轮南2油田JIV油藏水驱实验及微观剩余油分布特征

Waterflooding Experiment and Micro-Distribution of Remaining Oil in JIV Reservoir in Lunnan-2 Oilfield

根据铸体薄片、常规物性、扫描电镜、压汞等分析结果,对塔里木盆地轮南2油田下侏罗统阳霞组JIV油藏储集层孔隙结构类型进行了划分,选取主要的4类孔隙结构储集层进行砂岩岩心微观水驱实验。实验结果表明,不同孔隙结构储集层渗流特征不同,细喉低渗类和微细喉特低渗类储集层以指状渗流为主,较细喉高渗类储集层为指状—网状渗流,细喉中渗类储集层为网状—均匀渗流;水驱后微观剩余油以绕流形成的片状和簇状分布为主,其次为柱状、角状、膜状等分散分布。通过分析不同孔隙结构类型储集层水驱油微观渗流特征,为油田有效合理开发提供依据。

Based on the analysis of cast thin-section, conventional physical properties, SEM and mercury injection, the pore structures ofJIV reservoir of the Lower Jurassic Yangxia formation are classified. Microscopic waterflooding experiments for sandstone cores are carriedout in the reservoirs with 4 main pore structures. The experiment results show that the reservoirs with different pore structures have differ-ent percolation features. Fine-throat, low-permeability reservoir and microfine-throat, super-low permeability reservoir are dominated by fin-ger-like percolation, relative fine-throat, high-permeability reservoir by finger-like-net-like percolation and fine-throat, medium-permeabili-ty reservoir by net-like-uniform percolation. The remaining oil after waterflooding are mainly in sheet-like and cluster-like distributions re-sulted from by-pass oil with the secondary of scattered columnar, angular and film-like distribution. The analysis on micro-percolation fea-tures of waterflooding in reservoirs with different pore structures could provide basis for reasonable and efficient development of the oilfield.