SZ36-1油田注聚井和聚驱受益油井堵塞物的组成及成因对比分析  

Comparisons of component and formation mechanism of blockages in polymer flooding injection well and response well in SZ36-1 oilfield

作　　者：邹剑 陈华兴 高尚 赵顺超 刘长龙 冯于恬 Zou Jian;Chen Huaxing;Gao Shang;Zhao Shunchao;Liu Changlong;Feng Yutian(Tianjin Branch Company, CNOOC China Limited, Tianjin, China)

机构地区：[1]中海石油(中国)有限公司天津分公司

出　　处：《石油与天然气化工》2019年第5期77-82,共6页Chemical engineering of oil & gas

基　　金：中海石油(中国)有限公司天津分公司“十三五”总公司重大专项子课题“锦州9-3及绥中36-1油田Ⅰ期储层深部伤害机理”(CNOOC-KJ 135 ZDXM 23LTD TJ 02)

摘　　要：随着注聚开发的进行,SZ36-1油田的部分受益油井中出现了含聚堵塞物,导致了产能下降。采用多种表征手段对比分析了注聚井和受益油井堵塞物的组成,发现在所采集到的样品中,受益油井堵塞物以无机垢为主,无机垢/有机垢质量比为4.0~5.5,远大于注聚井的0.25~0.75,受益油井和注聚井中无机垢分别主要为Fe2O3和CaCO3,有机垢则均为部分水解聚丙烯酰胺。对比分析了注聚井和受益井中无机垢和有机垢的成因,重点分析了受益油井堵塞物的成因:在受益油井的近井地带,酸化作业后的残酸含有大量Fe^3+,与聚合物驱替液相遇后,液体pH值上升,形成Fe(OH)3沉淀,氧化后即形成Fe2O3无机垢;驱替液中降解后的聚合物在酸性条件下会选择性地与Fe^3+通过配位作用,形成水不溶的聚合物交联物,即形成有机垢。分析结果可为注聚井和注聚受益油井的针对性解堵以及预防注聚受益油井堵塞提供依据。As the development of polymer flooding, polymer contained blockage was appeared and the oil well production was decreased in SZ36-1 oilfield. In this paper, the components of blockage in polymer flooding injection well (PFIW) and response well (PFRW) were compared by several characterization methods firstly. The inorganic scale was the main substance in collected samples, the mass ratio of inorganic scale and organic scale in PFRW blockage was 4.0-5.5, which was much larger than that of PFIW (0.25-0.75). The inorganic scale mainly was Fe 2O 3 in PFIW and and CaCO 3 in PFIW, and the organic scale was partially hydrolyzed polyacrylamide. Then, the formation mechanisms of inorganic scale and organic scale in PFRW and PRIW were investigated, especially the formation mechanism of blockage in PFRW was studied. In the area which was close to the response oil well, there was a lot of Fe^3+ in residual acid solution after the acidification operation, and when it was mixed with polymer flooding solution, Fe(OH) 3 was formed as the pH increased and Fe 2O 3 blockage was formed after the oxidation. In addition, the cross-linked polymer blockage which was organic scale, was formed by the selective coordination between polymer and Fe^3+ when the degraded polymer was mixed with Fe^3+ solution in acid condition. The results in this paper are helpful for the targeted removal of plugging in PFRW or PRIW and preventive blockage in PRIW.

关 键 词：渤海油田 聚合物驱油 注聚受益油井 含聚堵塞物 

分 类 号：TE53[石油与天然气工程—油气田开发工程]