摘要
特种凝胶是一种处理钻井恶性漏失的堵漏剂,它必须具备特殊的流变性才能满足封堵裂缝性及破碎性地层恶性漏失的要求。为此,用可控的HAAKE RS6000型流变仪锥板系统稳态测试了凝胶的流动曲线和黏度曲线,采用了多种经验本构模型拟合凝胶的流动曲线和黏度曲线,均获得了较高的相关系数。在此基础上对凝胶的黏弹性、黏温性以及触变性进行了研究。结果表明,黏弹性实验确定了凝胶的零剪切黏度数量级在102 Pa.s,且具有Burger模型蠕变回复曲线特征;通过密闭同轴旋转系统稳态测试凝胶的黏温性质确定了温度从室温上升到50℃时凝胶表现出轻微的升温增稠现象,当温度高于50℃时,凝胶的黏度温度曲线满足Arrhenius关系;用直观的触变环法测量了凝胶的触变性,凝胶的下行曲线始终低于凝胶的上行曲线,表明凝胶是一种剪切稀释流体,且随着温度升高,凝胶的剪切稀释作用有增强的趋势;凝胶的流变性足以满足解决裂缝性及破碎性地层恶性漏失的要求。
The special gel is of a mud loss control agent that is used to deal with severe loss,and it must has special characteristics to control severe mud loss in fractured and fragmented formations.The flow and viscosity curves of the gel are tested by HAAKERS6000 rheometer,and of which are fitted withs everal empirical constitutive models,which obtains some high coefficient of correlation.The experimental results show that in viscoelastic experiment,the quantity degree of zero shearing viscosity is 10 2 Pa.s and it has Burger model creep recovery curve characteristic,and the gel is thickened slightly when the temperature rises from room temperature to 50 ℃,the ZND gel relation of viscosity-temperature is of Arrhenius relation when the temperature is higher than 50 ℃.Furthermore,the thixotropic property of gel is measured that the downgoing curve is always lower than upgoing curve,which means the gel is a kind of shear thinning fluid and the affect of shear thinning is strengthened with higher temperature,consequently,the rheology of the gel can meet the demands of severe mud loss in fractured and fragmented formations.
出处
《钻井液与完井液》
CAS
2011年第6期4-7,91,共4页
Drilling Fluid & Completion Fluid
基金
国家科技支撑计划课题"三高气井固完井安全保障技术与装备"(2008BAB37B03)
关键词
凝胶
堵漏
流变性
蠕变回复
黏温性质
触变性
Gel
Mud loss control
Rheology
Thixotropic recovery
Viscosity-temperature property
Thixotropy
