摘要
低渗透储层常规水驱后残余油以分散状态附着在储层岩石表面,提高驱油效率的难点是破除或减弱吸附力剥离残余油膜。通过光电子能谱分析(XPS)试验方法定量评价离子交换/吸附及差异,通过石英晶体微天平(QCM-D)方法精确测定原油中特征极性组分在岩石表面吸/脱附量,通过原子力显微镜方法定量测量油膜在岩石表面的黏附力和油膜厚度,提出通过离子匹配和离子交换提高水驱油效率的新方法,并以吉林Q60储层为例进行驱油试验和现场先导试验。结果表明:岩石表面的Ca^(2+)与水溶液中的Na^(+)可发生大幅度离子交换,高岭石、绿泥石、石英3种矿物表面离子交换作用更加明显;通过离子交换作用后,带有—COOH、—C_(6)H_(5)和—CH_(3)极性官能团的沥青质分子(C_(5)Pe、BisA、PAP)在亲水、疏水岩石表面的脱附量均有增加;相同质量分数情况下溶液、原油与岩石表面的界面张力从小到大的顺序是NaCl溶液、Na_(2)SO_(4)溶液、CaCl_(2)溶液;Na^(+)等一价离子和Ca^(2+)等二价离子交换作用后,岩石表面水膜厚度增加,油膜厚度减小,可以实现油膜的有效剥离。通过调整Q60储层注入水离子组成,室内驱油试验表明,驱油效率可提高10%以上,现场先导试验取得初步效果,验证离子匹配水驱提高采收率机制,有望为低渗透油藏的增产提供新的途径。
After conventional water flooding in low-permeability reservoirs, a large number of residual oil films are attached to the rock surface of the reservoir, which restricts the final recovery of water flooding. In this paper, ion exchange/adsorption and differential quantitative evaluation are evaluated by means of photoelectron spectroscopy(XPS). Then adsorption/desorption amount of characteristic polar components in crude oil on rock surface is accurately measured by quartz crystal microbalance(QCM-D). Additionally, the adhesion force and thickness of oil film on rock surface are quantitatively measured by atomic force microscope. The principle of improving water flooding efficiency through ion matching and ion exchange is put forward. Taking Jilin Q60 reservoir as an example, the ion matching oil displacement experiment is carried out to verify the mechanism of ion matching EOR. The research shows that Na+is more easily absorbed on the surface of various minerals than Ca^(2+), and Ca^(2+)on the rock surface can have a large range of ion exchange with Na+in aqueous solution, especially on the surface of kaolinite, chlorite and quartz. After ion exchange, the desorption amount of asphaltene molecules(C5Pe, BisA, PAP) with —COOH, —C6H5and —CH3polar functional groups on hydrophilic and hydrophobic rock surfaces increase. On the hydrophilic rock surface, the desorption amount of asphaltene molecule with carboxyl group(C5Pe) increases the most after ion exchange with low salinity water. On the hydrophobic rock surface, the desorption amount of asphaltene molecule(BisA) with symmetrical alkyl chain increases the most after ion exchange. At the same concentration, the order of interfacial tension between solution, crude oil and rock surface from small to large is NaCl solution, Na_(2)SO_(4)solution and CaCl_(2) solution, respectively. After the exchange of monovalent ions such as Na+and divalent ions such as Ca^(2+), the thickness of water film on the rock surface increases and the thickness of oil film decreases, which result in effective stripping of oil film. By adjusting the composition of injected water ions in Q60 reservoir, the oil displacement experiment shows that the oil displacement efficiency can be improved by more than 10 percentage points. The pilot test has achieved preliminary results and verified the mechanism of enhanced oil recovery.
作者
伍家忠
韩海水
王秉合
陈兴隆
WU Jiazhong;HAN Haishui;WANG Binghe;CHEN Xinglong(State Key Laboratory of Enhanced Oil Recovery,Beijing 100083,China;Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;Research Institute of Petroleum Exploration&Development,Yumen Oilfield,PetroChina,Jiuquan 735019,China)
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2023年第1期116-124,共9页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家重大专项课题(2017ZX05013-003)
国家自然科学基金项目(21872152)
中国石油天然气股份有限公司项目(2019A-0910,2021DJ1302)。
