论文详情
从束缚水、自由水的介电特性差异出发,测量相同几何尺寸岩样的电容值反映其介电特性,研究了一种新的岩石孔隙水分布状态分析方法并定量确定束缚水饱和度。采用岩石质量-电性参数自动测量系统实现岩石不同质量和不同频率下电容数据的连续采样。扫频测量的实验结果表明,100×103 Hz是一个比较理想的测量频率,该频率下水的分布状态对岩石电容-含水饱和度曲线的形态影响较大,岩石电容-含水饱和度曲线呈N形分布。将N形曲线上、下拐点作为吸附水、束缚水含量分界线来得到岩石吸附水和束缚水的饱和度。实验结果表明,采用介电实验研究岩石孔隙水分布状态的方法可行,并证明了岩石吸附水、微毛细管水和自由水具有不同的介电特性,且受测量频率和含水饱和度的影响。
The irreducible water saturation is usually obtained with centrifugation method,phase permeability experiment,semipermeable membrane method and sealed coring.In the term of rock electricity,they are not bound water saturation parameters involved in double-water and three-water model in well logging interpretation.In this article,a new method is tested to get rock pore water distribution properties based on dielectric property difference of free water and bound water.Rock weight and capacitance data is continuous sampled using rock weight-electric parameter automatic measurement system.Measurement results show that 100 kHz data is ideal,water distribution difference is obvious at the frequency,and the rock capacitance-water saturation curve is in the shape of N.We use up-inflection-point and down-inflection-point of N-shape curve to partition adsorption water and bound water saturation of porous rock.Our data proved that adsorption water,capillary water and free water have different dielectric properties and it’s influenced by measuring frequency and water saturation.Our data shows that this method is useful to study rock pore water distribution.Since the exploration and development target of oil field inclined to be low permeability,low porosity and low resistivity with high bound water and adsorption water saturation,complex pore texture and complex conductive properties,our experiment research will play a great role in the interpretation of low permeability,low porosity and low resistivity reservoir for three-water model.
国家科技重大专项(2011ZX0504)资助。