稠油蒸汽驱方案设计及跟踪调整四项基本准则

文章编号:1000-0747(2008)06-0715-05

稠油蒸汽驱方案设计及跟踪调整四项基本准则

张义堂,李秀峦,张霞

(中国石油勘探开发研究院热力采油研究所)

基金项目:中国石油天然气股份有限公司/稠油汽驱方案动态跟踪及稠油剩余油分布预测技术研究0项目(030124)

摘要:利用数值模拟方法研究注汽速率、井底蒸汽干度、采注比及油藏压力对稠油油藏蒸汽驱开发效果的影响,给出了具体的量化指标范围。研究结果表明,对于普通稠油油藏,要达到较好的蒸汽驱开发效果,必须满足以下条件:¹注汽速率大于等于1.6m3/(d#hm2#m),从而保持蒸汽带的不断扩展,并保持井底蒸汽干度;º井底蒸汽干度大于等于40%,反映蒸汽驱对单位注入流体热焓的要求;»油藏压力小于5.0M Pa,最好为1.0~3.0M P a,保持较低的油藏压力可提高蒸汽波及体积;¼蒸汽驱稳定阶段的瞬时采注比大于等于1.2,才能真正实现蒸汽驱。辽河油田齐40块蒸汽驱先导试验和扩大试验的方案设计、跟踪调整及评价表明,提出的有关量化指标已成为蒸汽驱方案设计、跟踪调整和评价的四项基本准则。

图6表1参10

关键词:稠油油藏;蒸汽驱;注汽速率;井底蒸汽干度;采注比;油藏压力

中图分类号:T E345文献标识码:A

Four fundamental principles for design and follow-up of

steam flooding in heavy oil reservoirs

ZH ANG Y-i tang,LI Xiu-luan,ZH ANG Xia

(Resear ch I nstitute of Petr oleum E x p lor ation&Develop ment,PetroChina,Beij ing100083,China) Abstract:N umerical simulat ion is used t o under stand the impact s of steam injection r ate,bo ttom-ho le steam quality, product ion/inject ion rat io and r eser voir pressur e o n the perfo rmance o f steam flo oding in heav y oil reserv oir s,prov iding the concrete r ang es of quantified indices.Fo r co nv entional heav y oil r eservo irs,to r ealize better perfo rmance by steam flo oding, the follow ing co ndit ions must be met:(1)steam injection rate should no t be less than1.6m3/(d#hm2#m),thus keeping the co nt inuo us ex tensio n o f steam chamber and mainta ining t he bo ttom ho le steam quality;(2)bo ttom hole steam quality sho uld no t be less than40%,which reflects the requirement of ent halpy for unit inject ed fluid by steam flo oding;

(3)r eser vo ir pressure should be less than5.0M P a,had better in1.0-3.0M P a,thus maintaining a lo wer r eser vo ir pressur e

to impr ov e t he sw ept v olume of steam;(4)instant pr oduction/injection ratio should not be less than1.2dur ing the st able stage o f steam floo ding,r ealizing pr act ical steam flo oding.T he desig n,follo w-up and evaluation of steam flo oding in pilot test and ex tensio n t est in Q i40Blo ck o f Liaohe Oilfield show that the quantified indices have become four fundamental principles for such desig n,fo llo w-up and evaluat ion.

Key words:heav y oil reservo ir;st eam flo oding;steam injection rate;botto m-ho le st eam quality;pro ductio n/injectio n ratio;

reserv oir pressur e

0引言

蒸汽驱是普通稠油油藏的重要开采方式。目前,普通稠油油藏大多先进行若干周期的蒸汽吞吐开采,之后转为蒸汽驱,以进一步提高原油采收率[1-4]。蒸汽驱过程中,由注入井连续注入高干度蒸汽,大量的热能加热油藏,大幅度降低稠油黏度,将原油驱动至生产井采出[5,6]。

我国在/八五0至/九五0期间曾开展了11个蒸汽驱先导试验,除个别试验外,大多数试验效果不甚理想。从当时的蒸汽驱状况看,试验失败的原因主要在于对蒸汽驱的认识程度不够,没有充分掌握蒸汽驱技术。

在选择适合蒸汽驱油藏的基础上,科学地设计开发方案并认真地实施及管理,才能实现蒸汽驱。笔者经过多年的研究和总结,发现注汽速率、井底蒸汽干度、采注比及油藏压力对蒸汽驱开发效果具有显著的影响。本文分析各因素对蒸汽驱开发效果的影响程度,给出了合理的量化数值,称之为蒸汽驱开发方案设计及跟踪调整的四项基本准则,并在实际应用中进行

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石油勘探与开发

2008年12月PET R OL EU M EXPL OR AT IO N A N D DEV EL O PM EN T V o l.35No.6