疏水化聚乙二醇/钾离子体系提高页岩稳定性机理  

Mechanism of shales stabilization by hydrophobized poly(ethylene glycol)/K+in water-base drilling fluids

作　　者：VILLABONA-ESTUPIÑAN Santiago de ALMEIDA RODRIGUES JUNIOR Jorge de ABREU Carolina Ferreira NASCIMENTO Regina Sandra Veiga VILLABONA-ESTUPIÑAN Santiago;de ALMEIDA RODRIGUES JUNIOR Jorge;de ABREU Carolina Ferreira;NASCIMENTO Regina Sandra Veiga(Colombian Petroleum Institute-Ecopetrol S.A.,Freeway via Piedecuesta Km 7,Bucaramanga 681011,Colombia;Federal University of Rio de Janeiro,Institute of Chemistry,Pólo de Xistoquímica,Hélio de Almeida St.,40,University City,Rio de Janeiro 21941-614,Brazil)

机构地区：[1]哥伦比亚石油研究所,布卡拉曼加681011,哥伦比亚 [2]里约热内卢联邦大学化学研究所,里约热内卢21941-614,巴西

出　　处：《石油勘探与开发》2021年第3期620-629,共10页Petroleum Exploration and Development

摘　　要：通过室内实验研究了疏水化聚乙二醇(PEG)/K^(+)体系抑制页岩水化的作用机理。通过岩屑热滚分散实验、膨润土性能测试和接触角测量,发现抑制剂体系的抑制能力随着接触角的增加和PEG浓度的增加而增强。改进岩屑热滚分散实验表明抑制剂并未通过热活化钻井液乳化机理(TAME)机制发生作用。通过吸附量、傅立叶变换红外光谱(FT-IR)、X射线衍射(XRD)图谱和热重分析(TGA)研究了PEG/K^(+)体系与黏土样品的相互作用,吸附等温线分析表明K^(+)的存在增加了PEG对黏土表面的亲和力。FT-IR光谱、热重和微商热重分析证明,PEG的吸附可以减少黏土的含水率,即抑制性良好;XRD图谱分析K^(+)的存在使PEG的插层仅为一层,且连接在PEG链上的疏水尾增强了抑制水化的能力。最后采用添加PEG/K^(+)的水基钻井液进行了岩屑热滚分散实验,验证了PEG/K^(+)体系的抑制性能。The mechanism of the hydrophobized poly(ethylene glycol)(PEG)/K^(+)system inhibiting shale hydration was studied by laboratory experiment.The inhibition performance was evaluated through cuttings hot-rolling dispersion,bentonite inhibition and contact angle tests.The inhibition became stronger as contact angle and PEG concentration increased.A modified cuttings hot-rolling dispersion experiment suggested that these molecular systems did not act through the thermally activated mud emulsion(TAME)mechanism.The interaction of the PEG/K^(+)with clay samples was investigated through adsorption studies and by Fourier transform infrared spectroscopy(FT-IR),X-ray diffraction(XRD)and thermogravimetric analysis(TGA).The adsorption isotherms showed that the presence of K^(+)increased the PEG affinity for the clay surface.This inhibition effect was accompanied by a reduction of the bentonite hydration with PEG adsorption,evidenced by FT-IR,TGA and differential thermogravimetric(DTG)curves.XRD patterns were conclusive in showing that the presence of K^(+)ions limited the expansion of the clay interlamellar region to only one PEG layer,and the terminal hydrophobic segments of the PEG chains turned out to be determinant in enhancement of the inhibitory efficiency.The cuttings hot-rolling dispersion was carried out on water-base drilling fluid with PEG/K^(+),which proved the inhibition performance of PEG/K^(+)in oil field drilling.

关 键 词：页岩水化 水基钻井液 水化抑制剂 聚乙二醇 页岩稳定性 

分 类 号：TE254[石油与天然气工程—油气井工程]