1.Research Center,China United Coalbed Methane Company Limited,Beijing ,China;2.School of Petroleum Engineering, China University of Petroleum-East China,Qingdao ,China

为了解决煤岩表面亲水润湿性差导致的煤层段固井质量差的难题，优选了不同类型的表面活性剂和硅烷偶联剂作为煤体表面润湿改性剂，试验研究了对煤体表面的润湿改性对界面胶结强度等改善效果，并测试评价了对水泥浆流变性能、凝结时间、抗压强度等影响规律。研究结果表明：表面活性剂、硅烷偶联剂均可有效改善煤体表面亲水润湿性；但硅烷偶联剂却不会提高煤层界面胶结强度，其原因是硅烷偶联剂水解产生Si-OH基团吸附在水泥颗粒表面形成包裹层，阻止水泥与水进一步接触，对水泥有较强的缓凝副作用，不利于煤层界面胶结；含醚、硫酸根的阴表面活性剂对水泥没有缓凝副作用，与水泥浆相容性好，能够显著提高煤层界面胶结强度达1.71 MPa，其最优浓度为0.3%。

In order to solve the problems of poor well cementation quality at the seam section caused by the poor hydrophilic wettability of coal surface,different type surfactants and silane coupling agents were optimized as the wettability modifier of coal surface. The wettability modification,interface bonding strength and other improved effects of coal surface were tested and studied. The test evaluation was conducted on the rheological performance,setting time,compressive strength and other influence law of the cement slurry with wettability modifer.The study results showed that the surfactant and silane coupling agent both could effectively improve the hydrophilic wettability of coal surface,but the silane coupling agent could not improve the interface bonding strength of the coal. Because the hydrolysis of the silane coupling agent would produce the Si-OH groups,which could adsorb on the cement partical surfaces to form the wrapping layer,and stopping the further contract between the cement and water,the silane coupling agents would have a high retarder effect and would not be favorable to the interface bonding of the seam. The anionic surfactant with the ether and sulfate would have no retarder side effect to the cement,and a good compatibility with the cement slurry.So that the anionic surfactant could obviously improve the interface bonding strength (1.71 MPa) of the seam and the optimum concentration of surfactant was optimized as 0.3 %.