高矿化度盐水泥浆条件下常规感应测井响应变化规律及其校正方法的研究

【作者】 高举纲；

【导师】 夏宏泉； 肖承文；

【作者基本信息】 西南石油学院 ， 地球探测与信息技术， 2002， 硕士

【摘要】 感应测井视电阻率（或视电导率）不可避免地要受到泥浆侵入的影响。泥浆侵入深度受诸多因素的影响，如地层孔隙度、渗透性、孔隙流体性质及粘度、泥浆性质及浸泡时间、井筒与地层间的压差等，特别是在盐水泥浆条件下，气层及渗透性好的地层会形成较深的泥浆侵入带，它对视电阻率曲线的影响更加严重，造成视电阻率明显降低。一般来说，泥浆侵入带是影响感应测井读数的最重要的环境因素，其校正也是比较困难的，迄今仍是电法测井和测井数据处理中的重要研究课题之一。 本文结合部361项目《大北、吐北地区低孔低渗岩屑砂岩测井响应机理和测井相研究》，主要就库车坳陷北部山前的克拉苏构造带和依奇克里克构造带的低孔低渗砂岩储层的泥浆侵入特征和常规感应测井响应变化规律及其校正方法展开研究。首先分析了低孔低渗地层的泥浆侵入特性和泥浆滤液动态侵入模型以及感应测井动态响应计算；在此基础上详细研究了泥浆侵入剖面及其电阻率测井响应；开展了高矿化度盐水泥浆条件下常规感应电阻率测井响应变化规律及其校正方法的探索与研究，并编制了相应的常规感应电阻率测井曲线的泥浆侵入影响校正程序。 最后，通过具体实例分析，对文中所提出的校正方法进行了验证。从大北1井的感应电阻率测井曲线校正处理结果可以看出，常规感应电阻率测井曲线的泥浆侵入校正方法是正确可行的。对于KL2气田，根据实际情况，我们用距气水界面高度、孔渗综合指数的乘积H×K／Φ^1/2作为一种新参数来拟合含气饱和度S_G，由阿尔奇公式反推出地层电阻率Rt，来对常规感应电阻率测井曲线进行泥浆侵入校正。将毛管压力曲线确定的含气饱和度与上述方法拟合的含气饱和度进行对比，二者一致性好，这说明使用上述这种方法对常规感应测井进行泥浆侵入校正是切实有效的。更多还原

【Abstract】 The apparent resistivity (conductivity) of induction log is inevitably influenced by invasion of mud which are affected by many factors, such as: porosity of formation, permeability, fluid characteristic of the pore, viscosity, mud property, invasion time, difference between well and formation, especially under the condition of using brine mud, in gas stratum and permeable layer, the influence of invasion will be more and more serious and the apparent resistivity will lower obviously. In general, mud invasion zone is the most important environmental factor, at mean time, its correction is difficult. It is one of the important subjects in resistivity log and log data process until now.Combine with 361 project of CNPC-study of responding principle and logging phase of sandstone formation in dabei, tubei area? the article try to do some research on characteristics of mud invasion and responding regulation of induction log and its correction methods. Firstly, analyse characteristics of mud invasion of low porosity and low permeability formation, study dynamic model of mud filtrate and calculation of dynamic response of induction log; On the base of it, dissect mud invasion profile and its log response; develop the research of response regulation of common induction log under the high mineral concentration brine mud and its correction methods, establish proper correction procedure of mud invasion for common induction log.Finally, through example analysis, verify the correction methods which we put forward. From the corrected results of induction log curves of dabei 1 well, we know our correction methods are right and feasible. As to KL2 oilfield, use H(height to the surface of gas and water) ^Kl 0 (square root of quotient of permeability and porosity) to calculate saturation of gas, then from Archie’sformulas, formation resistivity is figured out, thus also can correct mud invasion of induction log. Compare the gas saturation which are defined by capillary pressure curves to the gas saturation that are computed by , two results almost coincide. It also mean effectiveness of the new method of mud invasion correction.更多还原