CAJ | 학술논문

自然电位和激发极化电位测井响应所涉及的离子导体激发极化电位的微观机理解释,主要依据双电层形变假说和浓差极化假说,缺少定量描述的数学模型和理论体系.本文利用孔隙介质的微观毛管模型,给出了毛管模型中双电层理论和阳离子交换量与Zeta电位的关系,推导出毛管中离子流量和电流强度表达式.由电荷守恒定律和物质守恒定律,推导出毛管中离子浓度分布的解析表达式,建立了描述含水泥质砂岩激发极化电位和自然电位的数学模型.从而系统地严格证明了含水泥质砂岩激发极化现象是在电流场和浓度梯度场的共同作用下,由孔隙中离子浓度浓差极化电位和双电层形变电位形成的.并且证明了描述泥质砂岩自然电位的数学方程和描述激发极化电位的数学方程及形成机理是一致的.计算结果表明:激发极化极化率随孔隙度和渗透率的增大而减小;极化率随溶液浓度的增加而减小,随阳离子交换量的增加而增加;证明了地层水浓度、阳离子交换量是影响自然电位大小的主要因素.
자연전위화격발겁화전위측정향응소섭급적리자도체격발겁화전위적미관궤리해석,주요의거쌍전층형변가설화농차겁화가설,결소정량묘술적수학모형화이론체계.본문이용공극개질적미관모관모형,급출료모관모형중쌍전층이론화양리자교환량여Zeta전위적관계,추도출모관중리자류량화전류강도표체식.유전하수항정률화물질수항정률,추도출모관중리자농도분포적해석표체식,건립료묘술함수니질사암격발겁화전위화자연전위적수학모형.종이계통지엄격증명료함수니질사암격발겁화현상시재전류장화농도제도장적공동작용하,유공극중리자농도농차겁화전위화쌍전층형변전위형성적.병차증명료묘술니질사암자연전위적수학방정화묘술격발겁화전위적수학방정급형성궤리시일치적.계산결과표명:격발겁화겁화솔수공극도화삼투솔적증대이감소;겁화솔수용액농도적증가이감소,수양리자교환량적증가이증가;증명료지층수농도、양리자교환량시영향자연전위대소적주요인소.
The microscopic mechanisms of induced polarization potential involved in the spontaneous potential and the induced polarization potential logging response is mainly from the hypothesis of the electrical double-layer deformation and the concentration difference polarization. There is no mathematical model to describe this up to now. In this paper, we formulated the flux of ion and the electric current from the theory of electrical double-layer and the relationship between the cation exchange capacity and Zeta potential based on the microscopic capillary model of porous media. We derived an analytical expression of ion concentration distribution and the mathematical model of the induced polarization potential and the spontaneous potential for water bearing shaly sandstone from the conservation law of charge and the conservation law of matter. The work rigorously proved that the induced polarization of water bearing shaly sandstone is caused by the ion concentration difference polarization potential and the deformation potential of electrical double-layer under the common influence of the electric current field and the concentration gradient field. And it proved that the mechanism and the equation describing spontaneous potential in shaty sandstone are consistent with that of induced polarization potential. The results show that the induced polarizability decreases with the increase in porosity, permeability and concentration of solution but increases with the increase in the cation exchange capacity. It noted that the concentration of formation water and the cation exchange capacity are the main factors that influence the spontaneous potential.