海上强底水驱油藏水平井合理开采速度研究——以秦皇岛32-6油田Ng_2砂体为例

A research on reasonable production rate of strong bottom-water drive reservoirs by horizontal wells:a case of Ng_2 sandbody production in QHD 32-6 oilfield

利用水平井开采渤海油田强底水驱油藏存在2种截然不同的开采模式,即秦皇岛32-6油田Ng2砂体的低速开采和曹妃甸11-1油田Ng3砂体的高速开采。在对比分析这2种模式的开采特征和开发效果的基础上,提出了适当放大生产压差,提高秦皇岛32-6油田Ng2砂体开采速度和最终采收率的开发思路。建立了秦皇岛32-6油田Ng2砂体油藏数值模拟模型,利用油藏数值模拟方法,研究了不同生产压差下水平井开采时Ng2砂体含水率、产液量、开采速度和采出程度的变化规律,结合海上生产受平台处理液能力和平台寿命限制的实际情况,确定了Ng2砂体水平井合理的生产压差为0.8MPa。上述开发思路已实践于秦皇岛32-6油田生产实际,取得了好的效果。

There are two different patterns to exploit the strong bottom-water drive reservoirs in Bohai oilfields using horizontal wells,i.e.the low-rate production of Ng2 sandbody in QHD32-6 oilfield and the high-rate production of Ng3 sandbody in CFD11-1 oilfield.Based on comparison and analysis of production characteristics and development effects between these two patterns,a development idea to increase the production rate and the ultimate recovery factor by suitbaly enhancing drawdown pressures is proposed for Ng2 sandbody in QHD32-6 oilfield.For Ng2 sandbody,a numerical simulation reservoir model was built,by which the changes in water cut,liquid production,production rate and production degree of the sandbody when exploiting by horizontal wells were researched under different drawdown pressures.By considering the platforms liquid treatment capability and its life,the reasonable drawdown pressure of horizontal-well production was set at 0.8MPa,for Ng2 sandbody.This idea has been applied in the exploitation of QHD32-6 oilfield,resulting in quite good effects.