小洼油田洼38断块试验区蒸汽驱参数优化

Parameter optimization on steam drives for Wa 38 fault block pilot,Xiaowa oilfield

小洼油田洼38断块试验区经历12a的蒸汽吞吐开发后，已进入蒸汽驱试验阶段，在目前注采条件下，出现油层压力水平较低、油井产油量小、油汽比低等矛盾。在分析洼38断块东三段油层蒸汽驱先导性试验效果的基础上，利用数值模拟方法优化主要注采参数，最大限度地改善其蒸汽驱开发效果。结果表明，注汽速度以100～120t／d为宜；采注比为1．2～1．3，井底蒸汽干度要求在50％以上；合理的注汽压力为7MPa左右，不宜超过9MPa，油井合理井底流压应为1MPa左右。与目前注采参数生产效果相比，应用优化的注采参数进行蒸汽驱生产20a，采出程度将增加5．46％，累积增油量为3．6×10^4t，能取得较好的开发效果。

Wa 38 block steam flooding pilot achieved good development performance,steam flooding has entered the pilot stage,under the present injection-production condition,many problems appeared such as lower oil pressure level,low rate,and low oil/gas ratio.This paper analyzed the effectiveness of steam drives in Dong 3 formation of Wa 38 fault block,and optimized reservoir injection and production parameters by numerical simulation method,and maximized the steam flooding development to improve its performance.The results show that: the speed of steam injection is appropriate at 100-120t/d,and production injection ratio at 1.2 to 1.3,and steam bottom dryness more than 50%,and steam injection pressure at 7MPa but no more than 9MPa,and bottom hole flow pressure around 1 MPa.Numerical simulation indicates that,compared with the current parameter,the optimized steam injection may obtain a better development performance by enhancing the recovery percent of 5.46%and accumulated oil increment of 3.6×10~4t within 20 years.