莺歌盆地高温高压储层含水饱和度评价

D气田新近系H1组储层位于莺歌海盆地中深层,属于高温高压储层,钻井取心层段受高密度泥浆侵入,电阻率曲线失真,电法模型计算的含水饱和度存在较大误差;H1组储层受多期成岩作用改造,储层微观孔隙类型多样、结构复杂,气藏具有较强非均质性,严重影响测井解释模型的计算精度.针对上述问题,利用研究区测井、岩心和测试资料,对储层进行岩石物理相分类评价,建立不同类别岩石物理相评价指标及解释方法,并基于岩石物理相划分成果采用J函数方法,利用压汞毛细管压力资料建立高精度非电法含水饱和度模型.现场应用效果表明,基于岩石物理相分类建模技术解决了研究区高温高压储层电阻率失真层段含水饱和度精确计算的问题,为气田储层定量评价、储量计算奠定了基础.

Evaluation Methods for Water Saturation of High Temperature and Pressure Reservoir in Yinggehai Basin

The Neogene H1 formation group in the field D is located at the medium-deep to deep intervals of Yinggehai basin and categorized as the high temperature and pressure (HTHP) formation.The resistivity logs are highly distorted by the invaded high-density mud in full-cored sections,which leads to relatively big errors when calculating water saturation by using conventional electrical model.H1 formation group has been reworked by multi-phase diagenesis,which results in various types of micro pore space with complex structures.The computational accuracy of the interpretation model is considerably impacted by such a high reservoir heterogeneity.To solve this problem,the reservoir is categorized according to the petrophysical facies based on data from wireline log,cores and tests.Different standards and interpretation methods are applied for different petrophysical facies where J function utilizes mercury intrusion capillary pressure to establish high-precision non-electrical saturation model.Field applications indicate that this petrophysical facies categorization technique provides an improved approach for the water saturation calculation in the HTHP formation where resistivity logs are distorted.