducted on dilution and viscosity reduction using an surfactant oil unblocking system composed of fatty alcohol polyoxyethylene ether sodium hydroxypropyl sulfonate,dodecyl trimethylammonium salt and sodium succinesulfonate in a molar ratio of 3∶1∶1.After adding 2%of this system,the diluted oil and the heavy oil containing 50%water were mixed according to the dilution-heavy ratio of 2∶8.Compared with the heavy oil containing 50%water(7 698 mPa·s),the viscosity was reduced by 98.5%,and the interfacial tension was reduced by 74.5%compared with that of the heavy oil and water(21.86 mN/m).In addition,the starting pressure of the emulsification zone was reduced to 1.86 MPa.Through numerical simulation,the injection volume of diluted oil and the surfactant concentration were optimized,predicting that injecting 2 000 m3 of diluted oil and adding 2%of the surfactant to the first 1 000 m3 of diluted oil could achieve unblocking in the emulsification zone,resulting in a net oil increase of 4 016.5 m3.Field tests show that after unblocking a well,the daily oil production reached 5.9 m3/d,with a cumulative oil increase of 980.7 m3,indicating a significant unblocking and production increase effect.This technology provides a guidance for plugging removal and increasing oil production in offshore heavy oil cold production wells.关键词
稠油/乳化/液阻效应/启动压力梯度/活性油/解堵/海上油田Key words
heavy oil/emulsification/liquid resistance effect/startup pressure gradient/surfactant oil/unblocking/offshore oil fields分类
能源科技引用本文复制引用
刘义刚,白健华,孟祥海,邹剑,张伟,韩晓冬,张梦琪,钟立国..海上稠油冷采井多元热流体吞吐堵塞机理及活性油解堵[J].石油钻采工艺,2024,46(1):89-96,8.基金项目
国家科技重大专项"渤海油田高效开发示范工程"(编号:2016ZX05058) （编号:2016ZX05058）
中海油重大科技项目"海上稠油热采有效开发技术"(编号:KJGG2021-0600). （编号:KJGG2021-0600）
