夹层对蒸汽辅助重力泄油的影响

Impacts of Interlayers on SAGD

风城油田SAGD开发区块位于辫状河沉积的河道或心滩微相中,内部夹层分布散碎,对蒸汽腔发育和泄油均有一定的影响。以重32井区典型非均质模型为基础,利用数值模拟方法,分析了夹层位置、形态、物性对SAGD开发的影响。结果表明:注采井间夹层与生产井距离小于2 m、长度大于100 m、厚度大于0.5 m或渗透率小于100×10^(-3)μm^2时,会严重影响水平井水平段动用;对于注汽井上方的夹层,距离注汽井3 m以内、长度大于100 m、厚度大于1 m或渗透率低于100×10^(-3)μm^2时,对蒸汽腔发育速度和形态影响显著,依此制订夹层分类标准,并在此基础上将风城油田SAGD井组分为4类。该研究成果为制订针对性治理措施、提高开发效果提供了一定的依据。

Blocks with steam assisted gravity flooding （SAGD） in the Fengcheng Oilfield distributed predominantly in river channels or shoal microfacies with development of braided river depositions. Sparsely distributed internal in- terlayers may affect development of steam chamber and oil drainage. By using the typical heterogeneous model of the Zhong-32 Block as an example, impacts of positions, configurations and physical properties of such interlaycrs on SAGD have been reviewed through numerical simulation. Research results show interlayers between injector and producer with distance from producer less than 2 m, with lengths over 100 m, with thickness over O. 5 m, or with permeability below 100×10^-3μm2 may significantly affect performances of horizontal wells. In addition, interlayers above steam injectors with the distance from the injector less than 3m, with lengths over 100 m, with thickness over I m, or with permeability below 100×10^-3μm2 may significantly affect development velocities and patterns of steam chambers. In accordance with above properties, standards for elassifieation of such interlayers have been clarified. Furthermore, wells with SAGD in the Fengeheng Oilfield can be classified into four categories. Relevant research results may provide valuable references to stipulate necessary countermeasures to enhance development performances.