基于多评价参数的海上低渗气藏分类方法

中国海上低渗透天然气资源探明储量逐年增加，为了经济高效地动用这部分储量，对低渗透气藏进行合理的分类至关重要。以莺歌海盆地东方区黄流组气田群为例，优选米无阻流量、渗透率、主流喉道半径、可动流体饱和度、含气饱和度、气层厚度6个评价参数，综合应用于海上低渗透气藏分类，建立了海上低渗透气藏的分类评价方法。综合考虑目前海上气藏的开发特点，各分类参数之间的相关性等因素，把低渗透气藏细分为4个亚类，确定了各评价参数的分类界限，并提出了各（亚）类低渗透气藏的开发建议。分类评价方法细化了对海上低渗透气藏的认识，避免了针对不同类型的低渗透气藏采用固定的分类标准带来的分类误差，可以较好地筛选出在目前海上开采技术和经济条件下适合开发的气层，对类似气藏的分类评价也具有一定的借鉴意义。

A New Classification Method for Offshore Low Permeability Gas Reservoir Based on Comprehensive Evaluation Parameters

The proved reserves of offshore low permeability natural gas resources increase every year, in order to economical and efficient exploit this part of the reserves, reasonable classification is essential. Target is gas reservoirs in Huangliu Formation of the Dongfang area in Yinggehai Basin, propose six parameters classification method to evaluate offshore low permeability gas reservoir, such as open-flow potential per meter, permeability, the radius of main flow throat, movable fluid saturation, gas saturation and gas reservoir thickness. Thus, a comprehensive evaluation method for low permeability reservoirs is proposed. Considering the current offshore gas reservoir development characteristics, the correlation between the various classification parameters, the low permeability gas reservoir is subdivided into four subgroups. Meanwhile, the classification limit of each evaluation parameters is determined and different development recommendations are proposed for each subgroups of low permeability gas reservoir. The evaluation method refines the understanding of offshore low permeability gas reservoirs, avoids inaccurate classification results which occurred in using the same standard of classification for low permeability gas reservoirs, can better filter out the suitable for development gas reservoir under the current technology and economic conditions, also has certain reference significance to similar gas reservoir classification and evaluation.