Title

Sedimentary evolution of barrier bars in 17 well area of DND gas field

单位

中国石化华北油气分公司，河南郑州 450000

Organization

North China Oil and Gas Company, SINOPEC, Zhengzhou 450000, China

摘要

DND气田太2段障壁砂坝是水平井开发效果最好的层位。文中以该气田17井区为例，基于砂坝内部岩相及测井相差异，结合海平面升降情况，研究障壁砂坝的沉积演化。研究认为，17井区障壁砂坝沉积演化分为海平面上升、下降、上升3个阶段。海平面上升，沉积物开始聚集并形成障壁砂坝雏形；海平面缓慢下降，障壁砂坝持续生长；海平面再次快速上升，砂坝被淹没。根据岩性组合特征及沉积演化，将17井区障壁砂坝按Ⅳ级层序垂向上分为3期砂体：Ⅰ期砂体在海平面上升过程中形成；Ⅱ期砂体在海平面下降过程中形成，发育程度高，是17井区障壁砂坝的主要储层；Ⅲ期砂体在海平面再次上升过程中形成。3期砂体由下至上呈现出砂坝的形成—生长—消亡的变化趋势。

Abstract

The barrier bars are the best formations for horizontal well development in DND gas field. Based on the differences of lithofacies and electrofacies inside the bars in 17 well area of the gas field, the sedimentary evolution of barrier bars was studied combining with the eustatic change. It is considered that the sedimentary evolution of barrier bars can be divided into three stages which are sea level rise, sea level fall and sea level rise. When the sea level rose, sediments began to accumulate to the prototype of barrier bars. When the sea level dropped slowly, the growing barrier bars could be formed. Barrier bars submerged by sea level when Sea level rose rapidly again. According to lithologic assemblages and sedimentary evolution, barrier bars in 17 well area can be divided into three sets of sand bodies vertically by strata sequence Ⅳ. Among them, the first sand body was formed in the process of sea level rise. The second sand body which was the main reservoir of barrier bars in 17 well area was formed in the process of sea level drop and it had high degree of development. The third sand body was formed during sea level rise again. Three-stage sand bodies present the changing trend of formation, growth and extinction from the bottom to the top.

关键词：

障壁砂坝; 沉积演化; 测井相; DND气田;

Keywords:

barrier bar; sedimentary evolution; electrofacies; DND gas field;

基金项目

DOI

10.6056/dkyqt202003004

DND气田17井区障壁砂坝沉积演化