深层超稠油油藏蒸汽吞吐后转汽驱实验研究

辽河油田曙一区深层超稠油油藏经历多年蒸汽吞吐开发，取得了一定的开发效果，但进入吞吐开发中后期，面临周期产油量低、油汽比低及稳产难度逐年增大等问题，蒸汽吞吐后接替技术的研究已迫在眉睫。在室内利用高温高压比例物理模拟装置，针对蒸汽吞吐后转蒸汽驱的影响因素、调控策略和生产特征开展了实验研究。结果表明，蒸汽吞吐阶段形成的温场对后续蒸汽驱开发有较大影响。蒸汽吞吐转汽驱的前提条件，一是注采井间油层热连通温度要达到原油转驱温度以上，二是吞吐阶段培育的蒸汽腔体积要足够大，横向波及注采井距1/3左右为宜。注采井段调整是改善汽驱效果的重要影响因素。对于层内无稳定分布的夹层情况，蒸汽吞吐及蒸汽驱阶段注汽井采用下1/2井段注汽，能够有效抑制汽体超覆，提高采出程度。当蒸汽驱达到剥蚀生产阶段后，将生产井由全井段调整为下1/2井段生产，能够在一定程度上扩大波及体积，提高采出程度；超稠油蒸汽驱生产特征以剥蚀作用为主，驱替作用为辅。研究结果为深层超稠油油藏蒸汽吞吐后转汽驱开发方案优化设计及矿场试验提供理论依据。

An Experimental Study on Steam Flooding After Huff and Puff in Deep Super Heavy Oil Reservoir

The deep super heavy oil reservoir in Shu1 area of Liaohe Oilfield has been developed by steam stimulation for many years, and has achieved certain development results. However, after entering into mid-and late stage of huff and puff, it is faced with the problems of low cycle oil production, low oil steam ratio, increasing difficulty of stable production, etc., so it is urgent to study the replacement technology after steam stimulation. In this paper, the influence factors, control strategies and production characteristics of steam flooding after huff and puff are studied by using the high temperature and high pressure proportional physical simulation device. The results show that the characteristics of temperature field formed in the steam huff and puff stage have great influence on the subsequent steam flooding development. The preconditions for steam stimulation to steam flooding are:first, the temperature of thermal connection between injection and production wells should be above the critical temperature of crude oil; second, the volume of steam cavity cultivated in the stimulation stage should be large enough, and the lateral sweep should be about one third of the injection production well spacing; the adjustment of injection production well section is an important factor to improve the effect of steam flooding. For the case that there is no stable interlayer in the layer, the steam injection in the lower 1/2 well section can effectively restrain the steam body overlap and improve the recovery degree. When the steam flooding reaches the stage of denudation production, adjusting the production well from the whole well section to the lower 1/2 well section can enlarge the wave and volume to a certain extent and improve the recovery degree; the production characteristics of super heavy oil steam drive are mainly denudation, supplemented by displacement. The results provide a theoretical basis for the optimization design of the development plan and field test after steam stimulation in deep super heavy oil reservoir.