摘要
酸化是超低渗油藏最有效的增注措施之一,但由于储层物性差、非均质性强等问题,造成目前常规酸化措施普遍具有施工周期长、有效率低、有效作用距离短等不足,且酸化过程中存在指进现象和储层二次伤害。针对这一问题,选取鄂尔多斯盆地环江油田三叠系超低渗油藏为研究对象,提出了在线分流酸化技术,并配套研制了一种多元缓速螯合酸COA-1S和一种新型的水溶性分流剂COA-1P。通过室内评价实验和在线分流酸化模拟实验,发现该技术在缓速性、配伍性、水溶性、螯合能力和暂堵功能等方面均显著优于常规酸化;现场先导性实验结果表明,酸化后剖面吸水均匀程度从28. 5%上升至50. 9%,视吸水指数增加2倍左右,降压增注效果显著;同时,该技术还具有"不停井、不泄压、不动管柱、不返排"的特点,简化了常规分流酸化工序、降低了安全环保风险,是一种能够很好地适应超低渗油藏特征的酸化增注技术。
Acidification is one of the most effective injection stimulation methods in the ultra-low permeability reservoirs.These reservoirs however,are usually characterized with poor physical property and high heterogeneity,leading to an unnecessarily long operation period,low efficiency,and insufficient effectively-operating distance for conventional acidification measures,as well as fluid fingering and secondary damage to the reservoir during the acidizing process.In this regard,we studied the Triassic ultra-low permeability reservoir in the Huanjiang oilfield,Ordos Basin,proposed the online diversion acidizing technology and developed COA-1S achelating acid system and COA-1P,a new water soluble diversion agent.After a large number of laboratory experiments,we found that,compared with the conventional acidizing method,this new technology is more retardant,compatible,water-soluble,and better at chelating and temporary blocking.In-situ pilot test has shown that the homogeneity of the water absorption profile has increased from 28.5 % to 50.9 %,that is,the water injectivity index doubled after the implementation of this technology.Meanwhile,its characteristics of “zero well shut-off and depressurization,zero impact on the tubing strings,and zero flow-back”,allows this technology to simplify the operation process of diversion and acidification,reduce the risks in security and environment protection,and thus can be recommended as a new acidification technology for stimulating injection of wells in the ultra-low permeability reservoirs.
作者
邓志颖
张随望
宋昭杰
王尔珍
杨乾隆
吴文超
Deng Zhiying;Zhang Suiwang;Song Zhaojie;Wang Erzhen;Yang Qianlong;Wu Wenchao(National Engineering Laboratory of Exporting and Development of Low-Permeability Oil/Gas Fields,Xi’an,Shannxi 710018,China;Oil & Gas Technology Research Institute of Chanqing Oilfield Branch Company,PetroChina,Xi’an,Shannxi 710018,China;No.10 Oil Production Plant of Changqing Oilfield Branch Company,Qingyang,Gansu 745100,China;Shaanxi Mingde etroleum Technology Co.,Ltd.,Xi’an,Shaanxi 710018,China)
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2019年第2期430-435,共6页
Oil & Gas Geology
基金
国家科技重大专项(2016ZX05023-005)
关键词
螯合酸
分流剂
降压增注
超低渗油藏
在线分流酸化
chelating acid
diversion agent
depressurization and injection stimulation
ultra-low permeability reservoir
diversion acidification online
