深层特稠油油藏蒸汽驱井网优化研究与应用

Steam Flooding Well Pattern Optimization of Deep and Super Heavy Oil Reservoir

W38块深层特稠油油藏蒸汽驱面临井底干度低、产液能力低等问题,采用常规的反九点井网采注比难以达标,开发效果不理想。为此,设计了回字形蒸汽驱井网,即内线反五点、外线反九点的嵌套式井网架构,利用数值模拟技术对反九点井网和回字形井网的采收率进行了预测对比,并对回字形井网注采井对应关系进行了优化。结果表明,回字形井网比反九点井网蒸汽驱采收率提高4.9%。当注汽井射开程度为50%（由下往上）,内线采油井射开程度为30%~50%（由下往上）,外线采油井全井段射开时,蒸汽腔推进更均匀。现场试验2个井组增油效果明显,蒸汽驱油汽比同比反九点井网提高36%。研究结果对改善深层特稠油蒸汽驱开发效果具有参考意义。

There are several problems of steam flooding in deep and super heavy oil reservoirs of Block W38,including low bottom dryness and low liquid producing capacity.Production and injection ratio is hard to meet the criterion with traditional inversed nine-spot well pattern and the development effect is not ideal.Therefore,we designed Hui-style steam flooding well pattern,i.e.a nested well architecture,including inversed five-spot well pattern inside and inversed nine-spot well pattern outside.We predicted the recovery of Hui-style by means of reservoir numerical simulation technology,as compared with inversed nine-spot well pattern,and probed into the injection-production well corresponding relationship of Hui-style.Results showed that Hui-style well pattern could improve the final recovery by 4.9%,as compared with inversed nine-spot well pattern.The perforated degree of 30 ~ 50% of the first-line production well（from bottom to top）when the perforated degree of gas injection wells was 50%（from up to bottom）,and full perforation of the second-line production well were advantageous to the steam chamber expansion.Stimulation results were obvious in field test of two well groups,and oil and steam ratio rose by 36%.Research results were of referential significance to improvement of steam flooding development effect of deep and super heavy oil reservoirs.