深层海相页岩储层精准评价与开发选层的评价体系问题评述

深层页岩是我国页岩气资源进一步发展的潜力目标,勘探开发潜力巨大.深层页岩储层埋深大,地层环境相对极端,高温高压和储层特征的差异导致了压裂开发效果受限,成本显著增加,容错率低,深层页岩的精细评价与精准选层的重要性日益突出.深层页岩宏观均质性增强,但小尺度微观非均质性增强.储层物质组分、孔隙特征、物性和岩石结构等与中浅层页...

Comments on the evaluation system of accurate evaluation and selection of deep marine shale reservoirs

Deep shale is a potential target for the further development of shale gas resources in China,with great exploration and development potential.The buried depth of deep shale reservoir is increased,and the formation environment is relatively extreme.The difference between high temperature and high pressure and reservoir characteristics leads to limited fracturing development effect,significant increase in cost and low fault tolerance.The importance of fine evaluation and accurate layer selection of deep shale is increased.The macro homogeneity of deep shale is enhanced,but the micro heterogeneity of small scale is enhanced.The material composition,pore characteristics,physical properties and rock structure of deep reservoirs are significantly different from those of medium and shallow shale.The controlled factors of reservoir with high-quality physical properties and gas bearing properties are different,with higher closure stress and different factors restricting fluid fluidity,resulting in the poor applicability of reservoir evaluation indexes,parameters and evaluation methods commonly used in the past.The deep shale has undergone diagenetic evolution and transformation with greater strength.Under deep geological conditions,the excess silicon interval with excess quartz source can form a brittle mineral skeleton that can effectively protect the pores.The pore protection mechanism and the superposition with organic rich intervals are important basis for judging high-quality shale reservoirs.To carry out accurate evaluation and prediction of deep shale reservoir,it is necessary to update the understanding of the factors controlling the development of high-quality reservoir,enhance the logic,systematicness and dynamics of the construction of evaluation parameters and indicators,and incorporate sedimentary structure,pore protection mechanism,multi factor coupling and heterogeneity into the evaluation parameter system.In view of the practical problems encountered in accurate layer selection and prediction in the evaluation and development of deep shale reservoir,combined with the experience of exploration and development and geological work,this paper puts forward new ideas and suggestions on the basis of reviewing the development progress,so as to provide reference for relevant geologists.