中国海相页岩气测井评价技术进展与发展方向

Progress and development direction of log interpretation technology for marine shale gas in China

海相页岩是中国海相页岩气藏的主要资源阵地,但海相页岩气成藏机理复杂、物性差、流体赋存形式多样。海相页岩气储层品质评价是页岩气勘探开发中甜点优选的重要评价内容,地球物理测井则是其储层品质评价的重要手段。通过分析海相页岩气地质特征及目前勘探开发面临的难题,介绍了孔隙尺度—岩心尺度—测井尺度的多尺度岩石物理分析技术,围绕含气页岩的有机质、储集性、含气性等地质品质关键参数以及脆性指数、应力、断裂韧性等工程品质关键参数,梳理了这些关键参数的预测技术,建立了页岩气储层品质分级及甜点优选的测井综合评价体系,并应用实例说明了该技术的应用效果和适用性。最后,通过分析页岩气测井评价技术目前存在的问题,提出了新的思路和未来的发展趋势。

Marine shale is the main sweet spot of marine shale gas reservoirs in China.The marine shale gas features complex accumulation mechanism,worse physical properties,and diverse fluid occurrence forms.The quality evaluation on marine shale gas reservoirs is important for sweet spot optimization in shale gas exploration and development,and reservoir quality is mainly evaluated by geophysical logging.This paper summarizes the geological characteristics of marine shale gas and the current problems on hydrocarbon exploration and development,introduces the pore-,core-and logging-scale petrophysical analysis technology,and also the prediction techniques of the above key parameters according to the key geological quality parameters of gas shale such as organic matter,reservoir property and gas bearing property,and the key engineering quality parameters such as brittleness index,stress difference and fracture toughness,establishes the comprehensive logging evaluation system for shale gas reservoir quality classification,i.e.,sweet spot optimization,and demonstrates the technology application effect and applicability by actual examples.Finally,it points out the existing problems,and puts forward new ideas and future development trends.