Eco-friendly calcium alginate microspheres enable enhanced profile control and oil displacement  

作　　者：Xiao-Han Zhang Chang-Jing Zhou Yuan-Xiang Xiao Bo Hui Yong-Gang Xie Yu-Bin Su Xin-Ru Li Jie Huang Mao-Chang Liu 

机构地区：[1]International Research Center for Renewable Energy,State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an,710049,Shaanxi,PR.China [2]Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs,School of Petroleum Engineering,Xi'an Shiyou University,Xi'an 710065,Shaanxi,PR.China [3]Oil&Gas Technology Research Institute,Changqing Oilfield Branch Company,PetroChina,Xi'an,710021,Shaanxi,PR China [4]Suzhou Academy of Xi'an Jiaotong University,Suzhou,215123,Jiangsu,PR China

出　　处：《Petroleum Science》2024年第3期1928-1943,共16页石油科学（英文版）

基　　金：supported by the Open Fund of Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs(No.KFJJ-TZ-2020-2);the National Natural Science Foundation of China(No.52104030);the Key Research and Development Program of Shaanxi(No.2022 KW-35);the China Fundamental Research Funds for the Central Universities。

摘　　要：Polymer microspheres(PMs),such as polyacrylamide,have been widely applied for enhanced oil recovery(EOR),yet with environmental concerns.Here,we report a microfluid displacement technology containing a bio-based eco-friendly material,i.e.,calcium alginate(CaAlg)microspheres for EOR.Two dominant mechanisms responsible for EOR over Ca Alg fluid have been verified,including the microscopic oil displacement efficacy augmented by regulating capillary force(determined by the joint action of interfacial tension and wettability between different phases)and macroscopic sweep volume increment through profile control and mobility ratio reduction.This comprehensive effectiveness can be further impacted when the CaAlg microsphere is embellished ulteriorly by using appropriate amount of sodium dodecyl sulfonate(SDS).The core flooding and nuclear magnetic resonance(NMR)tests demonstrate that CaAlg-SDS microsphere can balance the interphase property regulation(wettability alteration and IFT reduction)and rheology properties,enabling simultaneous profile control and oil displacement.Excessive introduction of SDS will have a negative impact on rheological properties,which is not favored for EOR.Our results show that the involvement of 4-m M SDS will provide the best behavior,with an EOR rate of 34.38%.This cost-effective and environmentally-friendly bio-microspherebased microfluidic displacement technology is expected to achieve“green”oil recovery in future oilfield exploitation.

关 键 词：Calcium alginate microspheres WETTABILITY Interfacial tension RHEOLOGY VISCOELASTICITY Enhanced oil recovery(EOR) 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]