超稠油直井-水平井组合开发蒸汽腔演变规律研究

稠油油藏蒸汽吞吐开发中后期，转换开发方式是提高采收率的重要方法之一，F油田依据现有井网条件进行综合调整，借鉴其他油田成功经验，将直井与水平井组合驱泄复合(VHSD)开发成为吞吐后期接替有效开发的主要方式。本文利用数值模拟技术，开展VHSD开发蒸汽腔发育规律研究，跟踪流体流动轨迹，剖析剩余油变化规律。研究结果表明，多轮次蒸汽吞吐建立注采井间水动力连通时，油层的动用情况决定了蒸汽腔的初始形态，随着蒸汽持续注入，蒸汽腔经历了形成、横向扩展、向下扩展三个阶段，各阶段蒸汽腔扩展方向不同，对应着不同的剩余油分布规律和生产特征变化，其中蒸汽腔横向扩展阶段为主要产油期，阶段产出程度达28.8%，油藏最终采收率可达58.3%。

Study on expansion law of steam cavity in ultra-heavy oil combined development of vertical well and horizontal well

In the middle and later stages of steam huff and puff development in heavy oil reservoirs, the conversion of development mode is one of the important methods to improve oil recovery. F oilfield has made comprehensive adjustment according to the existing well pattern conditions and learned from the successful experience of other oilfields. The development of vertical well and horizontal well combined flooding and drainage (VHSD) has become the main method to succeed the effective development in the later stages of steam huff and puff development. In this paper, numerical simulation technology is used to carry out research and tracking of the development law of steam chamber in VHSD development, fluid flow trajectory, and analysis of the change law of remaining oil. Research results show that the steam stimulation to establish injector-producer rounds between hydrodynamic connected, reservoir using situation determines the steam cavity of the initial shape, with continuous injecting steam, the steam chamber has experienced formation, lateral extension, scaling down three stages, each stage of steam cavity expansion in a different direction, corresponds to the different characteristics of remaining oil distribution and production change, lateral extension stage of steam chamber as the main oil producing period, and phase output level was 28.8%, and the ultimate recovery of the reservoir can be up to 58.3%.