玛河气田盐水泥浆侵入条件下双侧向测井电阻率校正方法

Dual laterolog resistivity correction method under the conditions of salt mud invasion for Mahe gas field

文中深入分析了玛河气田盐水泥浆侵入地层的时间推移双侧向测井响应特征及规律,以测试时间推移测井资料为基础,提出结合时间推移测井和台阶模型进行泥浆侵入电阻率校正的方法。该方法首先利用台阶模型对测试层段浸泡5d内的及时双侧向测井资料进行校正处理;在考虑含油性、物性、泥浆滤液矿化度Cmf/地层水矿化度Cw的情况下,对校正后的电阻率与完井深侧向电阻率进行统计分析,确定出相应的校正系数;最后对玛河气田4口井进行了校正处理。结果表明:用本文方法校正后的电阻率计算的含水饱和值与岩石密闭取心的实测含水饱和值十分吻合,证实了该方法的可行性,经过泥浆滤液侵入校正后气层的含气饱和度提高了13%,表明经校正后的含气饱和度参数更加准确,可用于储量计算。

The time-lapse dual laterolog response characteristics and laws for the formations with salt mud invasion in Mahe gas field were intensively analyzed in this paper. Based on testing and time-lapse logging data,the method of resistivity correction for formations with mud invasion was proposed by integrating time-lapse logging with the step model. Firstly the dual laterolog data for the testing intervals soaked for 5 days were corrected using the step model. Secondly,by taking oil-bearing properties,petophysics and Cmf/Cw into account,the statistical analysis of corrected resistivity and deep-laterolog resistivity of the drilled well,and the corresponding correction coefficients were determined. Finally,4 wells were corrected in Mahe Gas field. The results showed that water saturation calculated using resistivity corrected by this method perfectly matched that of pressure coring,so the feasibility of the method was proved. The gas saturation for the gas interval was increased by 13%,and gas saturation parameters were more accurate after salt mud invasion correction and the parameters could be used to calculate oil reserve.