单缝洞系统内部流态的初步模拟研究

Preliminary simulation of flow patterns in single fissure-cavern system

杨前雄 熊伟 高树生

YANG Qian-xiong XIONG Wei GAO Shu-sheng

中国石油勘探开发研究院廊坊分院, 河北廊坊 065007

Langfang Branch of Research Institute of Petroleum Exploration and Development, Langfang 065007,Hebei,China

在塔河油田奥陶系碳酸盐岩储层内,发育着很多溶洞,其直径最大能达到几十米,溶洞内的原油储量十分可观,因此研究流体在溶洞内部的流态很重要。通过室内示踪实验研究了水驱水以及水驱油过程中溶洞内的流态随流体流速的增加而产生的变化,利用数值模拟研究了单相驱替时溶洞内的流线分布,以期对溶洞内流体流动规律有一定的初步认识。结果表明,对高速下单相驱替,溶洞内会产生射流,从而增加了流体的流动损失;而对两相驱替(水驱油),由于油的黏滞力作用,高速下也不会产生射流,但是驱替效率会较低。因此,应针对原油黏度不同的情况,采取合理的注入速度。

A great many solution caves developed in the Ordovician carbonate reservoir of Tahe Oilfield,with their maximal diameter reaching tens of meters each.So oil reserves in the caves is huge and it is important to probe into the flow pattern of the fluid in caves.Laboratory trace experiment is conducted first to research the change of the flow pattern in caves as the fluid velocity increases during the displacement of water with water and the process of waterflooding.Then the streamline distribution of single-phase displacement is studied on the basis of numerical simulation,with an aim to obtain a preliminary cognition of the regular pattern of flow in caves.Results show that,for single-phase displacement under high velocity,jet will occur in caves,which will increase the fluid flow loss,however,for two-phase displacement(displacement of oil with water),jet will not appear even under high velocity due to the viscous force of oil.But the displacement efficiency will be low.Therefore,proper flooding rates need to be selected to adapt to different oil viscosity.

10.3969/j.issn.1000-7393.2007.03.030