深水重力流储层宏观非均质性控制因素——以华庆地区长63为例

Macroscopic Heterogeneity Controlling Factors of Deepwater Gravity Flow Reservoirs:A case Study of Chang 63 in Huaqing Area

宏观非均质性是评价含油储层的重要控制因素,深水重力流储层的宏观非均质性通常较强,是油气勘探开发的首要难题。通过深水重力流沉积理论、岩心观察、测井资料、实验测试等分析,描述鄂尔多斯盆地华庆地区长63深水重力流储层宏观非均质性特征。研究表明:华庆地区长63层内非均质性较强,主要发育浊积岩、滑塌岩、砂质碎屑流、泥质碎屑流4种重力流沉积物;层内夹层分为泥质、钙质和泥砾3类,泥质夹层出现频率较高,对沉积物内部非均质性影响较大,钙质夹层主要出现在砂质碎屑流中;根据沉积物砂体的叠置关系,将重力流沉积物砂体分为4类,层间非均质性由弱到强分别为连续叠加型、间隔叠加型、侧向尖灭型、砂泥互层型;分析砂体厚度与沉积微相、孔渗、流动单元等影响因子在研究区的展布,得出华庆长63储层宏观非均质程度平面分布情况图。总结6个角度的影响因素,建立影响储层宏观非均质程度综合评价表,为油田勘探开发提供帮助。

Macroscopic heterogeneity is an important controlling factor for the evaluation of oil-bearing reservoirs.The macro-heterogeneity of deep-water gravity flow reservoirs is rather strong,which is a primary difficult problem of oil and gas exploration and development.Through the analysis of deep-water gravity flow sedimentary theory,core observation,logging data and experimental test,etc,the macro-heterogeneity characteristics of Chang 63 deep-water gravity flow reservoir in Huaqing area of Ordos Basin are described.The research shows that Chang 63 in Huaqing area has a strong in-layer heterogeneity,mainly including turbidite,sloping rock,sandy debris flow and argillaceous debris flow.The interlayer is divided into three types:argillaceous,calcareous and gravel.The frequency of argillaceous interlayer is high,which has a great influence on the internal heterogeneity of sediment.The calcareous interlayer mainly appears in the sandy debris flow;The gravity flow sediment sand bodies are divided into four categories,continuous overlapping type,interval overlapping type,lateral pinch-out type and sand-mud interbedding type,with the interlayer heterogeneity from weak to strong.Analyzing the distribution of sand body thickness and sedimentary microfacies,pore infiltration,flow unit and other influencing factors in the study area,and the plane distribution of macroscopic heterogeneity of Huaqing Chang 63 reservoir was obtained.It summarizes three influencing factors,establishing a comprehensive evaluation table that affects the macroscopic heterogeneity of the reservoir,so as to provide assistance for oilfield exploration and development.