第四系天然气藏储层物性参数测井解释模型

以柴达木盆地东部台南第四系松散未成岩生物气藏为例 ,研究建立该类储层物性参数测井解释模型的方法。主要包括 :(1)应用“JD 5 81”常规测井资料 ,通过定量计算对声波测井进行了压实、泥质及含气影响的校正 ,建立了孔隙度测井解释模型 ,探索性地提出声波测井曲线天然气影响的定量校正方法 ;(2 )根据毛管理论 ,综合应用毛管压力曲线、岩石物性、岩性分析及测井资料建立了渗透率测井解释模型。研究结果表明 ,利用电阻率曲线对声波测井进行天然气影响的定量校正方法是可行的 ,该方法提高了气藏孔隙度声波测井解释模型的精度 ,实现了应用“JD 5 81”常规测井资料即可进行储层孔隙度参数评价的研究。储层微观孔隙结构参数孔喉半径均值的主要影响因素是岩石比表面及孔隙度 ,综合利用孔隙度与岩性测井曲线可以较为准确地计算该参数 ,这为储层渗透率参数的评价奠定了基础。

Logging interpretation model for reservoir physical parameter in the Quaternary natural gas reservoir

Taking Quaternary unconsolidated biogas reservoir of Tainan area in Eastern Qaidam basin as an example, the building methods of logging interpretation model for physical parameters of this kind of reservoir were studied. The JD 581 conventional log data were used to establish the porosity logging interpretation model by making compaction, correction of shale content and gas bearing influence on acoustic logging and quantitative calculation. A quantitative correction method for gas influence on acoustic logging was developed. According to the capillary theory, the capillary pressure curve and log data were applied to establish the permeability logging interpretation model. The interpretation accuracy was improved much more than that of the conventional method. It is a feasible method to make a quantitative correction of natural gas effect on the acoustic log by the use of the resistivity log. It can improve the accuracy of acoustic logging interpretation model for gas reservoir porosity and implement the evaluation research on the reservoir porosity parameters by applying the JD 581 conventional log data. The rock specific surface and porosity primarily influence the mean radius of pore throat. This kind of parameters for the reservoir micro pore structures can be calculated accurately by the integration of porosity and lithologic log. This model can provide a solid foundation for evaluating the reservoir permeability parameters.