塔河油田奥陶系碳酸盐岩缝洞储层油气成藏动力学与油田水体类型

Hydrocarbon Accumulation Dynamics of Tahe Ordovician Fractured-Caved Carbonate Reservoir and Types of Oilfield Water in Tahe Oil Field, Tarim Basin

塔河油田是大型的碳酸盐岩不整合—古岩溶缝洞型奥陶系油气藏。由塔河油田主体往南,油气驱替程度逐渐降低,缝洞系统中含水量逐渐增加。油水界面分布总体上由潜山顶部向周围斜坡波动中降低。塔河油田的区域构造背景、储层缝洞系统以及成藏动力学过程导致了流体分布的非均质性。根据储层孔隙结构特征、油气驱替过程、开发过程中产出水的化学—动力学响应,塔河奥陶系缝洞油藏的水体类型可以区分出三种:洞穴底部油气驱替残留水、洞穴周缘小缝洞系统驱替残留水、储层下部层间水。不同水体类型的出水时间、水体能量、含水率、水化学性质等会呈现出不同的变化规律。

Tahe Oilfield in Tarim Basin is a large-scaled unconformable and palaeokarst fractured-caved Ordovician carbonate reservoir. The extent of hydrocarbon displacement descends and residual water increases from the main part of the oilfield to the southem part. The oil-water interface declines irregularly from the top of the buried hill to the surrounding slope. The regional tectonic setting, fracture-cave system and dynamical process led to the heterogeneous fluid distdbution during hydrocarbon accumulation. According to the pore structure of formation,the process of hydrocarbon displacement, and chemical-dynamical response of produced water during reservoir development, three types of formation water can be identified： residual water in bottoms of caves after hydrocarbon displacement, residual water in fractures and vugs around caves after hydrocarbon displacement,and interlayer water under reservoir. The alteration regulation of water breakthrough time, water energy, water content, and hydrochemical characteristics for various types of water are different.