关键词: 潜山, 油气藏, 输导体系, 成藏模式, 冀中坳陷

Abstract:

When water drive gas reservoir is exploited to a certain extent, the water will be produced, and then gas and water two-phase flow will increase the resistance of gas flow, which leads a sharp decline on gas well production. The determination of reasonable gas well deliverability is the foundation of scientific development of gas field and has very important guiding significance. According to the change of gas and water two-phase seepage rule, based on stable percolation theory, this paper introduced pseudopressure and threshold pressure gradient of gas and water two-phase, and established a new gas well productivity prediction model for gas-water producing horizontal wells, taking the influences of threshold pressure gradient, slippage effect, stress sensitivity, formation damage and high-speed nonDarcy into account. Studies show that the water/gas ratio has a rather greater impact on the deliverability of gas well, so water breakthrough must be controlled during the gas production. With the increasing of threshold pressure gradient, stress sensitivity and water/gas ratio, the deliverability of gas well decreases, while with the decreasing of slippage effect, the deliverability of gas well increases. The gas phase threshold pressure gradient plays a more important influence on the gas deliverability than water phase threshold pressure gradient.

Key words:  buried hill, reservoir, migration system, hydrocarbon accumulation model, Jizhong Depression