滩坝相砂岩油气分布特征及主控因素分析——以王家岗油田沙四上亚段为例

Hydrocarbon Distribution Characteristics and Play Elements of Beach-bar Sandstone: Taking the Upper Es_4~s Formation in Wangjiagang Oilfield as an Example

王家岗地区沙四上亚段发育大量滩坝砂岩储层,逐渐成为勘探人员关注的重点。在对地震、录井、测井、分析测试等资料综合分析的基础上,结合模拟实验对王家岗油田沙四上亚段滩坝砂岩油气分布特征及成藏主控因素进行了分析。结果表明:研究区滩坝相储层主要以砂泥薄互层状分布,油气分布具有较强的不均一性;研究区构造运动强烈,发育大量断层和裂缝,油气输导条件是控制该区滩坝砂岩油气成藏的重要因素;储层非均质性是造成油气不均一分布的另一个原因;模拟实验显示油气运移动力大小的变化会导致油气对非均质性砂体进行选择性充注,使得储层质量高的区域含油性好,储层质量差的区域含油性差或不含油,从而影响油气聚集分布规律。

A number of beach-bar sandstone reservoir beds which have attracted more and more attentions,are developed in the upper fourth member of Shahejie Formation （Ess4 ）of the Wangjiagang oilfield.Based on the analysis of seismic and logging data and an experiment,this paper analyzes the hydrocarbon distribution charac-teristics and play elements of beach-bar sandstone in the upper fourth member of Shahejie Formation （Ess4 ）of the Wangjiagang oilfield.The results showed that the beach-bar reservoir beds with thin interbedded sandstone have strong heterogeneity.Hydrocarbon distribution and properties were extremely non-uniform.Migration path-ways are the important condition of hydrocarbon accumulation in the regions which suffered strong tectonic move-ments.Reservoir bed heterogeneity is another controlling factor of non-uniform distribution of hydrocarbon. Simulated experiment indicated that the change of driving force for hydrocarbon migration impacted selective accumulation mechanism in the process that hydrocarbon moved vertically along fault zone to the reservoir and distribution of hydrocarbon in the reservoir.