层序地层格架下的岩性圈闭识别与描述技术——哈萨克斯坦南图尔盖盆地实例

Identification and characterization of lithological traps within sequence stratigraphic framework-a case study of South Turgay Basin,Kazakhstan

随着岩性油气藏储量和产量占比的日益增加,岩性圈闭已成为现今油气勘探的重点领域。本文以哈萨克斯坦南图尔盖盆地为例,针对该区存在的河道砂、岩性上倾尖灭、古潜山等三种主要的岩性圈闭类型,介绍了基于层序地层格架的岩性圈闭识别与描述两步法技术流程。即首先以层序地层学研究为基础,定性地界定岩性圈闭的类型、储层特征及分布范围;然后根据岩性圈闭类型选择适用的地震储层预测技术,定量地描述岩性圈闭的形态、储层厚度和物性等。该技术流程在南图尔盖盆地的上侏罗统Akshabulak组的河道砂、中侏罗统Doshchan组的岩性上倾尖灭及变质岩潜山等三类岩性圈闭的勘探实践中取得了较好效果。

Stratigraphic/lithologic traps are playing an increasingly important role as hydrocarbon reserves and productions from them are growing.Focusing on three dominating types of lithological traps in South Turgay Basin,i.e.channel sand body,up dip wedge-out and buried hills,this paper introduces a two-step work flow for identification and characterization of lithological traps.The first step is to setup the sequence stratigraphic framework and to qualitatively describe the type,characteristics and distribution of lithological traps.The second step is to quantitatively characterize the shape, thickness and physical properties of the traps by some seismic reservoir prediction approaches.This work flow has been proved to be effective in the exploration practice in South Turgay Basin for above-mentioned three types of lithological traps.