羌塘盆地侏罗系碎屑岩储集层综合评价

Comprehensive analysis of the Jurassic clastic reservoir rocks in the Qiangtang Basin,northern Xizang

运用储层综合评判分析方法对羌塘盆地侏罗系碎屑岩储集层进行分析和评价。首先选择影响储层性质的8种参数,包括定性参数,如岩性、成岩作用、储集空间类型和定量参数,如储层厚度、孔隙结构、物性等,对其进行单因素评价。在此基础上,根据各单因素对储层贡献的大小,确定各单因素的加权系数。最后,利用评判分析方法,计算各剖面的综合判别得分。综合判别分析评价表明,北羌塘坳陷中部、东部和中央隆起带北缘发育好储层;北羌塘坳陷西部发育中等储层;而南羌塘坳陷储层较差。

The Jurassic clastic reservoir rocks in the Qiangtang Basin, northern Xizang are examined with the aid of the method of comprehensive analysis. Firstly, eight main parameters which have greater influence on the reservoir rocks are selected and the single factor evaluation is made. The selected parameters include qualitative parameters such as lithology, diagenesis and pore space types, and quantitative parameters such as reservoir thickness, pore space structure, porosity and permeability. Then weighting coefficients of individual parameters for reservoir evaluation are given according to their influence on reservoir rocks. Finally the scores for each section in the basin are calculated by using the method of comprehensive analysis. The results of comprehensive evaluation show that the best reservoir rocks occur in the eastern and middle parts of the North Qiangtang depression and the northern margin of the central uplift. The better reservoir rocks are in the western part of the North Qiangtang depression and the poor reservoir rocks are in the South Qiangtang depression.