水泥环二界面胶结机理及胶结强度提高方法  

Bonding Mechanism of the Second Interface of Cement Sheath and Methods to Improve Bond Strength

作　　者：徐璧华 钱思蓓 罗伟强 刘世彬 袁彬 XU Bihua;QIAN Sibei;LUO Weiqiang;LIU Shibin;YUAN Bin(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu,Sichuan 610500,China;CNPC Ch-uanqing Drilling Engineering Company Limited,Chengdu,Sichuan 610051,China)

机构地区：[1]油气藏地质及开发工程国家重点实验室,四川省成都市610500 [2]中国石油川庆钻探工程有限公司

出　　处：《钻采工艺》2025年第2期200-205,共6页Drilling & Production Technology

基　　金：国家自然科学基金项目“CCUS地质封存井磷铝酸盐水泥固井提高水泥环耐碳化腐蚀机理研究”(编号:52204014);四川省青年基金项目“废弃高温气藏注超临界CO_(2)开采地热井水泥环劣化机理及控制研究”(编号:2023NSFSC0926)。

摘　　要：水泥环二界面受冲洗效率、地质条件等因素影响,使其成为水泥环实现层间封隔最薄弱的部分。目前水泥环二界面的胶结机理仍未被揭示,导致其胶结质量未得到有效提高。针对该问题文章首先分析了二界面胶结破坏形式;然后通过研究二界面胶结带宽度、微观特征、物相组成,揭示了二界面胶结机理,分析了胶结影响因素;提出了提高二界面胶结强度的方法。研究表明:胶结带宽度一般大于100μm,疏松多孔,氢氧化钙、水化硅酸钙含量和强度均低于水泥环本体;机械咬合和化学胶结作用为水泥环提供了胶结力,井壁越粗糙咬合力越大;水泥浆水化越充分化学胶结力越大;胶结带宽度越小,结构越致密,胶结强度越大;地层渗透率和压力越高机械咬合力越大;地层温度越高化学胶结力越大。通过提高冲洗效率和加入膨胀剂材料能够增加界面机械咬合,同时减小胶结带宽度,有效提高胶结强度。The second interface of cement sheath is affected by factors such as flushing efficiency and geological conditions,which makes it the weakest part of cement sheath to achieve interlayer isolation.However,at present,the bonding mechanism of the second interface has not been revealed,which leads to the failure to effectively improve the bounding quality of the second interface.Aiming at this problem,the bond failure form of the second interface is analyzed firstly.Then,by studying the width,microscopic characteristics and phase composition of the second interface bonding zone,the bonding mechanism of the second interface is revealed.Then on this basis,the influencing factors of bonding are analyzed.Finally,the method to improve the bond strength of the second interface is put forward.The research shows that the width of the bonding zone is generally greater than 100μm,which is porous and loose,and the content and strength of calcium hydroxide and calcium silicate hydrate are lower than that of the cement sheath body.Mechanical bite and chemical glue provide bonding force for cement sheath.The coarser the formation,the greater the biting force and the more sufficient the hydration,the greater the chemical bonding force.The smaller the width of the zone,the denser the structure and the greater the bond strength.The greater the formation permeability and pressure,the greater the mechanical bite force;The higher the formation temperature,the greater the chemical bonding force.By improving the flushing efficiency and adding expansive agent materials,the mechanical bite force can be increased,while the width of the bonding zone can be reduced,and the bond strength can be effectively improved.

关 键 词：水泥环 二界面 胶结带 胶结特征 胶结强度 

分 类 号：TE256[石油与天然气工程—油气井工程]