坳陷湖盆斜坡带辫状河砂体分布与有利目标预测——以陕北绥靖油田延长组长213为例

Sandstone distribution pattern and the prediction and evaluation of lithologic oil reservoirs in braided channel of slope belts:A case from Chang-2_1~3 oil reservoir of Yan chang Formation in Suijing area,Shanbei

认识鄂尔多斯盆地陕北斜坡延长组砂体展布与油藏分布是达到加快该区油气勘探与开发步伐目的所要面临的重要问题之一。本文以陕北斜坡绥靖油田延长组长213为例,利用岩芯、测井、录井和分析化验资料,研究了斜坡带辫状河沉积微相展布与砂体分布规律,应用地质综合评价法,预测与评价了有利目标。研究区延长组长213主要为河道砂坝(心滩)和河漫滩两种沉积微相,河道交织分叉现象明显,砂体大致呈北东-南西向条带状展布,与沉积微相展布基本一致,砂厚主要分布在4~16m之间,平均厚度15.5m;一类目标4个,预测含油面积为311km2,地质储量为2824×104t;二类目标5个,预测含油面积为373km2,地质储量为2984×104t;三类目标4个,预测含油面积为100km2,地质储量为800×104t。

It is one of the main problems for speeding up oil exploration and development to recongnize Ordos basin.Taking the Chang-213 oil reservoir of Yanchang Formation of Low Jurassic in Suijing area of Ordos Basin as an example,microfacies and sandstone distribution are studied by core,well logging and chemical data in braided channel of slope belt to predicted and evaluated by comprehensive geological study.The microfacies of Chang-213 oil reservoir of braided river include channel bar,river floodplain.The main distribution direction is northeast-southwest.The thickness of banded channel sandston is 4m^16m,and the ribution direction is the same as that of the channels.There are 4 Ⅰclass targets,5 Ⅱ class targets and 4 Ⅲ class targets.