苏里格气田东区马五5气藏主控因素及富集区优选

为提高鄂尔多斯盆地马五₅气藏有效储集层钻遇率,运用钻井、测井、录井、岩心及生产试气等资料,通过对沉积微相、成岩作用、古地形等有效储集层主控因素分析,明确了马五₅气藏白云岩分布规律,并对储集层进行综合分类评价,优选出马五₅气藏有利富集区。研究结果表明,苏里格气田东区马五₅储集层呈局部透镜状分布,连片性不强,最有利的储集体是颗粒白云岩和粗粉晶白云岩,主要储集空间为晶间孔、晶间溶孔和构造裂缝。沉积相和成岩作用是马五₅储集层的主控因素,颗粒滩是马五₅储集层白云岩最有利的沉积微相;有效储集层主要受控于准同生白云化作用和埋藏白云岩成岩作用对储集层的改造程度;相对高部位的古斜坡是马五₅气藏开发的有利区。

Main Controlling Factors and Gas Enrichment Area Selection of Ma55 Gas Reservoir in Eastern Sulige Gas Field

In order to improve the drilling rate of pay zones in the Ma5₅ gas reservoir in eastern Sulige gas field, Ordos basin, using the drilling, logging, core and gas production testing data, and analyzing the main factors controlling pay zones such as sedimentary microfacies, diagenesis and paleotopography, the distribution law of dolomite in the Ma5₅ gas reservoir was clarified. Moreover, the reservoirs were comprehensively classified and evaluated, and the favorable gas enrichment areas in the Ma5₅ gas reservoir were selected. The research results show that the pay zones in the Ma5₅ reservoir are distributed as “lens” in local areas, with poor continuity. The most favorable reservoir rocks are granular dolomite and coarse powder crystalline dolomite, and the main storage space consists of intergranular pores, intergranular dissolved pores and structural fractures. Sedimentary facies and diagenesis are the main controlling factors of the Ma5₅ reservoir, and the grain beach is the most favorable sedimentary microfacies of the Ma5₅ dolomite. The pay zones are mainly controlled by quasi-contemporaneous dolomitization and buried dolomite diagenesis. The paleoslope on the relatively high position is a favorable area for the development of the Ma5₅ gas reservoir.