基于防气窜失重预测模型的胶乳水泥浆参数影响规律分析  

Influence Rule Research on Parameter Analysis Based on Anti-gas Channeling Prediction Model for Pressure Reduction of Latex Cement Slurry

作　　者：刘仍光 LIU Rengguang(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 102206,China;SINOPEC Petroleum Engineering Technology Research Institute,Beijing 102206,China)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室 [2]中国石化石油工程技术研究院

出　　处：《钻采工艺》2021年第6期7-12,共6页Drilling & Production Technology

基　　金：国家自然基金联合基金“海相深层油气富集机理与关键工程技术基础研究”(编号:U19B6003)。

摘　　要：候凝期间,水泥浆失重易导致井筒—地层压力平衡失衡,引发早期环空气窜。掌握水泥浆失重趋势与规律是建立防气窜方法及缓解环空带压现象的重要途径。基于静胶凝强度的传统失重预测模型难以表征水泥水化过程中复杂的物理化学变化,导致拟合失真,文章通过大规模物理模拟实验,建立了可综合考虑水泥浆性能、地层及井筒条件的无量纲失重预测模型,对相关参数的影响规律进行进一步研究。以苯丙胶乳水泥浆体系为研究对象,以浆体静液柱压力衰减率为主要目标函数,通过敏感性分析,开展参数影响规律研究。结果表明,高温与深井可导致水泥浆快速失重,而较高的气压与胶乳加量可缓解失重趋势;压力衰减率对温度变化最敏感,井筒深度次之,底部气压与胶乳加量则影响较小。在井筒及地层条件无法改善的前提下,提出了以优化胶乳加量、气窜评价实验与环空加压为主的防气窜技术措施。研究成果对于指导防气窜固井施工具有一定的借鉴与参考意义。While waiting on cementing,the cement slurry weight loss can easily lead to the unbalance of wellbore and formation pressure,resulting in early annular gas channeling.Studying the weight loss process is an important means for establishing anti-gas channeling method and reducing gas channeling risk.Due to the complex physical and chemical changes during cement hydration process,conventional pressure reduction prediction models based on static gel strength theory produce distorted fits.Hence,a new dimensionless prediction model considering the slurry performance,formation and wellbore conditions has been established through a large-scale physical experiment,and the effects of relevant parameters require further investigation.In this study parameters were investigated through sensitivity analysis with a styrene-acrylic latex cement slurry system as the study object.The results showed that a high temperature and a deep wellbore depth could cause the cement slurry to lose weight rapidly,whereas a high gas pressure and a high latex content could alleviate the weight loss trend.Weight loss rate was the most sensitive to changes in temperature,followed by wellbore depth,gas pressure and latex content.On the premise that the wellbore and formation conditions cannot be improved,the research results of anti-gas channeling technical measures,which mainly include the optimization of latex dosage,gas channeling evaluation experiment and annular pressure,are of certain reference significance for guiding anti-gas channeling cementing.

关 键 词：固井 失重 防气窜 预测模型 敏感性分析 影响规律 

分 类 号：TE256[石油与天然气工程—油气井工程]