地球物理学进展 ›› 2016, Vol. 31 ›› Issue (4): 1670-1677.doi: 10.6038/pg20160435

• 应用地球物理学Ⅰ • 上一篇    下一篇

有效介质对称导电理论在复杂泥质砂岩中应用基础研究

唐晓敏1,2, 宋延杰1,2, 刘玥1, 王超1, 于宝1,2, 李鹏举1,2, 张庆国1,2   

  1. 1. 东北石油大学地球科学学院, 大庆 163318;
    2. 非常规油气成藏与开发省部共建国家重点实验室培育基地, 大庆 163318
  • 收稿日期:2016-01-09 修回日期:2016-05-30 出版日期:2016-08-20 发布日期:2016-08-20
  • 通讯作者: 宋延杰,男,1963年生,黑龙江五常人,博士生导师,教授,主要从事测井方法与资料解释研究.(E-mail:syj1963@263.net) E-mail:syj1963@263.net
  • 作者简介:唐晓敏,女,1981年生,黑龙江齐齐哈尔人,博士研究生,讲师,主要从事测井方法与资料解释研究.(E-mail:txmdqpi@163.com)
  • 基金资助:

    国家自然科学基金项目(41274110)资助.

Basic research on application of symmetrical effective medium conduction theory in complex shaly sands

TANG Xiao-min1,2, SONG Yan-jie1,2, LIU Yue1, WANG Chao1, YU Bao1,2, LI Peng-ju1,2, ZHANG Qing-guo1,2   

  1. 1. College of Geo-science, Northeast Petroleum University, Heilongjiang Daqing 163318, China;
    2. Accumulation and Development of Unconventional Oil and Gas, State Key Laboratory Cultivation Base Jointly-constructed by Heilongjiang Province and the Ministry of Science and Technology, Heilongjiang Daqing 163318, China
  • Received:2016-01-09 Revised:2016-05-30 Online:2016-08-20 Published:2016-08-20

摘要:

复杂泥质砂岩储层的饱和度评价一直是测井解释领域亟待解决的难点和热点问题,基于并联导电理论和阿尔奇公式建立的导电模型扩展性有限,在一定程度上限制了该类模型扩展描述孔隙结构更复杂的高泥高钙砂岩储层的导电规律,而有效介质对称导电理论能很好地描述复杂泥质砂岩储层导电规律,具有很好的应用前景,但仍需深入研究.首先针对纯砂岩,使用有效介质对称导电理论建立纯砂岩有效介质对称导电模型,理论分析与实验研究表明纯砂岩有效介质对称导电模型优于阿尔奇方程,不但可以描述纯砂岩阿尔奇规律,而且可以描述纯砂岩非阿尔奇规律,并且满足当孔隙度等于1时地层因素等于1,以及当含水饱和度等于1时电阻增大系数等于1的物理约束,可更好地描述纯砂岩导电规律.其次,针对分散泥质砂岩,使用有效介质对称导电理论建立泥质砂岩有效介质对称导电模型,理论分析与实验研究表明,泥质砂岩有效介质对称导电模型优于泥质电阻率模型和双电层模型,不需要采用经验拟合就能完整地描述饱含水分散泥质砂岩的电导率与地层水电导率之间曲线和直线关系,模型预测的粘土含量和粘土电导率变化对岩石导电规律的影响与理论认识相符,可更好地描述分散泥质砂岩导电规律.第三,针对两组分混合介质,使用有效介质对称导电理论、并联导电理论、串联导电理论,分别建立了有效介质对称导电方程、并联导电方程、串联导电方程,理论比较表明有效介质对称导电理论与并联导电理论和串联导电理论均不等价,即当两种组分混合介质遵循并联或串联导电规律时,混合介质的导电规律不能用有效介质对称导电理论描述.有效介质对称导电理论能够描述骨架和水以及粘土均为连续项的岩石导电规律.它通过引入渗滤指数和渗滤速率几何参数来描述各种组份的连通性、表面的粗糙度、形状、润湿性等对岩石导电性的影响,因此,有效介质对称导电理论的适用性更广,可用于描述孔隙结构更复杂的高泥高钙砂岩储层的导电规律.

Abstract:

Evaluation of saturation in complex shaly sand reservoirs is a difficult problem in logging interpretation. Compared with the conduction models derived with parallel conductance theory and Archie formula, symmetrical effective medium conduction theory can be extended to describe the conductivity law of shale-rich and calcite-rich sand reservoirs with more complex pore structures well, and will have a good application prospect. Even so, basic research on application of symmetrical effective medium conduction theory in complex shaly sands is still need to be made. Firstly, symmetrical effective medium conduction model for clean sands is derived with symmetrical effective medium conduction theory, and analyzed as parameters vary theoretically, and validated with experimental data. It shows that symmetrical effective medium conduction model can describe the conductivity law of clean sands better than Archie equation, and not only explains both Archie and non-Archie behaviors, but also complies with meaningful physical bounds, that is, as porosity is 100%, formation factor is equal to 1 and as water saturation is 100%, resistivity index is equal to 1. Secondly, the symmetrical effective medium conduction model for dispersed shaly sands is given with symmetrical effective medium conduction theory. Theoretical analysis shows the model has the advantage over resistivity models and electric double-layer models, that is, it can describe the curved and linear relations between the conductivity of water saturated dispersed shaly sand and that of formation water without empirical fitting, and also the influence of clay content and clay conductivity on the conductivity law of sands calculated from the model is consistent with the common theoretical knowledge about clay, and so the model can describe the conductivity law of dispersed shaly sand better. Thirdly, three conduction equations for a two-component mixture are derived with symmetrical effective medium conduction theory, parallel conductance theory and series conduction theory respectively. Theoretical comparison shows that symmetrical effective medium conduction theory is neither equivalent to parallel conductance theory nor to series conduction theory, that is, as the conductivity law of a two-component mixture follows parallel conduction theory or series conduction theory, its conductivity law can't be described by symmetrical effective medium conduction theory. Symmetrical effective medium conduction theory can describe the conductivity law of sands with three continuous components: sand grain, water and clay. In it, geometric parameters such as percolation exponents and percolation rates are introduced to describe the effect of the connectivity, the surface roughness, shape and wettability of each component on the conductivity law of sands. Therefore, symmetrical effective medium conduction theory has a wide applicability and can be extended to describe the conductivity law of shale-rich and calcite-rich sand reservoirs with more complex pore structures.

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