论文部分内容阅读
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.
Saturation evaluation of complex shaly sand reservoirs has been a pressing issue and hotspot to be solved in the field of well logging interpretation. The limited extensibility of the conductive model based on the parallel conduction theory and Archie’s formula limits the expansion of such models to a certain extent The conduction law of the higher porosity and high calcium sandstone reservoirs with more complex pore structure is described. The effective dielectric symmetry conductivity theory can well describe the conductivity law of complex shaly sand reservoirs, and has good application prospects, but still needs further study. First of all, for the pure sandstone, the symmetrical conductivity model of effective sandstone is used to establish the effective medium symmetric conductivity model of pure sandstone. Theoretical analysis and experimental studies show that the effective medium symmetric conductivity model of pure sandstone is superior to Archie’s equation, not only can describe Archie’s law of pure sandstone, Describes the non-Archie laws of pure sandstone and satisfies the physical constraints that the formation factor equals 1 for a porosity of 1 and the resistivity of 1 for a water saturation of 1 to better characterize the conductivity of pure sandstone. , For the dispersion of argillaceous sandstone, the use of effective dielectric symmetry theory to establish effective symmetry of argillaceous sandstone The electrical model, theoretical analysis and experimental studies show that the effective medium symmetrical conductivity model of shaly sands is better than that of the mud resistivity model and the electric double layer model, and the conductance of saturated water-dispersive shaly sands can be completely described without empirical fit The relationship between the rate and the conductivity of formation water and the relationship between the clay content predicted by the model and the conductivity of clay on the conductive law of the rock are in line with the theoretical understanding and can better describe the conduction law of the dispersed shaly sandstone.Thirdly, Two-component mixed media, the effective medium symmetric conduction theory, parallel conduction theory, series conduction theory, respectively, to establish an effective medium symmetric conduction equation, parallel conduction equation, series conduction equation, the theoretical comparison shows effective medium symmetric conduction theory and parallel conduction theory And the series conductivity theory are not equivalent, that is, when the two mixed media follow the parallel or series conduction law, the conductivity of mixed media can not be described by the effective medium symmetric conduction theory.The effective medium symmetric conduction theory can describe the skeleton and water and Clay is a continuum of conductivity law of the rock, it is through the introduction of percolation index and The geometrical parameters of the filtration rate describe the influence of various components on connectivity, surface roughness, shape, wettability, etc. on the rock conductivity. Therefore, the theory of effective dielectric symmetry is more applicable and can be used to describe the pore structure Conducting regularity of more complicated high mud and high calcium sandstone reservoir.