枣园油田孔一、二段储层成岩作用和孔隙结构特征

CHARACTERISTICS OF DIAGENESIS AND PORE STRUCTURES OF THE RESERVOIRS IN THE FIRST AND SECOND MEMBERS OF THE KONGDIAN FORMATION IN THE ZAOYUAN OILFIELD

本文综合应用研究区目的层段岩芯样品的各项分析测试资料,对储集砂岩的成岩作用和孔隙结构进行研究,揭示了枣园油田储集砂岩的成分成熟度和结构成熟度均较低;各组分含量变化大是造成储层成岩变化和孔隙结构复杂的因素之一。孔一、二段砂岩经历了压实、胶结、交代、溶解和自生矿物充填等成岩作用。孔一段上部孔隙类型以原生孔隙为主,孔隙和喉道发育、孔渗高,但孔喉分选差;下部原生和次生孔隙并存。孔二段主要是次生孔隙,孔喉细、分选差,孔渗性较孔一段上部差。

The sand reservoirs in the Zaoyuan Oilfield are low in compositional maturityand textural maturity, as revealed by the investigations on the diagenesis andpore structures on the basis of the core analyses. The great variation of the con-tents af various components in the reservoirs is one of the geological factors respon-sible for the digenetic change and complex pore structure of the reservoirs. Thediagenesis in the First and Second Members of the Kongdian Formation is repre-sented by compaction, cementation, replacement, dissolution and authigenic mineralfilling. The pores in the upper part of the Fiist Member of the Kongdian Forma-tion are mainly primary ones with high porosity and permeability and large porethroats, but poorly sorted pore throats. The primary and second pores coexist inthe lower part of the First Member of Kongdian Formation. Most pores in theSecond Member of the Kongdian Formation are secondary ones with fine throatsand poor sorting. The porosity and permeability are not so good as those in theupper part of the First Member of the Kongdian Formation.